How to put a ATV motor in your buggy

[metalstudman1]

This is a 2006 Tomberlin Punisher that I found on Craigslist for $250. it was sold with the disassembled motor in a box (Howhit GY6 150 w/reverse) and for all intents and purposes no seats (just the seat frames).It was a little expensive for not running but everything else on the buggy is great with no rust-perfect for this type of project- it needed to be rescued!!!This particular frame is very well built and will withstand the addition of a few more horses.This thread is going to show the basic things needing to be done to install a ATV/motorcycle engine into it with very little expense and tooling- just some simple skills.I picked what should be a little more challenging engine to transplant- '85 Honda 250ES (shaftdrive) 5 speed semi-automatic w/reverse.

[metalstudman1]

Let's get started by stripping everything off the swingarm- axle,brakes,electricbox,battery, ect.... You need to be able to work on the swingarm from all angles.Clearly I can see that this engine isn't going to fit in the original support rails- so let's get them out of the way.You can cut with either a reciprocating saw,portable band saw,jig saw or with a cutting disk on a grinder (a hacksaw for the die-hards).I used a 4" grinder w/ cutting disks as these allow for ease of use and cleaning up the left-over material.Set the engine in the swingarm and get your clearances for the brake rotor and anything else that sets in the swingarm.This engine has a right angle output shaft so the motor will sit sideways like the newer ATV engines do.If you use the newer type shaft/chain drive ATV motor the configuration would be normal. After cutting all that away I decided to slide the center support rail closer to the disk rotor by 1/2" and rolled it on it side to give me more surface area for the engine support plate to sit on.I blocked the engine up to verify the oil drain plug would be accessible.Using a framing square and finding an engine seam you can align the motor.

[metalstudman1]

Lets get the engine setting in the swingarm by making some support brackets. I make templates from paper as I can mark, cut and modify them with little to no effort or cost.You can use the original suport brackets that came off the ATV if it's easier (usually a lot less fabricating).After setting the engine in the swingarm level and in the near finished location I can check the new brackets for alignment and fit.Never set an engine directly on the swingarm frame-always allow some clearance.The engine supports should do exactly that "support the engine".I've allowed a 1/4" clearance and made a footplate that will slide on another tube member.I drilled a hole 1-1/2" apart and cut the center out for a slotted hole for the engine to adjust the chain slack.Bolted the brackets on the motor and marked where the footplate sat and welded a tube rail for it to slide on.I made the footplate longer to the front of the engine to allow for support under torque load.Once the new rails were added I marked the bottom for an angle plate- this provides 2 functions-end stop for adjusting bolt and to help the engine slide straighter forward when adjusting the chain.

[metalstudman1]

Let's get the engine support brackets to bolt down to the frame and put in the means for the adjusting bolts to work. I simply used 3/8" couplers as they were the right size to span the the height of the frame tubing.You can drill a hole and weld a bolt anytime you need threads without the hassle of tapping on thin walled tubing.The swingarm tubing is thin so having the coupler spanning the thickness and welded on both ends makes it very structural-it's supporting a 109 lb. motor in a rollover without ripping loose and landing on you or the passenger.I use a long piece of all-thread to visually verify that the coupler is squared up while welding.Put a greased bolt in any nut while welding it to keep splatter out of the threads.Engine support brackets now can be secured down to the frame when the chain is adjusted.The adjusting bolt is from all-thread with 2 nuts, the end nut gets welded.The inside nut can be used as a jam nut against frame rail.Tip: when cutting all-thread spin a nut to the location to be cut and use the nut as a guide,when cut off the nut will chase the threads clean.

[metalstudman1]

With the motor secure let's deal with how to make this shaft drive a chain drive.When I bought this engine I got the drive shaft to ensure I'd have the correct spline.I already know that I'm using #530 chain so you'll need to get a sprocket to match the chain you intend on using.Measure the output shaft on the motor and add at least a 1/4" to it ,then cut that length off the splined end of the drive shaft.I had to cut the splined shaft off the GY6 sprocket too.Your sprocket will probably already be flat or without a sideshaft.I leveled the sprocket in the vise and plumbed the splined portion of the driveshaft-I found a bolt that was the right diameter to fit in the splines and extend enough to put a torpedo level on it.This task is critical--check with level in at least four locations-Take your time & CHECK IT AGAIN.Too much wobble can cause vibration and short output shaft life.Tac it and check it again!!I made 3 passes just too be sure of good attatchment since I'm only welding it from one side.Clean up the weld to help balance it.

[metalstudman1]

Now that we have a sprocket let's keep it on the output shaft.The output shafts are case hardened steel-this takes the majority of us out of the loop for having the right tooling.The best way to accomplish this is to take the output shaft to a machine shop and have them drill and tap threads for you. But I'm going to give you an alternative! By adding that extra 1/4" to the shaft you have room enough to weld a nut on the end of the case hardened output shaft. Since the load applied to the new sprocket isn't where the bolt is this will work and keep you well within your working & tooling element. My output shaft had a center machine hole so centering the nut was easy as sharping the end of the bolt to sit in the hole.I protected the splines with a piece of tubing-I cut a vertical slit in it just incase I touched a weld to it and needed to get it off easier, like the lid on a canned ham! An old cutting disk was the perfect size to protect the bearing seal.A little grinding to clean it up and some careful filing of the end splines we now have threads for the retaining bolt of course make sure that the new sprocket installs smoothly by hand.The retaining bolt only needs about 12 lbs applied to do it's job. You can use blue loctite if you have any fear or if your sprocket didn't weld up straight and wobbles.

[metalstudman1]

Let's get the axle sprocket where it needs to be. This axle sprocket carrier is welded on the axle-Depending how and where it's at it can be cut and re-used. This particular one is too close to the rotor carrier and has an internal weld I can't get at. If you decide you can grind the weld out ,take your time and don't over heat the axle. I found a piece of pipe that was 1-1/2" I.D, and with a small amount of massaging the rust out it slid right over the axle.Your pipe needs to be about a foot long to start with even though it'll only be a few inches long when it's done. If you don't have a larger hole saw trace your radius needed and cut it out by hand. I use the large hole saw to basically score the plate front and back and cut it with my grinder. Someday I'll get a plasma cutter!!!!! I cleaned the pipe size hole with a die-grinder. I have 2 different type axle sprockets so I'm drilling for both patterns just incase.The reason for the longer than needed pipe is so you can square/level it up with some accuracy.Once again this part needs to be as true as possible.Level the bolt pattern plate and use a square or torpedo level on the pipe multiple places around it get it right. Tack it and CHECK IT AGAIN!!! Once your welded up you can now cut the excess off and position it on the axle for alignment of the drive sprocket and chain. Rotate the chain and watch the sides of the chain for binding before welding the pipe sleeve to the axle.I used a square along the chain and sited the axle for 90 degrees.

[metalstudman1]

You might need to get the motor out later!!! I cut the rear roll tube in the middle of a straight run-added a sleeve and welded a nut on the lower portion. I cut a short piece of tubing for the bolt to ride in and welded that just above the upper cut.With the sleeves it bolts up solid and now I can get the motor out and still have rear protection. More to come but this gets the hard part complete without breaking the bank and you got to use your skills

[383]

Wow, nice work!! You make it look easy.

[Rarerat]

Great job!!

[SYCARMS]

Nice Job

Tom

[RedTeam]

very nice! this should be a sticky

[NissanNut]

Very nice work.

[SFORCES]

Nice anymore?

[metalstudman1]

Working out of town so it's strickly a weekend project after domestic duties!!!!!

[SFORCES]

ok thank's

[sgt_ic3m4n]

Hey metalstudman, what'd you do with the stock engine and/or parts you had with the thing??? I'd be interested in most if not all of it. Thanks in advance!!!

K. Foreman

[metalstudman1]

The main reason I bought this Punisher was because it missing ALL the electrical except for the key switch and lights. I was planning on taking the reverse hub (didn't have the cable, brackets or shifter) and put it on my wife's black Spiderbox. (assuming I can get home long enough) Intake, carb & exhaust were gone -so not much left. Can't confirm if the engine is good and I have no plans for it along with 2 other used GY6's.

[racemybuick]

ok... i loke your work here... it is very, very simular to my first monster buggy. I had purchased a sunL from a guy named "newbuggier" from buggynews, with a honda TRX300 4X4 motor shaft drive installed. After riding for only a few days, we found that the welds just wouldnt hold with the sprocket on the motor, even with a lock nut installed, the torque and rough terrain kept snapping the sprocket off the shaft... We eventually came up with the idea of running a jack shaft to more evenly distribute the tension... Again, our welds never sucessfully held up to the torque like we anticipated... I sent the sprocket, the spline shaft, and our 1" bar to a machine shop and had them assemble it as one peice... Thats right about when I found out that the original fabricator made NO provisions for engine tension adjustment or axle adjustment to tension the chain... on top of that, he welded the 530 sprocket to the axle, making it permanent, and also, not able to adjust or flip to align with our new jack shaft. So the project is sitting right now, for about 2 years, lol, without any progress because we know what needs to be done... The whole engine cradle needs to be re-engineered with adjustability in mind, as well as a whole new rear axle design so that the sprockets will line up properly, without having to be welded...

All in due time!!! lol

I like your craftsmanship, and your attention to detail... I really hope yours works much better than mine, and I can copy yours!!!! lol




John

[metalstudman1]

Thanx for the input on the sprocket. Haven't got to work on mine since I'm working out of town. I guess testing it's durabilty will come with a close eye on the sprocket connection. Can you post some pics of your dust collecting project? I'd love to see your inovations. Question about your drive sprocket- did your sprocket itself end up near the splined output shaft or was it extended way off the end?

[metalstudman1]

Been waiting on a friend to bring me a stator for the Honda 250es motor for a long while- The kid's have been bugging me about getting their buggy running so here's the next opportunity that came of that request.
I took one of my Honda TRX200SX engines and put it in the Punisher. I've been working on it for a week now, still have the shifter, throttle hook-up & exhaust left to do before they can drive it. Figured I'd post a few progress pic's. Spent the better part of 2 days making a wiring harness-- so much to consider and I don't have spools of factory color coded wires makes for a slow process (for me anyways)

You'll see from the pic's this motor fit's so much better than the GY6 motor did- lot's of clearance. I made a new control/ignition box similar to the stock one that comes on the buggy. The junkyard seats fit very well and boy are they comfortable-not bad for $50.

[SYCARMS]

Man I wish we lived closer , I think I would be a regular.

TOM

[Bootboy1488]

would a stator from any other models inter change with this motor?

[metalstudman1]

Thanx-Tom!
Bootboy- Not according to a Honda mechanic I asked. The 250 will wait till my friend get's around to pulling his as he needs some other parts I have- I'll use it sometime in the future. The 250es engine is a work-horse engine (slower reving and lot's of torque) where as the TRX200SX is a sportier type engine, If I'd had a spare 200cc last year I wouldn't have put the 250cc in at all.

[locohead]

This is a really cool thread. Man you guys are really smart. X-bird seems really smart too. I know there are probably a ton of really smart guys here and i'm just a lurker. Lol. But x-bird has helped me out using his brains.

It is really fun to watch the transformation of your buggy (cart, whatever, remember, i'm only a lurker, wannabe welder and mechanic. Everyone has to start somewhere. Maybe when i'm 52 i'll be smart like Metals too. :-)

I can't hardly wait to see the finished machine - again, really cool thread!

[x-bird]

Thanks for the kudos, BUT Buggymaster, Metal, CKAU, Rarerat, Speedshopmike and many others here have far more experience with small engines and buggies than I do. I just have a really diverse background with mechanical items that makes me sometimes knowledgeable and sometimes dangerous ;~) (AMF certified pinsetter class A mechanic, body man, saab mechanic, exotic/race car restorer, fab shop production line manager etc.) Anywho, if another member posts something contrary to my advice or posting, by all means--follow their advice! lol.

[metalstudman1]

Turn the camera on and the battery lights blinking so this all I could get:
http://youtu.be/JyLd70ZXK6k
Still have small stuff to do to it but it runs and drives
My 7 yr. old is a little too short for it as the seats only adjust 4"(stock adjuster)

[SYCARMS]

Your Son seems to handle it fine. Great video.

Tom

[AceFab]

looking good! Watched a couple of your vids on YouTube, love the one with the Honda CBR400.
Get back to Craigslist now and find another one, we can't wait to see the next project! lol

[metalstudman1]

Happy New Year everyone!!!
Tom- that's my daughter in the vid!!! But my son does fit much better @12 yrs.old

[SYCARMS]

Happy New Year to everyone as well. Well she seems to handle the buggy just fine for 7 yrs old considering she was halfway up in the seat. She is a natural. Even though I'm addicted and love my buggy I get the most satisfaction watching the kids have fun in them.

[metalstudman1]

Tom- Once again we're of like thinking I get the most from these with the kid's anticipating me getting it built and then the joy on their faces when they're out in the dirt tearing it up!!!! Of course the build is my love for this sport- the self-satisfication I get from taking something junk & turning into a "fun machine".

[SYCARMS]

I know what you mean, I can still remember my son's face when he first got his for Christmas 2004 and now he is 16 and when we go ridding he still has that look on his face. I just had 2 customers send pics of their kids in their new Christmas buggy's and the expression of joy on their faces really made my day.

[metalstudman1]

I never know what information maybe helpful for someone or what other application it may be applied to: This is the simple chain tensioner I made for this project. I tried a different method for mounting this engine just to see what's the easiest to build and maintain. These engine mounts don't have any adjustment for the chain other than this chain tensioner. Normally the slotted plates/brackets for bolt adjustment takes quite a bit of fabrication time- but allows versatility through wear and tear. The tensioner took about an hour to make and is really simple in design & material, if it failed I could make another one pretty quick. I turned the skateboard wheel on the "redneck lathe" (drill press) just using a sharp chisel the right width of the chain- took about 10 minutes. The reason I continue to use skateboard wheels other than the availibilty and low cost is, they are hard enough to do the job yet soft enough not to wear out the chain- also they nearly always have high speed bearings.

[SYCARMS]

I looked at the first couple pics and thought "this will fail after time cause he did not figure for relieving or taking up slack in chain" but then I come to the last pic and thought " oh yes he did. Nice job. Looks neat and easy to make. I have used the skate board wheels before for several projects since they are tough and will hold up to weight and shock.

TOM

[metalstudman1]

I post failures as well as success's!!! The weather turned nice so we took this project out for a beating. After a couple of hours chasing each other through the trails my son decided to do a bunch of donuts on our track. I parked and was going to get the video camera and I hear a strange grinding/skipping noise. So I had him pull it in the mancave- The motor looks wraped/cock-eyed in the swingarm. Investigating for metal to metal contact and it's the bolts holding the disk brake rotor(pic below). Further investigation leads to a warped/bent swingarm. This little motor is only about 14-18hp which isn't much more than the GY6. Proof that any additional HP should be dealt with re-enforcement!!! In the pic's you can see the bow, and changes in dimension from front to rear (1/4"). Though not a radical change it caused damage. Since this much warping occurred in such a short time I've pulled it all apart and rebuilding the swingarm. The chain tensioner did well, but since I'm rebuilding the swingarm I'm adding 2" to the length to allow for engine adjustment.

[x-bird]

Small failures are nothing but large steps towards success! I discovered last night that I bent the rear frame cross bar that the swingarm mounts to in pretty much the same manner. I've got plenty of 1/4-in. wall 2x2 inch square tubing, if you don't mind building a battleship, i've got plenty to share (I think one cross section frame tube would weigh 15-20 pounds) ....

[SYCARMS]

Just a thought, isn't round tubing stronger then square tubing?

TOM

[x-bird]

In most applications, yes. My bent frame piece is also square--my suggestion was tongue in cheek. That's why i have a massive pile of the 2x2. it was installed on top of 75 foot poles to extend our range netting another 15 feet higher. First winter storm bent them over nearly 90 degrees--about 2 months after they went up. One of those "i told you sos" that I can never mention to my dad. We had a heck of an argument over using it. about 20k down the toilet.

[metalstudman1]

If I'd known that this little amount of extra HP would've been so destructive I'd rebuilt it from the start (live & learn)!! I'm using round on the re-build/cross members simply because it's a heavier gauge. I'm on the fence about which is better in most applications, round get's really strong when bends are incorporated over longer spans. Square is much easier to fab. The tubing on this was only 12g. I probably contributed to it's failure with my welding on it. I chuckle a little when I hear someone saying they're going to strap on a 100+hp motor on the back of buggy thinking they can just bolt it on there and it'll work without massive re-enforcement/engineering through out the whole buggy.
Kid's are a little upset as the weather is spring like- Dad's not perfect- but I'm making every attempt to keep them happy and on the fun end of this addiction!!!! I might have it all finished by tomorrow before the cold/wet stuff rolls in.

[x-bird]

Ditto on the ease of working with square. For my new subframe mount, I've been mulling over putting in a piece of angle iron between the side rails with a square tube welded to the back of that and the horizontal of the angle iron pointing to the front.

[metalstudman1]

I gave some thought to all the forces being generated and realized the most abrupt force is when downshifting at high rpm's. Ended up with 4 sliding engine mounts, in the pics you'll see the rear bottom was a challenge (channel in a channel) for disassembly & re-assembly clearances for the axle, brakes and adequate support. With the lower carriage I got a skid pan/protection to boot!. The failure of the swingarm was easy to see- not enough support across the swingarm from front to rear. Test drove it and couldn't be happier with the result. Still have the reverse lever to fabricate and putting 3 point belts in will require some additional tubing on the rollcage. After my wife gave it a spin she asked that I put somemore tubing/frame by the seat- she says she feels like she's going to fall out!! So maybe a swinging tube with a latch- like a door.
I posted a pic of the shifter cable mount just so you can see what's needed for chain adjustment and fine tuning.

rarerat- I managed to find some red paint

[SYCARMS]

Lookin good.

TOM

[metalstudman1]

Kid's went away for the weekend so I took advantage of the down-time. I made well needed rear fenders, the reverse lever and a new sprocket holder to be able to add a larger axle sprocket (37t) I started this with a 26t (way too fast), then went to a 31t (still way too fast) the 37t is still well over 40mph but that's as tall a sprocket I can fit. Kid's are out of school Monday and I'm hoping the weather holds out to get some video of the kid's abusing it! The wife and I took it for some entertainment- brrrr it's cold! I may have to make a body for this one too.

[AceFab]

Those fenders turned out nice. I imagine the 37t sprocket gives a bit more bottom end grunt for climbing too. Great job!

[SYCARMS]

Nice fenders, like the reverse lever as well.

TOM

[metalstudman1]

Thanx gentlemen- I'm at a loss as to why the same gearing on two similar buggies with the same motor don't give similar results. This thing would climb well with the 26t, my wife was/is upset that it's too fast for the kids. So in an attempt to slow it down I changed the drive sprocket-12t down to a 11t, still too fast (my wifes opinion) , I put the 31t on and run it with the Spiderbox (Yerf gearing 12t & 31t)- Punisher steadly pulled away. We had another drag race today with the 37t and it still pulls away from the Yerf, Her motor is the same only newer, exact same transmission gearing, the tires on both buggies are the same diameter, I'm heavier than my wife, the Punisher is heavier and it still runs faster
I know I'm not the sharpest tool in the shed but could someone please explain this to me.
Monday I'm going to vid the kids in a drag race.

[Bootboy1488]

driver error? the new buggy is looking cool metal! after doing that little bit to the hyper, i have the itch!

[SYCARMS]

I would just install some 5 pt. harnesses and have the kids wear the appropriate saftey gear. Just tell your better half that you have done all you can do but it is still a beast that is posessed by some unknown entity. I think if you want to slow it down go with a 16T small and 26 big sprocket. It should slow it down off the line. Kinda like changing from a 308 gearing in your truck to a highway 276 gearing. It will slow it down on the trails but make it quicker over the long haul. The 11-31 sprockets will give you a 2:82 gearing whereas the 16-26 will give you a 1:63 gearing. You know It just occured to me that your better half might just want to be the domonent one and not beat by the kids. LOL

TOM

[metalstudman1]

I put in a 4 point harness, the downfall of this is the kid's are swapping buggies so much and the harness's require time/adult to adjust- safety first! My daughter can't pull the release on a 5 point yet. The engine sprocket 11t is the smallest I can get (the biggest that will fit is a 13t), the 37t is about the biggest that will fit without having to modify the carriage again. It's @ 3.36 ratio now, the Yerf is 2.58. That's pretty low gearing for the Punisher. Here's some brief entertainment of me this afternoon after we got done playing in the trails. After I watched the vid I was very happy with the stability- the tires stay on the ground pretty well.

http://www.youtube.com/watch?v=ehQa5gFqbGU

She thinks the kid's will drive like we do!!! My wife is very competitive but "FAR" from being dominant, she is mostly paranoid about the kid's getting hurt from excessive speed (rather the abrupt stop that occurs when hitting something a higher rate of speed) Great driving skills are developed young and mastered quicker. I want my kid's to out drive me!!!

[SYCARMS]

You need to bring them to the Bash in June.

TOM

[Bootboy1488]

maybe a lanyard on the release, keeping her arms from being completely bent to release the hardness?

[metalstudman1]

bootboy- that would help but she can't close/latch it either!!!
I mocked up a gate for the drivers side just trying it out.Need to see if it presents any obstructions. The kid's wouldn't co-operate when it came to the video, both of them were singing the blues about it being cold & the faster you go the colder it get's-and they can't drive with gloves on! so no drag race today. But here's my kid's : 7yr.old daughter & 12 yr.old son: My daughter doesn't have the muscle to shift the shorter shifter in the Punisher yet.
http://www.youtube.com/watch?v=RZg3wFvOlpg

[SYCARMS]

Nice video, like yout latch.

TOM

[Bootboy1488]

Decide whether or not you will make a body kit for the punisher?

[metalstudman1]

After looking closely at the design of this buggy, a full body instead of just side panels may take some real ingenuity- So I completed the driver/passenger swinging bars that my wife requested and I'm going to let the kid's play in it while till I get a brain fart about the body! The Frankenbuggy has a "no spark" issue again that I need to resolve first.
How's your Helix coming?

[Bootboy1488]

its always something to keep our hands dirty!.. the bigger projects for the helix have to wait as we are preparing everything to take a trip back home (ohio) on leave. last weekends battle ( me vs beer can guy ) ripped off both front mud flaps. i have a trash can that a storm bounced off the neighbors house and broke so i am trying to decide to shape and size that i want to cut from that.

[metalstudman1]

Finally got the kid's to have a drag race!!! Daughter (7 yrs. old) in the Yerfdog & son (12 yrs. old) in the Punisher, neither of them have the shifting skills to make this very competitive. I've since started teaching my daughter what to do- driving straight,shifting and braking!!!! She ran this race in 2nd gear most of the way, they only got to about 30-35 in 1200'- not too good.

http://www.youtube.com/watch?v=oXpGrIuAQ4s

[roysheepdog]

How fast will it go now?

[metalstudman1]

Gps is broken- but my buddy paced me on his Harley at 44mph in 4th gear, my best guess is about 50-53 mph. In the length on the vid (1200'+/-) I can just barely get into 5th gear and it takes several hundred feet beyond that to get to top speed.

[roysheepdog]

thats faster than I would have thought.

[zzbudzz]

AWESOME ..I need to learn how to weld.. Great work metalstudman1!

[metalstudman1]

Update: After 3 months or so of pounding/driving it like it was stolen on this swingarm modifications. My son tells me last night racing to the house from the rain that something didn't feel right. I pulled it in the man cave for an inspection-- WOW, we're so lucky this made it back to the house without a total catastrophic failure. Once again- It's so hard to calculate the forces apllied to different parts when doing modifications. Two of these cracks were located at the fender mount location-so they definitely contributed to the stress (vibration & weight of mud). This is another example of added horsepower (even a small amount needing considerable re-enforcement). Since this will be the 3rd rebuild of the swingarm on this buggy due to torque issues- I'm going to OVER do it!!!!

[SYCARMS]

I've always been told round tubing is much stronger then square tubing. Do you think the square tubing failed first putting too much stress and twist on the round tube. I remember a cheaper version of a 150 buggy which the carrier was built with square tubing and it always had problems cracking. Your thoughts.

[metalstudman1]

After engine removal the swingarm literally folded up - the engine bolts were the only thing holding it together!!!!!
Tom- I've never seen a factory swingarm for a GY6 made from round tubing? but I'm sheltered!!!
I believe the THIN (16 gauge) rectangular tubing cracked due to stress near the holes I drilled for the fenders & welds creating a chain reaction on the rest of the tubing due to torque loads from the engine and the excessive bouncing when doing slides/donuts. I knew the stock swingarm was thin- just didn't realize how thin!!!! As I said before about which is stronger- depends on the loads and distance between the next structural component. I went to buy some rectangular tubing- the only thing they had in stock was 2" x 3" x 1/4"(way too heavy) So I'm using 1-1/2" x 1-1/2" x 3/16" square tubing for the swingarm rails (too many parts that need a flat surface). Since I just got started rebuilding it AGAIN, I'll decide as I go based off the loads I think will be apllied. I can say that every part will be at least 1/8"/12g. min. Something that we noticed soon after the fender installation was a vibration/sound frequency from the plastic at higher RPM's. I know from my construction experience that the right frequency can cause all kinds of damage to certain materials. The swingarm I made on the Spiderbox is a much heavier gauge tubing- no failures so far with the same abuse.

[x-bird]

Where's the engine mass in relation to the rear axle, in front or behind? NM, see it now-- Reason i asked, it think a lot of the cracked Gy6 tails are from some of the engine mass acting as a counterweight behind the axle and working against the suspension movement. Been looking long and hard at swingarm mounts, shock points and rear axle in relation to the weight of the engine and how it acts on the suspension and swingarm. Looks like your one crack started possibly from the fender hole, the drill may have left a stress riser when it first broke through inside the tube if you went in from the "inside" of the swingarm. Likewise, maybe not from big hits, but harmonics from a lot of short, rapid suspension oscillations ... do you ride on any washboarded-out trails/roads?

[metalstudman1]

Originally Posted by x-bird

Where's the engine mass in relation to the rear axle, in front or behind? Likewise, maybe not from big hits, but harmonics from a lot of short, rapid suspension oscillations ... do you ride on any washboarded-out trails/roads?

Axle placement is seldom based off engine mass on this or stock, wheel base is nearly always the criteria. When in stock form the engine mass is similar to my transplant. The GY6 shouldn't cause any serious stress near or at the axle as the supports are loaded to the front & rear of the swingarm & IMO an excellent design for weight distribution.
All our trails are rough-even the smoother ones due to lot's of big chunks of crystal as this was gold mine property back in the late 1800's- so it's all a washboard effect on the chassis.
The smoothest area we have is an old paintball arena where the kid's are always doing donuts in my vid's.
My new swingarm (almost complete-holiday weekend delays) is made of much heavier steel which it should've had from the start (had I realized how thin the stock swingarm rails were) to tolerate the constant beating. The thin material and my added holes & welding were definite contributors to the failure.

[metalstudman1]

Update: Still building the new swingarm (all parts newly fabricated)-. This just shows the progress. I made it ridgid mounted to shorten up the wheel base again - I'm making another style chain tensioner that will mount on the bottom of the chain to eliminate chain slap on the motor. I also mounted Suzuki LTZ400 front shocks on the rear to get rid of the bouncy ride. I might get it done tomorrow but will have to wait on the intake I sent off to be heli-arc'd (small crack) to test drive it- maybe this weekend!!!!

[metalstudman1]

Some things shouldn't get so complicated when the application is simple. This is my new chain tensioner!!!!!-This isn't what I had pictured in my head. My original plan was to have just one wheel under the chain but after spinning the axle forward and backward- I realized that in reverse there was chain slop too- sometimes we drive pretty hard/under a load in reverse. I used a simple 1/2" milling bit in my drill press since I have the bi-directional vise to cut the recessed guide slots. Wasn't a serious job since it was aluminum. I used nylon spacers to ride in the slots to avoid excessive wear and galling in the aluminum. This tensioner is spring loaded two different ways to cover either direction. I shouldn't have to do any type of adjustments till the skate board wheels wear out!!! I'm ready to when I get the intake manifold back.

[x-bird]

Swingarm looks excellent. You should get some new skateboard wheels and go into production on the chain tensioners, very clean design.

[metalstudman1]

Thanx for the compliment- I got new wheels!!!(used the old ones for testing) but going into production is a s-t-r-e-t-c-h!!!!! I made this 15 sec. vid to show why I made what I made- the first attempt on this type tensioner (single wheel) went on the Spiderbox- it works but wears the wheels pretty fast (too much spring tension) and I can still hear chain slop from time to time.

http://www.youtube.com/watch?v=d2z8ATY7vBE

[metalstudman1]

Here's a couple of short vid's to show how it worked-
http://www.youtube.com/watch?v=a3h9bPlr3aw
This one shows the improvement of my 7 yr. old daughters shifting skills
http://www.youtube.com/watch?v=0NHz_an6d1w

[metalstudman1]

My daugther made me go back and slow the video down to verify a winner-So who won?

[SYCARMS]

Too close to call, need a re match

[metalstudman1]

Update: only 2 months on the newest swingarm and the same type of failure. With over a hundred hours of punishment I noticed a crack while doing my daily inspection. Pulled it in the shop, pulled the motor and...... the pic's pretty well tell the story!
I used much heavier steel this time and I'm still under-engineered- AGAIN!!! I'm getting pretty good with this failure!!!! I'll need to add many gussets to carry the load away from the welds.

I'm now trying to figure out why this occurs on this buggy and not on the Spiderbox- the major difference is their suspensions & of course chassis design. Back to the drawing board

[roysheepdog]

did you weld that with a gas less welder?
In pic#4 did the tube break around the weld or did the weld not have penetration?

[metalstudman1]

I've got a Miller Passport Mig/Tig with CO2. it's metal fatique (twisting), all the failures are right where the weld terminates (with thin wall mild steel the molecular properties change enough to make it slightly harder/brittle due to full penetration) With thicker mild steel and only half +/- penetration this usually doesn't occur. I'm going to have to spread out the welds and loads forces with gussets.

[kliff]

Sounds like you're on the right track to cure the weld separation MS1. Workmanship is first class, and I think the gussets will be the answer. BTW, I love that chain tensioner! Gonna use that idea on one of my future builds, maybe even the Puddle Jumper project,

[chuckorlando]

Top notch work bro. Everything looks well thought out. On the arm have you considered possibly replacing the bushings with heims at the frame? It may give just enough flex. I would figure the axle is wanting to articulate and is doing so as much as it can. The shocks allow for it but the bushings do not. The only problem with going to heim, I aint sure how the upper links will react or not react for that matter. I've always wanted to take a 150 swing arm, add 2 heims at the frame and a stabalizer bar or even 2(4 link) above the engine. Trophy karts do it with a fixed engine as does protodies new 450 and a few others. So a fixed engine would be all the easier. Dont mind my babble. hahahaha

[metalstudman1]

Happy Fathers Day!!!!!!Thanx for the compliments gentlemen-Chuckorlando-It's not babble!!! My "different type of buggy" uses similar links as described (mini sprint)
I'm convinced the abuse comes from the constant up/down shifting at the wrong speeds!! when the kid's downshift at WOT to the next lower gear (intentional or not) there's a huge load applied to the swingarm. I've watched the engines torque want to twist/roll-over sideways in the swingarm.
The major issue is driving/jumping beyond the design intent-just pushing it to failure due to excessive abuse, but then that's why we play in these toys! I'll keep improving the structure till I get it right.
kliff- The tensioner is still working like it was intended. My only complaint-there's alot of noise(snapping/slapping) associated with it steadily moving the springs

[roysheepdog]

Maybe tig it, that will help with the heat.Ive had nothing but good luck with tig.
Gussets are a good idea.

[x-bird]

Are you solid or rubber bushed at the engine mounts? If solid, adding some "give" at the mounts with rubber bushings might solve the issue. Otherwise the tubing simply can't take the torque and you still may be chasing the same issues at the end of the gussets. The more i work on my rear swingarm, the less i'm liking its tubing.

[metalstudman1]

I really appreciate all the input gentlemen-I'd never thought a 200cc engine could be so destructive!!!
x-bird-I haven't tried any bushings as the engine in the quad is solid mounted. But i'll give that some thought. I'm still at a loss as to why this ocurrs in the Punisher and not in the Spiderbox- both have almost the same mounting set-up.The Spiderbox is driven alot more than the Punisher too.
roysheepdog- If I can't resolve the design issue I may just round up some chromoly and tig it. I did increase the square side rail tubing quite a bit over the last failure and the round tubing by just a little. More thought and understanding of the motors torque load points is still needed on my part !!!!

Note: when I experiment with these things I'm always trying to simplify the process so others could hopefully near duplicate the modification.

[SYCARMS]

Engineers are so under rated these days. Alot of R&D goes into these toys. But being that we are creachers of habit we tend to do things by trial and error. You will have this figured out I'm sure. I had to pull a 200 out of an 85 Honda 3 wheeler and was amazed at how cheesie the frame was. I could have bent it with my hands but with all six points bolted to the engine it was strong. Its weird how this stuff works. Just look at a Top Fuel when he hits the wall at 300mps and survives the crash in a tube frame holding a 1000 lb engine probably the weight of a 1000cc buggy.

[SYCARMS]

Oh let me add I'm off to the buggy bash. Don't know if I'll have internet there.

Later, TOM

[x-bird]

aside from mounting setup, what about gearing (same between the two?) and or tire tread "bite". Good traction breaks a lot of things ... re. tom's comment, i just chopped a main down tube section out of the polaris trailboss frame to use for the rear crossmember on the yerf swingarm and nixed that idea after seeing that it was such a thin wall tube. Frame top tube was crushed from the junkyard claw, so no great loss--surprised me how light it was.

[Zapper]

She is not flooring it or not enough throttle on hers

[x-bird]

Originally Posted by chuckorlando

On the arm have you considered possibly replacing the bushings with heims at the frame? It may give just enough flex. I would figure the axle is wanting to articulate and is doing so as much as it can. The shocks allow for it but the bushings do not. The only problem with going to heim, I aint sure how the upper links will react or not react for that matter. I've always wanted to take a 150 swing arm, add 2 heims at the frame and a stabalizer bar or even 2(4 link) above the engine. Trophy karts do it with a fixed engine as does protodies new 450 and a few others. So a fixed engine would be all the easier. Dont mind my babble. hahahaha

On a swingarm type setup, heims would actually be the same as solid bushings. A pair of them mounted on a single arm eliminates any sideways rotation on the ball and limits it to just vertical travel. They would eliminate what little deflection/shock absorption the bushings offer.

The whole thing boils down to the basic buggy design of putting the engine and an unhoused live axle on a dead axle frame configuration. The lack of a housing to attach any pivots to eliminates any chance of putting in an effective linkage system. the end result is a one-plane frame that has to soak up the bumps of uneven terrain, cornering and acceleration forces. push it hard enough beyond the little bit of deflection the mount and shock bushings provide and something has to give. It's going to be the weakest part of the axle, engine, subframe or main frame connection.

Now if you could create a very, very effective chain tensioner, you could make a secondary suspension component out of the bearing hangars, (separating them from the swingarm) add locating rods/linkages to those and allow the axle to have a small amount of roll movement in relation to the swingarm. think skateboard trucks ...

Metal just needs to put in a throttle stop and cut his jump heights in half

[metalstudman1]

Originally Posted by Zapper

She is not flooring it or not enough throttle on hers

Now that's funny!!!!

x-bird- I've had nightmares trying to come up with a viable semi-articulating swingarm as you've suggested. I agree that it would take the hard impacts out of the swingarm and motor connection-If someone can make it fly let me know!!!
"Metal just needs to put in a throttle stop and cut his jump heights in half" - anyone that knows me knows that's not possible!!!!!

[x-bird]

Originally Posted by metalstudman1

x-bird- I've had nightmares trying to come up with a viable semi-articulating swingarm as you've suggested. I agree that it would take the hard impacts out of the swingarm and motor connection-If someone can make it fly let me know!!!

If it was fall/winter when i have the time, the golf cart axle would be going in differently. What i came up with was four Fox 1 to 2 inch travel oil/spring mountain bike shocks, 2 on either side of the swingarm lower tube going between the axle tube (staggered front and rear) and swingarm, and a pair of angled trailing rods from the axle tube to the swingarm mounts along with a good scissors link spring loaded chain tensioner would do the trick. You would get deflection oversteer in the turns which would help with the poor turning radius of a solid axle and less torque from uneven terrain going into the swingarm tubing. You have to limit the amount of axle housing travel at the wheel ends because of the chain sprocket going on an angle in relation to the drive sprocket.

[metalstudman1]

I hate to say it but that sounds too complicated to get it right!! with alot of stuff to break/maintain and jumping would basically go away as I'd be worried about bottoming out the whole set-up and causing more damage. The axle tube would bottom first then the swingarm suspension would recoil harder.-or am I not getting your concept?

[roysheepdog]

Why not try a 4 link like on a truck?

[x-bird]

the shock idea is a bit of overkill (ok, a lot ... LOL) but basically think of it as installing a rear axle housing under one of these swingarms with just a couple of the rectangular rubber leaf spring isolator pads between the spring perch and swingarm. just enough "give" to eat up the initial shock, vibration/harmonics and allow the axle to have a little roll. The travel would still be regulated by the original shocks/swingarm setup--no changes there. the links just serve to keep the axle travel in the vertical plane.

Correction to my post above, the deflection of this system (mainly from the bushings in the link ends--unless you heimed or went solid bushed) would give understeer, not oversteer in the corners.

The axle housing i picked up is from a 70s to 80s ez-go marathon electric. by the 80s, most of the rear housings went to a split case that you wouldn't want to deal with. Just figured you might want to give a go at something like this if you stumbled across one.

with the shocks, it would actually work more like the dual-spring shocks that have the short and tall coil split on the same shock body. in this instance as long as the axle's spring is stiffer than the swingarm's, it should work progressively with no noticeable transition.