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10-16-2005, 08:01 PM | #1 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
| PTI MMT Stretch Question...
Hello, I have my PTI Goliath stretched out to a little shy of 15" wheel base, now i'm having Real issues... the truck will NOT stay upright, axles yes, main body/chassis/tranny area always went to lean. i've boosted the shocks (added spacers), but it still wants to lay over to one side or the other. And when it does so, it basically pivots in the middle. here are pics, so you can see what i'm talking about: http://www.villagephotos.com/pubbrow...der_id=1488412 i'm thinking i need to spread out my control rods, but wanted some of Ya'lls opinions. LMK phantom309oo7@msn.com Last edited by phantom309; 10-16-2005 at 08:18 PM. |
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10-16-2005, 08:24 PM | #2 |
Pebble Pounder Join Date: Jul 2005 Location: Denver
Posts: 182
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you've almost got zero triangulation with your links. they're all parallel (looking down).
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10-16-2005, 08:26 PM | #3 |
Rock Crawler Join Date: Nov 2004 Location: Thats a Good question
Posts: 552
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try moving your shocks out more on the axle, that will help a bit.
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10-16-2005, 08:27 PM | #4 |
Quarry Creeper Join Date: Aug 2005 Location: On the yellow dummy dumper
Posts: 447
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plus you might wanna lower the weight a little bit, that should help things as well.
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10-17-2005, 07:27 AM | #5 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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Cool, thanks guys, looks like the shocks will get mounted at approximately the same area as the lower links, which means i'll need to make some mounts for the lower links too... as any of you MMT owners know, there isn't a WHOLE lot of options for mounting/modding unless you make your own mounts, thus the shock mounts.will make links to take the lower links out farther towards the hubs, and then bring my top links up and together, similar to the Clod top-link on their axles. hopefully that will do it. Crawled some stairs and a child gate last night, other than the Leaning Tower of PTI syndrome, it did good, I did slip my shaft extensions, so looks like i'll be making another shaft extender too... I have BB's in the tires, and it seemd to work NIcely, however when i came up to the stairs, the rears wanted to bite in and flip truck over, should i make the rear tires lighter than the fronts? so fronts will bite more? Each tire/wheel weighs 15.5 oz, ie just shy of a pound each. |
10-17-2005, 09:07 PM | #6 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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um.... got the leaning corrected, Triangulated and used Maxx Super heavy dark blue springs, adn vioala. of course, relocating lower links, and upper links..... Now, i have a new issue, besides eating driveshafts....... check the link to see the problem...... i mean really, i wanted Good articulation, but shoot, this is a little OVERKILL..... See what i mean, first 4 pics: http://www.villagephotos.com/pubbrow...der_id=1488412 |
10-17-2005, 09:28 PM | #7 |
Pebble Pounder Join Date: Jul 2005 Location: Denver
Posts: 182
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HOLY ISHT! that things twists 180 degrees! |
10-17-2005, 09:45 PM | #8 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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LOL< Yeah, i'm thinkin either; shock limiters, or have shocks mounted attach to control arm...not sure i want to put cants back on it or not....LOL, would look cool. also, i may have the weighted tires a little OVERKILLED, i'm going to play with all that. |
10-18-2005, 04:58 AM | #9 |
I wanna be Dave Join Date: Feb 2005 Location: Cleveland, OH
Posts: 8,009
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in a lot of ways it reminds me of Microgoat 1.0 (nearly stock TLT-10 build). top-heavy, loves to lean, axle steer, torque roll, too much artic. thanks for the memories! unfortunately there's no one "do this and it'll fix everything" mod. you'll have to redesign the chassis from scratch, probably 3 or 4 times just like everyone else here, before you hit the right combination. but if you want to cheat, here's what i've learned: triangluate the links as much as possible. double-triangluate (W configuration) if you can. get the motor as low as you can. battery on the upper front links. 3-6 ounces in each wheel is plenty. a pound is a bit overkill, but whatever blows yer skirt up. lighter springs once you get the chassis flop under control. shorter WB will help you in high-center situations, and lets you run less center clearance. shortening WB by a half inch improves breakover angle much more than raising the chassis by the same amount. lower ride height prevents tipovers. 60* of artic is plenty. any more and you're just waving your dick around. that's all i can think of for the moment. good luck with the project. |
10-18-2005, 05:59 AM | #10 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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either going to relocate shocks to chassis like the original setup with cants, was nice and smooth then too, or just add some fuel tubing to the shock shafts to limit the amount of shock stroke. and I AGREE, Little Heavy on the tires/wheels...... came off the clothes basket last night, and (have not glued tires yet, do to experimenting) and the fronts blew, BB's everywhere. Could not blame the oldest boy this time, wife was setting right there...... lets hear it for hard-drive magnets. Thanks for the Advice MicroGoat, So far the PTI axles (TC3 Clones) are proving to be a little lightweight (gears), but i have a TLT w/ new gears front-to-Rear, and i may just have to swap axles.... also, will be going by the parts store to try the driveshaft stretch (steel fuel tubing) as i shredded my shafts last night... time to look for some Donor CVD's...LOL |
10-18-2005, 02:59 PM | #11 |
I wanna be Dave Join Date: Feb 2005 Location: Cleveland, OH
Posts: 8,009
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depending on the wheelbase you want, you may be able to use off-the-shelf Associated dogbones for the T3 or GT. if you really want to be slick, figure out a way to attach a CVD to your pinion. maybe the brake-line trick would work for that? that way you'd have a captured driveshaft and spend more time crawling and less time looking for your driveshafts in the rocks. just a thought. |
10-18-2005, 04:58 PM | #12 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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T3 dogbones are, i believe, 89 or 90 mm long..... my dogbones are, or need to be 143mm long... with the 6mm ball on the end.
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10-18-2005, 05:27 PM | #13 |
I wanna be Dave Join Date: Feb 2005 Location: Cleveland, OH
Posts: 8,009
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only if you're in love with that 40 inch wheelbase think about going shorter. it will help. see Microgoat 4.0 thread. |
10-18-2005, 06:52 PM | #14 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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LOL, once its going good, if its POS, then i'll shorten them...LOL, i like to try everything, in the past i have found a way around things people say dont work, dumb luck, possibly... i call it good ole Redneck Determination..... not catchin any fish, use more dynamite.....hehehe
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10-18-2005, 07:34 PM | #15 |
Web Wheeling Join Date: Jan 2005 Location: Twin Cities
Posts: 3,004
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I would shorten the wheel base or extend your shock rails on the frame.
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10-19-2005, 01:11 PM | #16 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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i made a set of shock mounts for the lowers, so i can adjust them adn hopefully i'll be able to use softer springs, and alleviate the 180 deg articulation issue.....i basically made a lexan version of those adjustable clod shock mounts you see on Ebay. also, i'm using a clod-like toplink setup, going to raise the upper links .5 from their current location, and bring them together inthe center of the axle. this willgive me a mor definite point in center of "W" LOL. Now that i'm looking at it, and watching vids of other crawlers, think i'm going to shorten the front by an inch, to make the front end less of a cantilever for flipping... i'm still trying to figgure out how to get the weight to the bottom, can not invert tranny and put motor on bottom due to driveline outputs. my hardened aluminum driveshaft system failed...LOL so now its off to try the fuel tubing / brazing driveshaft system. |
10-19-2005, 01:21 PM | #17 |
I wanna be Dave Join Date: Feb 2005 Location: Cleveland, OH
Posts: 8,009
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can you lay the tranny on its side?
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11-08-2005, 06:47 AM | #18 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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brazed Driveshaft (fuel tubing and cut CVD shaft) works like a charm, and if it needs to be shortened, or lengthened, i just put the torch to it, adn slide the dogbone end in or out to fit what i need.... laying the tranny on its side, won't work, as the tranny is not symmetrical (to keep chassis stock width). at this point in time, the most i'll do is to bring the front axle back about 1 maybe 1 1/2" to shorten the wheel base a little. the next project is TLT, going to have to use a Pede tranny, as i can not get my hands on a stealth. but the Pede tranny seems to work fine so what the hell. I saw a TLT in here that had all the links, upper and lower, above the axle, i like the looks and performance of that system, so i'll come up with a PhantomStein design that works the same way. i'm lookin and researching the 3-link setup i've seen on a couple of trucks so hell, may use that idea as well. |
11-08-2005, 06:53 AM | #19 |
Rock Stacker Join Date: Mar 2005 Location: Topeka area
Posts: 58
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here's a link to my other post in here that has pictures: PTI Goliath... Finished.... |
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