my first torsion build. BMVII

[revin9k]

oh ok i have the plates backwards! im an idiot. ok thanks

[dezfan]

Originally Posted by revin9k

no? but there is only one hole, if you look at the last pic i posted

Hmmmmm?

[revin9k]

yeah yeah yeah

[revin9k]

Originally Posted by revin9k

oh ok i have the plates backwards! im an idiot. ok thanks

sorry im dum.

[dezfan]

[RedMeanie]

Well, contrary to popular belief, this isn't a torsion chassis at all. The rods are free to spin in the holes, so there is zero torsion applied to them. This leaves bending of the rods as the mechanism of achieving flex. Due to the way the rods are constrained by the 3 plates, they bend into very suttle "S" shapes on each side of the middle plate.

By removing the "torsion" element of the loading on the rods, a lower, more controlled spring rate is achieved.

Hope you like the Design.

Jeff (Not Blue Meanie)

Originally Posted by Turblankas13

Hey i am just starting to build my own rock crawler and i still dont get how this style of crawler flexes, can some one spell it out for me?thanks

[renoirbud]

I am a little scarred that Lawrence is going to kick my butt at the next course, maybe I can accidentally set his truck on fire.

[dezfan]

Originally Posted by RedMeanie

Well, contrary to popular belief, this isn't a torsion chassis at all. The rods are free to spin in the holes, so there is zero torsion applied to them. This leaves bending of the rods as the mechanism of achieving flex. Due to the way the rods are constrained by the 3 plates, they bend into very subtle "S" shapes on each side of the middle plate.

By removing the "torsion" element of the loading on the rods, a lower, more controlled spring rate is achieved.

Hope you like the Design.

Jeff (Not Blue Meanie)

This is true, I think the TORSION tag was added to this design because of the similarities (no shocks, links, chassis mounted directly to the axles) to a torsion rig.

Maybe we should call it a float chassis?

Regardless, it's a great design.

[nitromtcrawler]

so mine is not a copy of the bmvii because my rods(top secret) are not free to spin. so i made my own torsion. ill call it the nitromtcrawlerii

[revin9k]

Originally Posted by renoirbud

I am a little scarred that Lawrence is going to kick my butt at the next course, maybe I can accidentally set his truck on fire.

i would like to but i need to get this thing done first, then we can have a fire

[revin9k]

got some work done yesterday at Rene's house (thanks) ill post pics this afternoon!!

[scruff007]

Looks good Revin. Should be a very capable crawler.

[revin9k]

here are a few pics of the rig. the only problem i have is the front pinion angle is too step, its causing a horrible vibration at low speed! I'm going to try to fix it today. well see what happens. here are a few pics. if anyone has any ideas on how to raise the front axle please let me know...thanks

yeah thats my dog's bone in the pic

[revin9k]

here are a few body on shots. man i love how low this thing is
the pic at the bottom is the front and i wanted you guys to see how steep the angle was.

[maxboostbusa]

Hey Revin. On my copy chassis I took a piece of derlin 1/2 in thick, cutting board would work also and templated the holes in the axle and drilled them. Then I sawed it into 2 wedges from corner to corner. It made a shim of sorts to raise pinion up some. I also modified the yokes to allow more flex in them the way we do on 1:1 rigs. If you need some pics let me know I'll get some for ya. Rig looks good though. Look forward to seeing it at the next comp.

[dezfan]

Looks good, I'll have your wedge done shortly, so at least the rear angle will be good.

[revin9k]

Originally Posted by maxboostbusa

Hey Revin. On my copy chassis I took a piece of derlin 1/2 in thick, cutting board would work also and templated the holes in the axle and drilled them. Then I sawed it into 2 wedges from corner to corner. It made a shim of sorts to raise pinion up some. I also modified the yokes to allow more flex in them the way we do on 1:1 rigs. If you need some pics let me know I'll get some for ya. Rig looks good though. Look forward to seeing it at the next comp.

thanks for the idea's i am using the steel yokes on the axle side. can you please tell a little more info/ show a pic? i put a few nuts and a spacer on the front today and it helped a little. if i go any further i will either strip the threads in the hole or need to drill bigger holes on the chassis plate (and i dont want to do that)

yeah i cant wait to run it! i only ran it for about 2 mins to find out my truck gets the shakes at low rpm! hopefully if i can get my motor from Holmes ill have it out this coming Sunday at the dam

[revin9k]

Originally Posted by dezfan

Looks good, I'll have your wedge done shortly, so at least the rear angle will be good.

sweet! i went out to the hardwear store today and priced some aluminum. wow! its was pricey. for a 6 by 11 inch sheet it was $8.00 by the time i buy that and the tin snips and the hardwear i could just get one built by a pro thanks! let me know ure address and ill send da mo nay!

[revin9k]

here are some before and after shots of the pinion angle

[LIKES2CRAWL]

What's your WB? if it's under 12 1/2" you can push the front end out and that would help a little.