Out standing work dafni! Incredible, must turn alot of heads at the track!

i need that slipperential...

Nice how do you like those ti arms

The Flextek arms themself are incredible. Performance and design.
The bushings they come with, however, are BS. I had to make my own ones. I tried Delrin, Polypropylene and Teflon. So far I only tried the PPs and they still work. Other than that, nice arms.

Yep, the stock bushings don't flex enough. PP could be just right.!

Yet flextech states theyve tried alot of different material combinations in the bushing design..:032: Maybe thats under harsh conditions?

Nothing wrong with the material or flex I think. Mine just had too much play. Now they feel solid, just like stock or RPM arms.

I think the bushings need to be kind of chamfered.

When the arms bend, the bushings must flex in relation to a perfectly straight pin. If the bushings were made rounded in the inside, sort of like an O-Ring, where the center touches and the rest bends away, it could flex without damaging the pin, but also prevent any play, as the bushings could be any material from 6061 or 7075 T6 to Stainless or Titanium.

I see what you mean, BP. Like the bushings on Twinforce suspension arms, for example.
I had the same idea, and made my delrin bushings like this (with a "curve" in the middle) but so far the straight PP bushings held up fine.

The flextek guys must have had a similar idea, they just made their bushings shorter (only like 3/4 into the actual arm) to get the same effect.

Anyway, I have the feeling my arms don't flex much, or not at all, during normal running. I think they only flex under hard impacts.

If I were to make new ones, when my PP or Delrin or PTFE ones fail, I'd do them as you described again, but with brass.

Another update on the truck: Last week I got some parts, and now I can replace the pre-production prototypes of the 1/8 diff cases with the final product! Yay! And I re-wired my ESC, now it's definitely picture-worthy, as it looks nice and clean.

later, guys
DAF

Astonishing work! ASTONISHING!!!

:004: I thought this project was completed a while ago. What the heck was I thinking. Excellent work Dafni.

Lets see those pics Daf! :)

DAF,

I was doing some calculation and found that the sliperential and the buggy diffs gave a rather low gear ratio. Almost dificult to gear it up high enough. WHat KV motor are you running in that and whwat pinion/spurr gear are you running with it? Here is the genaric values I entered, but it seems with the ''average'' setup it is dificult to get the gear ratio up at all. In the below numbers I assumed the smallest revo spur available and the biggest pinion available on the RC-monster store.

That is actually one thing that steered me away from the slipperential. I was concernend about the flexability of the gearing ratios.

How do you have your truck setup? Just curious.

<TABLE cellSpacing=0 cellPadding=2 border=1><TBODY><TR vAlign=top><TD noWrap>Differential Ratio: </TD><TD>3.3076923076923075</TD></TR><TR vAlign=top><TD noWrap>Transmission Ratio: </TD><TD>2.2</TD></TR><TR vAlign=top><TD noWrap>Other Ratio: </TD><TD>1</TD></TR><TR vAlign=top><TD noWrap>Spur Tooth Count: </TD><TD>38</TD></TR><TR vAlign=top><TD noWrap>Pinion Tooth Count: </TD><TD>20</TD></TR><TR vAlign=top><TD noWrap>Total Voltage: </TD><TD>14</TD></TR><TR vAlign=top><TD noWrap>Motor KV: </TD><TD>1867</TD></TR><TR vAlign=top><TD noWrap>Tire Diameter (inches): </TD><TD>5.6</TD></TR><TR vAlign=top><TD noWrap>Tire Ballooning (inches): </TD><TD>.25</TD></TR><TR vAlign=top><TD noWrap>Motor Current Draw: </TD><TD>0</TD></TR><TR vAlign=top><TD noWrap>Motor coil Ω: </TD><TD>0</TD></TR><TR vAlign=top><TD noWrap>Spur/Pinion Ratio: </TD><TD>1.9 : 1</TD></TR><TR vAlign=top><TD noWrap>Total Ratio: </TD><TD>13.82615 : 1</TD></TR><TR vAlign=top><TD noWrap>Tire Circumference (inches): </TD><TD>19.16 inches (486.76mm)</TD></TR><TR vAlign=top><TD noWrap>Total Motor Speed: </TD><TD>26138 RPM</TD></TR><TR vAlign=top><TD noWrap>Vehicle Speed: </TD><TD>34.31 MPH (55.11km/h)</TD></TR><TR vAlign=top><TD noWrap>Effective Speed Rate: </TD><TD>2.45mph/V (3.94kmh/V)</TD></TR></TBODY></TABLE>

I think his motor is a 1950/12. Revs are somewhere below 1200rpms.

Hey, Jeff.
If I use the speed calculator of Brian's with all the data I have, the speed it estimated was 47.91mph..

Is there a possibility it could be faster?