My Race Revo

[Dafni]

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

[captain harlock]

Astonishing work! ASTONISHING!!!

[rc4x4nut]

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

[BP-Revo]

Lets see those pics Daf! :)

[jhautz]

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.

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

[captain harlock]

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

[captain harlock]

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?

[jhautz]

Originally Posted by captain harlock

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?

Not sure what data you entered Cap'n. Can you use the data output feature on brians calculator and post it so I can see your inputs vs my assumptions. Like I said before... I am only guessing at what setup he might be using and yes by pushing higher motor rpms you can get it up there, but in generall it seems that 1/8 diffs and the slipperential it has a pretty low gear ratio.

[BP-Revo]

I'm not exactly sure how Brian's calculator takes KV. It may take unloaded KV, which would result in less estimated speed if a loaded KV value was entered, or vice versa.

I think the calculator is a compensation of both, because when I enter Castle's unloaded KV ratings, speed ends up off the charts. However, when I enter in a LMT motor, speeds are quite low (and users on here with the same setup as I entered have gotten much more speed).

What did you use to make the swaybars? Are the parts off a different truck or are they custom bent metal.

[BrianG]

I use whatever KV values are published, loaded whenever possible. In a way I like using loaded kv values and then other ways I'd prefer an unloaded kv value.

Using loaded values helps the result be closer to the real thing. However, it seems like a "fudge factor". I highly doubt we load our motors the same way as whatever method they use to measure "loaded". IMO, the calculated result in the right range, but not as accurate.

IMO, using unloaded values is better.... as long as the motor resistance and amperage drawn is known, both of which causes the kv to drop. This kv drop is more accurate because it is specific to the application you are using it in.

[captain harlock]

You mean that the 1950/10 unloaded is rated for 1307rpm and loaded 1254?

[RideIcon]

i just read this whole thread and i think my head is going to explode, that is the sexiest revo i have ever seen. I'm working on building an electric revo and have been looking at ideas for a while and i think im going to be dreaming about your truck, lol

[BP-Revo]

"I'm too sexy for my shirt...too sexy for my..."

that popped into my head after I read your post RideIcon LOL

[Dafni]

Jeff, the slipperential allows perfect gearing range in my opinion. I aim for 30K rpm motors (1950/6 on 4S or 1950/8 on 5S or something like that) and gear for app 35mph. I was able to get this with the revo slippy done without probs...but I can't remember what gears are on there at the moment. It works, though. Mike and me did the math when we designed it, should work for almost all combos. Not far from an E-Maxx tranny.

I remember when I had the 1950/8 on only 4S, I had to run a 38/20 or something like that, but it worked.

Yes, I have the buggy diffs, not truggy.

If you need any more info, just let me know. Okay, jeff?


All others, thank you for the kind words! Pics are still on page 14, just in case you're wondering :)

Cheers guys
Daf