I use my air compressor after every run, but I think that is what packs the dirt/sand into the suspension pins. The only cure I've found is to take the suspension apart every once in a while and clean it.

IMO you should do that anyways... haha. your lucky you havent sucked some real fine sand into your engine. i know my filter let through some really fine dust and it ruined my engine...

Filter? a good setup doesn't require a filter!

^^ :lol:

This happened with my revo too, if you cbf removing the pins and cleaning it properly, a spray with some silicone lube with one of those thin directional tube things around the hinge pin joints makes about 1000x better - its just dirt etc. getting trapped. Or you could take it a step further: my brother got a heap of tiny ball bearings and completely bearing-nated his savage suspension (shocks and inner/outer swingarms at least) and it had unbelievably smooth suspension - zero difference if you pushed it down a let it come back up compared to lifting it and letting the weight of the vehicle compress the suspension.


Be careful here around bearings (and not crazy bearing suspension bearings, wheels any other bearings, motor and wheel for example) compressed air will force little bits of dirt into your bearing seals - I learned this the hard way. Air compressor is great with a spray bottle of metho for cleaning your nitro vehicle, now I always do anything near a bearing with a paper towel though.

OK, I finally got a couple of days off and got my Evo together. Still need to do a few little things like clean up the wires some more and play with the settings on the MM. The 50% brake setting gives instant endo's I found out, very powerfull brakes. I am running 50% punch control as well, and really like the smooth power delivery, and it will still wheely on demand. The Trakpower batteries are awesome, they hold their voltage right until the cutoff, and I have it set at 3.2v/cell as an extra safety margin. I ran 4 packs so far, and the temps were really good. 120-140 on the MM esc with no fan, 90-105 on the motor and room temp on the batts. I am running the 14 tooth pinion for now, can go up if I want to go faster. Speed calc says 37-38 MPH, which looks about right.

Differential Ratio: 4.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 14
Total Voltage: 14
Motor KV: 2084
Tire Diameter (inches): 5.8
Tire Ballooning (inches): .25
Motor Current Draw: 0
Motor coil Ω: 0.0073
Spur/Pinion Ratio: 3.29 : 1
Total Ratio: 14.12857 : 1
Tire Circumference (inches): 19.79 inches (502.72 mm)
Total Motor Speed: 29176 RPM
Vehicle Speed: 38.7 mph (62.17 km/h)
Effective Speed Rate: 2.76 mph/V (4.44 kmh/V)
Estimated Adjusted Speed: 37 mph (59 km/h) - 5% loss
Effective KV Value: 2084

OK, now for the pics

http://homepage.mac.com/lonewolf039/...o/P3090040.jpg
http://homepage.mac.com/lonewolf039/...o/P3090041.jpg
http://homepage.mac.com/lonewolf039/...o/P3090018.jpg
Not real happy with the wiring yet, like to get it a little neater.
http://homepage.mac.com/lonewolf039/...o/P3090023.jpg
http://homepage.mac.com/lonewolf039/...o/P3090027.jpg
http://homepage.mac.com/lonewolf039/...o/P3090028.jpg
http://homepage.mac.com/lonewolf039/...o/P3090030.jpg
http://homepage.mac.com/lonewolf039/...o/P3090032.jpg
Had to clearance the hump a bit to fit the smaller pinions.
http://homepage.mac.com/lonewolf039/...o/P3090034.jpg
I love how simple this setup is.
http://homepage.mac.com/lonewolf039/...o/P3090035.jpg

Pinion came off during first run, I forgot to lock tite it:rules:
Luckily it stayed on the chassis and I didn't have to go looking for it.
http://homepage.mac.com/lonewolf039/...o/P3090043.jpg

Also ground a fair bit off the ends of my wing doing wheelys:lol:
http://homepage.mac.com/lonewolf039/...o/P3090046.jpg
http://homepage.mac.com/lonewolf039/...o/P3090048.jpg

I am really happy with the truck overall, now I just have to get some more batteries.

Yes! When my Revo goes electric, it too will have a center diff only. Thanks for the inspirational pics! Just one question, though: How did you mount the front center diff mount?

lets see a video of that thing man. looks great. good job on the build

Thanks MetalMan.

I drilled 2 holes in the chassis and used 4mm screws from the top side. You can see them in this pic.
http://homepage.mac.com/lonewolf039/...o/P1210001.jpg

Thanks, I have some crappy vid, just need to do the editing. It's surprisingly hard to drive and video at the same time:tongue: The truck keeps going out of the frame. I need to find a cameraman for a good video.

there isnt a woman or friend that can hang around for 5 minutes?

Tape the camera to your forehead, then just point and shoot!

I really do like the simplicity of the center diff mount, plus there arent any real limitations on the size of the spur- just clearence the chassis a little and jobs a good'n.

Do you need any more pics? I have a revo with a center diff and a slipper setup, workmanship is crappy, but I bought it like that:wink:

My "slippy-diff revo is almost done. I'll send pics asa i'l put my final touch!:wink:

I am working out of town still, so nobody around to help. I should be done for a while in another week or so. I will definitely get some good video then.


LOL, that's great. I have attached the camera to my controller before when I was videoing my crawler, but that moves a lot slower.


Can't wait to see them, David.


Here is the crappy vid, it's nothing fancy.
E-Revo Test

Thanks for the inspiration lonewolf039. The erevo looks much lighter than my BLMaxx which scares me with its potential to damage itself (and others). I might try to find a second hand one to convert to BL. The centre mount motor has a certain attraction due to the lovely symmetry you get. Thanks again.

Hey Lonewolf039, do you have the RCM hybrid truggy diff in your revo???
Because i've look to make a system like your's but i need a 4.3 diff ratio to don't have to put a 5T pinion and stay in the 40 m/h range:lol:

Awesome build bro. I am waiting on my stuff to get here so I can get mine up and together. I already bought the emaxx tranny for mine but i like the looks of this if I can get the motor mounts made somehow (hard to do in the sandbox). I guess I will find out though. This looks awsome though.

Yes, I am using the 4.3 ratio hybrid truggy diffs. Like you said, it's the only way to get the gear ratio in a decent range. They are awesome, the machining is top notch, and the HB diffs are way beefier than the Traxxas diffs.

BTW, the Traxxas cvd's fit in the HB diff outdrives perfect, but they are a little short and barely stay in, so I used the RCM adapters and the Traxxas dogbone cups. I am curious as to how the Traxxas cvd's will stand up to brushless power.

I installed the fan on the MM, and ran a pack in the hotel parking lot. It sure is sweet to just walk outside with the truck and controller and let it rip. I probably don't need the fan, but was bored so I put it on. I can always take it off again. I should have taken the pics before running in the snow:lol:
http://homepage.mac.com/lonewolf039/...o/P3140008.jpg

Here is a pic of the Traxxas cvd's using the HB dogbone cups. You can see that it is a little short. The bone hasn't popped out yet, but it could.
http://homepage.mac.com/lonewolf039/...o/P3140004.jpg

And here is the front with the Traxxas dogbone cup. It is a bit longer and holds the cvd better.
http://homepage.mac.com/lonewolf039/...o/P3140005.jpg

Next time I have the rear diff apart, I will change the dogbone cups to the Traxxas ones. Too bad I have to split the bulks to get the diff out.:tongue:

do you have a video of it? id love to see what it can do

You may want to put some fuel tubing behind the bone in the cup. Should help prevent everything and keep rattling to a minimum.

Awesome work though!

Here is the crappy test vid I have, hope to get some better vid soon as I get some more days off.

E-Revo test Vid


Thanks, but cvd's usually don't need anything behind the bone to keep it centered, plus the traxxas rubber boots keep everything from rattling.

I got some more video finished today. I took this after work the other day. The suspension was a little stiff due to the cold, lol. You will have to forgive the shaky camera work, I am still working alone on this. I am really liking the way this truck turned out, although I might try some thicker oil in the center diff to slow down the unloading on the front tires.

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Here is the video from yesterday. Most of the snow is melted from my sandpit, so I went bashing. I'm still not sure about the center diff. I have 120k diff fluid, and will try some 300k or 500k, but might just make a center spool like David Lamontagn did. Temps stayed pretty good, the motor got warm, but not hot, everything else was barely warm. Got a good 20 minutes of bashing from the batteries, now I have to get a couple more pairs.

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Well, I ran it some more and blew up the motor. Everything was running really nice, motor temps around 130-140, esc 110-120 and batts around 80-90 degrees. I was doing backflips off my big jump, and with the center diff, it was taking a lot of rpm to complete the rotation. I think the motor was over revving, as the magnet split in half.
http://homepage.mac.com/lonewolf039/...o/P4130214.jpg
http://homepage.mac.com/lonewolf039/...o/P4130218.jpg
The magnet separated and scuffed up the windings. I can see that some of the enamel is rubbed off, but I don't think any of the windings are shorted out.
http://homepage.mac.com/lonewolf039/...o/P4130217.jpg
I JB welded the magnet back together and wrapped it with some kevlar thread. Hopefully it will hold together until I can get a Neu or some other better motor. After 6 hours, I reassembled the motor and test ran it at low RPM and it seems to be running normal. I am planning on running it tomorrow, so I will see if it does hold up.
http://homepage.mac.com/lonewolf039/...o/P4130229.jpg
While I had the truck apart, I decided to change the wires on the esc to 12g wire, don't know if it will make much difference, but it can't hurt. I also cleaned up the wire routing a bit.
http://homepage.mac.com/lonewolf039/...o/P4130228.jpg
http://homepage.mac.com/lonewolf039/...o/P4130225.jpg
http://homepage.mac.com/lonewolf039/...o/P4130226.jpg
I picked up a pair of the Checkpoint 5400's to try out. They seem to be pretty good for an 18c battery, about the same power as the Trakpower 4900's, but they seem to run 10-15 degrees warmer. I only have 1 run on them so far, so I can't say for sure, but I am happy so far.

Well, it ran perfect for a half pack then the glue failed. The kevlar wrap protected the windings, so no damage done.
http://homepage.mac.com/lonewolf039/.../P41400021.jpg
So, does anybody know of a glue stronger then JB Weld? It will take a couple of weeks to get a new motor from the states, plus nobody has a 1515/2d in stock, so I would like to try and fix the Feigao. I was going to wait until the Castle Neu's are out, but that won't be for a while yet.

RCM has the 1515/2.5d in stock, how will it work on 4s? The speed calculator says that an 18 tooth pinion will give me the same speed, but the motor rpm is only 23100, which seems really low. I would like to stay with 4s for now, as I just bought some new batteries.

Thanks

I think red loctite is the best permanent glue for metal- it penetrates in to the surfaces to form a nice strong bond. I do know of other places that sell Neus- scroll down this list to the plane/boat section: Clicky. I wouldnt go any lower than about 2000kv for 4s lipo operation, at least thats the general feeling I get from reading around this place.

Hmm, I might try the red locktight. Can't hurt at this point. Thanks for the link, that is an awesome list you have there. Bookmarked:lol:


I needed my fix, so I swapped the twin tranny back in, and the Novak 6.5 is pretty tame compared to the Feigao. Plus not having all the programming options is a step backwards.
http://homepage.mac.com/lonewolf039/...o/P4140002.jpg
http://homepage.mac.com/lonewolf039/...o/P4140004.jpg

While the center diff was out, I decided to take some pics. It is a little rough, but works good.
http://homepage.mac.com/lonewolf039/...o/P4150006.jpg
http://homepage.mac.com/lonewolf039/...o/P4150007.jpg
http://homepage.mac.com/lonewolf039/...o/P4150008.jpg

Well, off to find my red locktight.:mdr:

That looks pretty cool- a nice drop-in unit/assembly. I wander if Mike could do somethig like that, and provide a little template for drilling the required mounting holes in the chassis....

There is quite a few differant types of red locktite so becareful. The stuff I first got was locktite 569 and that stuff was too strong. I would suggest going with something a lil weaker :)

but with the armature spinning that fast and hard, wouldnt you want the strongest stuff you can get?

I guess so I wouldnt suggest using it though in most areas of the car unless necessary. I just get all sorts off locktite from work so I prefer to use the weaker stuff cuz there is no need for it yet. First time I used it I had a hell of a time breaking torque with out stripping out the screw so i try to advoid it. If he plans on leaving the same motor in there then I dont see any problem with it.

then you might have solved his adhesive problems!

Do you need a hug? You seem a lil grumpy, lol

I also had to open up the brake area a bit to fit the spur gear, but it is a pretty easy conversion. Mike is more than welcome to make a conversion based on my design, I would buy one just to get his awesome machining.:lol:

I also blew up one of the rear pinion bearings today. The small 8x12 bearings just can't take the load of the spiral cut gears.
http://homepage.mac.com/lonewolf039/...o/P4160002.JPG
I took an old Kyosho 8x16 metal bushing and machined it down to fit. It won't break, but now the rear diff is temping at 90-95 degrees:tongue: I guess there is a little bit of friction. I guess I will have to get a bunch of the 8x12 bearings and just change them every dozen runs or so.

Sike had the same issue with his inner bearing on the rear diff of his revo when using the spiral cut gears. I suggested making a spacer that would fit between the 2 bearings, and distibute the load onto both bearings. Basically it would allow you to clamp the bearings between the pinion and the drive cup, and it would be impossible to push the center out of the bearing. Just a thought...

Good idea. I will do that as soon I can get some more bearings.

I picked up a FlyCamOne the other day and tried it out. I mounted it in my E-revo and ripped around my yard. The camera slipped a little half way through and you can see the rockers doing their thing, looks pretty neat. The donuts can make a person sick though.:lol:
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