Re: Adventures with Associated's CR-12...
 

As soon as I saw that snake, I’d be outta there.

Great pics though!!

Re: Adventures with Associated's CR-12...
 

I'd leave stock motor, replace esc with Hobbywing WP1080 (dial it in with the included program card), bump your battery up to 3s lipo and use stock 1-2 teeth less on the motor pinion gear. "thumbsup"

Re: Adventures with Associated's CR-12...
 

Yes, I'll leave the motor stock. The original pinion is 11t, i think. Would you know which pinion with lower teeth might fit? Thanks!

Re: Adventures with Associated's CR-12...
 

Morning all, and greetings from the UK. Just found this thread and have now read from start to finish, some great info & tips there, thanks. Is anybody still running these? Thread has been a little quiet lately. I have the TT Hilux version of this little rig, which has been well used since I got it last Christmas. Basically the same apart from no LEDs and friction shocks.

Whilst I've really enjoyed using this little truck, the main limitations I've found with it centre around stability. I use it a lot on rocks, boulders etc, and as standard all the elecs sit very high up on their tray. So, I've started to make a lower across chassis battery tray, and separate trays to sit either side of the motor/transmission to take ESC and RX. My plan is to swap the std radio out and use this with my GT3C so I can dial in some expo on the throttle channel - as std it is very jerky, particularly in crawler mode.

I have already modded the drag link angle to try to improve steering, which has helped a bit, but ultimately I think the servo needs to be re-positioned further back, but unfortunately the bend in the chassis rails prevent you from just mounting further back with existing fixings. So, will need to figure something out there...

Re: Adventures with Associated's CR-12...
 

Could this help you?
https://uploads.tapatalk-cdn.com/201...91ae895189.jpghttps://uploads.tapatalk-cdn.com/201...9bdc73c9d9.jpg

The servo mount fixes the steering geometry as well as the option to use a track bar which eliminates bump steer and greatly improves the steering.

Re: Adventures with Associated's CR-12...
 

Cool... thats just the kind of info I was looking for! Although that looks like one very trick CR12 - mine will be a bit more ghetto as I don't possess your fabrication talents! And I'm glad to see there are still peep(s) out their messing around with these little rigs.

Tell me, is there any advantage from a functional point of view in running the servo front to back, so to speak, i.e. in line with chassis, or does it perform similar to a servo mounted across the chassis (as stock), albeit a bit further back than standard? Just trying to decide which route to take with mine.

Re: Adventures with Associated's CR-12...
 

Thanks! There is no real benefit but I wanted to keep the servo winch option open. The performance should be exactly the same as long as the servo horn rotate from the exact same position.


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Re: Adventures with Associated's CR-12...
 

Cheers dude, I'll have a think about that.

Re: Adventures with Associated's CR-12...
 

Heya!

TT/Graupner variation owner here. I got one on a whim when Tamico had them for €129.- ( mebbe useful for our UK and Germany fellow crawlers to have a look there, before they’re all gone)

Couple of observations ( and remember that I’m not a “true” crawler afficionado, more of a scaler/trailer kinda guy)

-Steering geometry is bizarre, yet works fine. ( looking at Your solution here to fix that in due time)
-somewhat noisy gearbox, alleviated for a bit by replacing the bronze bushings of the spur by tiny flanged bearings I had left over after upgrading a tank gearbox ( by the by.. everything with ball bearings, yet, the spur running on bushings? Whût?? )
-Nice Looking yota body, but no mirrors.. grmbll. ( pet peeve.. :P )
-bit too fast for my taste, so ìn goes a slower running, long-can 390 motor.
-dampers leak like a sieve!!

The only thing I really spent some time on, subsequently, were the dampers.

I disassembled them, and discovered they had tiiny compensation bladdders, and even more tiiiiny o-rings in the cartridge, so, in theory they could be filled with oil.
Well.. not so.. the oil squeezed out about as fast as I had poured it in.

After a bit of head-scratching, I realized the cartridge was fine, but the rubber o-rings in it were juuuust a tad to thin, and weren’t squashed enough to do ànything to keep the oil in.
Solution?

A bunch of tiny washers left over from a 1/12 D90 build. Opened the cartridges, fiddled the tiny o-rings out, put little itty-bitty washer in between the rubber o-rings, close cartridge again... voila. Leak-free shocks, be it that the cover cannot be screwed-on too tightly or it will squash the o-rings so hard, the shock shaft gets stuck.


Some 100CPS ( about 7.5 WT, I believe) shock oil later, and we were in business.

Ran it for about an hour, just bombing around on my parking lot and garden, bouncing up and down ridges and stairs. No leakage, none whatsoever. Yay!

All in all, despite some oddities ( steering! ) it is an absolute fun rig. Small enough to be fun in my postage-stamp sized garden, yet big enough nòt to get stuck on the tiniest objects.

And, Though I like the Marty McFly-esque black yota body. I ordered the F150 unpainted body and accessories at modelsport. I just prefer big muscle trucks, and my own colour-scheme.

Re: Adventures with Associated's CR-12...
 

Good to hear there's another Hilux owner here. I also think the truck is a little fast, even on 2S, and was initially looking at gearing down, but I've had no luck trying to find a smaller pinion... stock is 11T, 2.3mm bore, and either 0.6m or 0.7m - kinda in the middle somewhere...

Tell me, what spec 390 can did you go for, RPM etc? Think the stock 380 is 15000rpm. And can you recall the ID & OD of the washers you used in the shocks?

Re: Adventures with Associated's CR-12...
 

I haven't done anything more with mine recently... other projects. But yeah... it's a little jerky on the throttle. I've got a FS GT5 and BS6 rx ready to install and set-up but still haven't got that done. Hopefully it'll help the performance. Also agree that the high COG hurts the stability but going ghetto here too means I won't be able to get it as dialed in as good as Ethan has. I'm going to fabricate something similar to what Ethan did to raise the drag-link off the axle and try to use a track-bar... to correct the steering geometry and reduce bump.

Re: Adventures with Associated's CR-12...
 

I believe the washers were left overs from a WPL build. Size is about 5mm x 2.5 or 3 mm

Edit.

Size is 3/0.3mm They’re from a turnigy shimset “Pro Shimset”

The 390 ( often called 480 too) is actually 16500 rpm. Sounds too fast. However, because of the longer can, it has more, mùch more torque in the lower- and middle rpm’s and thusly one never actually needs to go ‘pedal to the metal’

I’m also about to try a 380 5-pole Igarashi. I use those with great success in tanks. They run about 10000 rpm on 2s.
In my tanks they séem to have less torque, but thats deceiving, because the 5-poles are vèry smooth in their power curve. So smooth even, that one never realizes the amount of power thats coming in. Added bonus, they run about 14500rpm on a 3s. Plenty power for me. Ànd frugal with the amps.

I’ll try and report the results asap.

There’s a reason the better crawler motors are often 5-poles, and that Holmes chooses 5-poles ( or ‘5-slot’) for his high performance crawler motors. Once You tried a fat 5-slot 540 or 550, every 3-pole feels like a jerky, nervous, hard to dose piece of annoyment :lmao:

Re: Adventures with Associated's CR-12...
 

Thats some great info there for us TT Hilux / CR12 owners, thanks. Tell me, are you still using the stock brass 11T pinion?

Re: Adventures with Associated's CR-12...
 

Yup.

Basically because I’m too lazy to attempt to ascertain the pitch, and trawl the web for 10t pinions with 2.3 mm holes to fit on 380-type motors. I think our best bet is pinions for model heli’s. They often use 380-type motors with small 2.3 mm shafts.

By the by : just found-out the pitch is 0.6. I had an old ( rather : antique) Tamiya pinion, left over from way back, when the first on-road Tamiya’s came with 380 motors and pinions with two tooth-counts, one on each side ( quite ingenious) and it fit precisely . Added bonus, it has a 10 tooth, and a 12 tooth side on one pinion. Handy, if a bit more wheelspeed, òr more torque is needed. No extra pinion necessary.

EDIT:

Well. Tried the 5-slot igarshi 380. The results are nice. Much smoother throttle. Power comes in very linear. No sudden ‘jolt’ when crawling up my garden steps. As long as the tires have grip, It’ll keep going.
Though, on LiPo its performance is quite a bit better. On NiMh, on carpet, I can sort of stop the car with my hand. On LiPo the wheels just keep turning. ( cannot be good for the gears, me thinks)

So, imho experiment succeeded.

If You’re in the EU, the 5-slot Igarashi 380’s are a available via Conrad uk or Germany. Conrad also has the Motrax XFly 480 ( i.e. RS390) if You’re in for brute force.

Remember that You need either a long outgoing shaft, or a pinion with a long neck, because the motorplate is rather thick, and keeps the motor face quite far away, hence the need for a long shaft or long pinion. Helo pinions are often the long-necked kind.

Re: Adventures with Associated's CR-12...
 

Thanks for the info dude, unfortunately I don't have any old tamiya pinions to hand, so will just have to find another source. May try one of the 390 style motors in the meantime - are they all pretty much the same? Lots on ebay but all look identical to me...

Re: Adventures with Associated's CR-12...
 

Most of them differ in winds. The China-offerings are always somewhat vague in their stated performance numbers.

I know for a fact that the Traxxas 390’s run way too fast. 22500 rpm or thereabout. You want something in the order of 14000 to 17500. My best luck for a small crawler 390 was with one meant for electric airplanes meant for 9.6v

Sorry I cannot be more specific. It’s a matter of choosing a motor that’s meant to run lower rpm’s than the 15000rpm of the Reely 380, or get the stock rs390sh and just limit the throttle.. You còuld try a FS390PH (mainly used in automotive industry for electric windows, and such). It’ll run about 12000rpm ( 1080Kv) on a 3s lipo. And 7800rpm on 2s. It’s used a lot in 3s electric planes. I am not sure if it’ll fit, since it’s a flat motor, and the screwholes seem to be a bit off.
Cheap, though. Cost about €3.- before VAT.

Edit:
FS390PH works like a charm. Òne caveat, and that’s a rather big one. : there àre holes in the right spot for the CR12’s motorplate, however, they aren’t threaded. I had to cut a new 3mm thread in the existing holes. Consequently I had to drill the motorplate holes to 3mm. So the FS390PH, though pretty close to what I wanted, dòes need a bit of modifying.

Running with the PH immediately showed its increased torque. The extra length can makes quite the difference. Good slow control, but also a good amount of oomph for faster bits, but not as strangely fast as with the 15000rpm 380. It’s now only the tires that hold the truck back a bit.

Re: Adventures with Associated's CR-12...
 

Thanks for all that info, really helpful. I have an M3 tap set somewhere so might give the FS390PH a go. I'm just finishing off relocating the servo at the moment, about 10mm further back. Hopefully this will improve the geometry a wee bit and prevent the rock strikes on the servo horn and drag link. I've already moved the battery down across the rails, just need to decide where to put the esc & RX now.

I think I'll stick with the HW1040 for the time being, and just use my GT3C instead to dial in some better throttle control with the stock motor while I decide which way to go with that.

Thanks again dude "thumbsup"

Re: Adventures with Associated's CR-12...
 

Thank you all for the great info and inspiration! Still tinkering but she’s getting there. Bought the CR-12 for my son, but I’ve enjoyed it even more than my Traxxas Blazer.

Shapeway servo mount and servo...custom steering link from ExtremeRC4x4 (thank you!) ...upgraded suspension...RC4WD LC emblem...painted the inside black and more.

Attachment 383834
Attachment 383835
Attachment 383836

Re: Adventures with Associated's CR-12...
 

Just discovered this : At Tamico in Germany, the Graupner/Thundertiger Yota now goes for €102.-

One could check out the international shipping costs to see if it’s feasible to order it if you are from the States.

https://tamico.de/navi.php?a=195131&lang=eng

For me, being in the EU it’s a no brainer to order a second one for a Blackfoot custom. ( Shapeways body posts are already on my bench)

Re: Adventures with Associated's CR-12...
 

Hey everyone, first post here. Have a Traxxas Bigfoot but also just bought a CR-12 F150 a few weeks ago, my first crawler. Already put new wheels and tires on and am having a blast with it. I'll get some pics of the CR-12 tonight and post them tomorrow, but I've already found a bunch of useful info here, so thanks!