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-   -   Tamiya mini cooper (https://www.rctech.net/forum/electric-road/20068-tamiya-mini-cooper.html)

eR1c 03-24-2015 02:31 PM

more speeeeed, fasssssster!! :)

monkeyracing 03-24-2015 03:33 PM

Have anyone of you guys ever had a spider gear weld itself solidly to the carrier in a stock gear diff? Just had another one do this to me. Couldn't pry them apart without breaking. Only ever seems to happen in the RWD cars. Very odd.

sakadachi 03-24-2015 03:47 PM


Originally Posted by eR1c (Post 13923298)
more speeeeed, fasssssster!! :)

:lol: Yes, but if I can't control it... :sweat: CRASH! :cry:



Originally Posted by monkeyracing (Post 13923404)
Have anyone of you guys ever had a spider gear weld itself solidly to the carrier in a stock gear diff? Just had another one do this to me. Couldn't pry them apart without breaking. Only ever seems to happen in the RWD cars. Very odd.

I haven't had the diff weld like that. Is it that there is not sufficient lube inside to reduce friction and lower overall temperature? :confused:

My V2 seems to have an issue where the gearbox gets hot due to the motor heatsink and evaporating the ceramic grease that came with the kit. :rolleyes: my gear teeth were dry when I opened it up due to excessive noise. The gears were all shot in less than 3 months. :(

No bid deal replacing the gears, but I've not had this issue on my M03.
My M05's gearbox is well lubed with the cheap grease that came with the kit.

sakadachi 03-24-2015 04:12 PM

Maybe I should get those shorty Lipo's for my V2 before upping motor power.

I don't need 100C like the ORI14066 you guys use for racing, but maybe around 40-50C.
Can someone please recommend me a shorty 2S I should check out?
Honestly I don't need large capacity either. ~3000mAh would be more than plenty.

monkeyracing 03-24-2015 04:29 PM

Diff - Yup, there's lube, but for some reason the rwd cars kill these things. Totally weird. I even went through a thorough preparation and break in process.

Shorty - You can't get a much better deal than the Turnigy Nano-Tech 4200. Killer battery. Good price.

sakadachi 03-24-2015 04:44 PM


Originally Posted by monkeyracing (Post 13923526)
Diff - Yup, there's lube, but for some reason the rwd cars kill these things. Totally weird. I even went through a thorough preparation and break in process.

Shorty - You can't get a much better deal than the Turnigy Nano-Tech 4200. Killer battery. Good price.

Huh, that is weird that it only happens on your M04... :confused: Can you fit ball diffs in there?

Thanks on the shorty, I will check it out! :D

axle182 03-25-2015 05:55 AM

Jim, its probably due to the "diff out" on corner exits. Considering the torque of the BL motors, that would be my guess. Try different lubricants. Have you tried silicon grease? Spray on Teflon? carbon dust? Obviously not all together lol

caltek1 03-25-2015 06:09 AM

2 Attachment(s)
Yes I rate the silicone spray on lube on the gears and diff in my mini. The best part is it runs quiet and does not fling off like other lubricants.
I do have another issue with my MO5V2 chassis though as do two other racers at our track with the front of the chassis cracking in front of the droop screw bulges.
I will post pictures in the morning, but so far it has not interfered with the cars performance but have ordered a replacement set of A parts.

patorz31 03-25-2015 07:44 AM


Originally Posted by sakadachi (Post 13923484)
Maybe I should get those shorty Lipo's for my V2 before upping motor power.

I don't need 100C like the ORI14066 you guys use for racing, but maybe around 40-50C.
Can someone please recommend me a shorty 2S I should check out?
Honestly I don't need large capacity either. ~3000mAh would be more than plenty.

Here is what some of the guys are running up here In Edmonton.
http://www.amain.com/rc-cars/protek-...100-14/p271097

It weighs 155g. They like it for they can put weight where ever they want.

monkeyracing 03-25-2015 07:59 AM


Originally Posted by axle182 (Post 13924468)
Jim, its probably due to the "diff out" on corner exits. Considering the torque of the BL motors, that would be my guess. Try different lubricants. Have you tried silicon grease? Spray on Teflon? carbon dust? Obviously not all together lol

I'm pretty sure you're right about it diffing out being the problem, but we can't blame torque - I've been running silver cans on the last two. I'm just going to get it over with and put a ball diff in it. Simple!

Congratulations on the new little Freind, btw. Very happy for you.

Granpa 03-25-2015 08:38 AM


Originally Posted by eR1c (Post 13922775)
If your driving in a parking lot you won't notice much of a difference between the silver can and a 21.5t brushless. However if your racing competitively you will notice a slight improvement, but it isn't a HUGE leap of speed. Now if you could alter the gearing, then you could get much more speed out of that 21.5t brushless. --this is my experience racing at our outdoor asphalt track. We have a few guys who ran silvercans w/ the rest of us running 21.5t brushless, ..the difference wasn't that great in my opinion. Not what you might expect? It's not like putting a TC car out there w/ the Mini's! --Now that would be a difference you'd notice.

Actually, there is a huge difference and the larger the track the larger the difference. At the Tamiya USA track for example, the difference is a little more than 1 full second per lap. This would put you well over a lap down in a 5minute heat. And this is with a "blue printed" Silvercan versus a well "tuned" 21.5. I used to build some "wicked" Silvercans back in the old days and a 21.5 was the equivalent to a mild race tuned Silvercan. The low end grunt of a 21.5, even the RPM versions, would kill a race tuned Sivercan in the infield.


Originally Posted by sakadachi (Post 13922927)
Thanks for the insight eR1c!! :D I don't really need my V2 to be 'faster', I just want to try new technology. The silver can is control-ably fast in my basement track, I just want the extra umph, but not a big bump in speed.

I know I can just stick a black Mabuchi motor and probably get what I want, but where's the fun in that? :lol:

The black can or Sport Tuned motors are Junk, junk, junk. They are unreliable, inconsistent, run hot, and need the care and tender attention of a knowledgeable motor guy. It's best to stick with a stock Tamiya #53689 Johnson silver can. There's an old thread called Silvercan Tips/Tricks, if I remember correctly, devoted to the care and feeding of a Sivercan. I posted several times there on how to clean the comm so that your motor will be running at max potential. Also, purchase some VooDoo drops which you can find on e-bay. A drop of those each run, an occasional cleaning, and your Silvercan should give well over 500+ runs.

Also, if you have an rpm checker, a silver can should give you over 12k at 5v and 18k at 7.2v.

Also try a "Stinger" or similar motors. HPI used to make a 20 turn that was decent and better than the Blackcan. They were about $20 and again, if memory serves me correctly, were available from Stormer Hobbies. They were pretty close to a good 21.5 at least in my hands.

Hope this helps.

Granpa 03-25-2015 09:25 AM

Another thing that many don't realize is the even and smooth throttle response of the Silvercan compared to the 21.5. The drivability is much better.

With all that being said, if you've got some money just burning a hole in your pocket, new technology is almost irresistible. Look for a combo that gives you a smooth transition of power. Some combinations are just unpleasant to drive. One of the smoothest motors was the Thunderpower, but wasn't the fastest in a Mini. On a short, technical track, I believe this would be a good choice. Of course, as in all 21.5's, you might have t change rotors etc. My Killshots were fast but you had to stay on top of them and just needed a little more attention in the driving dept.

eR1c 03-25-2015 01:21 PM


Actually, there is a huge difference and the larger the track the larger the difference. At the Tamiya USA track for example, the difference is a little more than 1 full second per lap. This would put you well over a lap down in a 5minute heat. And this is with a "blue printed" Silvercan versus a well "tuned" 21.5. I used to build some "wicked" Silvercans back in the old days and a 21.5 was the equivalent to a mild race tuned Silvercan. The low end grunt of a 21.5, even the RPM versions, would kill a race tuned Sivercan in the infield.

I may be wrong and may stand corrected. --oops.
I ran a 21.5 last month for the first time after a year of silvercans. It wasn't as fast as I'd have expected. BUT, today I went out w/ my 21.5 and it seemed to come alive. I am not sure if the brushless needed some time to break in? But the front tires of my M05 were ballooning up ...i've never seen them do that. It is a heck of a lot faster. So i may have spoke too soon. I have my next race this Sunday, ...i just hope the speed I saw today continues!

Sorry for any mis-information, I was actually coming in to post this regardless of Granpa's message as I didn't want to send you astray...

eR1c 03-25-2015 01:22 PM

also, on the cracked chassis near the arms from a few posts earlier ...you didn't use threadlock anywhere on your M did you? threadlock will eat through the Tamiya plastic like nobodies business. I learned the hard way, ...my chassis cracked just like the one in your photos ...lots of stress cracks.

monkeyracing 03-25-2015 02:48 PM


Originally Posted by caltek1 (Post 13924491)
Yes I rate the silicone spray on lube on the gears and diff in my mini. The best part is it runs quiet and does not fling off like other lubricants.
I do have another issue with my MO5V2 chassis though as do two other racers at our track with the front of the chassis cracking in front of the droop screw bulges.
I will post pictures in the morning, but so far it has not interfered with the cars performance but have ordered a replacement set of A parts.

Hey Cal, some silicone sprays can actually degrade the plastic. I think it has something to do with the solvent base. I had an M03 once, where the whole area around the gearbox faded from black to dirty white, inside and out. Took me ages to figure it out. M05 v2 cracked in the same spot. Nothing to worry about.


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