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AndyB_Evo1411

Brushed Motor Questions

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Counterclockwise as viewed from the pinion end is standard rotation for every RC motor I've ever seen. The only applications I can think of that require a reverse-rotation motor are "mirrored" twin-motor monster trucks like the Clod, Wild Dagger, and the old Kyosho Double Dare/USA-1. One gearbox or the other has to run in "reverse," otherwise the truck will just try to get longer or shorter. ;)

It's worth pointing out, with regards to published motor RPMs, that these are mass-produced items (yes, even "hand wound" modifieds) and as such, there are a lot of manufacturing tolerances that can affect performance either for the better or worse: brush/magnet alignment, bushing/bearing tightness, armature balance and trueness, and so on. It's why the serious stock-class racers bought five or six motors at a time and tested them all, and why, when I was racing spec-class with M-chassis cars, when you found a "good" silver can, you hung on to it for dear life. Take every published motor RPM/power/torque stat with a grain of salt, and realize that a difference of probably up to 1000 rpm is just manufacturing tolerance.

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Also meant to ask if anyone has used the Modelbuild motor rebuild service? Seems good value as I don’t have a comm lathe so would need to outlay more than that for just 1 motor. Just keen to get my Reedy back in tip top condition. I am content just cleaning the other motors & fitting new brushes.
Noted that the Parma has HPI stamped on the end bell, so guessing that’s who made it!!

https://www.modelsport.co.uk/product/modelsport-uk-motor-restoration-service-13257
 

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Cheers Alangt4. Got higher standards & expectations now than I had when I was a teenager.

Testing now completed. My setup isn’t as flashy as the ones you can buy, just my old Acoms hooked up to a TBLE04S powered by 2S Lipo with a quick clamp to stop the motor moving around.

3BACEFCD-ED94-4B15-A01E-178D9A79649B.jpe

All measurements with throttle positioned to give 7.2V on DVM across motor and measured using the laser tachometer.

Silver Can (27Tx1) :

Struggled to turn then started smoking!! 😳 Quick clean with brake & clutch cleaner & now working. 🤞

17622 @ factory timing👍

 

Sport Tuned (23Tx1) :

20880 @ factory timing

 

Parma Pro Modified Cyclone II (18Tx2 or 16Tx2) Brass Bushed :

25257 @ 0deg timing

 

Super Stock TZ (23Tx1) Brass Bushed :

26128 @ factory timing fixed at 20deg

 

Reedy Ultra Mr R (16Tx3) Ball Raced :

25679 @ 0deg timing

30900 @ 30deg timing Advance 😀

 

Schumacher Ultra Stock G601J (no idea on turns) Brass Bushed :

21298 @ factory timing (crimped endbell so is fixed)

Time to clean them up & fit some new brushes. Def keen to get the comm refurbed on the Reedy. The rest not too fussed about just now.

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2 hours ago, AndyB_Evo1411 said:

Silver Can (27Tx1) :

Struggled to turn then started smoking!! 😳 Quick clean with brake & clutch cleaner & now working. 🤞

17622 @ factory timing👍

Sport Tuned (23Tx1) :

20880 @ factory timing

Super Stock TZ (23Tx1) Brass Bushed :

26128 @ factory timing (not sure on deg)

Interesting numbers for the silver can and ST, both above their rated RPM @ 7.2V. Could explain why I am getting higher GPS speed as I input the kv based on 14000 RPM on the calculation app. 

The TZ is slightly below rated numbers though. 

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To be fair with the TZ is practically out the box so it has barely been run, so it probably needs to be run in.  I got the figures for timing advance for the TZ from Tamiyabase and with it set to 20deg, it is making me wonder if I should put more advance on the Reedy motor.

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Ok, I got confused by the timing marks on the Reedy label which are in mm and not degrees!! 

Done some calcs and its a 36mm diameter can, so 1 degree timing advance = 0.314mm of movement of the endbell in relation to the outside of the can;

That equates to ~3.18 degrees timing advance for each mark.  I previously tested it about 2mm beyond the 8mm mark (so 10mm total) which I had initially written as 10deg advance when in reality it was over 31deg advance.  I'll set it up again and test it at the 6.5mmm mark so it is around the 20deg advance this time which is a more optimum setting.  B)

Still keen to send it off for refurb so interested in feedback on the modelsport service if anyone has used them.

 

 

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On 2/4/2022 at 7:42 PM, InsaneJim69 said:

I mean the cheap Chinese ones that claim to be 12x2 etc. They are just garbage. 👍

James.

Quite intrigued by these cool spec and stock old race motors. If I wanted to pick one up for a touring car runner and not pay silly money (I.e. I am not spending £100 on a dynatech or something) what should I look out for? And would they be noticeably quicker or better than a Superstock? 

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1 hour ago, ThunderDragonCy said:

Quite intrigued by these cool spec and stock old race motors. If I wanted to pick one up for a touring car runner and not pay silly money (I.e. I am not spending £100 on a dynatech or something) what should I look out for? And would they be noticeably quicker or better than a Superstock? 

The Superstock motors are very good for the price of them and still have decent enough torque. I do like my Reedy Modified which has more RPM but less torque. 4k-5k RPM will definitely be noticeably faster as long as there is enough torque to hit peak speed. Playing with gearing helps.

To be fair if you are running in a touring car then torque isn’t as big an issue as an off-road buggy so a low turn higher RPM motor should be fine. This thread here is a good source of vintage brushed motors with RPM listed on some of them. 
https://www.rc10talk.com/viewtopic.php?t=18586

Also the Tamiyabase motor database is good for all the vintage Tamiya ones. This is a great one for touring cars. Might be expensive but it gives you an idea of the number of turns/winds that you should be looking for.

https://tamiyabase.com/parts/4923

 

 

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Part of the problem on picking up the old fast motors is they likely need the com skimmed not just new brushes. hope that magnets are ok as well.

I picked up a Tamiya super modified 11T which is rated around 38,000 rpm at 7.2v but was only 27,000 rpm when I got it. Seemed pretty dead. Skimmed the comm, which took a few passes, and new brushes and it’s at 44,000 on nimh more on Lipo!
 

The fast brushed motors also eat brushes so brushless is such a benefit for running faster motors.

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10 minutes ago, Alangt4 said:I picked up a Tamiya super modified 11T which is rated around 38,000 rpm at 7.2v but was only 27,000 rpm when I got it. Seemed pretty dead. Skimmed the comm, which took a few passes, and new brushes and it’s at 44,000 on nimh more on Lipo!

That’s pretty impressive after the skimming! I was toying with doing it on the Reedy but think you have me sold!!

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1 minute ago, AndyB_Evo1411 said:

That’s pretty impressive after the skimming! I was toying with doing it on the Reedy but think you have me sold!!

Yes- the comm was pitted and covered in carbon. So explained why is seemed pretty weak initially.

has taken a while to get comfortable with the comm lathe- tried a few old demon rotors first.

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7 minutes ago, AndyB_Evo1411 said:

This would be a quick brushed motor.

https://www.ebay.co.uk/itm/REEDY-RADON-2-15T-3-SLOT-4100KV-BRUSHED-MOTOR-AS27425-/254858362719?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=710-127635-2958-0

Make sure to be using a suitable ESC like the Hobbywing 1060 as the Tamiya ones won’t handle it.

These are basically the same as the GoolRC, Surpass and many other names that are sold on eBay and AliExpress etc, can tell by the hole shape on the face of the can and the brassy coloured end bell

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3 minutes ago, AndyB_Evo1411 said:

Thanks, but I probably don't want anything that fast. I was interested in those advanced timing 27t and stuff like that. Old "stock" motors and the like. 

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1 hour ago, AndyB_Evo1411 said:

Sorry just I see you used to run an LRP 12x2 last year, so you’ve been there & done that already. 

Yes, and that was kind of a means to an end. I an really enjoying my rally cars with Torque and Sport Tuned motors in for street running, so thought it might be fine to find something punchy but relatively high turns. I got a random 27t motor with a DB01R I bought a few years ago which performed way in excess of a silvercan. Didn't really know what it was and sold it with a buggy a while back. Kinda wish I hadn't. Now I know more, it was probably quite a cool stock motor. 

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A quick note from my brushed motor days.. if you don't have access to a lathe, I would stick to silver cans and it's variants or just go brushless.

I use to cut the comm after 3-4 runs depending on how hot the stock and mod motors were.  I still own a lathe so I bought the BZ motor recently, but had I not, I would've just stuck to a SportTuned motor on my Egress or wired up a lower power ThunderPower BL which I found to run kind of similarily to a brushed motor way back when.  

 

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FWIW I've run only brushed motors my whole life, and I've never owned a lathe. I'm still running some of the same motors I started with years ago, and they were old then.

The generic China motors you can get these days come with fairly hard brushes, which don't wear out nearly as quick as some of the softer brush compounds that used to come on the old race motors. If you use a harder brush and a softer spring, it really extends the life of the motor and can in some cases increase your ultimate top RPM due to less resistance on the armature. It also means you have to condition the comm much less often, so you can possibly get through without a lathe. I just chuck the armature in a dremel and do very light passes with superfine sandpaper, then metal polish to smooth everything out.

I just pulled the brushes on the cheapo 27T in my Sledgehammer for the first time all year, and other than being a bit dirty and well-broken in, they're still perfectly usable for another year at least. And the comm is of course dirty like everything else, but it's still shiny underneath the dirt (no discoloration), and there's no deformation yet. I drove it in the snow last night and it still packs plenty of punch after a year exploring trails of all kinds--sandy, rocky, muddy, snowy, and everything in between.

Sure, that motor could use a good cleanup, but my main point is that brushed motors aren't the "maintenance nightmare" they're often made out to be. If you get rid of all the weird stuff people were trying back then to squeeze just a bit more speed, most brushed motors will last a long time. (except those wicked hot 40+ degree stock motors... just nope!)

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30 minutes ago, El Gecko said:

I've run only brushed motors my whole life

I recently dipped my toes in the brushless world and boy, what a nightmare! Turbo, boost, timing and what nots. Sensored and sensorless. Not to mention the cost, a brushless system can buy me a brushed system with 3 or 4 spare motors. With a brushed, just make sure the ESC will support the number of turns and done. Some don't even need to set neutral-high-low points. 

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Brushless gets expensive if you go for the top end stuff. £130 -£200 for a top sensored ESC with all the toys & then £50-£100 for a similar spec sensored motor.

Of course you can get cheaper ones but even then you can be £80 for a reasonable branded combo.

£24 for those LRP motors (cheaper if you just go silver can) & £20 for a Hobbywing 1060 ESC you can get going a lot CHEAPER on a brushed setup. Also quite a good idea on vintage cars with no slipper too as the brushes motors don’t generate the same torque.

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@El Gecko I mean if you’re just running brushed motors in your back yard you may decide not to need a lathe, but motors do degrade in performance.  Some folks may think their motor is just dead, but chances are it’s just the comm needing some cutting and brushes cleaned/replaced. 

The reason why I mentioned silver cans not really needing a lathe is because their carbon brushes are hard, housing is crimped, and they don’t have any adjustability.. and mostly inexpensive to replace. 

The whole point of going BL was not to have to cut the comm so often to maximize performance at the track initially.. and the consistency in performance as there is no brush to adjust. 

Cutting the comm is no more than brushing and flossing your teeth.  It’s not difficult to do, just a hassle but the return is significant.   Yes you can go for days without brushing your teeth.. I suppose.  :blink: :lol:

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Interresting Thread, it would be awsome to have all infos in one Thread.

 

Here is another Motor Topic:

 

The GT Tuned Motors do have 19.000 rpm, so thats most likely the reason my Clodbuster isn´t noticable faster with the 2 GT tuned Motors than with the Silvercans installed....

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2 hours ago, whahooo said:

Interresting Thread, it would be awsome to have all infos in one Thread.

The info on that thread seem to be info copied from Tamiyabase. 

https://tamiyabase.com/parts/motors

Anyway, these days, any thread about brushed motors will always attract brushless fanboys jumping in singing phrase on how superior brushless are over brushed motors. 

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