Brushless to brushed?

[JimRK]

What would be the brushed equivalent to a Tekin ROC 1800 on 3S

[dentonmac]

To answer your question, Probably the Brood Axle Buster would be the closest brushed motor. Excellent company, excellent motor, but will require much more maintenance (any brushed motor would) in the Losi platform.

But that really is an apples to oranges comparison...in the Losi. You can get the RPMs there, but the amount of torque and efficiency that the sensored brushless motors are able to produce is not even in the same ball park (and especially comparing it to the ROC). Also with us crawlers (and motor vendors) pushing the ESC industry for better slow speed resolution out of the sensored brushless ESC programming and motors. It seems that the gap between the two is narrowing...quickly.

The sustained amount of resistance from the worm geared axles puts alot of stress on the brushed motors, so they will require more maintenance. Not that they can't do the job...very well.

The other problem is the price to get into that kind of brushed technology. The Axle buster is about twice what a good brushless crawling motor (BCM) costs new. I am not the smartest person, but spending twice the money for a technology that does the job almost as well (with downsides) in a particular platform, just does not make sense.

[JimRK]

Great info, thanks. As I already have an RS, the ROC is a great fit. Not quite sure whether to get an 1800 or a 2500. Would appreciate a bit of advise there. The Losi is a bit modified but not crazy. (Rubba tranny/motor flip, DLux links, wheels, wheel weights. 3S 1800 DLux lipo, HD front worm etc,etc) Nothing new or unique, just proven advice and mods from the many threads/posts on this site, including yours (thank you people). Nothing against MOA's, but I'm a shafty through and through. My only 2 rules with the Losi are to always use the grappler body and original chassis, slight mods permitted.

[WAM]

I pulled a ROC out of my LCC and put it in a go-fast EXO. It and another Tekin brushless had a tendency to cog going steep downhill where smoothness was required. The juddering caused the rear to flip off the rock a bit earlier than with a smooth brushed motor. I run the Axle Buster and it is expensive. A quality 21 to 27T brushed motor from Holmes or Brood is nearly as good but they give up some wheelspeed to the AB.

From my experience, motor maintenance isn't as big a deal as people make out. But this assumes you only comp the car and run for 5 minutes at a time. If you trail run it or just drive around battery after battery, that might make maintenance an issue. In two years and many dozens of comps I've only replaced the armature once and that was due to a small pebble getting in and chewing things up.


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[JimRK]

Appreciate the comments. My formal comp days are over. Now it's pleasure crawling for extended periods of time or informal comps at the site. I think it would be too much maintenance for a brushed and I am familiar with that (too many years of racing modified 1/10th sedan and modified 1/12th on-road. Comm and brush cutters be gone. lol)
I guess precise slow speed crawling difficult lines is what I now prefer.

[JimRK]

I may have worded my initial posting poorly.
I can relate to 8T, 10T, 15T, 27T, 35T, 55T etc, etc as I have used and rebuilt them over the years. After a long lay-off from RC I have gotten into crawling. I am not quite up to speed with the brushless yet.
I would like to know what turn in a brushed motor would be comparable to a ROC 1800 and a 2500.
From what I have read and heard a ROC can be difficult or it can be buttery smooth. it's all in the radio/esc settings and it can take a while. .i have more than enough settings to play with (DX3R Pro & Tekin RS plus LiveWire)
Thanks for your patience guys.

[WAM]

My ROC 3100 was somewhat comparable to my AB 25T in wheelspeed capability. I'm not aware there is a ROC 2500.

[JimRK]

Sorry, brain cramp! I do know it's 2300kv. My apologies.

[JimRK]

Finally found some threads re motor kv and turns. I'm going with a ROC 1800, as I don't comp and don't need the big wheel speed.

[SilmarilS]

Damn... you put a ROC in a vehicle that won't do comps?, or don't need wheel speed?

This is what I got, and couldn't be happier in my LNC.

SKY400003-18 - Ares 1/10 Sensored 17.5T 540 Brushless Motor @ Great Hobbies

[JimRK]

Picked the 1800 up yesterday and started installation. Everything went A1. Did all my initial set-ups with the RS and Spektrum DX3R Pro, no problems.. NO reason to use the Hotwire yet, but it's a good extra tuning device to have. Please understand it's winter up here in Canada with snow. I put up a small makeshift course (bricks, wood, even brought a few rocks in from outside) etc.) in the basement to Trial Test.. Sometime in the next 5-6 weeks I'll get into the big indoor rock course in Toronto to see what we really have and do more accurate tuning. For NOW it runs great, smooth snail-like crawl speed and enough quick jump for what I need (or what I think I need) and great control on response to strg and accel. Man that 4 pole 12 slot motor style has brutal torque, just what I was looking for. I foresee some broken driveline parts in my future. I have already built in some 'beef-up' tips (Eric DLux and others. thanks guys)) Am using 3s 1800, 15t pinion and Sedonas at the moment and that will eventually change. Bear in mind it's not the real crawling world and I do see a lot of adjusting, tuning and chassis tweaking down the road. After all isn't that what makes the hobby so great. I'll do a proper report in the summer after I've 'wrung' it out over a number of climbs.