Wrapping my head around practical brushed motor maintenance/longevity

[AxRub]

So, I have one RC truck - for now. I've seen a lot of people that have many more than one truck/vehicle and that love brushed motors. I understand that they are a "wear" item, at the least the brushes and com, and I'm just wondering, when it comes to something like turning coms for example, and you have a bunch of motors to deal with, are these guys sending them out, doing the work themselves with a lathe, something else? Out of interest I looked around at availability of lathes and they don't seem to be a widely available thing.

Anyway, it just got to thinking, I wonder just how often brushed motors need work, such as having a com turned for example, when the main use is crawling, trail running, that sort of thing, and if you all that have multiple motors and what not, how you deal with it. Maybe it's a dumb, total noob question.....

[Jboucher]

For trailing and water / mud i would use throw-away sealed can motors like the traxxas titan or holmes trailmaster sport.

No maintenance other than oiling the bearings and keeping it dry

Sent from my Nexus 6 using Tapatalk

[mewalsh100]

What Jboucher said. You can score "disposable" sealed can motors from $12-20 bucks. Use, burn up, replace.

[durok]

I just buy closed-endbell motors and replace them... Super-easy, and since the motors are $15-$20 and last a long time, I'm fine with that.

An excellent source for these is Holmes Hobbies - the TrailMaster Sport lineup, in 540 and 550 can sizes, the 550 size in 21t being my personal favorite.

Pair it up with a HobbyWing QuicRun 1080 Waterproof and programmable ESC (around $40) and you have an unbeatable budget crawling combination!

RPP Hobby | Radio Controlled Cars, Trucks, Boats, Helis, Planes, Plastic Models

Hobbywing QUICRUN WP1080 Waterproof Rock Crawler Brushed ESC, (2-3S)

[HumboldtEF]

I've got 99% of my fleet running rebuildable Brushed motors from Holmes Hobbies (oldest I've had is a year and a half) and I've not had to do any maintenance yet but I did fry a motor (bad gearing) and I sent it in for service at Holmes Hobbies, they'll do it all.

Some hobby shops have lathes but not all

[Hydrocarbon92]

IMO if you consider rebuilding high-end brushed, it might be easier & cheaper in the long run to get a good sensored brushless with a good ESC. Brushed has some advantages, but a good ESC helps level the field.

[EZCompany]

A shot of electric motor cleaner and a few drop of light machine oil on the bushings every now and again goes a long way for longevity. More often if you like to play in mud or dust/sand. Just don't use wd40. It's more of a solvent and IMO, causes premature wear.

An example of what to use is 3 in 1 oil or the zoom spout oil.
La-Co 4 ounce Zoom spout oiler 79704G https://www.amazon.com/dp/B0029NHARC..._DYm7AbGX21HVK

3-IN-ONE 10038 Multi-Purpose Oil 8 oz (Pack of 1) https://www.amazon.com/dp/B00065VGWK..._nZm7AbY30TSN0

[JohnRobHolmes]

I typically get 50 to 100 hours between rebuilds keeping them clean and not overgearing. Get into mud/sand/dirt and a rebuildable motor might need immediate attention or get ruined. For this reason, I typically recommend Trailmaster Sport sealed cans for getting into dirty condition. It is less cost in case the motor does get ruined, but the nature of the brushes makes it less likely since there is no brush channel to get jammed.

Lower power motors wear longer. The slower the motor or higher the turn, the less the brushes wear on any given voltage. Direct example, a 27t will need more attention than a 55t. This is due to both slower surface speeds of the commutator having less abrasive wear, and lower amp draw having less ablative wear.

Additionally, a higher turn motor ran on higher voltage to get wheelspeed back will also wear longer. Higher turn motors require less amperage (but more voltage) to produce the same level of torque and power. Amperage is the highest contributor to ablative wear until leading edge arcing becomes a problem, thus the higher turn motor ran on higher voltage will have better brush wear in most cases.

5 slot motors have lower current ripple, and this contributes to longer service life as compared to 3 slot. Lower current ripple means lower peak current for the same output torque or power.


Summary, keeping a motor clean, using a motor that is not faster or more powerful than you need, using a lower turn motor on higher voltage, and using a 5 slot instead of a three slot will all contribute to maximum brushed motor life.

[AxRub]

Thanks gents. Confirming a lot of what I've read, which is good. I appreciate the detail John, especially the comments pertaining to wear with respect to turns and power.

I don't know how you avoid dust and grime in a trail truck, I guess you just don't. I have made some extra "shielding", floor pan parts essentially, for my SCX10 II that, along with inner fenders, is to try to decrease the amount of dust and dirt that would be thrown up into and otherwise totally wide open chassis. I suppose that can only help.

Gearing - I assume an easy first step would be to just drop the tooth count of a pinion down a couple of notches, correct?

Never mind, re-read your stuff at the website John, I'm good with understanding the gearing changes.

[durok]

Regarding dust and grime, when I get back from running in South Central Texas dry, dusty gravel and dirt - I blast my truck with compressed air from a short distance - and then occasionally put a couple drops of oil on any squeaky bearings... I have a really nifty power blaster I use in place of bad-for-the-environment cans of compressed air (It's steel, Made In The USA, and user-serviceable):

https://www.amazon.com/Metro-Vacuum-...er+model+ed500



It's not that cheap, but I use it constantly around the house for all sorts of things, and I've had mine for many years - still works like a champ.

My Holmes TrailMaster 550 21t sealed-can is very fast, torquey, and shrugs off mistreatment like the trooper it is. When I toast it eventually - I plan on trying out some cheap Holmes products I've picked up:

The Motor TopHat:

https://holmeshobbies.com/motors/par...uildables.html

And the injection molded Delrin® guard - The BWD Motor Sav'r:

https://holmeshobbies.com/motors/par...tor-sav-r.html

These can keep even more crud out of your motors...

The Motor TopHat is specifically for sealed-endbell types.

The BWD Motor Sav'r can be used on other brushed and brushless types as well.

Cool stuff!

[AxRub]

Thanks for that durok! Great ideas, appreciate it.

[Jboucher]

CowRC makes a version of that portable vacuum.
I think they changed something so it dosen't overheat on heavy use.

http://www.cowrc.com/#!/Jet-Blaster/...egory=11281157

[durok]

Originally Posted by Jboucher

CowRC makes a version of that portable vacuum.
I think they changed something so it dosen't overheat on heavy use.

CowRC | The R/C Maintenance King!

Mine would have definitely overheated by now if there was anything wrong with it! I have had it for at least 6 years. It has a removable foam filter in the base that I wash in the sink and reinsert after it's dried out.

I have blasted out apartment fireplaces, used it as a mini leaf-blower on my patio, dried my hair (back when it was long), cleaned multiple desktop computer interiors of years of accumulated dust bunnies, blasted my computer keyboards, etc.

I use it every few days, so I know how durable it is.

The trick is to realize it should not be turned on and left on for 10-15 minutes solid. It has a thumb-operated power button that is simple to toggle off and on, very easy to use. Blast in controlled bursts of a minute or so, turn off for a few seconds, turn back on. It has never failed me.

It's the same concept as if you rigged up a brushed RC motor for AC use. If you let it run without a break for a long time, it would burn up. It's just a big brushed motor, itself.

Their website admits that it is made by the same company (Metro Data Vac) and also states :

"Please note: This is not the more commonly seen and lesser (italics mine) MetroVac model ED-500. Our model is the ED-500 8/13, an upgraded version featuring a heavy duty switch, 11 foot cord, and most importantly for your RC electronics and safety a grounded plug!"

You can pay $84.99 instead of $69.98 for those differences and a COW RC sticker if you like. I'm simply stating that my switch has NOT worn out, and my cord is also 11" long. It's not 3 prong, so I will be careful not to drop it in the tub!

It doesn't mention an upgraded motor on the Cow RC site.

Here's a new link to the same one I previously posted but for the aforementioned $69.98, instead of $72.50 like I posted before:

https://www.amazon.com/Metro-ED500-D.../dp/B001J4ZOAW

[Inspector86]

Originally Posted by AxRub

So, Out of interest I looked around at availability of lathes and they don't seem to be a widely available thing.

I have a 7x14 mini-lathe which is what I used to cut grooves in my bead lock wheel cans. There are a number of mini-lathes which are sold under several different names but that are essentially the same. Little Machine Shop is my go to source for tools, supplies and upgrades for both mini-lathes and mini-mills.


https://littlemachineshop.com/info/minilathe.php