Motors and Gearbox Ratios! What works for you?

[willcaddy]

Hello everyone!

With Portsmouth Extreme Robots only about a month away, I need to get my robot together! Well it is already together I just need drive an......anyway! lol

I an looking for a more robust drive system. I currently use 18v 550s drill motors with a one speed gearbox that comes with it (36:1 ratio running on 22.2v lipo). I have been looking at the P60 gearboxes as an alternative so i can just replace bits if they break. But this got me thinking, why not use the beefier 775 range motors as the P60 has a model for this.

So I dont really know which way to jump being as i need a new gearbox regardless as the one I had blew up in spectacular fashion lol. So I though I would throw it out to you guys!

What motor/gearbox combo do you guys use and what ratios etc?

Any replies are much appreciated because I would really like to get something that works well in this robot before I move on to sticking a dirty great axe on it lol

Thanks a lot in advance!

All the best

Will

[shakesc]

What wheel size are you running?

The Saturns from Ellis (discontinued) were 16:1 and a good match to 775. Give or take thats what the old drill motor setups were

I use 6:1 on 100mm with NTM 5060 270KV. Works a treat

[Al_]

What issues are you having with robustness of the current drive system? I use the 12v argos drills in one bot at 4s, (around 50% over voltage), 4wd, one motor/gearbox per wheel on 100mm wheels. It doesn't feel under powered in any way. I do kill a motor every now and then, but at the price they cost, I think it is an acceptable trade off.

I'n my other feather I use the P60s and these do feel more robust than a drill gearbox. (Note they have been discontinued for the P61's which are an improved P60 AKAIK). I have only run one event with them but so far so good. They do have a faceplate available which will take 500 or 700 sized motors which is nice, and there are some brushless motors that will bolt on easily too. The big problem with these is they are expensive and the shipping from banebots is sky high. No idea on how long they will last yet, but a lot of US build seems to use them without issue.

[maddox10]

If you're looking for a robust drivetrain, the Banebots are the only commercial "lightweight" solution at the moment.

Unless Ellis resurrects the Saturns. As those are to my feeling the better option.

[Danjr1]

https://m.aliexpress.com/item/329012...c191284f06d276

These were shared recently on Facebook, and a few people commented that they use them with 775 motors on 16:1

[Ocracoke]

As I've mentioned before, I've used the 13.7:1 planetary gearboxes with the 18V 775 motors that Gimson sell as a single unit to great effect on 6S though I'd say that was the upper limits of its capability, 26.4V on 8S LiFe is OK but it can't stand the pounding for too long. Pretty sure I am going to put a couple of those in a new FW I planning.

As Al says, for the price, you could simply afford to get a new drill/gearbox if one breaks given the economics but if the 16:1 gearboxes Danjr1 work, then they are less than £20 a box. Tempted to get 4 of those (or the 20:1 variant) for a replacement Kaizen...

[willcaddy]

Thanks everyone for all your replies 😊 The quoting isn’t working quite right but I have bodged it so it makes sense for now lol

Shakesc said: What wheel size are you running?

The wheel size is 100mm, it’s a trolley wheel with a bike tyre screwed to it lol

Al_ said: What issues are you having with robustness of the current drive system?

Currently its gears stripping, but I think this might have been due to impact. The gears closest the wheel stripped and also I went through two 550s motors in one event lol.

It’s the cost of the P61s that makes me hesitant because I be a humble shelf stacker lol.

maddox10 said: If you're looking for a robust drivetrain, the Banebots are the only commercial "lightweight" solution at the moment.

Unless Ellis resurrects the Saturns. As those are to my feeling the better option.

Yea I really wish I could get the Saturns because they sound pretty great!

Danjr1 said: These were shared recently on Facebook, and a few people commented that they use them with 775 motors on 16:1

They actually look really decent for the price, I would have to re-think how I mount the wheels though, have you any suggestions? Its just a nylon wheel with a coupling nut pressed into it to screw on to a standard drill gearbox.

Ocracoke said: I've used the 13.7:1 planetary gearboxes with the 18V 775 motors that Gimson sell as a single unit to great effect on 6S.

Yea, they look great also! Never even knew this company existed. The main trouble I have at the moment is I am running a 6s LiPo which limits me to what I can use. Even the 550s 18v motors I was using (that could handle 24v) were getting pretty dam hot and breaking after a fight or 2. The only drills I can see that might be suitable are the GUILD 18v drill drivers on Argos. Assuming there able to handle the power, they seem to use plastic gears in a lot of drills now. I got a black and decker drill to try not long ago and it looked promising but then one stage was plastic gears :/

I’m kind of in a dilemma where I’m not sure which way to jump. Keep buying drills for parts or buy a purpose built gearbox and then get the motors cheap.

Any advice is much appreciated and thanks for taking the time to reply

[maddox10]

Why go for cheap trow away brushed motors? There are enough brushless motors in a 540 or 775 size.

Since we changed from brushed to brushless, we have a lot less motorfailures.

[Danjr1]

https://m.aliexpress.com/item/329045...4-5-6-7-8-10mm

Again from the Facebook comments, hub adapters for those motors.

[willcaddy]

Thanks again for your relies

DANJR1 said: Again from the Facebook comments, hub adapters for those motors.

Thank you!

MADDOX10 said: Why go for cheap trow away brushed motors? There are enough brushless motors in a 540 or 775 size.

Since we changed from brushed to brushless, we have a lot less motorfailures.

The only reason was because the guide I used originally used brushed drill motors so all my speed controllers now are brushed. I probably will in the future its just I'm invested in brushed now unless there is a easy way to reprogram the ESCs which I'm not confident with at all. I saw some videos about battle hardening brushless motors too which you can't do with brushed.

Again, any advice is much appreciated!