Speed controllers to use with mobility scooter motors?

Hi everyone, beginner here! (First post haha) :)
I'm looking to put together a testbed bot to build off to get started, and I was going to use some mobility scooter motors for the drive. For the ESCs, I was going to use the 85a Tz85a's because I know they're popular, but they are brushless. A lot of people use mobility scooter motors - but aren't they likely to be brushed? If so, can people recommend any high powered brushed ESCs to use? Should I go for the Botbitz 85a Brushed Tz85a, or even the Botbitz 30a Brushed ESC? Would the 30a one be powerful enough for most scooter motors? - Sorry I can't give specifics, most scooter motors on eBay don't detail the specs. Cheers all! :)

Welcome to the forums, yo! Now I'm not the most qualified to talk on motors yet, as I have very limited experience, but I'm willing to bet you'll need at least a Tz85a for scooter motors. 30a ESCs won't cut it, and you may even need something more powerful than an 85, depending on what you use. If you want, you can buy the Tz85 brushless version off HobbyKing, and mod it to be brushed using this guide. Anyway, hope you have fun building, and I'm sure plenty more people will have important advice for you too. :)

For very low power scooter motors the 30A "could" do the job. But then we're talking 10kg units with 250W of motorpower.
Those will move a heavy at a snails pace.

Botbitz TZ85 can do bigger motors, but I wouldn't go over 24V 600W. What is barely useable for a brick that moves at leisurly pedestrian speed.

To give you an idea. Most heavies use 36V 80A or more. And that is with esc's that have peak ratings of 120A+.

Yeah, speed controllers get expensive once you get above 500W motors (about the limit of a TZ85). Wheelchair and scooter motors can be used, but as a rough idea, most heavies use motors with about 1200W peak power (Bosch 750s).

If it's just a test-bed bot though, wheelchair motors and Botbitz TZ85s will be fine. These motors would probably also work ok http://www.ebay.co.uk/itm/ZY1020-Ele...kAAOSwz2lXDMyJ

A better but more expensive ESC are these: http://www.robotpower.com/products/vyper_info.html

Quite a few heavies use these and they let you run motors up to around 1500W

Thanks for the helpful responses guys!

So I've ended up getting two Robotpower Vypers and I've decided to get a couple of motors and do the drive from scratch. I'm on the hunt for the two drive motors... any suggestions? I'd get a couple of Bosch GPAs but they are really hard to find. I'd need something in that power range at 36v. To be honest, this is all for a HW I'm building with the intention of applying for Robot Wars series two. I'm one of those guys that watched Robot Wars fanatically on TV when it was on, now I'm 22 and I'm building one with my dad, who I'm pretty sure is more enthusiastic about this than I am!

I'll post a build diary when I've got more to show, I'm pretty sure what I'm building is somewhat unique.. :)

Unfortunately most of the good motors are sold in the US, and the shipping/ import costs are often more than the motor. If you can get hold of them though, 3 inch Ampflows are used a lot, and can even be bought with gearbox and wheels attached. Another easy to use unit are the NPCT64s. For UK options, you can get 1000W/ 800W scooter motors off ebay pretty cheaply; they'll shift your bot fine, but if it's meant as a ram bot or similar then they'll probably be a bit lacking. Other motors available are Iskras from Italy(?) which are similar to Bosch 750s.

if your budget allows, then things like LEM 130s and Eteks are also available, but they're potentially over kill :L

Thanks, I'll have to do some more research for motors.
As for the gearing and wheels, I'm going to build something from scratch - the bot I'm building will require two large wheels for drive.

I'm currently looking for wheels with a diameter of 12" or so. A lot of the wheels I'm looking at have been wheels for industrial trolleys, and have ball bearings making them impractical for drive. Do people normally get something like go kart wheels with wheel hubs, or something else?

What the best way to mount the sprocket and wheel to the axle? Do people normally get something custom made, ie gears and axle that they get keyed? Sorry for all the questions, I'm just trying to work out the best way to mount the wheels/sprockets. :)

The go-to solution back in the day was indeed go-kart wheels, which came with a load of standard drive components that mounted easily to each other - as long as you were happy using chains and avoiding punctures...You can always knock the central bearings out of commercially available wheels and make your own hubs, and in this day and age you'll probably require some degree of custom components no matter what you go for.

It's also worth noting 12" is pretty big if you're going for a low to the ground approach - standard go-kart front tyres are 10", and a lot of modern heavyweights are under 200mm for height...

Thanks for your help. The design I'm going for is invertible, that's why I'm looking at wheels that big.

The T64s from the US are excellent bolt in solutions. Yes they cost a bit more than just a standard motor on it's own but the fact that they have the gearing sorted in a single unit and if you get the adapter plate at the same time, the majority of sack truck wheels will bolt straight on. Once you factor in the cost of gearing etc there's not much in it.

The other advantage of NPCT64s is that you can bolt big wheels directly to them; my bot uses them with 500mm wheels (still small compared to Gabriel; there's no such thing as wheels that are too large :P)

https://www.youtube.com/watch?v=QQ6vofFf3ws

The gearboxes are a little fragile for full combat as shown by some of the US bots, but as long as the wheels don't take a direct hit it should be fine.

I'm looking at moving to 1000W scooter motors with 2 stage chain reduction, mainly for the sake of availability and robustness (T64s probably shouldn't have 500mm wheels bolted to them :L). The usual ball park figure is to aim for 12-13mph, so I'm looking at using a ~12:1 gear ratio.

The Chinese My1020 motors come in a few flavors, and ain't that bad in construction.
But I would recommend chains for reduction gearing.
The shaft ain't the the thickest I've seen for that amount of power. Now, some come with a small sprocket, and for a low gearratio first stage it should do.

The Italian Movimotors are also interesting, as Brutus demonstrated, but need more work to be ready for RW.

Iskra , a Slovakian brand, is very good in construction albeit a tad heavy. Those have so many variants it's even difficult to find the one you need/want.

The 800w 24v iskras are only around 2.5kg if my memory serves me correctly. Completely sealed as well so chance of crap fouling the insides or getting stuck to the magnets.

Ok, so I've have the Vypers on order for quite a while now... and they're still awaiting stock. It seems like there's a problem with the manufacturer. Does anyone have any suggestions for an alternative ESC? Something in the realm of 36v 120a.

Wotties spring to mind.
Mytras is also an option, if you can contact the maker of those.

Roboteq is a direct commercial option.

I would assume that the reason they have taken a while is that they had a rush of orders through for battlebots / robogames. Now that things have calmed down on that front build wise they will be able to catch up with the backlog.

The Vypers are showing up as in stock with Robot power, and back ordered with Robotmarket place, but there is a $50 difference in the price.

Robotpower had to increase the price by $49 USD at the start of the year; if the RMP honours the old $199 price (bet they won't!) you would be getting a real bargain.

I hope RMP honour their price, i've bought some from them on backorder.

Think Robot Power have them in stock, well that's what it says on their site.

Not sure what other options there are for Brushed ESCs, not had much luck buying a new worry from Ian, have tried a roboteq, but not happy with it.

Have ordered brushless ESCs too, and they are all on back order! whats going on!

Good ol vantec :)

Hey Tom! Would like to pm you but my work internet wont let me :( I work a seasonal job but when im back for 3 months over christmas i live with my perents in the Biggleswade area, so if you need an extra member id love to join in! Ta!

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Originally Posted by typhoon_driver

Good ol vantec :)

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:) Team Thorak are still running both our Heavies on these and Bosch 750's

I'm running a Vantec on the E30-400 Ampflows, if you can get hold of one then go for it :)

Which model is popular in heavies? Even the large Vantec RDFR47E has much lower ratings than the Vyper and costs three times more.

Robot Power ain't that popular in Europe. The market is divided between Roboteq, Wottie and Vantec.
With Mytras and 4QD as exceptions.

The 2 machines I'm sure of that use the older Robot Power Sidewinders are Bullfrog and Gravity.

Is that just due to the difficulty of buying them, or do builders go with older model ESCs 'cause they see them in existing bots? I know the Sidewinders had a chequered history but at least Robotpower replaced the first batch free of charge. Here is Australia, the small Scorpion ESCs have been popular and reliable.

Another new ESC option is the RageBridge 2. If you use 4 pole Ampflow motors, you can drive one motor with a RageBridge in bridged mode. Less current handling than a Vyper but better than the Vantec RDFR47E at a much better dollar per amp.

I recently ran the largest vantec with T64s running at 8s (so 33.6v give or take). Vantec survived two locked up T64s, one burned out completely. Solid controllers for sure.

I'm very interested in the rage bridge due to the cost and size.

Only reason I'm running the Vantec RDFR47E is because I have one already and know it it's a solid controller, sure I could go and source something more powerful but why spend money I don't need too :)

Snowlabs; I've done some serious testing of motors lately and have found some rather spicy ones (as this is a new build I am taking on id rather keep the models to myself) - however a fantastic supplier of High power DC motors in the UK (such motors used in cncs and the like) are: http://www.ellis-components.co.uk/

They usually deal with larger orders but if you have exactly in mind the spec you want they are more than helpful. They offer modern equivalents to classically used motors such as the Bosch GPA 750.

Also if you have the cash Parvalux do some spot on motors! I cant say who uses them (sworn to secrecy); but I can say is he is a friend with a world champion title bot and has used them for many years!

Also stick with the Vypers as they have plenty of beneficial extras! However they are not well tested in battle yet...

Cheers for the advice Tim, but my dad and I have actually made a rather large order recently. We've finally got confirmation that our supplier is getting stock of Vypers on June the 4th, so we should get those soon. We've also gone for a couple of 1000w 36v MY1020 motors for drive, and a pair of Zippy Flightmax 8000mAh 18.5v LiPos to power them. Eventually we'll need a weapon motor, so that'll take some further research... In terms of the weapon motor, is it a stupid idea to not use an ESC? Just have a relay or some kind of switch to turn the motor on and off?

I would start a build diary so I can properly introduce myself and the robot, not sure, but I don't really want to give too much away...

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Originally Posted by Albear

Hey Tom! Would like to pm you but my work internet wont let me :( I work a seasonal job but when im back for 3 months over christmas i live with my perents in the Biggleswade area, so if you need an extra member id love to join in! Ta!

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Hi Alexander, sorry I didn't respond sooner! What experience and skills do you have? Feel free to send me a PM!

Ellis components were the standard go to company for years for the bosch 750.

With regards to your question on weapon motor control, it depends entirely on what it is you want to do. Is this a spinner? An axe? What motor do you plan to use?

It'll need to power a single spinning weapon. I haven't made a concrete decision on the weapon motor yet, but I've been looking at AmpFlow motors but they're USA based. Are there any you could suggest from the UK?

Second hand ampflow or etek if you can find them.

Most of the high power motors are US based. Sods law and all that but that's just the way it is.

As to the control of an ampflow, using a big switch isn't an issue as long as you gear it suitably. I've used 200A power solenoids in the past with an RC relay to turn on and off the solenoid to great effect.

Is a big switch a good idea though? I'd imagine that events would require you to have as much control over the speed of the weapon as possible?

Well the only event you will be running a heavyweight spinner at will be robot wars. No other arenas in the UK can run heavyweight spinners. Your machine will run through a tech check to establish that it failsafes and your machine switches off if it loses radio signal.

As I said, it's a perfectly legitimate and reliable way to control a spinner.

Yeah, I'm aiming for Robot Wars so that shouldn't be a problem. I've also heard that some live events are looking at allowing heavy spinners, so that would be great too.

Believe it or not Ampflow have an Amazon shop; on Amazon.com and the shipping is surprisingly cheap as it's an Amazon based warehouse! Ours arrived for our weapon within 5 days!

Oh yeah cheers, AmpFlow coming from US Amazon isn't a bad idea. I'm liking the look of the A28-400. It's rated for 24v, whilst in sure 36v is safe do you think it's safe to run at 48v? It would be for the weapon motor, a spinner.