Cheapo motors..............

[recumpence]

Exactly!

The PK is an exercise in fun blasting around. Also, I do not like speed as much as accelleration.

I also agree that speed is scarey from a "Drawing attention" perspective. I am very careful when around people.

Matt

 

[Jeremy Harris]

There are some other good reasons for buying a very cheap motor. I've been experimenting with adding sensors to a big outrunner and wouldn't have wanted to risk damaging an expensive motor just for an experiment that might not have worked. Also, I've just stripped all the windings from another $45 TowerPro 5330, so that I can rewind it as a low kV, high torque, wind, better suited for what I want to do. I'll add Halls to this one as well, now I know they work so well.

As someone else has already said, these cheap motors are a good source of parts - I'm pretty sure I couldn't have got a decent stator, can with 14 reasonable magnets and a reasonably well-machined bearing tube for such a low price.

BTW, I'm aiming for a motor with a kV of around 60 or so, wye terminated and able to be driven with a cheap Infineon controller at reasonable power levels. A cheap motor re-built like this seems a good way to go.

Jeremy

 

[gwhy!]

My current proto-type setup consists of a £54.00 2.4kw tornado thumper motor and a £9.00 100a mystery esc and 2x sla 7ah batterys @ £11.00 each and about £100.00 on additional hardware all put on a 24" wheel bike . The whole setup works very well. The motor and esc havent missed a beat ( so far after about 20-30 miles of just riding and the very minimum of peddling ). I wanted away of playing around with the rc stuff with minimum cost and this was the best way (for me anyway). The thought of going down the route of a £180.00 motor and a £180.00 esc just would not have happened. Not sure if the motor I have falls into the very cheapo range of motors but im very pleased with it but i havent pushed as hard as I can yet due to the battery's are not up to it, the esc has some issues starting up from a dead stop so im just about to try a cheapo boat esc to see if this improves things..

 

[Jeremy Harris]

.......... the esc has some issues starting up from a dead stop so im just about to try a cheapo boat esc to see if this improves things..

Just fit Hall sensors to the motor and use a cheap Infineon ebike controller. You'll be amazed at the massive low speed torque increase over the cheap RC ESC.

Jeremy

 

[gwhy!]

.......... the esc has some issues starting up from a dead stop so im just about to try a cheapo boat esc to see if this improves things..

Just fit Hall sensors to the motor and use a cheap Infineon ebike controller. You'll be amazed at the massive low speed torque increase over the cheap RC ESC.

Jeremy

Hi Jeremy,
I do intend to give the hall sensors ago at some point as I think it may be my only option for what sort of performance I require and would be a vary cheap way of achieving this. Thanks.

 

[EVnewbie]

I have some ponderings,
Not sure if you think a Powerpack Motor (rewound BMC) is considered a cheapo motor but it got hammered by my sons and it never had a problem. They smoked the SVR AGM batteries and rear tire with no problems from the brushless motor and 36V 35 amp controller. Since it was a scooter, it was easy to do a gear reduction with the #25 chain to the 12.5 inch rear wheel. I want to use that same combo on a bike with gears this time...and LiFePO4 batteries in the 36V 20Ah flavor. Compared to the RC motors, the power pack is HUGE and only spins at 3116 RPM under load. I would like to put that motor in my old AeroEnvironment Charger bike with a Nexus 7 speed hub.
Hot rod scooters were a hobby, take those parts that worked and replace the stuff that did not. That is a hobby thing...beat the living crap out of things to see what goes first, rinse and repeat. At a point during your hobby fun, you realize the stuff you are building can actually be transportation! Wow! A hobby that can actually do something. 8)
Now if I jumped in with both feet and blew $3K on electric bike parts and did not like it... my wife would let me know it! :lol:

 

[liveforphysics]

.......... the esc has some issues starting up from a dead stop so im just about to try a cheapo boat esc to see if this improves things..

Just fit Hall sensors to the motor and use a cheap Infineon ebike controller. You'll be amazed at the massive low speed torque increase over the cheap RC ESC.

Jeremy

If you are looking to use your e-bike for a trials or any sort of performance critical usage, make sure you don't get the soft-start controllers, or you will end up just parking your bike because it's too infuriating to try to ride it. Like my bike right now...

 

[swbluto]

Ok, just thought of the another benefit I got from starting with a cheap, small motor - so I can intimately know of this type of motor's issues/costs before plunking down considerate sums of money for a larger, future project! It's better to be knowledgeable so you can get an idea of what your delving into and potentially save.

So far, I've had bearings problems so upgrading the bearings seems like it'd be a necessity with the HXT motors. I'll eventually determine if magnet-bonding will be a problem and if inefficiency is an inherent heat problem.

 

[Sam_Q]

I know this is a bit of an old thread dig up but I have a question for you guys

There is quite a bit of talk about bearing failure in these cheap motors. Now I don't think thats really fair on the brand of motor when thats not what they are designed for. Its like putting a thrust force a normal bearing and expecting it to last. The more expensive motors may hold up because they have been over-sized in that department. What I am curious about is how these would fare with an aditional bearing support to stop all side load, as this is exactly what I have planned for my own build.

The same goes for the magnets falling apart, these motors are made to be cooled by air being forced through them at a high speed, I find it little wonder that people are having the glue melt when they are installed inside enclousures/behind seats/90 degrees to the foward motion/etc... Seeing that all these motors have no possitive cooling they should all be fitted with something.

I do understand though that some motors fail because they are simply crap, I am just wondering how many failures are because non designed use.

 

[Miles]

Good points, Sam.

AFAIK, they use ordinary radial motor bearings. They may or may not be up to the radial loads, but the bearings themselves don't seem to be specifically for axial thrust (angular contact).

Most of the experiences of magnet bond failure come from RC use.

 

[Sam_Q]

RC use in planes or cars? if its in planes its pretty disapointing although not that suprising.

 

[Miles]

Planes.

 

[Sam_Q]

wow that really sucks then, no excuse for that

 

[Jeremy Harris]

In my experience, the bearings in some of these cheap motors are just badly fitted and assembled. In two of my TowerPro motors the bearings were partially, or completely, filled with glue from when the stator was bonded to the hub. The fact that the shafts turned at all was something of a miracle. There was also a complete lack of lubricant in the bearings, which won't have helped.

I don't think that the bearings themselves aren't too shabby, but as they almost always need replacing because of assembly damage it's daft not to much extra to fit decent SKF or NSK bearings.

To redress the balance I should just add that I stripped a Turnigy 63-74 last night. The magnet bonding is superb, each magnet is nicely encapsulated in epoxy that looks to be very well bonded to the can. The bearings were of good quality, with no apparent glue ingress and they appear to be well greased. Overall it looks like at least one manufacturer of cheap motors is taking heed of the criticism and doing something about it.

As all the winding wires on this big Turnigy are brought out of the motor, it's relatively easy to rewire it from delta to wye, too, which is a useful bonus.

Jeremy
Jeremy

 

[Miles]

To redress the balance I should just add that I stripped a Turnigy 63-74 last night. The magnet bonding is superb, each magnet is nicely encapsulated in epoxy that looks to be very well bonded to the can. The bearings were of good quality, with no apparent glue ingress and they appear to be well greased. Overall it looks like at least one manufacturer of cheap motors is taking heed of the criticism and doing something about it.

That's good to know, Jeremy.

 

[Grinhill]

Arrrrghhhh!!!!

Today I had to pedal home unassisted due to a grindy very hard to turn motor.

Pulled my Turnigy SK 6364-230 apart and found 10 of the 14 magnets require regluing. It's only got about 200 km on it. Was running well up until then, but I suspect these magnets have been loose for a while and today they bumped into each other and wouldn't seat down again.

I'll glue with epoxy, in two batches (every second magnet) to give me more room to work in.

I'm going to investigate fitting an Astro 3210.

 

[recumpence]

That is a bummer.

If you need a 3210, I stock the 6 turn version.

It is good your bike is relatively light weight and easy to pedal home.

Matt

 

[swbluto]

Arrrrghhhh!!!!

Today I had to pedal home unassisted due to a grindy very hard to turn motor.

Pulled my Turnigy SK 6364-230 apart and found 10 of the 14 magnets require regluing. It's only got about 200 km on it. Was running well up until then, but I suspect these magnets have been loose for a while and today they bumped into each other and wouldn't seat down again.

I'll glue with epoxy, in two batches (every second magnet) to give me more room to work in.

I'm going to investigate fitting an Astro 3210.

For longevity, it seems the HXT/Turnigy/Hobbcity motors require "preventative maintenance". I had installed extra epoxy and changed out the bearings and the motor has not had any issues so far despite the fact that I periodically run it through dirt/rocky terrain and the motor is sitting right next to the ground and back wheel, so it gets covered in dirt. It's gone over 400 miles so far.

This is with a motor that had cost 60 dollars initially, 85 with shipping included. I run it regularly at 1200 watts.

 

[Jeremy Harris]

I've just stripped a new Turnigy 63-74 (to fit a new, longer, stainless shaft) and I've found that the magnets are now extremely well embedded in epoxy. Even the gaps between the magnets are filled with what looks like Hysol structural epoxy.

This is in marked contrast to my TowerPro motors that have magnets that were barely bonded in at all. Based on this one Turnigy motor I'd have to say that it looks as if they have upped the quality a fair bit.

Jeremy

 

[recumpence]

That is good news Jeremy!

It is frustrating that an motor, no matter how cheap, would be so poorly built that you have to rebuild it from the start.

I am glad to know there may be a decent change occurring.

Matt

 

[Sam-Q]

well I might as well have a follow up from your reports Jeremy as I took apart my newly delivered Turnigy 63-74 170kv and checked it out. Link:

http://hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=7870


Now I am new to this but heres my verdict:


Good:

- very nicely machined, the housing and all components are a perfect finish, no burrs/sharp edges/inconsistancies, couldn't ask for more

- the windings where pretty even and mostly tight, only in a few odd spots could I move any at the very ends with my fingernails

- shaft is definately hardened

- Circlip has heaps of springyness to it and was nicely packed out with some tiny spacers that looks to be made of copper/brass. Couldn't ask for more here

- Extra bundled fittings in the box such as the female gold coated connectors and the prop adapter are great quality and look excellent

- Included was a piece of paper showing exact radii and dimentions of the mounting bolts for the motor which I have no idea if its normal or not but its awesome for us home builders.


Medicore/ok:

- The glue for the mangnets was faily even with the exception for a for some deviations in the middle, no extra glue where it shouldnt be however I can see some extra glue could of been added to be flush with the edges of the magnets instead of roughly just past the mid point. Certainly not bad but I prefer no option for easy improvment.


Bad:

- The so called "Dual oversize (Japanese)" bearings have Singapore written on them?? Easy changed but advertising something thats just wrong is not on and gives people a false sense of security. I will put the covers off shortly and see what type of bearing they are. I am going to call hobbycity and ask them to explain.

 

[gunthn]

Children would be my number one reason.

I have three and a questionable experiment with RC motors warrants no more than $100 because that is where you start. then how much for the rest $1000?

It gets a little ridiculous if you ask me.

Who here has a working 5kw RC motor mt. bike that can do what a mt. bike. does?

Which is go down trails not fire roads?

It's an experiment and some of don't have personal machine shops and unlimited budgets.

Personally I have a shitty basement in the middle of the city with a few power tools and a drill press and about $100 to $200 spare to spend on this at some points and mostly none at all.

 

[lesdit]

Here Here!

My aim to to build my donor GT IT1 for offroad only, and not weenie fire roads either.
I yearn for news of a real mountain bike setup. I am not at all impressed or interested in news of another
'squirt' bike . Squirt bike do lots of acceleration bursts on the street or on a lawn.

Truck analogy: Stadium trucks vs trucks for the SCORE Baja 500.
Or, 1/8 th mile drag strip vs Pikes Peak.

Now, I do realize there are members here that do some impressive distances on the road, so I respect that.
Sure would be nice to compare ride log files in the future, I might add.

I must be in a pissie mode tonight because from my front lawn I can see the flames of the forest fires
here in Los Angeles. Surreal, it looks like lava at night. And my favorite trail has burned, as far as I can tell....

Who here has a working 5kw RC motor mt. bike that can do what a mt. bike. does?

Which is go down trails not fire roads?

.

 

[coln72]

After what happened down here in Oz this year, I hope the closest you see that fire is from your front lawn in the distance and all you loose is your favorite trail. Remember to stay safe and one of the stupidest thing in the world is to try and defend an insured house if it gets to that situation.

 

[recumpence]

Children would be my number one reason.

I have three and a questionable experiment with RC motors warrants no more than $100 because that is where you start. then how much for the rest $1000?

It gets a little ridiculous if you ask me.

Who here has a working 5kw RC motor mt. bike that can do what a mt. bike. does?

Which is go down trails not fire roads?

It's an experiment and some of don't have personal machine shops and unlimited budgets.

Personally I have a shitty basement in the middle of the city with a few power tools and a drill press and about $100 to $200 spare to spend on this at some points and mostly none at all.

I am not sure what question you are answering with your post. But, Deecanio is running the best mountain bike with RC motor that I can think of off hand.

RC drives are definately not the cheapest route to go, that's for sure. They do have good longevity if decent products are bought and used properly. I have over 1,000 miles on my recumbent. The ony issues I have had were the controllers. That was before I figured out how to use them properly in E-bike applications.

It is true they are difficult to mount and relatively costly to buy. Not every product works for every poerson and/or every application. Hub motors are definately attractive for their ease of installation and cost. I like the Bafang, personally.

Anyway, yes, RC motors are kind of like the small displacement turbo of the E-bike world; Lots of power, lots of RPM, very small and lightweight and a bit costly to innitially setup. However, they are quite good for long distances even with hard use if setup properly.

Matt