[ken will]

Originally Posted by skooler

Just had a reply from the seller of the ebay milk float motor

"Hi
The motor has 2 pairs of wire coming off it, one pair for the cage and one pair for the stator.

He says there are two pairs of wires, one for the cage and one for the stator. Could anybody explain this? Apologies but I would assume there would just be 2 wires?

Like I said before I am new at this but, I thought the part that rotates is called the Armature and the connections are labeled A1,A2

Series wound: the stationary winding is called the Stator and it's connections are labeled S1,S2

Sepex: the stationary winding is called the Field and it's connections are labeled F1,F2

So A Series motor would have 4 connections labeled A1,A2,S1,S2
and A Sepex motor would have 4 connections labeled A1,A2,F1,F2

Are you sure he knows what he is talking about?
He mentions cage and stator. I though cage and stator were both names for the outside windings.

We are both speaking "English" but I call a car's bonnet a hood and it's boot, a trunk.....

[Woodsmith]

The seller may not know motors very well and so has misnamed parts.

Two plus two wires seems about right but doesn't say what sort it is.
I would chance it being a series wound motor as milkfloats are old and all the ones I've seen are series wound, including the 12" one I bought and the 9" one I rejected.
Both of those also had 25sqmm cable coming out of the motor frame rather then bolt studs.

Having said that it is your money and £225 is a big bit of budget.
Could you go and see it before it ends?

You would be looking for the wires to be the same size, both about the thickness of a small finger, for it to be likely to be series. If you can get a look inside then you might see the field coils, series ones are usually rolled from copper flat bar rather then fine round strands of wire.
You may be lucky and the wires are marked S1 S2, as Ken says. Mine was marked A,B,C,D.

Also, if you do get a look you should check the size of the brushes and commutator bars.
There should be plenty of comm bars (around 40-60 bars I guess) in the comm and the brushes should be big and there should be four of them (or eight in pairs). The comm bars should be about 1 1/2" - 2" long.

If I was looking for a motor I would go and have a look and take cash with me, if it doesn't sell then negotiate the price down.

My main concern would be the drive end cap. It looks to be slightly domed shaped and that could make it a little more difficult to mount to an adaptor plate. It would need to be machined to give a flat area for location but that isn't a deal breaker if you are having machine work done anyway.

Good luck with it. I won't bid against you.

[skooler]

Some really useful advice here!

Im guessing he doesnt know a lot as he also said he had spun it up while strapped to a pallet using a forklift battery! without any load???!!!

thanks for letting me know what to look for. If it doesent sell i'll contact the seller and view it over the weekend.

I did notice the curved drive end cap. Would this be a lot of work to have it machined? Would I be better off looking for another motor?

Any ideas how much an adapter plate and coupler would cost? I was thinking £300 at the most?

Thanks again!

Mike

[Woodsmith]

You could contact him to arrange a viewing if it doesn't sell.

The DE cap could be put onto a mill or a lathe and a rim turned onto it to locate it in a large diameter hole on the adaptor plate. That needn't be a big bit of machining but it needs to be accurate and in a way that securing bolts can be used to mount it.
The DE isn't currently used to do any more then to centre the bearing against radial loads of the chain drive and so the bolts on it could be quite small. Also it may be aluminium and/or very lightly made and unable to support the weight of the motor.
That needs checking too.

That doesn't rule it out but it can mean a more fiddly construction with a motor cradle to support the weight while the DE locates the position relative to the gearbox.

There are plenty of motors out there, somewhere, so bear all this in mind when you view.

Chesterfield may be worth a visit. I have been there from Manchester and also picked up motors from London and Surrey.

Another thing is to look for dead electric forklifts from businesses nearer you. Have a look on Ebay for some and also ask at industrial estates that have fork lifts if they know of a dead one or where they get theirs serviced or repaired.
I have a fork lift motor rebuilder only a couple of miles from me in the middle of Trafford Park. Only found it by accident.

An adaptor plate will depend on the motor you choose.
A simple one will be a bit of aluminium plate with a hole in the middle. Then it can be two plates to ease location and add thickness.
Then it could be two plates and a bit of pipe to add more thickness. The price will depend on the materials and how much machining you need to pay for and what you can do yourself.

Don't forget to measure the magic number when you pull the engine out. That is the distance from the friction face of the flywheel to the mounting face of the engine against the bell housing. You will need this whether you keep the clutch or not.

[dtbaker]

to run at high voltages, to get performance you want, you will need a KNOWN good motor like Warp9 and while you might get by with a Curtis 1231, you probably will find it worthwhile to go for a 'modern' controller like Soliton Jr, especially if you intend highway performance.

so..... save up you money, create a little spreadsheet showing savings, and take a loan from family or bank to do it right rather than re-do piecemeal.

[skooler]

Thanks again for all the input.

dtbaker, In an ideal world I would buy a warp 9 however this is out of my budget for now. If this project is successful I will definately get known parts next time round! as for the controller, I still quite fancy a soliton Jr to help futureproof myself. again, cost will be the main factor in this decision.


I am hopefully going to view the motor on the weekend. The seller says that all wires are the same thickness and it has a 10" diameter and 16" length. It sounds ideal apart from the dome shape!

This got me thinking... Does the motor have to be directly coupled to the gearbox/transmission? Could a chain or belt not link them together? This would allow for the gearing to be changed(a larger/smaller sprocket could be put on either end) and also provide more flexibility on where the motor is mounted.

The only drawbacks I can see are that it would be noisier and that it is another part to break.

Another option I have thought about is using a shortened driveshaft with CV joints either end to couple the two.


Thoughts?

thanks again,

Mike

[Woodsmith]

Having the motor separate from the gearbox is fine but makes the build more fiddly and can take up more room.

If you use a short drive shaft with CV joints then you will need to factor in maybe 12" of extra width in the front of the car and you may also find that the front end of the primary input shaft needs a pilot bearing to support the outer end.

Using a chain drive is fine but it does put the weight very high up over the gearbox and you may then have clearence problems. Also the alignment of the chain drive needs to be good to prolong chain life and reduce noise. You will also have the weight of a very strong chain guard to protect things from a snapped chain. I know of a Fiesta conversion that has two Agni motors over the gearbox and toothed belt drive. That worked well but needed a car jack to apply enough tension to the belt to reduce belt slip.

On top of all this, it also reduces the space available for batteries in the front.

It all adds up to a lot of extra precision engineering to use something that may not be the best you can get for your money.

The other option, if the DE is unsuitable, is to make your own DE cap. Have a look at my tractor thread to see how I adapted a golf cart motor that had no DE and also my Trike thread to see how I did the same with a 4 ton, 11" forklift motor.

I would go with simple where cost allows. Direct coupling of the motor to the gearbox on the DE cap. The motor directly replaces the old engine and can then use the same mounting points. There are less components, less engineering, less losses in efficiency, less loss of usable battery space.

[skooler]

Thanks woodsmith,

I will take your advice on this one and mount it directly to the transmission!

As for the adapter, could I use a taperlock or something similar?

I was looking at these
http://www.fptgroup.com/fenner.asp?t...gs&pageid=2727

Or would I be better off taking it straight to a machinist?

This drive end cap could turn out to be a deal breaker

I love the plywood approach on the tractor! do you think I could do the same with say 1/4" or 1/2" sheet aluminium?

Sorry for all the questions! I just want to get off to a good start!

I am getting more and more tempted to have a drive up to Chesterfield!

Cheers,

Mike

[Woodsmith]

Taper locks are the usual way to go if you can and have a plain shaft with a keyway.

There are many builds here showing how others have made their couplers, with and without the flywheel and clutch. You will need the centre of the clutch for the gearbox side splines though. If the motor you get has a splined shaft then you could try a taper lock, some think that should be ok if it is a good fit. I have found that some splines are not a standard shaft size and so the taper lock doesn't fit well.
If you had the gear or sprocket that has the internal splines to fit then that could be used as part of the coupler.
On my Trike I turned the gear teeth off the gear pinion and used the outide of that for a taper lock whilethe inside is splined to the motor shaft.

The jaw coupling you linked to may not work. The general experience seems to say that they rubber part isn't up to the job with the intermittant high loads from driving a car. They are fine for pumps and machenery though.
You are better off with a proper coupler that is fixed to the motor shaft and slides on the gearbox splines. Any cushioning can come from the springs in the clutch plate that you use.

The plywood DE cap on the tractor motor was a temporary one to test the motor worked. I did the same for the 11" trike motor. Then I turned one on the lathe to fit it. I have made a mistake with that one though as the bearing isn't tight in the DE cap and slowly vibrates down the shaft. I fitted a spacer on the armature to stop it moving.

The trike motor was too big for my lathe so I took it into work to turn on the college machines. Then I used a hand held wood router to finish it off.

The aluminium plate I used was found as off cuts on Ebay. Search for aluminium plate and the thicknesses you can use and see what comes up. Also if you have a friendly local scrap metal yard you may be able to buy scrap peices from them for a lot less.

[Woodsmith]

Have a look at this thread for adaptor and coupler making:
http://www.diyelectriccar.com/forums...=adaptor+plate

This is also worth a read. Jack uses a jaw coupling and it fails so he changed to a rigid one.
http://www.diyelectriccar.com/forums...hlight=coupler

This is what goes wrong with a bad coupler and adaptor on M38mike's Jeep.
http://www.diyelectriccar.com/forums...hlight=m38mike