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kenrinc
01-13-2009, 10:30 PM
So I've got this general purpose 1/3 hp GE motor. I want it use it for one of my projects but the problem is that the shaft (1/2") is split for some type of connection to a gear box or washing machine etc... It only sticks less than 1" and as you can see is difficult to get any type of coupling on it. Previous owner had machined a coupler that he locked with a set screw in between the split shaft and of course now it's all messed up and the coupler no longer runs true making the motor vibrate really bad.

So, I'm wondering If I might be able to replace the shaft with a longer one to make it usable. I've got some 1/2" 1144 that would be perfect for this and the only machine work would be a groove for an e-clip at the front. I don't know much about electric motors so where I need the help is in how to get the the other pieces off the shaft. Is it pressed on? I've got a small press but wanted to look for help before trying anything. Any help appreciated. Pics follow...

Ken

http://kenrinehart.org/motor1.jpg

http://kenrinehart.org/motor2.jpg

http://kenrinehart.org/motor3.jpg

HSS
01-13-2009, 10:34 PM
Ken, that is a soda fountain pump motor. The pump mounts to the circle flange with a clamp and the pump has a tang that fits the motor shaft.

Patrick


Edit: Never took one apart, so I can't help you there. Changed a many of them tho.

sch
01-13-2009, 10:45 PM
If it is built like motors I have messed with the rotor
is pressed on but in such a way that nondestructive
removal would be difficult. The centrifugal switch
part would be more easily removed with a gear puller
set up than the rest of the rotor. How about a
mortise and tenon set up with a pin and sleeve over
it as an extension?

gunbuilder
01-13-2009, 10:49 PM
kenrinc,
Do you have a welder and a lathe? That would fix it, weld a stub on it and turn down the welding smooth enough to make it through the bearings.

Or so it looks to me.

Thanks,
Paul

kenrinc
01-14-2009, 01:15 AM
That's what I was afraid of. I do have a MIG setup; it's just a small 120v 90amp jobber. Never tried anything quite like that before. I don't see how I'd be able to "burn" in deep enough for something to take hold.

Ken

macona
01-14-2009, 04:17 AM
The technical term is a carbonator pump mount.

It vibrates with nothing attached???

Circlip
01-14-2009, 05:23 AM
Machine a "Tang" centrally on a piece of shaft the same diameter as the motor shaft. Then bore a piece of round bar the shaft diameter ( A Sleeve ). Slide sleeve onto new bar so it overlaps the tang and weld sleeve in position on new shaft. Probably like original fitting.

Regards Ian.

Andrew_D
01-14-2009, 08:24 AM
The 12V fuel pump I use for transferring diesel to the tractor has the same end on the motor (a little longer maybe, but the same split). The pump has a circular shaft hole in it with two "ears" machined out as well. Sort of like keyways. A piece of material simply slides in to join them. Sort of like a shear pin if something goes horribly wrong...

Andrew

HSS
01-14-2009, 08:34 AM
Actually Macona, the pump could be either a carbonator pump OR a circulator pump. The only difference being that the carbonator pump is brass and the circulator pump is stainless steel.;) You shouldn't circulate carbonated water with a brass pump as it will create carbonic acid or so we were told in school.

Patrick

Evan
01-14-2009, 10:06 AM
I fixed a motor like that recently without welding as I didn't want to put that much heat so close to the meltable parts. I cut off the damaged portion and machined a taper about the same as a jacobs taper on the end of the shaft. Then I drilled and tapped the end of the shaft for 10-32. Then made an extension shaft slightly oversize in OD and put in the matching taper using a small boring bar at the correct angle in the compound. Drilled through the extension and counterbored it to take a 10-32 cap screw with the diameter of the head reduced as much as possible by grinding. Loctite the entire works together and then machine off the slight oversize to produce perfect concentricity of the extension. If you are good (:D ) you can omit the last step.

gnm109
01-14-2009, 11:58 AM
The technical term is a carbonator pump mount.

It vibrates with nothing attached???


Correct. It is a carbonator pump mount. I have two of them in my shop right now. Both run Procon water pumps. One is on a water circulator and the other is on a Bernard cooler, both for TIG welding.

Those motors are generally very smooth and quiet. It sounds like the previous owner has ruined that one. If it vibrates, it's all done.

.

kenrinc
01-14-2009, 12:16 PM
The motor runs smooth and quiet; amazingly so. It's just the hacked motor coupling that has a small pulley on the end that causes the whole thing to vibrate. I'd be curious to try the non weld fix just because I'm not sure the plastic in there won't melt. I've also got to figure out a way to rig it between centers with all the stuff on it since there are no center holes.

Ken-

John Stevenson
01-14-2009, 01:57 PM
You didn't answer the question, do you have a lathe? and I'll add to that do you have a steady for it ?

.

kenrinc
01-14-2009, 03:21 PM
Sorry John, yes, I have a lathe and a steady rest.

Ken

John Stevenson
01-14-2009, 04:56 PM
Ken, looked at the pictures and the second one tells all.

This is just my take on this and others ideas may vary, it's not the only way to extend the shaft but given the criteria you have described it's the way I'd go about this.

First off we are given the shaft size of 1/2" and it's a sleeve bearing motor, this means the part that runs in the sleeve has to have no distortion or damage, to me this puts welding out.

There is a part of the shaft that non critical and that the bit between the sleeve bearing journal and the rotor, the inside the fins bit.
Now it's a 1/3 HP so that not powerful and it will accept a stub.

The shaft is 1/2 and if we bore to 7/16" to get max diameter for the stub it would leave the rotor very weak, so drop down a size and choose 3/8", now you may wonder if 3/8" is too weak for a stub but many motors such as this neck down even further than this to take pinions for gearboxes.

So measure the sleeve bearing if it is 1/2" than put your piece of 1144 in the chuck and as close to the chuck as you can get set your steady up to run on the piece of 1144. Now once set slide it down the bed and fit the rotor to the chuck and steady, it will be on centre as you have set it on the piece of bar.
saw off the forked but and face off, centre drill then drill just under 3/8" and ream to size if you have one, if not final drill to 3/8"

Drill deep enough so some of the stub goes into the shaft where it enters the rotor. Then turn you piece of 1144 down so it's tight sliding fit into the rotor, turn it down 1/8" shorter than the PARALLEL part of the hole.
Smear with loctite, tap in and cross drill in the non critical part of the shaft and tap a roll pin in.

That should complete the job.

DICKEYBIRD
01-14-2009, 06:03 PM
...and go easy on the LocTite lest it hydraulic lock and keep the new shaft from seating all the way. (I got the tee-shirt.)

kenrinc
01-15-2009, 02:01 AM
Well I thought it was going to work. Turns out I can't get my steady around the shaft because those fins are in the way. My steady jaws are on the tailstock side also which makes me loose quite a bit in terms of how much I can hold. The steady will only come up to the split connector and that's it. Perfect application for a cat head here alas I just don't have the time to make one (the project that requires a project that requires a project .... ) May try Evan's idea instead we shall see...

ken-

kenrinc
01-17-2009, 03:24 AM
Wanted to thank everyone for input on this. I fixed my problem. So the steady wouldn't work because I just don't have the clearance. What I need is a cathead and that's a project I'm working on now. May have some questions about that one John :-) Anyway, I cut the split shaft part off, adjusted my 3 jaw to run the motor shaft true by tapping it in and cinching the bolts up. I figured I could live with the runout at the other end since I didn't have a steady that would work. It was pretty rigid as it was enough so to actually face off that end using really light cuts. I then center drilled, drilled out to 3/8 and then cleaned it up by boring. Cut my piece of 1144 to match, milled a flat, loctited it in and done. I spun it between centers to check the runout. Not bad at all. Put it all back together and it runs beautifully.

Thank's to all especially John who at least pointed me in the right direction..

http://www.kenrinehart.org/motorfix.jpg

Ken-

John Stevenson
01-17-2009, 04:58 AM
Well I thought it was going to work. Turns out I can't get my steady around the shaft because those fins are in the way. My steady jaws are on the tailstock side also which makes me loose quite a bit in terms of how much I can hold. The steady will only come up to the split connector and that's it. Perfect application for a cat head here alas I just don't have the time to make one

ken-

Steadies are the bane of my life because of the work I do, as Ken has found out a lot of steadies aren't made central and if you have a vee bed lathe it's not as simple as just turning it round.
On my CVA I set to one day and machined a new vee in the opposite side, there is plenty of meat, so now that steady will fit both ways.

Glad you got sorted Ken.

macona
01-17-2009, 06:29 AM
Actually Macona, the pump could be either a carbonator pump OR a circulator pump. The only difference being that the carbonator pump is brass and the circulator pump is stainless steel.;) You shouldn't circulate carbonated water with a brass pump as it will create carbonic acid or so we were told in school.

Patrick

Never seen a stainless version of one of those pumps. Cant imagine how much one of those must cost.

When carbon dioxide is mixed with water it creates carbonic acid. Thats soda is tangy tasting.

Best guess is the carbonic acid will attack something in the brass. Probably the zinc?

John Stevenson
01-17-2009, 06:43 AM
Not wanting to hi-jack macona's post :D but a note for anyone working on stainless pumps.
Even though the shaft may be stainless it will be either sleeved or stubbed.
The part of the shaft running thru the rotor has to be magnetic to get the return path for the flux.

I was instructed to built some motors with all stainless shafts some while ago and they didn't work correctly, low on power, sounded like a phase was down and got hot quickly.
The company did some research and we had to swap them for normal steel with stainless stubs fitted and they were back to normal.
.

Evan
01-17-2009, 07:57 AM
I can see that if using austenitic SS but what about using ferritic SS? It's perfectly well magnetic.

John Stevenson
01-17-2009, 08:10 AM
Don't know Evan.
I have often wondered about that, using the 400 series.

I have suggested it in the past but no one wants to take the chance when they know there is an easy work round.

In a lot of cases as well 400 series isn't a regular stocked item at stock holders and has to be ordered in so that means minimum quantities and

I have thought about trying it but the only 400 series I have is about 20' of 2" bar that was ordered wrong at a company and after a short time scrapped so the error wasn't on show :D

HSS
01-17-2009, 08:44 AM
Macona,
The stainless pumps aren't that much higher than the brass. Multiplex drink systems use the brass pumps to carbonate and the stainless pumps to circulate soda water thru the syrup bundle to keep the soda water cold up to the fountain head. Warm soda water causes the drinks to be flat.
This is where I get my pumps.

http://foxxequipment.com/cart/shop/zc045.html


John, That makes sense to me but the motor is a normal motor except for the short, split shaft. Only the clamp on pump is stainless.

Kenrinc, sorry about hijacking your post. You did excellent on that motor repair. ;)

Patrick

John Stevenson
01-17-2009, 08:58 AM
Macona,

John, That makes sense to me but the motor is a normal motor except for the short, split shaft. Only the clamp on pump is stainless.

Kenrinc, sorry about hijacking your post. You did excellent on that motor repair. ;)

Patrick

Understood. Many of the pumps I work on only have the lower part of the shaft in stainless, just enough for the seal and whatever it's pumping to come into contact with.

Stainless weld with stick very well to steel, in fact it's the recommended way to weld armoured panels on tanks.
I often take a normal steel shaft down undersize, build up with stainless weld and re machine back to size. Quicker and stronger than stubbing.

The worse pumps I come across are ferric Chloride pumps, this stuff eats everything, including stainless but except Nylon and titanium.
The pumps are all moulded nylon, shaft and bolts in titanium.
problem is the fumes eats the motor away and after about 9 months to a year it looks like a lace curtain, so swap the titanium shaft, it too expensive to scrap and start again.

.

HSS
01-17-2009, 09:15 AM
My young bride rebuilds pumps where she works and they use titanium on some of their pumps. Clorine Dioxide and Sodium Clorate have to have titanium shaft sleeve, impellor, stuffing box, mechanical seal, and casing. The Clorine Dioxide pump has a solid titanium shaft.:eek:

My young bride at work with one of the pumps she rebuilds.

http://i267.photobucket.com/albums/ii285/goochiepepper/Warrendoublesuction24X30Small.jpg