With both Electric Motors side by side on the bench, its easy to see the Shaft sizes are different.

The Old Motor (The Blue One) has a 16mm Shaft

The New Motor (The Silver One) has a 20mm Shaft



Old Electric Motor with 16mm Shaft and Fitting



Pulling the 16mm Drive Fitting off the Old Electric Motor



The Drive Fitting to fit on a 16mm Shaft
The Outside diameter of the Fitting is 45mm
to match up with the Fitting on the Hydraulic Pump.



The Drive Fitting inside the Hydraulic Pump
Outside Diameter 45mm



Both Electric Motors with the Drive Fitting from the Motor on the Left.

16mm Shaft Size 45mm Outside Diameter.

All I need to do now is find a way of putting that 16mm Fitting off the Old Electric Motor onto the 20mm Shaft of the New Electric Motor.

Unless someone can come up with a much better or easier idea?

Maybe they do a similar fitting with a 45mm OD to fit on a 20mm Shaft but I haven't been able to find one, though maybe someone can.

Ideas Guys!

 

OB,
I am a bit confused. Are you saying that the bronze piece you are pulling off is too small to go onto the new motor? If so, just get it on someone's lathe and get it bored out.
It looks like there is no Woodruff keyway on the new motor's driveshaft. Is this correct? If so, that is the biggest problem you face, namely how to ensure the fitting does not slip on the driveshaft. The absolute best way would be to take the motor apart and have the shaft slotted in a milling machine. The bodger's way (never done it, just an idea ready to be shot down) would be to file a flat onto the shaft, mig on a "hump", and see if you can make the fitting's slot catch sufficiently (with a bit of trial and error, building up and filing/grinding). A bit at a time so you do not get the shaft too hot etc etc.
Greg
Greg

 

What is OD of the flange behind the coupling, my concern in boring would be making this too thin. Also here in Australia I can buy a 240V 1hp motor for $130 having a shop bore the coupling might end up being almost as much as buying a motor with a 16mm shaft. 16mm is a pretty standard shaft size for small machinery, Lathe, Mill etc.

My Lathe is belt drive with a keyway on the motor shaft and NO keyway in the pulley. a setscrew holds the pulley and is screwed into the keyway on the motor.

 

Hi Greg

Yes!

The hole in the Bronze fitting is 16mm and too small to fit on the Shaft of the New Motor which is 20mm.

The New Motor also has a Key Way but I took out the Key for safekeeping, just in case I dropped it.

There is also an Allen Key Grub Screw in the Bronze Fitting, which 'Would' locate in the Key Way Slot. (as Warrjon mentioned)

Boring it out would be right on the limit, so I'm looking for 'out of the box' ideas before I get to that.

 

Hi Warrjon

You are quite correct, having someone bore that fitting out, would probably cost as much as a New Motor.

Unless I decide to do it myself with a 20mm drill but it would be right on the limit of the Fitting.

(I'll try and get a pic of the other side) But the Grub Screw in the fitting, would go into the Key Way slot with the Key removed.

 

OB,

What is the OD of the part of the fixing through which the shaft passes? Could you not just drill that out to 20mm and drill a setscrew hole into it?

Paul

 

Hi Paul

Its 26.70mm OD on the end that slides over the Shaft

But on the other side where the Brass Triangular bits are, the gap between those is 17.46mm

So drilling a 20mm Hole right through would chop the ends of each Triangular Brass bit, which in the Scheme of things may not matter that much?

Its already drilled for a grub screw (which I have safely put by) so that might solve the problem although it will be on the limit.

Plan 'B' would be Switch on the Motor and then use a running Angle Grinder to reduce the Shaft Diameter.

I've heard that you can get it pretty accurate for doing stuff like that.

But which do I want to Sacrifice more, the Motor Shaft or the Fitting.

Probably the Fitting if I can find a 20mm drill.

Which way would you go?

 

OB,

Looking at the photos of both parts of the fitting, it doesn't seem as if even the original 16mm shaft can go past the beginning of the triangles, so you can't drill the 20mm hole past that point anyway. So perhaps that's the easiest quickest solution as you'll still have over 3mm of brass on the fitting all around the new 20mm shaft?

Paul

 

The Hole is 15.64 across
The Collar is 26.58 across
The Coupling is 44.50 across

Ah Yes!

Well done Paul!

As I was thinking the drill had to go right through the Whole assembly but now I see that isn't so.

The Drill only needs to go through the Collar of the fitting and no more than that, which doesn't chop any metal off the Brass Triangles, so as you say I would have quite a lot of Metal to play with.

It looks like you have nailed it, so that's the way to go!



The Hole is 15.73 across
The Collar is 26.74 across
The Coupling is 45mm across



The Drive End of the Coupling




Side View of the Coupling



Side View of the Coupling

 

OB


Are the two motor shafts the same length? I only ask as, assuming you get the fitting on the shaft but only so far (following Paul's canny observation), will fixing the hydraulic pump to wherever the fitting end up, be a problem?
Greg

 

Hi Greg

The Shaft on the New Motor is about 5mm Too long (which is better than being 5mm too Short!)

Paul's suggestion is brilliant!

All I need now is someone with a Milling Machine and a Lathe (Maybe a hobby Machinist)

Or I could take the lot to the 'Technical College' and get them to do the whole thing and give them £20 or £30 to put in their 'Tea Tin'

 

Drilling the fitting in a drill press you will end up with the hole either concentric or off centre. Also in my experience unless you buy good quality, (read expensive) drill bits they are almost always a few thou larger so the hole will be a sloppy fit on the shaft, and this will lead to failure.

A boring bit in the drill press would be a better bet. These are adjustable and you bore the hole in small increments. If not you could use drills up to 25/64 and then a 20mm reamer for the final finish.

 

OB, like Warren said, a drill press, while good, is just not stable enough to guarantee a good true bore even if you use a good press vise. Surely it would not be that expensive to have a machine shop bore it out to 20mm. If so just let me know when you can be here for dinner, we'll throw some steaks on the grill and some beverages in the cooler and you can use my lathe.

 

Hi Warrjon

May be a job best left to the professionals, we're almost there so I don't want to screw it up now.

 

HI JL

If only I was a nearer, I would take you up on that and bring a King Size bottle of JD.

It was a nice thought anyway.

AL

 

i read this thread, and i miss my machine shop even more!

if that problem showed up in shop, id just take it to the lathe and modifiy it without a second thought!

could you bring motor and coupling to a machine shop and have it done, if job cost more than $25. dollars, it would seem a bit high.

 

Hi Ron

I would gladly pay someone £25 to have that done, a new Motorised Hydraulic Pump would cost about £150.

And a Car Lifter like I have got around £1,000 S/H

So worth it just to get it back in action.

 

Al looking at those motors side by side the original motor (blue) is a lot larger than the new on. What is the power and RPM on the old motor? Does the motor run?

 

Hi Warrjon

No idea of the HP of the Old Motor but its Toast anyway (it burnt out)

But the New one looks plenty big enough to do the job at 1.5 to 2hp

Worst case scenario, the lift might go up slower than it did before.

 

That sure is an interesting "dog" drive. The fact that it is brass does
lend it to easier machining. But, "soft" enough to bore accurately in drill press? Perhaps, but would sure be a shame to ruin the part.


My vote would be to take the part and the "new" motor to a machine shop. The school shop is indeed a great possibility. Easily done there with an end mill or lathe. Even if school machines are usually old and a bit sloppy.


I'll bet any machine shop around here would want a lot more than 25, either pounds or dollars!!


?'s:


1. Howe do you plan to mate the "'new" motor to the pump housing. The faces of the "new" vs "old" motors seem much different!!


2. As to capacity, an undersized motor at over load might run slower, it will do so only for a while. It will join the "old" one.


I would be tempted to have another look at the "old" motor with a view of fixing it. Armature, fields insulation.. Or merely the capacitor!


But, I admire the effort to restore the lift to service.


Carl.