New to me Hartford Mill

[Susquatch]

Now we are going in circles...… You said the shaft was .870 not .875?

https://canadianhobbymetalworkers.com/threads/new-to-me-hartford-mill.3490/page-3#post-46747

The pulley won't fit a 7/8" shaft.


I'll just shut up and watch now

OK ok ok. Now you have me laughing!

I confess to rounding it a bit. I've basically assumed I will be reaming my pulley out a few thou to fit a 7/8 shaft since I'm pretty darn sure there are no 0.870 shafts out there but mine.

And if you really want to entertain yourself, don't forget my original measurement was of the shaft shoulder - I just didn't know it then.

But now that I know you are being entertained, perhaps I'll find a way to keep you confused.

Too funny!

 

[YYCHM]

OK ok ok. Now you have me laughing!

I confess to rounding it a bit. I've basically assumed I will be reaming my pulley out a few thou to fit a 7/8 shaft since I'm pretty darn sure there are no 0.870 shafts out there but mine.

And if you really want to entertain yourself, don't forget my original measurement was of the shaft shoulder - I just didn't know it then.

But now that I know you are being entertained, perhaps I'll find a way to keep you confused.

Too funny!

You have a metric motor, I had the same problem. I'm sitting on a metric 2 HP single phase that's 0.870 with a 2.5" long shaft (wrong frame for your needs). Rather than mess with my pulley I turned the 7/8" shaft down on my replacement motor. The keys were a different size as well, so a custom key had to be made.

If the Bridgeport motor fits the Hartford apart from shaft dia. maybe you can source a cheap pulley to perform the evaluation.

Craig

Zip......

 

[Brent H]

The Bridgeport motor will not fit the Hartford at all. The variable speed Bridgeport will have a 4” long motor shaft with a special nylon coated key to allow the pulley discs to open and close. The Hartford will just have the step pulley.

You can probably machine the Bridgeport motor to fit, but that would be very sad as then you would need a motor for the Bridgeport and - they are not as easy to find due to the shaft length/keyway etc

the Hartford should be able to take a run of the mill 2 HP 3 phase 220V motor with a face mount and machine a plate to fit the top of the mill.

 

[Dabbler]

@Brent H the Hartford already has the plate needed. That's the say the old motor has to be mounted. He may need to locate and drill new holes if his motor diameter changes.

 

[Susquatch]

the Hartford should be able to take a run of the mill 2 HP 3 phase 220V motor with a face mount and machine a plate to fit the top of the mill.

@Brent H the Hartford already has the plate needed. That's the say the old motor has to be mounted. He may need to locate and drill new holes if his motor diameter changes.

Hmmmm..... I didn't see a plate in there. But maybe I missed it. Is there any chance that what looks like the front surface of the motor is actually an adapter plate?

If so, it's a pretty fancy adapter! It looks like a casting and it even has air vents!

What kind of risk am I taking if I remove those four Bolts on the front face?

 

[Susquatch]

You have a metric motor, I had the same problem. I'm sitting on a metric 2 HP single phase that's 0.870 with a 2.5" long shaft (wrong frame for your needs). Rather than mess with my pulley I turned the 7/8" shaft down on my replacement motor. The keys were a different size as well, so a custom key had to be made.

If the Bridgeport motor fits the Hartford apart from shaft dia. maybe you can source a cheap pulley to perform the evaluation.

Craig

Zip......

Very odd. 0.870 doesn't work out to anything metric. It's about 22.1mm

If necessary, I can machine another pulley to fit. Or I could make a Bushing for it.

In fact I have made entire custom pulleys before. Farming machinery can be impossible to find parts for. Hence my need for a better mill.

What does the closing "zip" mean?

 

[Dabbler]

If so, it's a pretty fancy adapter

It looks just like mine, except a little thicker. If you remove the 4 bolts, either the end of the motor comes off (then I was wrong) or you find the plate is independant of the motor (which is what I was thinking)

Mine has been adapted to 220V 1PH, but I have the original pancake 3PH motor. It mounts on the same 1/4" thick plate with the micky mouse ears on it.....

 

[Susquatch]

It looks just like mine, except a little thicker. If you remove the 4 bolts, either the end of the motor comes off (then I was wrong) or you find the plate is independant of the motor (which is what I was thinking)

Mine has been adapted to 220V 1PH, but I have the original pancake 3PH motor. It mounts on the same 1/4" thick plate with the micky mouse ears on it.....

Wow! Potential Game Changer!

I will be taking that plate off as soon as I make it out to the shop!

 

[Susquatch]

Bad outcome @Dabbler .......

It actually is the end plate of the motor.

At least I can use it to make a template for a new adapter plate.

When I pulled the motor apart, I realized that replacing the stator actually is an option. Both bearings are good and everything looks to be in great shape.

I think I'd prefer another motor though.

 

[Susquatch]

I ran across this motor on ebay. It is WAAAYYY too much money, but I think it would work just fine.

The mounting is correct. My Hartford has the same bolt spacing and same "mickey mouse" ears as my variable speed Bridgeport.

Therefore, I could:
Cut the shaft shorter - if needed.
Make a custom key - if needed.
Turn the shaft down - if needed.
Or ream out the pulley - if needed.

I have been wondering why Hartford decided to do a custom motor like the Bridgeport. The adapter plate would have been superior in my view and would have saved them big money on the motor.

In so doing they also made repairs and replacements expensive.

 

[Susquatch]

Finally got word back from emotor tech support.

They recommend this motor:

https://www.emotorsdirect.ca/item/nidec-u2p2dcr

It is:
2 HP, 1800 RPM, 145TC
7/8” shaft x 2.25” long
230/460V 3 Phz
TEFC Enclosure

It's not ideal, but the price isn't bad. If I can't find a better alternative, I'd prolly turn the shaft down by a few thou and make an adapter plate that lowers the motor down into the mill housing a bit such that the shaft length works out ok. The old motor has a shaft that is 2.520" plus another 1/4 inch that the motor hangs down below the mounting surface. So I need about 2-3/4 inches altogether from the top of the mount on the mill down.

 

[Dabbler]

-- Did they mention 'inverter duty'? It makes a difference at RPM extremes, but not enough to pay $$$ for....

There isn't a huge load on the pulley; My pulley is engaged about 1.25" and it has stood up under every day use for 35+ years...

 

[RobinHood]

I wonder it the shaft is pressed into the motor armature? I would not be surprised if you could press it out, make a custom length one and save you a bunch of head aches with special adapter plates, recesses and shaft extensions.

Adam Booth had to replace a bent shaft in his K&T motor. Here is one of the videos in the series.

 

[Susquatch]

-- Did they mention 'inverter duty'? It makes a difference at RPM extremes, but not enough to pay $$$ for....

There isn't a huge load on the pulley; My pulley is engaged about 1.25" and it has stood up under every day use for 35+ years...

They did not mention Inverter duty. However, I asked about it in both my original question and in a followup question.

I have had similar thoughts about how much engagement is required. Frankly, I am not sure that any engagement beyond an inch or so means anything at all. I was only trying to duplicate the original implementation. I'll stop worrying about it so much.

 

[Dabbler]

On a 1" bore usually 1" of engagement us considered adequate. However under high loading conditions, it can cause undue stress on the pulley and th fit of the shaft. That's not the case here.

 

[Susquatch]

I wonder it the shaft is pressed into the motor armature? I would not be surprised if you could press it out, make a custom length one and save you a bunch of head aches with special adapter plates, recesses and shaft extensions.

Adam Booth had to replace a bent shaft in his K&T motor. Here is one of the videos in the series.

Wow. I don't think I would have the guts to press out and replace the shaft in a brand new motor......

Good video. I'm always impressed by what some people are able to do.

 

[Susquatch]

On a 1" bore usually 1" of engagement us considered adequate. However under high loading conditions, it can cause undue stress on the pulley and th fit of the shaft. That's not the case here.

Same rough rule of thumb as I use for fasteners.......

I agree that this application is not onerous.

 

[Susquatch]

On a 1" bore usually 1" of engagement us considered adequate. However under high loading conditions, it can cause undue stress on the pulley and th fit of the shaft. That's not the case here.

What material and what thickness do you recommend for a motor adapter? Does it need to be two part (two layers) to drop the motor back down where it belongs?

 

[Brent H]

The bearings would be (51) for the step pulley model

 

[Susquatch]

View attachment 15514
The bearings would be (51) for the step pulley model

Thanks Brent, I can easily see them both with your breakout. I can only imagine what that top bearing looks like in my machine.... I hope the housing isn't buggered too...... Do you think the bearings changed with the 2HP version?