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New to me Hartford Mill
- Thread starter Susquatch
- Start date
Excellent video. The author explained and demonstrated it all in a way that I totally understood. Then again, I was already well primed by an explanation that this fellow I know out west gave me who had pretty much explained it already minus the diodes, capacitors, and transistors.
Glad I found that ATO to step up the voltage or I might have tried to invent my own......
Took the motor off as soon as the bride and grandkids blew out of town. That's one heavy motor!!!
Turns out that the shaft has a 0.980 (w calipers square) shoulder. The shaft itself turned out to be 0.870 (21.98mm) over 2.024" with an OAL of 2.561 including the shoulder. The key is 0.269 x 0.275 and appeared to be ground on both of the wider sides.
The motor housing is mounted with a 9-5/16 (236.5mm) bolt spacing on special 7/16-20 [] 1/2-18 shouldered cam bolts for easy belt changes and adjustment. I gotta admit that these cam-bolts are pretty slick!
The pulley was a press fit to the shaft. I had to use a puller to get it off. To top that off, it was attached with two Allen Plugs with Blue Lock-Tite. Somebody must have been scared to death of having that pulley come off.
I can open the pulley enough to take a standard 0.875 shaft, but I confess that I am worried now about the other motor dimensions.
I tried looking up motor dimensions and ended up totally bewildered (AGAIN). Don't those motor people talk to each other? How the heck do I figure out what motor I need?
That's worth doing. You never know what you might find in there. But the bride just got home and wants attention so it will have to wait till tomorrow.
OK, I pulled the cover off this morning. Nothing in there to provide any opportunities at all. It's just the hi/Low switch stack on top of a rubber grommet leading into the housing. It's a regular 550V 3-Ph 2HP motor - nothing more, nothing less.
I'll need to find a 230V 3-ph 2HP version with a 0.870 shaft 2.5" long preferably with a 9-5/16 bolt spacing. I'd hate to loose the cam-bolt feature.
It looks like the jury is back on the VFD decision too. 230V single phase in and 230V 3-Ph out.
The hunt is on......
While I was in there with the motor off, I did some poking around. Looks like the bearing (assuming there is one) on the back gear pulley is shot. There is a good tenth of an inch side to side rocking on the pulley when I push on it by hand.
I assume this is not normal......?
I assume this is not normal......?
No wiring diagram on the back of the cover plate?
Nope. Nothing. I'm resigned to getting a new motor for it.
Thinking 2HP motor cuz, that's what was in it. But 240 three-phase to work with the VFD.
Thinking 2.5 to 3HP VFD to provide some cushion. Prolly a TECO. Gunna call them on Monday.
Can't wait to get the rebuild manuals I ordered that @Brent H suggested. I really don't like how the back gear pulley on the mill wobbles around. If that's normal than so be it. But I doubt it. So I'd like to take it apart and fix it asap.
I also got a quote from the local motor supply company. 400 bucks for a brand new 230V 3-ph TECO motor and............. a grand to rewind mine! Holy Cow!
Also called emotor and got fed BS. I plan to try again today and hope I get someone who actually knows what they are talking about.
I also got a quote from the local motor supply company. 400 bucks for a brand new 230V 3-ph TECO motor and............. a grand to rewind mine! Holy Cow!
Also called emotor and got fed BS. I plan to try again today and hope I get someone who actually knows what they are talking about.
Brent H
Ultra Member
I sent @architect this link here regarding changing the stator out for a 220 volt one:
https://www.icai-online.com/Bridgeport-Motor-Stator-Assembly.html
not exactly a “cheap” solution but may work if a motor cannot be located. Also there is this:
https://www.machinerypartsdepot.com/product/RBK-20
this is the place I get lots of parts from - nice folks and the owner is the guy that shoots all the video on YouTube
https://www.icai-online.com/Bridgeport-Motor-Stator-Assembly.html
not exactly a “cheap” solution but may work if a motor cannot be located. Also there is this:
https://www.machinerypartsdepot.com/product/RBK-20
this is the place I get lots of parts from - nice folks and the owner is the guy that shoots all the video on YouTube
That stator appears to be an exchange arrangement, so could one actually exchange a 550V unit for a 220V unit?
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Thanks @Brent H, it's steep, but it might solve some problems.
Dumb question: never having taken a motor like that apart, how do you/they stop that stator from banging around (rotating) as the load changes?
Yes, we are talking about the Hartford here. I still need a motor and a VFD for it.
The motor in my Bridgeport is already a 3 phase 230v motor so I just need a VFD for it.
I plan to use the same VFD on both for evaluation purposes. The VFD will stay with whichever mill I keep.
I have found motors for the Hartford, but they have all had disadvantages to them. I will keep looking until I find one that works or until there is no more work to do on the two mills. At that point, if I have not found one, I will buy a new one. I have a few good leads but none of them has come through yet. As far as I can tell, I can get a new one for around $400 give or take a bit depending on the supplier. The main advantage of a new one is that I can get one that is designed to play well with a VFD.
That's the plan anyway.
As far as I can tell, they are more or less the same. They have the same mounting dimensions.
I do not know if the shafts are the same though. The motor in the Hartford has a 7/8 main shaft that is 2-3/4 inches long. About an inch of that is just shy of an inch OD. This provides a step type effect to mount the 4 groove pulley. I do not think that the shoulder is required.
I do not know what the shaft on the Bridgeport looks like yet because I have not yet found a reason to remove it. That day may come soon enough.
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
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