Bridgeport Resto

[N8TheGreat]

The mill is looking good!

One problem I see is the motor RPM. Mills normally use a 1725 RPM (1800 RPM nominal , 4 pole) motor, as opposed to a 3510 (3600 RPM nominal, 2 pole). The torque from the 2 pole motor is going to be 1/2 at the same HP rating of a 4 pole motor. Normal spindle speed range is about 500 to 4000 when in direct drive on that mill. A 2:1 belt reduction in the drive would fix the problem on the low end of the range, but you can not spin that motor up to 8000 RPM to get the max speed. The 3 HP Baldor SuperE inverter motors are rated for 6000 RPM max, I don't know about yours.

Also the VFD you chose is not quite correct for a non vari-drive mill. That VFD is a volts/Hz type VFD, where you should be using a Sensorless Vector type VFD for full speed/torque control over the needed range.

At the very least, I would see if you can send that motor back and get a 4 pole (1800 RPM) motor.

Hey Jim, these aspects were already thought of and pros/cons weighted. This mill came with a 1.5hp motor and others came with 1hp, I stepped up to the 2hp to help compensate for the torque that will be lost at lower RPMs but for the planned uses of the mill it will be more than enough for me. I am going to use a 1:1 pulley ratio and spindle speed will be controlled via motor’s RPM that is why I went with the 3600RPM motor instead of the 1800RPM motors that would have come with the machine originally.

The sensorless vector drives are better however the benefit per cost just does not make sense for my application. Budget had a large impact on parts chosen and is the reason I went with the equipment I did. I got the NEW motor and drive for under $400 delivered and they both carry a 2-year warranty!!

Btw not sure what the motor’s maximum RPM is but the bearings inside are rated to 17,000RPM!! lol

 

[countryguy]

Glad to see everything is looking on the upswing. Some things on the Huanyang - Several typos exist in the manuals. I documented a few of them at 1 point. If something's just not working right in there..... Check for the same setting in another spot in guide. I found 2 settings like this on mine. But Very inexpensive seemingly solid in my Mill so far!

Keep the posts coming.

 

[JimDawson]

Hey Jim, these aspects were already thought of and pros/cons weighted. This mill came with a 1.5hp motor and others came with 1hp, I stepped up to the 2hp to help compensate for the torque that will be lost at lower RPMs but for the planned uses of the mill it will be more than enough for me. I am going to use a 1:1 pulley ratio and spindle speed will be controlled via motor’s RPM that is why I went with the 3600RPM motor instead of the 1800RPM motors that would have come with the machine originally.

The sensorless vector drives are better however the benefit per cost just does not make sense for my application. Budget had a large impact on parts chosen and is the reason I went with the equipment I did. I got the NEW motor and drive for under $400 delivered and they both carry a 2-year warranty!!

Btw not sure what the motor’s maximum RPM is but the bearings inside are rated to 17,000RPM!! lol

I well understand budget constraints, at least you went into it with your eyes open. 17 grand might be a wee bit much

 

[N8TheGreat]

Finally have some new updates!
Been slowly collecting parts and finally have all the pieces for my one shot oilier Thank you eBay, Amazon, Enco and H&W Machine Repair.


Got everything plumb in yesterday and only a few things I need to tweak in the future is the flex line going to the saddle, just setup temporarily now but it works. Also one of the line going to the ways on the saddle is horrible pinched and will need replacing, this is what caused the badly worn way on the saddle...it wasnt getting any oil

 

[N8TheGreat]

Finally got the table on last night


Ran into a couple issues .... The dial holder for the for the table are both different and either of them match the y axis

the one on the left is from the y axis and the other 2 were from the table. the two mismatched will not work on the table because they are either too short or not enough back clearance.

also when I tighten down BOTH table bearing bracket to the table, when cranking the table it is very difficult and not smooth? but if i loosen one side and free it up about 1/4", it frees it up some and much easier to crank. however still feels gritty when cranking the handle. I assume this is due to the bearings since when I had them out they spun freely but I could feel some dirt in there.
Are these symptoms due to the fact that I may need new bearings?
or is it the feed nut? when I am just spinning the lead screw through the nut by itself it fells nice and smooth.

 

[JimDawson]

It sounds like it's time to stop, take a deep breath, and review the work you have done so far. I'm not sure I can help with the specific problem, but it sounds like something is not assembled correctly. What you have there is a giant 3-D jigsaw puzzle, and it's possible to put some of the pieces in the wrong location. I'm assuming here that it was working more or less correctly when you took it apart, so it should work the same when reassembled.

 

[chips&more]

Those bearings are not going to be worn from any high speed use. More than likely got some dirt in them or old hard dried grease. Before you replace them. I would remove a shield/seal from the side that is NOT exposed the elements. And carefully clean the bearing(s) and re-grease it. Sometimes you can even put the old shield/seal back if you removed it without any damage. And those dial holder things typically have spacer washers so you can set the proper spacing from dial to bracket…Good Luck, Dave.

 

[N8TheGreat]

When I first picked up the machine it wasn't fully put together one of side brackets wasn't put on all the way so the table would still move back and forth. I assumed this machine once had a powerfeed and when I picked it up they pulled all the good stuff off, thats why I got is so cheap. I believe they took off the oil pump from the lube system, motor, drawbar and even the powerfeed or this is what i speculate.

Prior to install I have blown those brackets completely apart and cleaned all of it and soaked the bearings and clean them and then cleaned them again and grease/lubed them up the best that I could. They were better then before but still not that smooth new bearing feel.

I made sure to put everything back together to match this view... and according to this, all of the dial holders should be the same part number, whereas I have three different one.

 

[JimDawson]

I guess I would start by assembling it without the dials on the holders. That will tell you if the dials are rubbing. You may need to do some shimming. The axial preload is set by the the nuts (item 1). It's just a matter of taking it one step at a time until you find the problem. It could be rough bearings.

 

[N8TheGreat]

The problem with the dials is yes they rub and also the holders are to short to still be keyed on the screw so they just free wheel when on there making them pretty much useless for trying to lock them in.