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2J head questions

ronan

Cast Iron
Joined
Feb 14, 2009
Location
ireland
A couple of years ago i bought a 2j vari-speed head to mount onto my horizontal mill. The head was not expensive and the usual wear points, like the motor shaft keyway, were in good condition, the plastic bushings, splines etc were fine.

I have only gotten around to mounting the head now, powered by a vfd. The first thing i notice is when the spindle is at its fastest, it has very little torque, i can stop the spindle with my fingers, i doubt it could machine much steel that way. Vfd problem ?

The hi-neutral-lo lever on the right hand side of the head, sits in the correct position when in lo range, but i cannot get it to the correct place for hi range. The lever points directly down. What does this suggest can anyone tell me ?

Finally (for now) how do i adjust the spindle speed control ? It has a threaded rod or screw that sticks out on the top casting of the head, secured by a lock nut. How do i work out where this screw should be along its length ?

Thanks.
 
The high/low lever should not point directly down.
There is no "threaded rod" sticking out of the top of a STOCK BP head.

Do you have a manual?
Pictures would also help, but methinks somebody that didn't know what they were doing "fixed" your head.
JR
 
The high/low lever should not point directly down.
There is no "threaded rod" sticking out of the top of a STOCK BP head.

Do you have a manual?
Pictures would also help, but methinks somebody that didn't know what they were doing "fixed" your head.
JR

"Speed change plate pivot stud", it sticks out through the top casting. I'll try to take pictures. I don't think anyone did anything to the head, i think it did very little work as there is little wear in the usual places like i said.
 
I sorted out the hi-lo lever, it had just moved around on the shaft, two minutes with an allen key and its done. The VFD is a good one, ABB which i think is an American brand, confused as to why there is so little torque at full speed when at the bottom it is unstoppable, maybe its just the way it works out with the gearing, and at top speed the cutters would be tiny anyway.
 
I sorted out the hi-lo lever, it had just moved around on the shaft, two minutes with an allen key and its done. The VFD is a good one, ABB which i think is an American brand, confused as to why there is so little torque at full speed when at the bottom it is unstoppable, maybe its just the way it works out with the gearing, and at top speed the cutters would be tiny anyway.

Something is still up. While you won't get the same torque at high RPM I wouldn't describe it as "stop with my hand", not that I would want to try.

When it stops does the motor stop, a belt slips, what? Obviously you don't want to leave it there long, holding a stalled motor is a great way to fry them.
 
The VFD is a good one, ABB which i think is an American brand, confused as to why there is so little torque at full speed when at the bottom it is unstoppable, maybe its just the way it works out with the gearing, and at top speed the cutters would be tiny anyway.
What do you mean "full speed"? Are you using the vfd ONLY for conversion from 1 to 3 phase? Is it putting out 60hz? Or are you using vfd for control of speed?
Also there should be parameters to check or set in vfd itself, torque setting might be what it is. This would be discussed in the manual for vfd. Maybe the vfd had been set to a different motor's needs before and you just need to "reprogram" it.
 
I would also check the motor winding connections in the junction box on the motor. If as I assume the VFD is putting out 230V, and the motor is wired for 460, it will run, but not have much power. There should be a winding connection diagram on the motor plate, or inside the junction box lid.

Dennis
 
Right, i think i have it pretty much sorted out now. I think the reason for being able to stop the spindle by hand is the fact i put a new belt in the head, i ran the head for a half an hour yesterday and the torque is much improved.

I wired the vfd to suit the lo-volts tag on the motor casing, we run 50hz here in ireland, but i know i can safely up that to 60 hz with the vfd.

So most of the problems seem to have sorted themselves out, or were simple to begin with.

One further question, anyone know of a cheaper alternative to the bridgeport fine feed handwheel on the front of the head ? The supplier in the uk wants nearly £100 for a plastic handwheel, which is obscene.
 
I will ask the question again, do you have a manual.
From what you are explaining, I don't think that you have the Hi/Low working correctly.
JR

Just the manual i downloaded off the web. The hi/low is now working fine, its just the hand crank had moved on the shaft. I can get hi, low and neutral fine, and thankfully its quiet.
 
One further question, anyone know of a cheaper alternative to the bridgeport fine feed handwheel on the front of the head ? The supplier in the uk wants nearly £100 for a plastic handwheel, which is obscene.

My mill came with the indicator attachment but no handwheel. The original black plastic handwheel is too large and would interfere with the indicator. So I made smaller wheel from a 3.750 diameter stainless bar I had lying around. I like using the wheel sometimes.
 

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Silly me, KneeMills.com - Knee Mill Documentation

As for the handwheel, I have to ask why? I put mine is a drawer almost 30 years ago and have never needed it. I've been working in shops before Moses was a pup and I can not remember anybody using one. Ever! Now, having said that, https://www.practicalmachinist.com/...es/who-uses-fine-feed-handwheel-quill-147398/

JR

You are probably right, however , its nice to have the option to use it, even if like yourself i have it in a drawer and take the wheel out once in a blue one.
 
My mill came with the indicator attachment but no handwheel. The original black plastic handwheel is too large and would interfere with the indicator. So I made smaller wheel from a 3.750 diameter stainless bar I had lying around. I like using the wheel sometimes.

I have a piece of aluminium and a similar piece of brass, i could use to make up a wheel like that. Good idea.
 
its nice to have the option to use it, even if like yourself i have it in a drawer and take the wheel out once in a blue one.

I don't have all the money in the world contrary to what some might think. I have to make choices as to what I want to spend my small allowance on. I would rather have $100 worth of end mills than the fine feed handwheel. There are a lot of things that I would rather have than the handwheel or many other "toys" that some are fixated on. When I'm not doing other stuff, I really like making chips. Lately, it seems like there are more and more things that keep me from playing in my shop.
JR
 








 
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