Trouble with my Kurt power draw bar

[lin842]

I bought a new, old Bridgeport mill several months ago and haven't had time to play with it much. I had a little job a guy wanted me to do so I figured that would be a good time to try it out. In my old shop that burned down I had an older Bridgeport that was totally manual, so I'm not well versed on this fancy stuff that's on this mill. My brain hurts trying to figure out this Newall DP 700 DRO but that's something for another day.
I got my boring bar out along with a collet. When I tried to tighten up the draw bar nothing happened. I have the regulator set at 100 psi with good clean air and all that happened was I could see the unit move just a little bit like it was in a bind or something. I took the cover off so I could see what was going on and everything looked ok but would not move. I decided to tap on the side of the air motor to see if that would help get it going and when I did it would then turn enough to force the motor down against the spring but not enough to turn the draw bar. A little more tapping and I finally got it to turn but it was really slow. I did manage to get the collet tight, but it would not loosen it back up. I let it sit for a while and went in to get on the net to see if I could find anything that would help me figure out what is wrong but found nothing that was helpful. Now the thing won't move at all, when I push the buttons, I get just a little puff of air out of the vent tube.
I don't know how long this machine sit before I got it but I'm thinking that the motor is gummed up and is why it won't turn but don't want to mess anything up when trying to get it free so I figured it would be best to ask here from people that actually knows what might be going on and how to fix it. You guys have helped me several time before with problems I've had before and hopefully you would be kind enough to help out again. Thanks.........

 

[Clive603]

Sounds like the valves and solenoids are gummed up rather than the motor. My experience is that a motor that turns but has gummed up vanes lets vast amounts of air through. Gummed solenoid air valves usually shift a touch so a trickle of air comes through but won't open further.

Captain obvious question is do you have any QD air connections on the machine side of the regulator. If so make sure they are properly seated. I've got a couple of security types that drive me nuts because they need a second push to seat properly so the valve is open and a collar to pull back before they will actually come off. Idea is that they are mechanically connected so can't be blown off if disengaged with air on as only a trickle comes through then.

Clive

 

[lin842]

Sounds like the valves and solenoids are gummed up rather than the motor. My experience is that a motor that turns but has gummed up vanes lets vast amounts of air through. Gummed solenoid air valves usually shift a touch so a trickle of air comes through but won't open further.

Captain obvious question is do you have any QD air connections on the machine side of the regulator. If so make sure they are properly seated. I've got a couple of security types that drive me nuts because they need a second push to seat properly so the valve is open and a collar to pull back before they will actually come off. Idea is that they are mechanically connected so can't be blown off if disengaged with air on as only a trickle comes through then.

Clive

Thanks, When I push the buttons either in or out I don't hear a rush of air anywhere. It's more like a puff of air I hear. I hate to start taking stuff apart when I don't know what I'm really looking at to begin with. I went on the kurt web site and downloaded a couple pieces of literature but it's still not clear to me what to look for. And, I might add that now nothing happens at all when I push buttons now. Before I had to tap on the motor head to get it to turn at all.

 

[moonlight machine]

I bought a new, old Bridgeport mill several months ago and haven't had time to play with it much. I had a little job a guy wanted me to do so I figured that would be a good time to try it out. In my old shop that burned down I had an older Bridgeport that was totally manual, so I'm not well versed on this fancy stuff that's on this mill. My brain hurts trying to figure out this Newall DP 700 DRO but that's something for another day.
I got my boring bar out along with a collet. When I tried to tighten up the draw bar nothing happened. I have the regulator set at 100 psi with good clean air and all that happened was I could see the unit move just a little bit like it was in a bind or something. I took the cover off so I could see what was going on and everything looked ok but would not move. I decided to tap on the side of the air motor to see if that would help get it going and when I did it would then turn enough to force the motor down against the spring but not enough to turn the draw bar. A little more tapping and I finally got it to turn but it was really slow. I did manage to get the collet tight, but it would not loosen it back up. I let it sit for a while and went in to get on the net to see if I could find anything that would help me figure out what is wrong but found nothing that was helpful. Now the thing won't move at all, when I push the buttons, I get just a little puff of air out of the vent tube.
I don't know how long this machine sit before I got it but I'm thinking that the motor is gummed up and is why it won't turn but don't want to mess anything up when trying to get it free so I figured it would be best to ask here from people that actually knows what might be going on and how to fix it. You guys have helped me several time before with problems I've had before and hopefully you would be kind enough to help out again. Thanks.........

Probably just needs some lube. Air motor oil. Free it all up with some PB Blaster. Make sure the air cylinder pulls the impact wrench down, It is all pretty simple if nothing else just strip it down, clean and lube it up reassemble it and run it.

 

[moonlight machine]

Thanks, When I push the buttons either in or out I don't hear a rush of air anywhere. It's more like a puff of air I hear. I hate to start taking stuff apart when I don't know what I'm really looking at to begin with. I went on the kurt web site and downloaded a couple pieces of literature but it's still not clear to me what to look for. And, I might add that now nothing happens at all when I push buttons now. Before I had to tap on the motor head to get it to turn at all.

I have 2 Kurt drawbars neither one has any solenoids. Just a push button in out valve. air in and 2 air out lines. All it is is an impact wrench. Dirt simple.

 

[lin842]

Probably just needs some lube. Air motor oil. Free it all up with some PB Blaster. Make sure the air cylinder pulls the impact wrench down, It is all pretty simple if nothing else just strip it down, clean and lube it up reassemble it and run it.

That's what I thought, I pulled the in and out lines off at the air wrench and filled the lines with PB Blaster hooked them back up and hit the in/out buttons a couple times and let it sit for a couple hours. It would try to pull the wrench down but never enough to turn the drawbar. Basically, the same thing it was doing all along. Once I did that I found a leak in the air line going to the base plate. Not a very big leak but once I put the pb blaster in there I could see and feel the leak. I tried re-seating the air line but the only thing happened is now it's leaking on the other end too. I guess I'll replace all the fittings and airlines and then see what happens. It's weird thought that it will work sometimes and then quit.

 

[lin842]

I have 2 Kurt drawbars neither one has any solenoids. Just a push button in out valve. air in and 2 air out lines. All it is is an impact wrench. Dirt simple.

That's the same setup as I have. I'm wondering if yours when you push the in button does the air motor tilt to the right? When I push the in button it cocks the motor to the right, and it looks like it could be putting it in a bind and not letting it push down. Not sure if that is some of the problem, just an observation. From what I have read is that it has to travel a half inch or so before it will turn the drawbar.

 

[moonlight machine]

That's the same setup as I have. I'm wondering if yours when you push the in button does the air motor tilt to the right? When I push the in button it cocks the motor to the right, and it looks like it could be putting it in a bind and not letting it push down. Not sure if that is some of the problem, just an observation. From what I have read is that it has to travel a half inch or so before it will turn the drawbar.

You have a bind for sure, it should go straight down to engage the spline on the drawbar.

 

[lin842]

Well, I got tired of messing around with this unit and talked to a guy named Scott at Kurt. He was supposed to send me some literature by e-mail but for some reason nothing came through. I called him back and he resent it but It still would not come through. While I was on the line with him, I decided to just go ahead and buy a new one and forget about this old one.
I took the old unit off the machine and once I got into it, I see another problem. The old one is mounted to the front of the hi/lo switch by a bracket that is roughly 1/4" thick. under that bracket is a lever that is the same thickness as the mount plate. I think this lever is the safety device that keeps the draw bar from not working when the spindle is running. Not sure if that is right or not but I see no other reason for it being there.
I think I can just take it out and then put the aluminum plate back on the switch and be done with it. I then could remount the switch back up top where it is supposed to be, then mount the new control switch for the drawbar to the side of the mill with the bracket that is supposed to come in the kit. None of the information I have found shows this setup and the guy at Kurt didn't know anything about the way this one is mounted. I would try and fix this one if I could find the right info on this setup but that doesn't seem like that's going to happen.
I'll probably sell this old one on e-bay once I get the new one to at least get some of my money back. What a pain this has been, but it seems to be the way it is with everything I try to do.

 

[lin842]

I ended up buying a whole new drawbar kit. When I went to install the new drawbar everything was going well until I looked at the drawbar. There is supposed to be some kind of washer that goes between the drawbar and the power unit. I can't find one anywhere, but I was on e-bay and found a R-8 drawbar that appears to have the washer with it. Is there a difference between the variable speed drive and the manual speed control head with regard to the drawbar itself.
I'm thinking that this missing washer maybe had something to do with the old one not working.

 

[eKretz]

Didn't catch this thread the first time around. Pretty clearly you had an issue if the power/wrench unit was tilting when activated, that shouldn't happen. I take it that Kurt didn't bother to give you the install and drawbar info you were mentioning previously? Maybe this will be helpful: