I just finished using the Bridgeport but the Power Drawbar won’t release the collet. The air motor sounds normal. The air pressure at the mill is at 60 psi. I didn’t want to mess with it without checking first. Should increase the air pressure to 80 psi? Or should someone with experience take a look at it?
Sorry guys…
make sure the spindle is UP all the way. it won’t release if down by any amount.
I think the pressure should be 90z. Try that. Also, the spindle does need to be all the way up.
The spindle was & is all the way up. When I tried releasing the collet again, the motor chug for a couple seconds then started revving up like it wasn’t under a load anymore. 
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It seems unlikely that the powerbar is faulty, but I guess it’s possible. I’m out of town for the next couple of weeks. Maybe someone can look at it in the meanwhile.
I will be around tomorrow. I will look at it.
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Okay, I looked at this and the problem does not appear to be the draw bar. The quill is not retracting fully. I played around with different gear settings on the quill advance controls and this moved the top end of quill before it stops about 1/4"; however, it will not retract to a fully retracted position. It sounds to me like something is loose in the gear box and is jamming the quill.
I am not comfortable taking the piece apart to fix; however, if someone has some experience with the internal mechanism on a Bridgeport I am more then willing to help.
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This appears to be an operator error, using the power drawbar to remove a collet, but without the quill locked.
The drawbar was unscrewed from he collet to where a shoulder is supposed to push up on the head, pushing the collet down. I believe without the quill locked, this instead pushed the quill down, instead of forcing the collet out.
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Can you tighten the power drawbar into he collet, then release it?
I had tried that and it didn’t work
I’m very certain the quill was locked. Another member noticed there appears to be a thin sleeve outside of the spindle that is preventing the Quill Stop Knob* from moving last 1/4" up. It’s hard to see without looking very close.
*See Figure 10 in http://manuals.chudov.com/Bridgeport/M105H-Series1.pdf.
Possibly the quill skirt shown on Page 34, Item 128…?
http://www.pts-tools.com/MSDS/online_automatic_power_drawbar.pdf?PAHDID=000000138202005&PARDID=632864356335655
Sorry, wrong link: quill skirt shown on Page 34, Item 128…?
http://manuals.chudov.com/Bridgeport/M105H-Series1.pdf
That sleeve is a dust/protective cover. If you lower the quill past about 2 inches down, that sleeve follows. With the quill one inch down, you can reach in with a tool and push that sleeve back up all the way.
Thanks @kbraby, apparently that did the trick because the mill is out now. Thanks to you or whoever took it out.
Absolutely no worries on any of it. The key thing is that it is up and running now. Just a bonus that it was an easy fix. We actually were showing up for a milling project when we found it. So we gave it a fair work out once we had it figured out. I’m guessing around 20 tool changes between edge finders, center finders, drill bits and end mills.
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