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chevy3755
04-20-2012, 09:59 AM
is there a way to increase the downward torque on the power down feed.....on a bridgeport.....it seems to kick off when i start to drill or mill......it wont even drill with a 1/4 drill......thanks........Larry

JCHannum
04-20-2012, 11:18 AM
There probably are, but the result would be stripped gears in the downfeed mechanism.

Boucher
04-20-2012, 11:33 AM
I thought the power downfeed was for boring operations.

uncle pete
04-20-2012, 01:09 PM
Bridgeport specificly warn against using it for drilling. If I remember correctly, They don't want it used for drills much above 1/4". That system is kicking out to prevent damage to the internal drive train. If it didn't kick out or was set too high, You could be looking at some real expensive repairs. As far as I know, The power feed on the spindle was designed only for single point boring. And that's a lot lighter duty than the pressures that are needed while drilling given a standard depth of cut. I've never used it for drilling at all on my B.P. clone.

Pete

Black_Moons
04-20-2012, 01:53 PM
Bridgeport specificly warn against using it for drilling. If I remember correctly, They don't want it used for drills much above 1/4". That system is kicking out to prevent damage to the internal drive train. If it didn't kick out or was set too high, You could be looking at some real expensive repairs. As far as I know, The power feed on the spindle was designed only for single point boring. And that's a lot lighter duty than the pressures that are needed while drilling given a standard depth of cut. I've never used it for drilling at all on my B.P. clone.

Pete

That makes me feel so much better about not having (paid for) power downfeed!

uncle pete
04-20-2012, 02:37 PM
BM,
LOL, Maybe. But it's just as handy as the power feed on a lathe or one on a mill table. I really wouldn't want to be without it now. After using mine for awhile, I think that a power feed that's used for the table feeds on a mill wouldn't be too tough to adapt up to the spider assembly for mills around your size. It might even be a better system since the stock Bridgeport type setup only offers 3 seperate feeds per revolution. Infinately variable power feeds on the spindle might be pretty handy too. But even those mill table power feeds might be a little quick without a slight gear reduction added since the Bridgeport types are set up with .0015,.003, and.006 per spindle revolution.

Pete

Rusty Marlin
04-20-2012, 06:57 PM
The manual for mine says the power down feed will kick out at 200# of load and they don't recommend using larger than a 1/2" drill. I drill holes with mine all the time. When I use really small drills I hand feed and when I have to drill larger holes (over 3/8) I core them out with a smaller drill first. I've power fed up to one inch holes, but they were progressively drilled out.

John Stevenson
04-20-2012, 07:09 PM
Don't worry too much if you strip a down feed gear in the gear box.
you can get plenty of cheap spare out of an old Timex wristwatch.

Mine hasn't worked since the second day I got it, never missed it and do quite a bit of boring, just feed by hand using the quill lever, don't even have the hand wheel on mine.

One mod I have made though is to fit a 6" vertical mounted Chinese cheap digital display to the quill seeing as all Bridgeport fitted was a 5" rule.

Don Young
04-20-2012, 09:20 PM
If your feed is 'tripping out' the trip mechanism needs cleaning and adjusting or perhaps worn parts replaced. There is a toothed overload clutch in the train that will slip with a chattering or grinding noise. The clutch is internally adjustable and I think the stated 200 pounds of force is the correct setting. My Bridgeport manual suggests limiting drills to 3/8" in steel or 3/4" in wood. The downfeed mechanism works well within its limits but is not sturdy.