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jrude
09-19-2011, 11:29 PM
Hello all, I just signed up recently. This weekend I purchased a Bridgeport J head step pulley machine. Was $1200, with working DRO, three swivel vises and a Servo X axis auto feed. Excited about the purchase, as I've wanted one for a long time, and finally I found a deal good enough for the boss to let me spend some money. The knee is a 1964 and the head is a 1962 according to the SNs.

Anyway, it has a few things which need addressing that I plan to take care of.

The main thing I'm stumped on is: since it did not come with a drawbar, when I install a new drawbar, does it just drop down through the top of the spindle? I want the 1J drawbar, correct? IE the 1J drawbar as available from McMaster Carr? - 29705A21, Drawbar for Milling Machine Type 1J, 18" Bar Length, 1-3/4" Hex Length, In stock at $14.61 Each

I searched for a "how to" on installing the drawbar and found none, which means it must be so simple nobody even asks the question. I don't have the drawbar yet so I can't try just dropping it into the top of the spindle.

It also needs some quill power feed repair and it needs a new head swivel adjustable shaft. Found out about the swivel shaft for the worm gear the hard way when I couldn't get the mill through the garage door on the trailer, and then I couldn't rotate the head either. :) I was able to nod it a little and then rotate the motor housing enough to get it all in the garage for temp storage prior to removal from the trailer.

Thanks

lakeside53
09-19-2011, 11:30 PM
Drop it in the top. Raise the spindle so you can tighten into a collet.

jrude
09-19-2011, 11:31 PM
Perfect, thanks :)

lakeside53
09-19-2011, 11:37 PM
If your head is really 1962, it's likely that the tilt worm is not supported in the rear case, and has bent. Replacement worms will be longer to include the far end support.

If so, make a guide for an undersized drill and drill out the far end casting, then ream to suit the "newer style" worm pilot.

JoeLee
09-19-2011, 11:37 PM
There are a couple different draw bars for those BP heads. I would go with the one for the head model unless someone started swapping motors and such. The variable drive head takes a longer one. I've also seen some with spacers under the hex. Shouldn't be too difficult to figure out.

JL.......................

JoeLee
09-19-2011, 11:40 PM
If your head is really 1962, it's likely that the tilt worm is not supported in the rear case, and has bent. Replacement worms will be longer to include the far end support.

If so, make a guide for an undersized drill and drill out the far end casting, then ream to suit the "newer style" worm pilot.

What does the worm have to do with the drawbar??????

JL..............

lakeside53
09-19-2011, 11:41 PM
The spacers are there so you can remove them when you strip the threads, you can cut of the same amount on the drawbar and get a "second life".

lakeside53
09-19-2011, 11:42 PM
What does the worm have to do with the drawbar??????

JL..............

You have to read his entire post! Last paragraph - It's not just about drawbars.;)

MichaelP
09-19-2011, 11:42 PM
Here is a good source for parts, professional advice and BP diagrams: http://www.machinerypartsdepot.com/

And if you want a nice Bridgeport repair manual, contact Steve ("SWBrooks" is his screen name on this forum) : http://bbs.homeshopmachinist.net/showthread.php?t=42412&highlight=bridgeport+repair+manual

ken
09-19-2011, 11:45 PM
get the 2j draw bar all that is longer is the top and most of the time you wont have to rase the spindle to chang a end mill Ken

jrude
09-19-2011, 11:46 PM
I saw that the shaft is not supported on the end for my year while doing the searches. Honestly I figured I'd just cut the end a bit shorter in the cold cut saw and get the machine back together ASAP. I suspect the shaft is actually broken, because it easily turns in both directions with my fingers. If it were bent it seems like it would bind and not turn, or am I missing something? I haven't pulled the head off yet.

My wife will be much happier if I walk in the house one day and say "it works great" rather than if I walk in and say "well I need to re-drill the head so I can adapt the shaft which I had to buy even though I thought I didn't need it". The shaft is only like $20 so it's not much money, but time to completion is important, so I figured I would just cut the shaft and make it work for now. I can pull it again later and re-do the work when she forgets about it. :)

lakeside53
09-19-2011, 11:48 PM
You might have just sheared the key.

The single ended worm shaft bends easily. The update was in about 1965. I'd do the upgrade - it's easy when you have it in pieces. Much "harder" later.

If the wife is the problem, just tell her it works great! :)

John Stevenson
09-20-2011, 03:50 AM
Book for download here.

http://bbs.homeshopmachinist.net/showthread.php?t=46601

Read the first post as regards copyright.

jrude
09-20-2011, 01:01 PM
Thanks for all the help.

That book on the Bridgeport rebuild is great. Wish I found it a couple weeks ago, I would have know better what I was looking at. I haven't used a mill in about 10 years, I've been hand cutting all my parts with a sawsall and grinders and an oxy acetylene torch and then sanding down the parts and welding them together. The Bridgeport is going to be a huge upgrade.

hornluv
09-20-2011, 05:33 PM
When I got mine (a 1963 model) my power down feed didn't work either. I took it apart and cleaned everything and it works just fine now. Try cleaning everything and giving it some fresh lube before you start buying parts. http://www.machinerypartsdepot.com is a great place to know and they're incredibly helpful on the phone too. BTW, you got a great deal. I paid 1200 for mine with no DRO, vise, or power feed.

duckman
09-20-2011, 06:35 PM
Jrude if the draw bar is missing go fishing in the hole where it goes and see if there is a spacer washer in there, if yes remove it your new bar should come with a new spacer, you can also buy a two life draw bar when you wear out the first end you cut it off and remove a spacer and your ready to go again.

lane
09-20-2011, 07:27 PM
The first thing I do when I buy a used machine is set it in the shop then tier it down to the last nut and bolt . Clean inspect and fix every thing that does not work on it. Now I will know just what I have and how it is suppose to all work.And at that point it is as good as it can be.Bridgeports are real simple and easy to fix.

jrude
09-22-2011, 09:10 PM
I pulled the head tonight and did not see a washer on the top of the splined spindle drive.

The adjustable worm drive swivel bar is definately broken, will order it and a drawbar tomorrow. The worm gear itself has a small gouge in it but I am going to try to polish it out with a dremel and see what it looks like after. If that doesn't work, I'll order a new one.

Thanks everyone.

Don Young
09-22-2011, 09:16 PM
I pulled the head tonight and did not see a washer on the top of the splined spindle drive.

The adjustable worm drive swivel bar is definately broken, will order it and a drawbar tomorrow. The worm gear itself has a small gouge in it but I am going to try to polish it out with a dremel and see what it looks like after. If that doesn't work, I'll order a new one.

Thanks everyone.

It will save that gear a lot if you do not try to crank the head back vertical after it has been tilted way over without manually helping push the head up. Stripped or badly worn gears seem to be fairly common.