Fixing pedestal drill

[bloodandsawdust]

Greetings,

I am fixing up a pedestal drill which was put out on hard rubbish (!). One of the handles has broken off, the table is full of holes but I have had lots of practice fixing these problems. The problem is the shaft with the pinion that feeds the quill has a threaded end with a slot in it, said slot engages with the spring that retracts the quill up. The screw thread on this bit is very fine, a 1/2" BSF or similar, and the threads have worn to the extent that the locking nut that keeps the whole thing together no longer holds. I am not sure what to do, I don't have a lathe else I would just form a new threaded stud. It's a pain to think that a perfectly good machine is wanting a few tenths of a gram of metal to work again.

Perhaps I need external thread inserts, but last time I went looking for there, they told me that they were out back with the left handed screwdrivers and the skyhooks

[pipeclay]

Greetings,

I am fixing up a pedestal drill which was put out on hard rubbish (!). One of the handles has broken off, the table is full of holes but I have had lots of practice fixing these problems. The problem is the shaft with the pinion that feeds the quill has a threaded end with a slot in it, said slot engages with the spring that retracts the quill up. The screw thread on this bit is very fine, a 1/2" BSF or similar, and the threads have worn to the extent that the locking nut that keeps the whole thing together no longer holds. I am not sure what to do, I don't have a lathe else I would just form a new threaded stud. It's a pain to think that a perfectly good machine is wanting a few tenths of a gram of metal to work again.

Perhaps I need external thread inserts, but last time I went looking for there, they told me that they were out back with the left handed screwdrivers and the skyhooks

Do you think you have enough thread left to use a nylock nut.

[Anorak Bob]

How about something like this clampable collar from Small Parts ? Not dirt cheap but it might work.

1C-050-A Collars - Shaft - Clamp Type

Bob.

[bloodandsawdust]

Do you think you have enough thread left to use a nylock nut.

Worth a go, I'm off to the local Bolt Bloke this lunchtime. Great idea, the engineers at work were on about machining it off and inserting a new stud, or building it up with a welder and then using a toolpost grinder in a lathe to get it back round. Nothing like a simple solution.

[bloodandsawdust]

How about something like this clampable collar from Small Parts ? Not dirt cheap but it might work.

1C-050-A Collars - Shaft - Clamp Type

Bob.

I don't think that these will work for me, as the stud has a slot through it lengthwise, and the collar might just close up the slot. Of course, I could always put a shim in the slot to keep in open.

Another good idea.

You can get these from Miniature Bearings in Queenland Clamps - Shaft Product Listing, but they are easy to make if you have a steel collar of the right size. Just hold it in a machine vise in a drill press and use a slot drill to form the counterbore for the hex head bolt, then drill & tap a hole.

[pipeclay]

Worth a go, I'm off to the local Bolt Bloke this lunchtime. Great idea, the engineers at work were on about machining it off and inserting a new stud, or building it up with a welder and then using a toolpost grinder in a lathe to get it back round. Nothing like a simple solution.

If there is enough thread to grip the nylon it may work,but if not its only cost a little time and a $1 or $2.

[SurfinNev]

If it's a stud can't you just remove it and replace with another or get a bolt with the correct thread, cut a slot in the threaded end, then cut to length.

Nev

[Michael G]

A photo of the part would be good so we could understand the issue better.

Michael

[bloodandsawdust]

If there is enough thread to grip the nylon it may work,but if not its only cost a little time and a $1 or $2.

The bolt bloke gave me a very old fashioned look "You want a Nylock? You'll be be lucky if we got that size at all. Sure yo don't want a BSW?". The only nut he could get was a steel, and cost me 50c as it had been machined out of bar. But he told me a great trick for making a locking nut. Just get a ballbearing about the size of the bolt, put in in the nut and give a good whack with a hammer. This deforms the top thread enough that it grips the thread tightly, without damaging it totally, and unlike the other trick of cutting partway through the nut with a hacksaw & squeezing it in the vice, does not weaken it at all.

The nut fits on my drill perfectly, even on the damaged thread, and now that I can make it go up & down I can get on with the rest of the restoration. And I know a new trick. And it cost me only 50c.

Thanks for the ideas!