Thread: The Burke Sensitive Drill Press

Originally Posted by BaronJ

I actually had a look at some this morning in the local scrapyard. They were 8" in diameter and 1.3" thick with a 1" bore. It would be easy to bolt two or three together to get the thickness required after skimming off the raised lettering. Though I did see some that had recessed centres and those I would avoid unless you welded up the gap after turning them down. I came away with a three foot length of 1" steel bar for £3 (about $6).

Baron,

I agree that the weights with recessed centres would not be suitable for pulleys for the reasons you mentioned, but even bought new they are probably the cheapest source of big cast iron rounds. I have made several backplates from weights like the one in the photo though, and they are OK for this purpose. However I had to make internally and externally threaded stepped bushes with the internal thread to suit the lathe spindle and a 16TPI external thread for the hole in the weight, and loctited them in place in the backplates. Otherwise, when the bosses each side of the weight were cleaned up and made parallel, the remaining thickness of the blank was too thin for the length of thread on the lathe spindle. Two out of three machined beautifully using HSS tooling; the third one had a hard spot which succumbed to carbide tools. After cleaning everything up there was only about 12 mm thickness left in the web area of the weight in the photo.

You said "after skimming off the raised lettering". Don't do it this way. I did. It is slow, noisy, time consuming and hard on the tools and machine. After the last one I made someone said "why didn't you just chisel the lettering off?" Doh! I know what to do next time.

Sorry for the drift off topic, but I thought the tip about chiselling off the lettering was worth mentioning.

Frank.

Originally Posted by franco

Baron,

I agree that the weights with recessed centres would not be suitable for pulleys for the reasons you mentioned, but even bought new they are probably the cheapest source of big cast iron rounds. I have made several backplates from weights like the one in the photo though, and they are OK for this purpose. However I had to make internally and externally threaded stepped bushes with the internal thread to suit the lathe spindle and a 16TPI external thread for the hole in the weight, and loctited them in place in the backplates. Otherwise, when the bosses each side of the weight were cleaned up and made parallel, the remaining thickness of the blank was too thin for the length of thread on the lathe spindle. Two out of three machined beautifully using HSS tooling; the third one had a hard spot which succumbed to carbide tools. After cleaning everything up there was only about 12 mm thickness left in the web area of the weight in the photo.

You said "after skimming off the raised lettering". Don't do it this way. I did. It is slow, noisy, time consuming and hard on the tools and machine. After the last one I made someone said "why didn't you just chisel the lettering off?" Doh! I know what to do next time.

Sorry for the drift off topic, but I thought the tip about chiselling off the lettering was worth mentioning.

Frank.

Hi Frank,
Yes I agree with you, skimming off the raised lettering makes one hell of a racket But thankyou for the tip about chiselling the lettering off. I wouldn't have thought to do that. It would have made it easier on the lathe, though I did skim off both sides for a tapping stand and a hight gauge that I made. I didn't have any problems with hard spots and only used a HSS tool.

Managed to crib a bit of time and get these done

P1020991 (Medium).JPG
The steel was horrible stuff but managed to take a polish (just). Thread diameter was sized with wires so I hope they will fit.
I also had a go at a pulley. Glad I did as I have something similar to make in a few week's time and it helped work out some issues with tool shape. Modelled more on the second photograph than the sketch. I've always found when making something as a replacement for a cast part, to look in keeping it needs draft added and radiused corners as a minimum
P1020995 (Medium).JPG

Can you send me your address via PM? You can have the pulley too although there is only one of them - a second one would have to wait until next weekend at least.
Michael

Michael G, Your a god amongst men!

Originally Posted by DSEL74

You're a god amongst men!

Nah - I just like to help out when I can

Michael

After playing Russian Dolls with the packaging I got to the treasure.


I had a bronze bush in almost the correct size, it would press in but It's to short. It did however allow a mock up. The brass bar needs to be shortened.


The bolt fitted perfectly and the small design changes to the pulley from my drawing in my opinion is an improvement at least aesthetically.

The help was really appreciated. Lets see if I can duplicate the pulley for the other side.

Originally Posted by DSEL74

After playing Russian Dolls with the packaging I got to the treasure.


I had a bronze bush in almost the correct size, it would press in but It's to short. It did however allow a mock up. The brass bar needs to be shortened.


The bolt fitted perfectly and the small design changes to the pulley from my drawing in my opinion is an improvement at least aesthetically.

The help was really appreciated. Lets see if I can duplicate the pulley for the other side.

What a teaser, only making one of them for you. Still, it was very nice of Michael to make one for you. Nice work by the way, and very generous of you, too.
Kryn

He only had time to make one, and it would have been a week or two at least before he thought he would be able to look at another. I was impatient to try them and thought he had done enough for me and I should attempt to make one.

Originally Posted by DSEL74

He only had time to make one, and it would have been a week or two at least before he thought he would be able to look at another. I was impatient to try them and thought he had done enough for me and I should attempt to make one.

I know Michael is really busy, my comments were a bit on the cheeky side, and apologise, if they were taken out of context.
The drill restoration is coming along very nicely.
Regards
Kryn