Thread: Making Dickson style quick change tool post holders (picture heavy)

Originally Posted by Dave J

Thanks for the replies,
I thought long and hard about heat treating them before I started and decided against it because of them warping.
They are only mild steel so no chance of doing it at home with low heat. John Stevenson did suggest Tuftriding them, but even if they where $10 each to get done (highly unlikely here) that would be $460 so sort of kills the cheap part of making them.
If they where drooped on the floor the V is protected as it's recessed in and so is the T slot, so it would only be cosmetic damage.
As for wear I have been using a few and they don't seem to be wearing. The only part that could really wear is the T slot where the plunger pulls them in,you would never have enough force to squash the V's and it would take a lot of use to wear they as they don't slide.

Dave

I don't think that the mild steel you used, which I assume is just hot rolled plate, would be suitable for Tuftriding or similar processes anyway Dave. Certain alloying elements are required to achieve a reasonable hardness.


Lex.

Originally Posted by Dave J

Hi,
As for repairing your tool post, a member on another forum was in the same position as you and made his own out of mild steel and they are going fine. Easy enough to make since you already have a lathe.

Yeah as long as you know how to use it! I'm still trying to get my self centring chuck to run true.

I will go through the steps with you to help out.

Find a bit of bar a bit larger than the larger diameter of the original plunger. It doesn't matter if your chuck is not running true as your going to make it all in one go which eliminates errors.

I take it you don't have a mill? If not take the bar to the drill press and cross drill the bar the same size as the factory one. If you mess up move up the bar and drill another one and just cut the scrap bit off.

Place the bar in the chuck about 10mm more than you need and machine the end to the length and diameter you need (copying the factory one) making sure the distance from the edge of the drilled hole is the same distance to the flange like the original one.

Then machine the large diameter (flange) to suit.

At this stage you can knock off the sharp corners if you want.

Once this is done you can either take it out and hack saw it off of cut it while it's held in the lathe.
Turn the part around and replace it in the chuck and face it. If your chuck is running out it wont affect your facing operation at all.

These tool posts will allow small inaccuracies on this part.
I hope this helps a bit.

Dave.

Originally Posted by Techo1

I don't think that the mild steel you used, which I assume is just hot rolled plate, would be suitable for Tuftriding or similar processes anyway Dave. Certain alloying elements are required to achieve a reasonable hardness.


Lex.

Thanks for that Lex,
Yeah just hot rolled plate,as I said earlier I had never intended to harden them from the start and it was only that it was brought up here and on a few other forums that it's being talked about. What they forget is in Australia it's not like the US or the UK where we can go down to the local corner and have them hardened for cheap. Most stuff around Newcastle is for mining and you need an account and to pay big dollars like the mines do.

Even if they where $10 each to get done it would be to expensive ($460) in my opinion. If I had a grinder (have been looking but missed a few) I would have gone down that track.

I remember years back I had a shaft ex rayed, the guy looked at me like I was an alien and they charged $250 for the job. They also mainly did stuff for the mines.

The V's on this tool post only get pulled together so no wear is going to happen there unless it squashed it (unlikely) it the get drooped they are inverted V's so they are protected. the only part that could wear is where the plunger pulls them in but again it would have to squash the metal.

After seeing a few other Dickson style tool posts with a square plunger I have been thinking for a long time of converting mine over from round. I am not sure what the factory was thinking there (probably cost and ease of making that part) but it would allow the plunger to spread the load out over the whole surface.
These would need to be hardened as the cam operates inside of them

Dave

Originally Posted by Dave J

I will go through the steps with you to help out.

Find a bit of bar a bit larger than the larger diameter of the original plunger. It doesn't matter if your chuck is not running true as your going to make it all in one go which eliminates errors.

I take it you don't have a mill? If not take the bar to the drill press and cross drill the bar the same size as the factory one. If you mess up move up the bar and drill another one and just cut the scrap bit off.

Place the bar in the chuck about 10mm more than you need and machine the end to the length and diameter you need (copying the factory one) making sure the distance from the edge of the drilled hole is the same distance to the flange like the original one.

Then machine the large diameter (flange) to suit.

At this stage you can knock off the sharp corners if you want.

Once this is done you can either take it out and hack saw it off of cut it while it's held in the lathe.
Turn the part around and replace it in the chuck and face it. If your chuck is running out it wont affect your facing operation at all.

These tool posts will allow small inaccuracies on this part.
I hope this helps a bit.

Dave.

The machining of those don't seem too hard as you say but attempting the cam and getting that offset seem way too difficult & would require the chuck to be true. I'm currently investigating if it is the jaws, or the mountplate, bearings etc that are the issue.

Mine is like these

Dickson Quick-set Toolholders

THE DIMENSIONS FOR THIS BLOCK ARE:
BLOCK: 72MM HIGH, 97MM SQUARE, BORE IS 25.4MM / 1" COMES WITH A REDUCING SLEEVE WHICH IS 16.8MM
THIS SET COMES COMPLETE WITH BLOCK, 2 STANDARD HOLDER'S, ADJUSTING KEY AND REDUCING SLEEVE
THIS BLOCK IS DESIGNED FOR MACHINES WITH A CENTRE HEIGHT OF BETWEEN 6 AND 7" OR THERE ABOUT'S

I have managed to source 3 holders, which isn't near enough. I would love to have the other two sides of the tool post functional as well.

Sorry I missed the cam out.

It need to be done in a 4 jaw not a 3 jaw. It could be done in the 3 jaw if you put a shim on one of the jaws to off set it. You could set up the factory one and get it running true with a dial indicator touching the cam, then just undo one jaw and slip your new one in it's place. As long as it was close it not going to matter a lot.

You could use parting tool (nice and slow with plenty of oil or coolant) to cut the top washers.

The top washer type cam can just be filed in the bench vise to match the original one, you only have to do one. It's the same with the hex, just file it on there, I have done plenty like that including chuck keys.

If your finding it hard to make you could silver solder the washers on a bolt and just use a bolt with the center turned down for the cam and cut the threads off end and file the hex down.


Dave

Very impressive work, I bet it took quite awhile to get done...

Originally Posted by .RC.

Very impressive work, I bet it took quite awhile to get done...

Thanks RC,
I read your post about the bandsaw clamps on the other forum, but didn't think you would get into them so quick, LOL. It just had to be a weekend my computer got a virus and by the time I got it back they where all spoken for. I like the idea and will make up something similar and give it a try. That was a truly generous offer you gave members, well done mate.

I had a book with me and was righting down the hours as I wanted to see how much time it took and knew the question would be asked as I was doing the photos for the forum.
I only worked for a few hours at a time then rest up, but the book got put a side because of other things going on in my life at the time.
I did them over about 3 weeks a few hours here and there but not every day.

Once I set up for a particular operation I just sat on a stool and watched the mill do the work as it has power feeds on all axis's and snapped a few photos. Then when that one was done, wipe the vise and re load the next and watch again, it was actually really boring doing them all, cant wait for the CNC conversion, LOL.

Dave

Originally Posted by Dave J

Sorry I missed the cam out.

It need to be done in a 4 jaw not a 3 jaw. It could be done in the 3 jaw if you put a shim on one of the jaws to off set it. You could set up the factory one and get it running true with a dial indicator touching the cam, then just undo one jaw and slip your new one in it's place. As long as it was close it not going to matter a lot.

You could use parting tool (nice and slow with plenty of oil or coolant) to cut the top washers.

The top washer type cam can just be filed in the bench vise to match the original one, you only have to do one. It's the same with the hex, just file it on there, I have done plenty like that including chuck keys.

If your finding it hard to make you could silver solder the washers on a bolt and just use a bolt with the center turned down for the cam and cut the threads off end and file the hex down.


Dave

I had to make a few simple cam fittings for a vice base a while back. Rather than use a four jaw to achieve the required offset, I made a bush with an offset hole. Worked well enough. especially if you are chasing repeatability. More info here - https://www.woodworkforums.com/f65/sw...ml#post1551982

Bob.

Good idea Bob, I am not sure what tooling he has as it sounds like he is starting out.

Dave