Member postings for Thomas Staubo

Thanks!

This is a drawing to make my idea clearer:

Thanks for the input everyone!

Just to make it clear, I will not clamp on the register, but on the 1/4" wide collar to the left of the register.

Hi Murray. You are probably right about the stiffness. But Schaublin somehow managed to clamp the backplate onto the register without slitting it!!

A simpler version that I thought about also, is machining a ~7mm wide spigot with the same diameter (40.9mm) as the collar on the spindle. And then using a steel clamping ring to clamp half on the spindle collar, and half on the backplate. Like this:

(found at http://www.model-engineer.co.uk/forums/postings.asp?th=47650 )

Your idea of a collar that is secured to the backplate but still has a small amount of free movement, is a good idea. I too thought about bolting the clamping ring to the backplate, but didn't think of the captive mounting and leaving it free to move, to avoid distortion. I wonder how important that is...?

I'm in the process of machining a backplate out of cast iron, for a new 5" chuck I have. This is for my Myford ML7, and the spindle nose is threaded as you know.

I have not had any problem with my chucks unscrewing, but it would be nice to have the possibility of running the lathe in reverse occasionaly. And I thought that I might as well make some sort of locking mechanism while I'm at it making the backplate.

I've tried searching for possible solutions. I've seen some (Schaublin?) use a clamping ring that compresses the chuck spigot onto the register, like this:

But I was thinking of utilising the collar that is next to the register on the Myford spindle, it's 1/4" wide and 40.9mm in diameter.

I can extend the backplate to act as a sleeve over that collar, then slit that sleeve part axially. Like this:

And then use a similar clamping ring, as in the first picture, to clamp and secure it to the spindle.

What do you think?

I found out that the Sheffield & district SMEE is open on sunday May 14th.

That's not far away from Doncaster. So if we are going to Doncaster, we would certainly visit their railway .

Edited By Thomas Staubo on 14/02/2017 13:39:34

I don't think we will travel by car. I see that there's a bus transfer from the city centre.

Ok, thanks for the heads up about that, Martin.

I went to the National Railway Museum last time I visited Harrogate, but my fellows might want to see it.

The North York Moors Railway is a bit too far for a weekend trip. But thanks for the info.

As I suspected then.

But it would be nice to visit a club railway while we are there. I looked at the events calender here, but have no idea of which events is close.

Preferably the same weekend, and hopefully not too far away from Doncaster/Sheffield would be nice.

I would appreciate any help in finding one.

I found out that the Markham Grange Steam Museum is quite near, only 9km, or half an hour by rail.

That is a must for steam enthusiasts.

Our one and only model engineering club here in Norway NMDF , is interested in attending the Model Engineering Exhibition at Doncaster 12. - 14. of May.

Some of us have been to Harrogate before, and I would think that it's quite similar.

From the pictures online from 2016, it seems that there's only a bit of 3,5" gauge running indoors. Are there any 5" or 7 1/4" gauge live steam railway at the site?

I would think that there's some steam and traction engines outdoors, as at Harrogate?

Thomas

I'm sorry John Pace, I forgot to reply and thank you for your photo and explanation.

You really thought it out when you made it.

It seems like you have 24 and 30 divisions. The 30 wheel must be for dividing into 5, 10, 15 and 30. Is that for special cutters, maybe like dovetail cutters?

Aha! That way you can slide the workhead to and fro, and take it off, without altering any angles.

Thanks!

In your picture, it seems you have two knurled rings on the index ring. Or is perhaps one of them a (very large) clamping nut?

After studying the Quorn, I see that the person that built this has made an alteration to the mandrel clamp in the work head. The mandrels should have a staright 1" shank, with a threaded clamping ring.

But instead the only mandrel I have are reduced at the rear, to 15/16" and itself threaded.

Instead the clamping ring should be threaded. This is the drawing showing how it should be:

I think I have to redo this, as my plan of using a 1" straight shank ER collet chuck can't be done, because the hole in the index ring is too small!

Both a new clamping ring, and an index ring therefore have to be remade.

I was wondering what this lug on the casting was for:

According to the drawings, there should be a (5/16"?) through hole here. The book doesn't mention it afaik.

I have studied a lot of pictures of other Quorns on the web, and some has a hole here and others don't.

I just checked my M5 counterbore. It has a 4.2mm pilot, and a 10mm cutter diameter. Go figure!

It's stamped M5 10 4.2 on the skank, so it's not altered just made for a special purpose.

My first thought is that it's for counterboring a threaded hole, but why would you do that!?

Aha! I see what you mean now.

My thought is that there should be an additional fiducial mark 90° to the left of the existing one.

I haven't read it, but this book looks the be the "ticket".

Posted by Simon Williams 3 on 01/02/2017 22:29:29snipped a bit)

Hello Thomas,

There IS room for an ER32 collet holder, because I've tried it. I had to grind a shoulder on the rear of the threaded portion of the holder (behind the nut) as this diameter fouled the detent knob which projects forward of the face of the Quorn toolholder.

I don't know of any real advantage of the ER32 size over the smaller one, as either will take a 16 mm endmill to sharpen it. But the Quorn that I bought did not have the tool holder collets included, so I thought buying something to use the ER collets was an easy answer.

HTH, if you would like to see pictures I can do that but it's cold and dark out there just now!

Best rgds Simon

Thanks a bunch Simon!

I remembered that I have some ER25 collets in the most used sizes, so I will order a 1" shank ER25 holder. I may have to grind/turn away a bit if it's in the way of the detent knob, as you say.

At the moment I only have one mandrel, with MT2 taper and Myford threaded spindle nose. I'm not sure what the threaded spindle nose is good for?

I would be great to see a photo of this, if it's possible.

I see that's it's near impossible to see the scale setting, when the work head is mounted.

The clamping of the front bar to the base is much tighter, and needs much less force.

By the way, I will buy a 1" straight shank ER collet chuck to use in the work head. I'm not sure if ER20 or ER25 is best.

If there was room (i doubt it), I would go with ER32, as I have a full collet set in that size.

Edited By Thomas Staubo on 01/02/2017 17:12:39

You may be right, Emgee. I have just played with it a little so far.

It seems to be something not quite right, when tilting the work head. But I have to disassemble a lot of things, just to put a thicker/thinner washer under one of the lower ball handles.

I do noticed that I have to exert a bit more pressure than I like, when clamping the workhead base to the front bar. I have to press on that ball handle quite hard. It may be that the bore is a bit over 1" (25.4mm)? Could it be that the bore opened up a tad, when the casting was slit?

I know that axle collars often are partially slit on the opposite side of the bore, to achieve greater clamping pressure.

Like this:

Is that a possible solution on the Quorn, or will it weaken the cast iron too much?

.

I'm in the process of ordering two CBN grinding wheels for use on HSS. And if I can find it, I have a dished diamond grinding wheel for carbide, whic hmay fit.

But arbors for these have to be made, until then I can only admire it and try to figure out how to set it up for grinding. I also have to make a holder for square lathe and shaper tools.

Edited By Thomas Staubo on 01/02/2017 13:17:47