Bought a Quorn, have som questions

[Thomas StauboParticipant @thomasstaubo12021]

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?

[Simon Williams 3Participant @simonwilliams3]

Posted by Thomas Staubo on 02/02/2017 13:04

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?

Mine came with a MT2 socket with a 1 inch parallel OD, I've never used it, though that's what gave me.the idea of buying a ER collet with a parallel back. As for the nose thread, I wonder if this was to use the old style Myford collets which slid up the spindle bore and used a front closer nut to push the collet up the morse taper.

Rgd Simon

Edited By Simon Williams 3 on 02/02/2017 17:03:29

[Martin KyteParticipant @martinkyte99762]

Hi Thomas

There are a couple of pics in my album of the scale modification.

regards Martin

[Thomas StauboParticipant @thomasstaubo12021]

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.

[Thomas StauboParticipant @thomasstaubo12021]

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.

[Thomas StauboParticipant @thomasstaubo12021]

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.

[John PParticipant @johnp77052]

Posted by Thomas Staubo 07/02/2017 08:20:25
I was wondering what this lug on the casting was for:

Hi Thomas ,the lug on that casting is a location to enable the
tooth rest bars shown on page 21 in the Quorn book to be fitted.

I have used this for the setup shown in the photo .The axis of the
rotating base and workhead spindles are aligned using the half pins,
using the bars and the tailstock casting the position can be maintained
when the toolholder is repositioned.
A full article was published in MEW 215 and 216 Grinding radiused edged milling cutters .
Some additional photo's can be seen in album Quorn and cnc cutter grinder.

John

[Martin KyteParticipant @martinkyte99762]

Ah that's useful to know. I must finish my tailstock.

The bar on the work head, as has kind of been mentioned is good as a handle when radiusing tools.

regards Martin

[Thomas StauboParticipant @thomasstaubo12021]

Posted by John Pace on 07/02/2017 09:02:57:

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?

[John PParticipant @johnp77052]

Posted by

Thomas Staubo 07/02/2017 13:43:47

 

"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?"

The index ring on my machine is made in several parts and has a
resetable dial and is constructed in a similar way to the index ring
on the front bar fig 9 on page 19 of Quorn book.
As can be seen in the photo the division rings are removable,the
two rings that i have cover most of the required numbers.
I over bored the casting to about 1 1/8 inch to fit a larger spindle,
the larger fixing collet is tightened using the pin spanner.

John
 

Edited By John Pace on 08/02/2017 10:57:07

[Thomas StauboParticipant @thomasstaubo12021]

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?

[John PParticipant @johnp77052]

Posted by

Thomas Staubo 13/02/2017 08:07:16

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?

It is just useful to have the facility to be able to divide these numbers.
I used the 24 division ring when making this dovetail cutter from some
scrap 1/8 inch carbide shanks.

John

[Neil WyattModerator @neilwyatt]

Wow John, your cunning is remarkable!

[egaParticipant @ega]

Posted by Thomas Staubo on 07/02/2017 08:20:25:

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 am grateful to Thomas Staubo for asking this question and to John Pace for answering it (and for his excellent article in MEW 215 and 216). The following is unlikely to be of interest to other than Quorn users.

When I built my own machine many years ago I was mystified by the drawing of this part (item 510), didn't put the hole in and have never missed it up till now, although I have used the tooth rest with its support attached to the column as normal. Departing from DHC's drawing was a bold step and I think I was influenced by the fact that the hole does not seem from his photos to be present in his own machine.

Now that John Pace has shown how useful the hole can be, I have put it in and in doing so have noticed that the lowest hole as drawn is the other way round from that in the photo and, indeed, from my own machine and DHC's!

Sadly, DHC is not here to help with these points but, on a different issue, those whose tilting brackets tend to slip should take note of the modification he outlined in ME of 5 September 1986.

 

Edited By ega on 09/06/2017 11:33:12

[HopperParticipant @hopper]

That's an excellent pile for the price you paid. Well done indeed!

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