----- Original Message -----

From: Jerry Durand

To: 7x12minilathe@...

Sent: Sunday, October 23, 2011 8:27 PM

Subject: Re: [7x12minilathe] wood

?

thanks, I'll tell her

On 10/23/2011 08:21 PM, Chuck Phillips wrote:

I’ve had good luck with using CA glue as a finish for cocobolo if you need to seal it.? Try to lay on a uniform coat, either wait for it to cure or hit it with accelerator, then sand & polish.? Alternatively, you can just polish the wood directly, although if anyone handling it has been sensitized they will likely react to it.

Chuck Phillips

Works more wood than metal…

--
Jerry Durand, Durand Interstellar, Inc.  
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype:  jerrydurand

?

?

That's for sure. I have gotten some nasty skin irritation making pens
from cocobolo wood. Pretty stuff when finished, gloves, mask, and good
vacuum to catch the chips as they come off.

Jerry

Cocobolo dust is a sensitizer and an irritant please wear
gloves and a mask when clearing up, if you have not done so already

Its not poisonous so don’t be alarmed but could cause skin
irritation and or sinus problems.

Hope this warning is not too late.



Cheers

Bernie




______________________________________________________________________
From:7x12minilathe@...
[mailto:7x12minilathe@...] On Behalf Of Jerry Durand
Sent: 23 October 2011 21:57
To: 7x12minilathe@...
Subject: [7x12minilathe] wood






I just did a little work on some cocobolo wood for a project my wife
is
working on, just had to round up and take out surface gouges in a
piece
of dowel). Sure makes a mess doing wood on these lathes. I think I'll
stick with metal and plastic. :)

Of course some plastics leave high static "snow" stuck to everything
in
sight, so I'm not sure that's better.

--
Jerry Durand, Durand Interstellar, Inc. www.interstellar.com
tel: +1 408 356-3886, USA toll free: 1 866 356-3886
Skype: jerrydurand

Can someone advise me about knurling, please?

I've been using an Eagle Rock scissor knurling tool with a couple of
medium diamond knurls for some years now with satisfactory results.

I've never given any thought to the work-piece diameter in relation to
knurl pitch and have always managed to get fairly clean results -
mostly in brass and alloy. Not quite sure why but they always seem to
turn out ok.


20Motorbikes/DSC00395.jpg

What I'd like to do now is buy some sets of straight knurls but never
having tried these before, I feel I need some advice.

For example, I assume it's critical with straight knurls to calculate
the OD of the work piece as a multiple of the dia or pitch of the
knurl.

What I don't understand yet is how the two knurls are positioned so
that they mesh male to female so that the crest of the "male" matches
the trough of the "female"? Just thinking about it, I can't see how
you prevent crest meeting crest and ending up with double-tracking.

Any advice would be much appreciated.

Trevor

----- Original Message -----

From: GadgetBuilder

To: 7x12minilathe@...

Sent: Sunday, October 23, 2011 10:38 AM

Subject: [7x12minilathe] Re: Knurling

?

There are two schools of thought on knurling: to prevent doubling the OD of the work must be adjusted to match the knurl, and if the knurl doubles then increase pressure. "Religious" wars occur between these schools so expect fireworks shortly ;-)

I'm from the increase pressure school. I was doing a diamond knurl and one knurl doubled and the other worked properly. Since both knurls were working on the same diameter I concluded that diameter wasn't the controlling factor.

Straight knurls work about the same as diamond knurls. With a diamond knurl, each knurl must sync with itself. With straight knurls each knurl must sync with itself and also with the other knurl, not generally a problem since they're identical.

The problem in either case is getting them started properly so they sync. My approach is with the work stationary, engage about 1/4 of the knurl on the work and crank on some pressure. Rotate the work slowly and check for sync - if it isn't sync'ed add pressure while rotating until it syncs. (It's possible that it won't sync but I've only seen it happen once and this was on material that work hardened easily.) It is sometimes difficult to recover when doubling occurs - turn the area down slightly and try again.

Once synced, check that depth of knurl is correct then traverse the area to be knurled. I generally go down and back but some go down and then release the knurl. If the knurl isn't deep enough add pressure and make another pass. A fully formed knurl can be rough on the hands so consider this when deciding how much pressure to add. Also, try to knurl in one pass since the knurl is cold working the metal and this can cause failure where chunks of the work pull away and stick on the knurl. Doubling increases the probability of this type of failure.

Some material is difficult to knurl no matter what you do - I avoid knurling stainless when possible and some types of aluminum are prone to chunks coming off.

Always use lots of oil and low speed. Clean knurls thoroughly after each use.

Expect someone from the OD adjustment school to come by and refute all this shortly... :-)

John

--- In 7x12minilathe@..., "trevor_rymell" wrote:
>
> Can someone advise me about knurling, please?
>
> I've been using an Eagle Rock scissor knurling tool with a couple of medium diamond knurls for some years now with satisfactory results.
>
> I've never given any thought to the work-piece diameter in relation to knurl pitch and have always managed to get fairly clean results - mostly in brass and alloy. Not quite sure why but they always seem to turn out ok.
>
>
>
> What I'd like to do now is buy some sets of straight knurls but never having tried these before, I feel I need some advice.
>
> For example, I assume it's critical with straight knurls to calculate the OD of the work piece as a multiple of the dia or pitch of the knurl.
>
> What I don't understand yet is how the two knurls are positioned so that they mesh male to female so that the crest of the "male" matches the trough of the "female"? Just thinking about it, I can't see how you prevent crest meeting crest and ending up with double-tracking.
>
> Any advice would be much appreciated.
>
> Trevor
>

Can someone advise me about knurling, please?

I've been using an Eagle Rock scissor knurling tool with a couple of medium diamond knurls for some years now with satisfactory results.

I've never given any thought to the work-piece diameter in relation to knurl pitch and have always managed to get fairly clean results - mostly in brass and alloy. Not quite sure why but they always seem to turn out ok.



What I'd like to do now is buy some sets of straight knurls but never having tried these before, I feel I need some advice.

For example, I assume it's critical with straight knurls to calculate the OD of the work piece as a multiple of the dia or pitch of the knurl.

What I don't understand yet is how the two knurls are positioned so that they mesh male to female so that the crest of the "male" matches the trough of the "female"? Just thinking about it, I can't see how you prevent crest meeting crest and ending up with double-tracking.

Any advice would be much appreciated.

Trevor