Author Topic: Grayson lathe...  (Read 17509 times)

Online steamer

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Re: Grayson lathe...
« Reply #15 on: April 04, 2013, 11:03:39 AM »
Looks like progress to me! :praise2:

Dave
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Offline John Hill

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Re: Grayson lathe...
« Reply #16 on: April 04, 2013, 11:19:11 AM »
Thanks, but I found a problem....... :'(

The top slide is held to the cross slide by a 10mm screw into a T nut but this does not have enough clamping force.  I can tighten the screw as hard as I dare and still move the top slide.  That is a mild steel plate on the bottom of the top slide sliding on the cast iron of the cross slide.  I wonder how I can modify the surface(s) to get more friction?

Online steamer

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Re: Grayson lathe...
« Reply #17 on: April 04, 2013, 11:23:38 AM »
Hows the bearing of the two parts John?....is it warped?

If it fits decent, a bit of paper in between will make a big difference.

Dave
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Online steamer

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Re: Grayson lathe...
« Reply #18 on: April 04, 2013, 11:46:27 AM »
John

I suspect that one or both interface surfaces is crowned...high at the bolt..so it's only touching in a small circle around the bolt....so no holding torque what so ever.

Do some investigation and check that...a little hi spot would do it, but a good layer of magic marker will do in pinch.

Might need a bit of scraping.....or a flycut on the mill...very gently...only take off as much as you need to get flat so it doesn't warp more.

Assume both surfaces are NOT flat, unless they prove to be innocent!   8)  CHECK IT...don't just cut it...you don't have a lot of stock to cut there needlessly.

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline PeterE

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Re: Grayson lathe...
« Reply #19 on: April 04, 2013, 05:58:13 PM »
Too bad when things like this occurs. But I got a perhaps wild idea as follows.

Would it be possible to turn or mill a shallow circular recess with a diameter large enough to seat something like a piston ring at the circumference of the "foot". That would lift the center away from the cross-slide and greatly increase the clamping force. The piston ring should be possible to glue in place as it only needs to be clamped between the cross-slide and the top slide, and I do not think it would remove too much material as it is for guidance only.

Crazy but just a thought.

BR

/Peter

Online steamer

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Re: Grayson lathe...
« Reply #20 on: April 04, 2013, 06:11:52 PM »
Actually Peter, thats a good idea.   A few thou deep recess in the middle would probably do it just fine.

Might be the easiest thing to do.

Dave
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Offline John Hill

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Re: Grayson lathe...
« Reply #21 on: April 04, 2013, 08:07:04 PM »
Thanks for those ideas.  The piston ring is a good idea Peter which I will look closely at!  Of course I will be trying your paper gasket first Dave.

Offline John Hill

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Re: Grayson lathe...all fixed!
« Reply #22 on: April 09, 2013, 07:41:34 AM »
Here we are with a nice coat of blue paint! :D


IMGP1417 by aardvark_akubra, on Flickr

Jobs done,  bull gear broken hub repaired, bull gear lock fashioned and fitted, top slide fashioned from a broken vertical slide, cross slide feed screw and nut fixed.  Also swapped out a lot of screws and bolts that had seen better days and treated it to half my stash of new steel washers!
« Last Edit: April 09, 2013, 11:26:18 AM by John Hill »

Online Jo

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Re: Grayson lathe...
« Reply #23 on: April 09, 2013, 07:49:24 AM »
 :ThumbsUp: Looking forward to seeing it make some swarf  ;D

Jo
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Offline John Hill

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Re: Grayson lathe...
« Reply #24 on: April 09, 2013, 08:00:41 AM »
That will be a little while Jo. 

I intend to make some sort of box to mount it on and having flat belts means I have to work out a drive system.  It came with the original ceiling or wall mount line shaft unit with fast/loose pulleys and gimbaled mounts but I don't really want to build something that big. 

An underdrive would be fine but the bed casting is wider than the smallest pulley diameter which complicates that idea.

Online Jo

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Re: Grayson lathe...
« Reply #25 on: April 09, 2013, 08:08:58 AM »
What you need next is something like my little R&B gas engine to run it  ;)

Jo
Enjoyment is more important than achievement.

Offline Rayanth

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Re: Grayson lathe...
« Reply #26 on: April 09, 2013, 08:20:15 AM »
dang, John, that looks too crisp and clean to use! It almost appears that it belongs in a museum... I'd be afraid to use it  8)

-- Rayanth
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Offline John Hill

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Re: Grayson lathe...
« Reply #27 on: April 09, 2013, 08:21:51 AM »
Yes, the blue is a bit of a shock when I see it on screen!

Offline John Hill

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Re: Grayson lathe...
« Reply #28 on: April 09, 2013, 08:28:39 AM »
What you need next is something like my little R&B gas engine to run it  ;)

Jo



That would be nice Jo!  I could take it all outdoors in the fine weather and not have to sweep the floor afterwards! :pinkelephant:

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Re: Grayson lathe...
« Reply #29 on: April 09, 2013, 11:36:48 AM »
Nice looking lathe John!....did you mark up that compound?....that one has been lurking in the back of my mind.... :headscratch:

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!