Author Topic: Micro lathe refurb  (Read 27109 times)

Offline tangler

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Re: Micro lathe refurb
« Reply #45 on: September 08, 2014, 09:51:02 AM »
John,

Your installation is really neat.  The sewing machine belt I've looked at is too narrow for the pulleys on mine.  Yours seem to sit very nicely.  What width is your belt?

Cheers,

Rod

Offline John Hill

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Re: Micro lathe refurb
« Reply #46 on: September 23, 2014, 02:40:11 AM »
Rod, the sewing machine belts are 6mm wide.

John

Offline tangler

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Re: Micro lathe refurb
« Reply #47 on: September 26, 2014, 11:39:04 AM »
John,

Thanks for that.  Clearly our pulleys are different.  Mine seems to be sized for an M size belt (3/8" or 9.5mm at the top).  I've managed to source some 8mm cogged v belt which sits in the Vs OK and doesn't bottom.

http://simplybearings.co.uk/shop/Belts-V-Belts-VB+Classical+V-Belts+5+/+6+/+8mm-VB+Classical+V-Belts+8x5mm/c4601_4790_5053_5056/p680026/Optibelt+VB-8x315-Li+Cogged+Classical+8mm+Wide+5mm+Deep+V-Belt/product_info.html

Cheers,

Rod

Offline ths

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Re: Micro lathe refurb
« Reply #48 on: September 26, 2014, 01:43:49 PM »
What was the issue with the round poly belt? I've had no trouble with mine. Hugh.

Offline tangler

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Re: Micro lathe refurb
« Reply #49 on: September 26, 2014, 02:15:14 PM »
Hi Hugh,

6mm round belt was too small for the pulleys and the 8mm seems reluctant to wrap round the pulleys without putting, what I feel, is too much tension on the various pulley bearings.  Possibly I'm being over cautious but the V belt shouldl allow me to have closer centres and a more compact installation.

Cheers,

Rod

Offline ths

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Re: Micro lathe refurb
« Reply #50 on: September 26, 2014, 09:55:50 PM »
Understood. My 8mm belt seems to work OK, but I hadn't considered the bearings.

Cheers, Hugh.

Offline bp

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Re: Micro lathe refurb
« Reply #51 on: September 27, 2014, 04:26:53 AM »
About Loctite.  I don't think you need to loose any sleep about the effectiveness of Loctite.  Two examples......
1/  I used to work for Norton Motorcycles, a long time ago.  The steering stem, fork yoke assy was being redesigned.  Loctite was suggested as an alternative to the original brazing, to secure the stem into the yoke.  Considerable tooth sucking by the Big White Chiefs.  A test was set up, after curing, a push out test was performed, the Loctite joint remained intact, the surrounding metal sheared.
2/  When I was making my post/clamp-on QCTP, the height adjuster screw had a brass "foot" Loctited to the M5 set screw.  To keep everything in line the set screw/brass pad was loosely assembled into the toolholder.  Guess what happened.... yup, some of the Loctite migrated from the brass to the toolholder.  This was discovered after the Loctite had cured, an allen key now has a two turn spiral wound into it.  The toolholder had to be warmed up with a gas torch to destroy the Loctite.  That's why one of my (23) toolholders has a nice blue finish!!
cheers
Bill

Offline tangler

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Re: Micro lathe refurb
« Reply #52 on: October 21, 2014, 05:42:11 PM »
This turned up in the post today.  I saw it on ebay and couldn't resist.





Looks like somebody has had a go (and failed) at repairing the Tee slot with sifbronze or something similar.  I'm going to have to think about this  :thinking:

Cheers,

Rod

Offline ths

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Re: Micro lathe refurb
« Reply #53 on: October 21, 2014, 10:49:50 PM »
Same as one of mine Rod, good find. I don't know how much use mine will get, but it's certainly nice to add to a well rounded kit.

Perhaps you could mill away the central T cap ( for want of a better description), and screw/glue on a suitable piece of steel.

Cheers, Hugh.

Offline steamer

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Re: Micro lathe refurb
« Reply #54 on: October 22, 2014, 12:50:19 AM »
3 screws and 2 pins in a flat piece of steel or Iron...Take a fly cut over the whole face when your done......

Done and dusted.
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline tangler

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Re: Micro lathe refurb
« Reply #55 on: October 26, 2014, 02:25:47 PM »
Screwing and gluing had occurred to me but I hadn't thought of pinning as well.  I guess closely fitted pins will stop any possible rotational movement.  An alternative might be to mill a tenon on the stub of the T and fit this to a slot for the new cross piece.  Or perhaps riveting right through with countersunk holes on both sides might do it.  That way the resultant repair wouldn't be obvious from the top surface after milling the whole lot flat

Thanks for your comments and helping me think about.

Rod

Offline tangler

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Re: Micro lathe refurb
« Reply #56 on: December 12, 2014, 12:18:46 PM »
Hi guys,

I finally finished the re-furb of this Flexispeed:



Closer inspection of the counter-shaft that I had been using showed that the bearings were shot.  So I bought a couple of pillow blocks from ebay.  The weight of the motor plus the counter-shaft provides adequate tension on the drive belt.  The box to the left contains the motor capacitor and an old reversing switch I have been hoarding for 30 years.





The DROs are those as used by AS for his mill, I haven't done the mains conversion yet.  At £30 each delivered they were cheaper than long scale DTIs.  The swarf covers are made from an ally extrusion bought from B&Q.  The scales are mounted with the sensing track underneath which should help to keep the swarf at bay.

Cheers,

Rod


Offline Allen Smithee

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Re: Micro lathe refurb
« Reply #57 on: December 12, 2014, 01:53:09 PM »
I do love that remote-mounting system for those scales!

I may be getting a unimat 3 in the near future and I may just copy that idea for it...

The DROs are those as used by AS for his mill, I haven't done the mains conversion yet.

If/when you do a little wrinkle I've discovered. I put a switch in the 3v cabple from the pwer adaptor, but (as you see above) the displays go into standby after a few minutes anyway. If you want to keep your datums just leave them in standby - touching any button wakes them up and they preserve the zero settings. On the other hand if you want an easy way to set a new zero datum on all axes at once - just cycle the power switch and Bob's your auntie. I've found myself using the power swicth to reset the mill when I've got the tool to my reference point (edge or circle-centre).

I would recomment using the mains PSU though, because even when switched off those displays will eat a pair of alkaline 2032 cells in about four days (or about six days for the lithium versions). The mains supply costs the same as about four batteries!

AS
« Last Edit: December 12, 2014, 02:01:25 PM by Allen Smithee »
Quidquid latine dictum sit altum sonatur

Offline fumopuc

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Re: Micro lathe refurb
« Reply #58 on: December 12, 2014, 07:39:46 PM »
Hi Rod, I like the re-furb of this lathe you have done there. This bearing carriers for the shaft will give the lathe the chance to survive for an other 100 years.
Kind Regards
Achim

Online Roger B

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Re: Micro lathe refurb
« Reply #59 on: December 12, 2014, 07:58:28 PM »
Very nice job  :praise2:  :praise2: I also like the 'remote' DRO's. Something for me to think about I the future when I move out of the dark ages  :old:
Best regards

Roger

 

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