How would you design a extra mini lathe (Adept size)

[Ian S CParticipant @iansc]

Don't always believe what you read in a dictionary. Anneal; toughen(glass or metals) by heating and usu slow cooling. The Concise Oxford Dictionary.

Ian S C

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Rainbows on 15/09/2015 21:21:24:

I like the concept of the Adept size super small lathes but it must be reluctantly admitted (or shouted with a megaphone from the rooftops) it wasn't that well made. The Wizard I own is certainly better but still no Schaublin.

Has anyone ever made a lathe of similar capacity out of stock metal? I have access to a lathe and mill (though the only tools I personally own are non functioning ).

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On the occasion of my 4,999th post on this forum, I hope that I will be permitted a small whinge:

I was really excited by the title of this thread

How would you design a extra mini lathe (Adept size)

… note the use of the word 'design'

In reality, Rainbows prescribed a very limited 'envelope' by assuming the use of stock materials and 'available' machining facilities … and the resulting suggestions have been predictably unadventurous.

As mentioned by others: If that's what you want to do, then read and inwardly digest L.C.Mason's book … his design can be treated as both modular and reasonably scale-able; so there is not much point reinventing that particular wheel.

However: We are currently blessed with the availability of accurate and precise mechanisms at prices that were inconceivable in Mason's day. So; if the question is really one of design, then let's look at the 'make from' possibilities.

A very small machine could, for example, use off-the-shelf ball or roller bearing slides without breaking the Bank; and a major part of our effort might then usefully be put to protecting them from the ingress of swarf.

MichaelG.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by Ian S C on 17/09/2015 10:21:07:

Don't always believe what you read in a dictionary. Anneal; toughen(glass or metals) by heating and usu slow cooling. The Concise Oxford Dictionary.

Ian S C

"In materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing." (Wickipedia)

"Annealing: softening of steel previously hardened" (Tubal Cain – hardening tempering and heat treatment)

I think the Oxford dictionary has it right. Don't get me started on EPIcentre though

Cheers,

Rod

[VicParticipant @vic]

This would make a nice combined chuck/headstock spindle:

**LINK**

Might buy one myself actually …

Do the Chinese make decent linear guides and ball screws?

[John McNamaraParticipant @johnmcnamara74883]

Hi
I have always thought that CNC would be the way to go if building a Lathe from scratch. it eliminates change gears, they are not needed with a CNC lathe, CNC allows you to cut any thread metric or imperial.

The lathe in the following link is a superb example.

**LINK**

I like the way the bed is comprised of granite pieces assembled and glued together also the EBay sourced second hand air bearings.
as Michael Gilligan mentioned ball bearing linear slides would also make a good bed. However not the circular type, you need the rectangular type with preload.

**LINK**

If size could be kept down the cost of making on would not be prohibitive. around 100 USD per axis (Motor and driver), even less if you buy bare board kits. Add in the ballscrews and guides surprisingly cheap these days.

**LINK**

&tbm=shop”>https://www.google.com.au/search?q=small+cnc+kit&biw=940&bih=550&tbm=shop&source=lnms&sa=X&ved=0CAcQ_AUoAmoVChMIk7zhxLX-xwIVot2mCh2qrQta&dpr=1.55#q=cnc+drive+kit&tbs=vw:l,p_ord&tbm=shop

What centre distance, centre height above the bed and saddle would be ideal? for most model making needs ?

The smaller the better for high precision parts. I think precision is the key. It makes the machine worth building.

Regards
John

[Neil WyattModerator @neilwyatt]

Even if I was doing a small one, I think I would also consider using a vertical lathe arrangement.

Neil

[RainbowsParticipant @rainbows]

I have only ever seen one from a distance so I'm curious on what you think the benefits would be. My understanding was that they were used for pieces so massive it would be difficult to mount them horizontally. Are you thinking of doing diameters that would usually require a large myford on a machine that is much smaller?

Also if anyone has alternative techniques to flat stock and machining I would still be fine to hear them. Those straight shank collets for a spindle are certainly an interesting idea.

[AjohnwParticipant @ajohnw51620]

The problem with screw cutting via cnc is the need to control the motor speed pretty precisely as loads vary. It needs servo motor type set ups really.

The Taigs make good use of some sort of concrete in the bed. Peatol reckoned it was a sort of slurry that is backed down into an aluminium extrusion with the metal part of the bed on top.

John

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[John McNamaraParticipant @johnmcnamara74883]

Hi All

Struck gold here…… We are not alone, some impressive work being done.

**LINK**

Also here for mineral cast machines. Something we can do in the home shop.

https://www.google.com.au/search?q=diy+cnc+lathe&biw=1231&bih=695&tbm=isch&tbo=u&source=univ&sa=X&ved=0CCYQ7AlqFQoTCNGqp5_K_8cCFYcYpgodMQcEoQ&dpr=1.25#tbm=isch&q=diy+cnc+lathe+granite

 

Regards
John

Edited By John McNamara on 18/09/2015 04:04:36

[Martin Field 1Participant @martinfield1]

In answer to the OP, I used to have an English made lathe called a SIMAT. It was produced by Brian Wexler in North Walsham and was an Adept/Flexispeed copy, which you assembled yourself to save money. It worked very well. I needed something smaller when I moved to a smaller workshop, so sold it.

I note a mention of an EW lathe above. My son recently bought one through ebay and has used it with success.

I believer the great LBSC made his own lathe originally.

Martin

[VicParticipant @vic]

I couldn't care less about CNC, I'd just like a small well made Lathe using modern off the shelf parts. I'm not sure I'd even want screw cutting to start with although it would perhaps be a good idea to design round possible inclusion later on. Another important point is that many small footprint Lathes have poor centre height capacity which is not neccesary.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Vic on 18/09/2015 11:13:24:

I couldn't care less about CNC, I'd just like a small well made Lathe using modern off the shelf parts. I'm not sure I'd even want screw cutting to start with although it would perhaps be a good idea to design round possible inclusion later on. Another important point is that many small footprint Lathes have poor centre height capacity which is not neccesary.

.

Excellent points, Vic … especially regarding centre height

I think a realistic 'total size of machine' envelope might be a 300mm cube

MichaelG.

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P.S. [as per your screw cutting]

I would like to see CNC-ability 'for possible inclusion later on'

[Neil WyattModerator @neilwyatt]

> I have only ever seen one from a distance so I'm curious on what you think the benefits would be.

Mostly it saves space and I think it would be easier to implement a pure CNC machine vertically.

I may be wrong…

Neil

[VicParticipant @vic]

The small CNC Lathe they had where I used to work was horizontal except the bed was not flat but nearer vertical.

[Neil WyattModerator @neilwyatt]

Posted by Vic on 18/09/2015 12:32:59:

The small CNC Lathe they had where I used to work was horizontal except the bed was not flat but nearer vertical.

Makes sense if you don't need to be able to manipulate the slides by hand – why shower them with swarf if you don't need to?

Neil

[AjohnwParticipant @ajohnw51620]

Don't expect the straight shank er collet holders to be on size. Every one I have looked at is undersized – enough to mean there isn't any chance of using it with a standard bearing size. I've been interested in spindles for a long time.

John

–

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John W1 on 18/09/2015 12:56:20:

Don't expect the straight shank er collet holders to be on size. Every one I have looked at is undersized – enough to mean there isn't any chance of using it with a standard bearing size. I've been interested in spindles for a long time.

John

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Miracle Cure = Loctite Bearing Fit

http://www.farnell.com/datasheets/319973.pdf

MichaelG.

Edited By Michael Gilligan on 18/09/2015 14:17:01

[jaCK HobsonParticipant @jackhobson50760]

Posted by Roderick Jenkins on 17/09/2015 12:08:20:

 

"In materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing." (Wickipedia)

Rod

I think toughness is just the ability to absorb energy.

Malleable is ability to deform plastically.

I think most engineers would think anneal is to make soft or malleable and would not think of the 'toughen' implications.

 

 

Edited By jaCK Hobson on 19/09/2015 10:07:52

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by John W1 on 16/09/2015 13:07:23:

One thing that is a fact is that plain bearings are best.

I wonder if that is still true given the development of small ball and roller bearings in recent years?

Russell.

[RainbowsParticipant @rainbows]

Can anyone recommend a particularly good supplier of leadscrews? Ebay has loads of 4 start screws but my understanding is that they would be harder to get high torque on.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Rainbows on 19/09/2015 11:26:59:

Can anyone recommend a particularly good supplier of leadscrews? Ebay has loads of 4 start screws but my understanding is that they would be harder to get high torque on.

.

Depending upon what exactly you require …

Marchant Dice seems a very good place to start.

MichaelG.

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Edit: ebay shop here

Edited By Michael Gilligan on 19/09/2015 11:35:24

[VicParticipant @vic]

Posted by Russell Eberhardt on 19/09/2015 11:01:04:

Posted by John W1 on 16/09/2015 13:07:23:

One thing that is a fact is that plain bearings are best.

I wonder if that is still true given the development of small ball and roller bearings in recent years?

Russell.

I suspect it's still the case but can most folks be bothered to mess about adjusting them?

[Neil WyattModerator @neilwyatt]

Posted by Vic on 19/09/2015 11:44:18:

Posted by Russell Eberhardt on 19/09/2015 11:01:04:

Posted by John W1 on 16/09/2015 13:07:23:

One thing that is a fact is that plain bearings are best.

I wonder if that is still true given the development of small ball and roller bearings in recent years?

Russell.

I suspect it's still the case but can most folks be bothered to mess about adjusting them?

LBSC made the same claim in 1947, this is how British Timken responded.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 19/09/2015 12:29:27:

Posted by Vic on 19/09/2015 11:44:18:

Posted by Russell Eberhardt on 19/09/2015 11:01:04:

Posted by John W1 on 16/09/2015 13:07:23:

One thing that is a fact is that plain bearings are best.

I wonder if that is still true given the development of small ball and roller bearings in recent years?

Russell.

I suspect it's still the case but can most folks be bothered to mess about adjusting them?

LBSC made the same claim in 1947, this is how British Timken responded.

Neil

.

All very valid, but [just for perspective] let's remember that this thread is about an 'Adept size' lathe.

MichaelG.

[Neil WyattModerator @neilwyatt]

All very valid, but [just for perspective] let's remember that this thread is about an 'Adept size' lathe.

MichaelG.

I looked at fitting angular contact or roller bearings in my new Adept headstock, and went for a tapered bronze bearing. A new small design could easily accommodate a small taper roller if it had a 'box' headstock, but it would spoil the look of an Adept..

A 30202 is 35mm OD and would allow a 15mm spindle, plenty for an MT0 spindle, noting that the full diameter of the taper would be forward of the bearing. An A2047 is even smaller.

Neil.

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