Micro-lathe suitable as multi-function system for small workshop?

[HollowpointParticipant @hollowpoint]

Posted by Jan-willem De Bleser on 08/03/2022 19:08:47:

DOC and speed of machining is a good point – "small cuts" seems to be the order of the day with micro lathes.

I agree, however DOC is pretty much interlinked with rigidity and big doesn't always mean rigid.

My Chinese mini lathe for example is so badly made there is slop and play all over the place. None of it can be adjusted out because it wasn't made to tight tolerances to start with!

Compare that to my tiny but beautifully made Cowells lathe, which believe it or not is actually more rigid!

I can press on the tool in my mini lathe with my hand and actually see flex in the compound and cross slide. No such problems with my Cowells! And this isn't an exception, I've had enough small Chinese lathes to know a lot of them are crap.

Just last week I had to finish machining a backplate I was making on my Cowells because my mini lathe couldn't cope! Go figure. 🙄

[Jan-willem De BleserParticipant @jan-willemdebleser98060]

Yeah, I was just browsing the Cowell site, and they look like really nice machines. Get what you pay for, I guess.

Freight to California would be rough, I expect.

[HollowpointParticipant @hollowpoint]

Posted by Jan-willem De Bleser on 08/03/2022 19:39:36:

Yeah, I was just browsing the Cowell site, and they look like really nice machines. Get what you pay for, I guess.

Freight to California would be rough, I expect.

Yes, they aren't cheap and might not be a viable option if you are stateside.

If you are in California then the Sherline a very attractive proposition since they are made there! And it's obvious they are made to good tolerances and with pride! 👍 I really like mine, it's a joy to use!

[TomfileryParticipant @tomfilery]

Jan,

Despite what others have said, some people do turn out very good work on a small lathe. On the HMEM website, search for the thread "Building Kozo's New Shay locomotive" where Crueby does his turning on a little Sherline lathe. He does have a mill as well, but (in case you don't know) Kozo's Shay is a 3.5 inch gauge loco – so not "clockmaking"!

I have had a Cowells lathe from new and don't rate it. You can only take tiny cuts, so turning anything requiring significant material removal is a real pain! A few years ago I bought a second hand Myford S7 and now don't use the Cowells – I guess supporting the views of the "bigger is best camp".

Doubtless your final decision will be constrained by space, or funding (or a number of other things). Good luck with making the right call.

Regards Tom

[Jan-willem De BleserParticipant @jan-willemdebleser98060]

The Sherline factory is an hour's drive from me, so maybe I should go have a look in person. Always more informative than looking at photos online.

I appreciate all the pointers and opinions people are giving me here. Knowing why a given machine is liked will be helpful when I finally decide on one myself.

[Peter Cook 6Participant @petercook6]

Posted by Hollowpoint on 08/03/2022 19:29:05:

I agree, however DOC is pretty much interlinked with rigidity and big doesn't always mean rigid.

DOC is an issue on small lathes, but the Taig (and I would guess the Sherline) are quite capable. I was taking 1mm DOC in EN1A mild steel today on my Taig with absolutely no protest.

[HuubParticipant @huub]

My first lathe was a mini lathe (60 kg) and I used over 10 years before I bought a bigger one 360 kg).

The small lathe is as accurate as the bigger lathe, but it takes more effort (need to measure more often).

On the mini lathe I can cut hot rolled steel at 0.5 mm (even more) CD so each pass a mm diameter reduction. The the bigger lathe can do way more but that also means more chips flying around, so I normally don't go beyond 0.5 mm CD.

Work holding of larger parts, can be an issue. Nevertheless, I turned a 170 mm aluminium face plate that took me half a day. On the bigger lathe, it would be done in an hour.

The mini lathe can run 2500 RPM, the bigger one just 1850 RPM. For small parts, I still use the mini lathe because the small (80 mm) chuck and the higher RPM is more suitable for small stuff.

[JasonBModerator @jasonb]

I suppose depth of cut is not really the best way to think about it, metal removal rate is perhaps a better term.

While 1mm DOC may be possible on small diameter work with a fine feed which gives a small volume removal rate the same may not be possible as diameter of work increases or if feed rate is increased from more than a snails pace.

With a smaller machine you will obviously be limited to the size of parts you can work on, take Chris's (Crueby) latest build as he has been mentioned a few times where the base of the engine is made up of six parts, whereas I would most likely have cut it from a single piece on my machines which are still hobby ones not industrial size so again more time to build up the part than it would have been on if done on something larger. He also uses a lot of easier to cut brass as steel or iron would slow the process down due to the need for smaller cuts.

[HuubParticipant @huub]

Posted by JasonB on 09/03/2022 07:36:31:

I suppose depth of cut is not really the best way to think about it, metal removal rate is perhaps a better term.

The metal removal rate on my mini lathe is quit good. Checkout this link at 2:40

https://youtu.be/zH332Z-Lqhs

Normally I do not run under such conditions. The wear of the lathe (just a half nut) would be to large and I use it just for hobby!

 

The shallow DOC at the start of the video (0.001 mm turning aluminium) at the used turning conditions, results in turning a fine screw thread. This test should be done, and I have done it, at 0.05 mm / rev. Even at this rate, the insert is still "cutting" but due to the high RPM the camera image is blurring. Under these conditions, you also need a loupe to see the chips come off.

 

There isn't a lathe that is suitable for all parts that you want to make. The choice is always a compromise!

 

 

 

Edited By Huub on 09/03/2022 08:25:02

Edited By Huub on 09/03/2022 08:26:21

[Neil LickfoldParticipant @neillickfold44316]

Posted by Jan-willem De Bleser on 08/03/2022 20:49:57:

The Sherline factory is an hour's drive from me, so maybe I should go have a look in person. Always more informative than looking at photos online.

I appreciate all the pointers and opinions people are giving me here. Knowing why a given machine is liked will be helpful when I finally decide on one myself.

Here is the link to Chris Hightower site. Worth looking at what can be done on the Taig system and the ideas that Chris has in what he sells. Not saying to buy that, but worth looking at for ideas etc. His stuff is all aimed at cue making, but the live tooling side of things is what industry is doing.

I really like the Sherline little 4jaw chucks, and also really like their little rotary table/dividing head. Used one when I was working in Pa for a few years. I should have got one while I was there, but did not think of an immediate use for it at the time.

https://www.cuesmith.com/cue-lathes-cue-smith/

 

Neil

Edited By Neil Lickfold on 10/03/2022 03:19:18

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