Something special coming in issue 253 of MEW

[Gray62Participant @gray62]

Posted by richardandtracy on 06/03/2017 12:24:02:

I'm doing a cnc lathe conversion (in very slow time at the moment!) and a tool turret is both an interesting possibility and something I have seen on some of the smaller commercial machines. I look forward to the ideas if nothing else, as it's always the basic idea that's the hardest bit to come up with.

Regards,

Richard.

There's a very good build thread over on HMEM of an 8 position lathe tool turret with downloadable pdf plans.

[JasonBModerator @jasonb]

Michael I was just pointing those interested in where they may want to look then they could come up with something to suit. But for you here is the ratcheting detail and I'm sure the gearing can be found on the net too. Could also mount the motor along the lathe axis and use spur gears or toothed belt rather than a right angle drive, maybe a one way clutch in there somewhere so the tool can settle onto the ratchet. Ratchet is not a lot different to Emgee's method in Graeme's link

[richardandtracyParticipant @richardandtracy]

Posted by Graeme W on 07/03/2017 09:26:05:

There's a very good build thread over on HMEM of an 8 position lathe tool turret with downloadable pdf plans.

Absolutely fascinating. Thanks for that. I do like the manual turret version shown at the end.

Regards,

Richard

[John Stevenson 1Participant @johnstevenson1]

That picture is a rendered version of an early tool changer.

As these are proprietary I'm not at liberty to share the current design but they differ quite a lot from the rendering and the prototype which was built over 8 years ago.

**LINK**

These are no longer controlled by stepper motors but by a 24v 3 phase motor running through a special controller that allows it to go immediately to any tool number in any direction in seconds.

These are very expensive units hence my remark to Richard but I knew he's want one made from a bean tin for tuppence with a 3p off voucher but the end customer is very pleased with them and they don't work for peanuts either.

Most units ship with at least 3 spare tooling plates, one even shipped with 10 so the end user can leave a plate setup with tool and just swap plates and programs for different jobs.

Some have a mixture of lathe tools and boring bars, some all lathe tools and some all boring bars, you can play mix and match.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 07/03/2017 10:34:36:

Michael I was just pointing those interested in where they may want to look then they could come up with something to suit. But for you here is the ratcheting detail and I'm sure the gearing can be found on the net too. Could also mount the motor along the lathe axis and use spur gears or toothed belt rather than a right angle drive, maybe a one way clutch in there somewhere so the tool can settle onto the ratchet. Ratchet is not a lot different to Emgee's method in Graeme's link

.

Thank you, Jason … but it wasn't really necessary to do anything especially "for me" …

When I wrote "my question remains open" I was referring to my question [addressed to JS] about the unidentified "you need one of these" item.

MichaelG.

.

P.S. … For the avoidance of doubt: I have read John's subsequent post and I accept that he is not at liberty to disclose further detail.

Edited By Michael Gilligan on 07/03/2017 14:21:30

[richardandtracyParticipant @richardandtracy]

Posted by John Stevenson on 07/03/2017 12:38:34:

…These are very expensive units hence my remark to Richard but I knew he's want one made from a bean tin for tuppence with a 3p off voucher…

What?!? Only 3p off!?!

I suspect John knows me better than I'd like. It could well be I'm trying to do something that is beyond what I can afford, really, but that's no reason not to try.

Regards,

Richard.

[Neil WyattModerator @neilwyatt]

Posted by JasonB on 07/03/2017 10:34:36:

That detent pawl looks a bit poorly…

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 07/03/2017 16:27:34:

That detent pawl looks a bit poorly…

.

… designed, … made, … treated

MichaelG.

[Neil WyattModerator @neilwyatt]

Posted by Michael Gilligan on 07/03/2017 16:37:21:

Posted by Neil Wyatt on 07/03/2017 16:27:34:

That detent pawl looks a bit poorly…

.

… designed, … made, … treated

As in feeling sorry for itself, surely it's split right through to the locating pin.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 07/03/2017 18:18:13:

Posted by Michael Gilligan on 07/03/2017 16:37:21:

Posted by Neil Wyatt on 07/03/2017 16:27:34:

That detent pawl looks a bit poorly…

.

… designed, … made, … treated

As in feeling sorry for itself, surely it's split right through to the locating pin.

Neil

.

Yes, Neil … I did notice that:

My 'multiple choice' was meant to be by way of analysis.

MichaelG.

[richardandtracyParticipant @richardandtracy]

Neil,

Just got my copy. Very interesting design. Thanks for doing this, very much appreciated.

Regards

Richard.

[Neil WyattModerator @neilwyatt]

Thanks to Alex, really

Neil

[HopperParticipant @hopper]

253 Just arrived here in rural Oz. Lovely article and drawings. Just like the good old days and good to see. Has inspired me to make one myself, perhaps scaled down to 75mm diameter to match the Mighty Drummond's MT1 talistock taper though.

One minor quible; the text seems to me to say the tapered arbor has a 10mm thread, while the drawings call out 12mm, which seems "more correct" by eye. I think the space dedicated to the one build article, complete with drawings was well worth it and is getting back to more like how the mag was in its early days, which is not a bad thing. Seems like as drawing has gotten easier with CAD over the years, fewer people are doing drawings!

Will issue 254 include a small triangle to cut out and paste into the hole left in 253 where the piece to stick on the cover of 252 came from?

[Martin ConnellyParticipant @martinconnelly55370]

At the moment I can't see anything in my future work that would require an automatic tool changer for my lathe. I can see the appeal for someone who wants to make 400 super special, identical hinge pins for a tracked scale model.

For the occasional use I can envision a simple tool changer that is manually moved to each position. All that would be required in the CNC code is a pause using M0 with a comment saying something like "change to 60° threading tool then press cycle start". I don't think my quick change tool post is quite up to the repeat accuracy required but that may not be the case with all of them. This is similar to the tailstock turret system where the required tool is rotated into position by hand as it is needed.

Regarding the pawl in the earlier picture I thought there was a possibility that there was dirt on it that looked like a crack. I also think it looks a little too slender for the loads that will be imposed on it and if not already cracked then it would probably happen at some point in the future.

Martin C.

[EmgeeParticipant @emgee]

See my Album for more pictures of the manual 8 position Tool Turret mentioned earlier.

.Emgee

[EmgeeParticipant @emgee]

Posted by Martin Connelly on 13/04/2017 14:06:31:

For the occasional use I can envision a simple tool changer that is manually moved to each position. All that would be required in the CNC code is a pause using M0 with a comment saying something like "change to 60° threading tool then press cycle start". I don't think my quick change tool post is quite up to the repeat accuracy required but that may not be the case with all of them. This is similar to the tailstock turret system where the required tool is rotated into position by hand as it is needed.

Regarding the pawl in the earlier picture I thought there was a possibility that there was dirt on it that looked like a crack. I also think it looks a little too slender for the loads that will be imposed on it and if not already cracked then it would probably happen at some point in the future.

Martin C.

Martin, thats exactly how I use the manual Turret pictured above, time between tool changes is less than 10 secs including the moves off the job and back to cutting position.

It is recommended for users of the Emco 5 cnc turret that the locking plate is replaced with something thicker than 3mm, there is plenty of room for a 6mm thick plate if you want to go OTT.

In use the motor driving the toolchanger is constantly ON, after rotating to the tool position the 12VDC motor reverses at a lower voltage to drive the pawl onto the locking plate and the motor remains ON but at the lower voltage of 6VDC

Emgee

added para

Edited By Emgee on 13/04/2017 14:25:46

[Neil WyattModerator @neilwyatt]

Posted by Hopper on 13/04/2017 12:42:08:

Will issue 254 include a small triangle to cut out and paste into the hole left in 253 where the piece to stick on the cover of 252 came from?

Typical Aussie

I hope we can do more of these in future. Problem is I should ask for the plan in the budget before the year begins so I need a suitable article + plan ready along time in advance.

In the short term I will look for things that fit on a double sided A3 (the centre pages).

Neil

[Neil WyattModerator @neilwyatt]

Posted by Emgee on 13/04/2017 14:09:44:

See my Album for more pictures of the manual 8 position Tool Turret mentioned earlier.

.Emgee

You know what I'm going to ask you to do now, don't you?

That would make a very interesting article, even if the photo is worth a thousand words.

Neil

[richardandtracyParticipant @richardandtracy]

There is one thing of particular interest, how the lathe tools are retained. Presumably they are jacked up against the 'top' face of their slot (machined to be at or slightly above lathe centreline) by two grub screws passing on either side of the axial tool collet aperture. Which would imply all cutting forces going through the screws. Possible, but I wouldn't have thought it 'good' practice as the tool itself is given relatively little support compared to standard fitting methods. The other option of clamping the tool down would need a wild muddle of long holes through the body of the plate.

Regards,

Richard

[EmgeeParticipant @emgee]

Hi Richard

Yes the tools are retained by 2 upward facing 6mm grub screws which does not present any problems. You can machine wider slots and use a tapered wedge to force the tool upwards, this would be a better method but much more work for in my case no gain as no really heavy cuts are made, this is a hobby for me.

The round tools are held in 1/2" diam split brass collets, clamped by 2 M6 grub screws.

The design is not mine, the drawings on HIMEM site are from the Emco PC50 lathe tool turrett and is ideal if using a 3" chuck, if using anything larger care is needed to ensure no tool projects to clash with the chuck, especially if the jaws extend more than the chuck OD. More likely to happen when turning small diameters.

The problem of tools clashing when using chucks larger than 3" can be overcome by making a larger diameter tool plate placing the tools at greater diameter than the chuck OD.

I would gladly add the PDF files to this site but unable to upload PDF files, perhaps I can save them as jpg ?

Emgee

[Neil WyattModerator @neilwyatt]

Posted by Emgee on 13/04/2017 20:09:33:

The design is not mine, the drawings on HIMEM site are from the Emco PC50 lathe tool turrett and is ideal if using a 3" chuck, if using anything larger care is needed to ensure no tool projects to clash with the chuck, especially if the jaws extend more than the chuck OD. More likely to happen when turning small diameters.

.

I would gladly add the PDF files to this site but unable to upload PDF files, perhaps I can save them as jpg ?

Emgee

As the plans are someone else's it's better 'nettiquette' to give a link to the page where they can be found as we don't have permission to host them (and we'd be miffed if someone took plans from this website and put them on another website!)

Neil

[EmgeeParticipant @emgee]

Neil

Michael already posted the link to the HMEM page where the turret pictures and a little detail is given, the plans are in the article as PDF of the Emco turret details. It is necessary to do a bit of calculating of dimensions to ensure the tool slots and hole centres come out at the correct height for your lathe.

Emgee

**LINK**

[EmgeeParticipant @emgee]

Neil

The drawings are from an Emco manual for the turret fitted to PC50 lathes, they are not plans to make the turret, you have to use a bit of imagination to arrive at the size to suit your lathe. Michael already posted a link to HMEM page but the article with downloadable PDF files starts at the following link.

Emgee

**LINK**

[HopperParticipant @hopper]

Posted by Martin Connelly on 13/04/2017 14:06:31:

At the moment I can't see anything in my future work that would require an automatic tool changer for my lathe. I can see the appeal for someone who wants to make 400 super special, identical hinge pins for a tracked scale model.

I've a mate up the road who made a tailstock turret to the Sparey design just for use on making his 9-cylinder Bentley rotary engine model, including most of the BA fasteners but also all the 9×2 pushrods, rocker arms, spindles, spacers, the 9 small end bushings and on and on. Lot of repetition work in those multi cylinder IC engines, which seem to be a growing popular facet of model engineering. I just could not be bothered with the tedium in making a V12 IC engine. Rather make half a dozen nice but different v-twins or some such. But even on the model Harley engine I am currently tooling up to make, there are quite a few repetition jobs for special fasteners such as head studs, case screws and the like so I reckon that's enough excuse to make a tailstock turret for me.

[HopperParticipant @hopper]

Posted by Neil Wyatt on 13/04/2017 16:15:44:

Posted by Hopper on 13/04/2017 12:42:08:

Will issue 254 include a small triangle to cut out and paste into the hole left in 253 where the piece to stick on the cover of 252 came from?

Typical Aussie

Oi, I might one day want to look up the correct style for the drawer handle on the cabinet of that Colchester Bantam lathe on the other side of the page, the back of the triangle, and there it will be, a gaping triangular hole right where the vital information should be. You know how it is I am sure: as soon as you throw something away you desperately need it. Same principle applies to triangular holes in magazines.

[Author]

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