Lathes & M/C tools

[snitzl]

On 18/12/2016 at 14:57, Dave John said:

Interesting thread, lots of good advice. I keep looking at lathes, but keep coming back to the conclusion that my old Perris Moldelmaker is all I actually need. The Tray on which it sits was "borrowed" from a works canteen back in the days when works had canteens and cooked yard square bakewell tarts and the like. 

 

 

 

 

 

 

 

Found this while looking for missing images : Seem to remember that the Perris Company was taken over by Cowells who made slight modifications to this lathe and still sell them today.  I used one these back in the 80's and for its size, it's a very nice lathe.

Snitzl

Edited April 7, 2022 by snitzl

[kitpw]

20 minutes ago, snitzl said:

the Perris Company was taken over by Cowells

There seem to have been various predecessors of the Perris lathe - Flexispeed, Simat and Norfolk lathes are listed at Lathes.co.uk.  I have a lathe which most closely resembles the Norfolk (ex eBay, now refurbished).  It's a nice little machine.  The only real headache is the 14x1.5 chuck thread/main spindle:  Cowells changed the spindle thread  to 14x1 and anything 14x1.5 is much sought after with the inevitable high cost when they do show up. 

 

Kit PW

[Dave John]

Cowells sell parts that will fit the Perris, the spindle and tailstock are MT 0 sized. 

 

I have now fitted it with a Chinese made servo motor having seen Snitzls conversions. Makes a huge difference , they are very controllable. 

 

As supplied the speed control is a lever operated hall effect device designed for use with a sewing machine treadle. It can be replaced with the following simple circuit with a nice rotary knob and a fast stop switch. 

 

 

 

Careful how you use the brake switch, it is a servo motor with active brake and stops so fast the chuck can unscrew. 

 

 

[AndyID]

For no particular reason other than I just remembered, the first lathe I had was a WADE C.A.V. Plain Lathe. It had a tubular bed and very "hi-tech" (for the time) aluminium alloy castings. It would be about 100 years old by now.

 

I bought it used in Scotland, took it to Arizona and sold it to someone when we had a garage sale. I wonder if it's still around.

[kitpw]

16 hours ago, Dave John said:

Cowells sell parts that will fit the Perris, the spindle and tailstock are MT 0 sized. 

Dave - thanks for the diagram.  I saw Snitzl's conversions and wondered about following suit but, so far, haven't risen to the challenge!  The lathe is shown below together with its present drive arrangement which I cobbled together from, amongst other bits, part of a cast iron box sash weight.  It seems to work ok, driven by (IIRC) a 1/8th hp motor.

 

The 0MT taper for the spindle and tailstock is a modified 0MT and shorter than the full version, using the thinnner end of the taper, not the thicker end.  This has the effect of producing a long overhang:  the drill chuck mounted in the tailstock has the orginal stub arbor which although has the modified 0MT still has more overhang than is desirable.  I did get a 0MT centre from Cowells but it's a proper 0MT and sticks out a long way. 

 

I'd like to source a collet holder for the 14x1.5 headstock spindle but other than missing one on eBay haven't really followed up on it.

 

Kit PW

https://www.rmweb.co.uk/community/index.php?/blogs/blog/2502-swan-hill/

Edited April 8, 2022 by kitpw

[Down_Under]

Asking a little bit of advice, 

 

I am wanting to attempt to mill some zinc alloy (mazak cast loco frames). Would there be any recommendation on cutter type / speed etc on my Unimat 3.

 

Where I am a I have access to PROXXON brand HSS bits like this https://www.hobbytools.com.au/milling-bit-tungsten-vanadium-hss-3mm-cylinder-2-pcs/

 

or would double fluted be a better option - https://www.hobbytools.com.au/milling-cutter-set-high-speed-steel-2-5mm-4-pcs/ 

 

Any tips or tricks I should be aware off? firs time attempting. 

 

James

 

[cctransuk]

14 minutes ago, Down_Under said:

Asking a little bit of advice, 

 

I am wanting to attempt to mill some zinc alloy (mazak cast loco frames). Would there be any recommendation on cutter type / speed etc on my Unimat 3.

 

Where I am a I have access to PROXXON brand HSS bits like this https://www.hobbytools.com.au/milling-bit-tungsten-vanadium-hss-3mm-cylinder-2-pcs/

 

or would double fluted be a better option - https://www.hobbytools.com.au/milling-cutter-set-high-speed-steel-2-5mm-4-pcs/ 

 

Any tips or tricks I should be aware off? firs time attempting. 

 

James

 

 

I am open to correction - but I seem to recall that paraffin is a good lubricant when machining mazak.

 

CJI.

[ozzyo]

23 hours ago, Down_Under said:

Asking a little bit of advice, 

 

I am wanting to attempt to mill some zinc alloy (mazak cast loco frames). Would there be any recommendation on cutter type / speed etc on my Unimat 3.

 

Where I am a I have access to PROXXON brand HSS bits like this https://www.hobbytools.com.au/milling-bit-tungsten-vanadium-hss-3mm-cylinder-2-pcs/

 

or would double fluted be a better option - https://www.hobbytools.com.au/milling-cutter-set-high-speed-steel-2-5mm-4-pcs/ 

 

Any tips or tricks I should be aware off? firs time attempting. 

 

James

 

 

Use about the biggest cutter that you can. I would not use the first cutter that you shown us, these are more bures than milling cutters.

The second set of cutters look good but are a bit on the pricey side. If you can find a model engineering tool company you may find better prices.

 

For cutting the metal it's a bit odd, in that it's on the soft side but tough and takes a bit of cutting. Depending what you want to do, will also show what will be the best way with your machine.

 

Plunge cutting on a Unimat 3 is not something I would recommend in Mazak if you have to, drill a pilot hole first.

 

HTH

 

OzzyO.  

Edited May 22, 2022 by ozzyo
to add a comer

[PaulaDoesTrains]

From what I can find out Mazac is a bit soft and gummy to machine similar to Copper or Aluminium. Personally I'd use a single flute end mill to aid chip evacuation.

[ozzyo]

21 hours ago, PaulaDoesTrains said:

From what I can find out Mazac is a bit soft and gummy to machine similar to Copper or Aluminium. Personally I'd use a single flute end mill to aid chip evacuation.

 

Mazac is nothing like copper or aluminium  to machine. 

Copper will rip and stick to the cutter and is a sod because of this if you have your feeds and speeds out. Tapping fluid is about the best you can use with this metal when milling.

Aluminium is is very good metal for machining, a bit of lub. is always good keep the cutting speed up a good rate of feed.

 

Mazac is totally different to both of them in that it will machine dry and not stick to the cutter but you want to run your cutter at slower revs. and a slower feed rate. You will notice that it takes the edge off the cutter faster than a lot of metals eg. free cutting steel ETC. 

 

Let us know what you are wanting to do with a photo or two could also help.

 

HTH

 

OzzyO.

[PaulaDoesTrains]

1 hour ago, ozzyo said:

 

Mazac is nothing like copper or aluminium  to machine. 

Copper will rip and stick to the cutter and is a sod because of this if you have your feeds and speeds out. Tapping fluid is about the best you can use with this metal when milling.

Aluminium is is very good metal for machining, a bit of lub. is always good keep the cutting speed up a good rate of feed.

 

Mazac is totally different to both of them in that it will machine dry and not stick to the cutter but you want to run your cutter at slower revs. and a slower feed rate. You will notice that it takes the edge off the cutter faster than a lot of metals eg. free cutting steel ETC. 

 

Let us know what you are wanting to do with a photo or two could also help.

 

HTH

 

OzzyO.

 

Thanks for the correction Ozzy.  It looks like my internet search on the subject landed on a bunch of arm-chair machinists who'd never actually machined Mazac. BTW it's the OP not me who wants to machine it but I'm sure he'll see your post.

[RedgateModels]

Agreed, I don’t use anything when milling mazak, but then I’m using a milling slide on my little lathe so I’m taking little cuts with slow feed rates. 8mm multi flute end mill works great

 

This is the sort of end mill that I use

 

https://www.ebay.co.uk/itm/384887718308?hash=item599d1881a4:g:5pQAAOSwjt1ifi2j

Edited May 23, 2022 by RedgateModels

[AndyID]

I heard today that my South Bend lathe is even older than me. It was shipped from the factory in 1938!

[Down_Under]

On 22/05/2022 at 22:31, ozzyo said:

 

Mazac is nothing like copper or aluminium  to machine. 

Copper will rip and stick to the cutter and is a sod because of this if you have your feeds and speeds out. Tapping fluid is about the best you can use with this metal when milling.

Aluminium is is very good metal for machining, a bit of lub. is always good keep the cutting speed up a good rate of feed.

 

Mazac is totally different to both of them in that it will machine dry and not stick to the cutter but you want to run your cutter at slower revs. and a slower feed rate. You will notice that it takes the edge off the cutter faster than a lot of metals eg. free cutting steel ETC. 

 

Let us know what you are wanting to do with a photo or two could also help.

 

HTH

 

OzzyO.

 

Hey OzzyO,

 

Thanks for all the advice and tips. So, treat like Aluminum. I have found a single flute cutter at "Adams bits'. One of my concerns / queries was how does it cut and how gummy it was. I have a little experience cutting Perspex and wood on a larger CNC router, but that is the limit of my experience. 

 

The work that I was wanting to achieve was much finer - machine of 0.65 - 0.75mm each end of this diecast casting to widen the shunter steps to the correct width and bring the valances back to the correct position.  Depth of cut 8mm, length of cut 15mm and material to remove 0.65mm. Hopefully that isnt too ambitious 

 

 

 

In a little more detail:

 

 

 

 

Regarding tool paths -  I was thinking of multiple passes top to bottom (or bottom to top, which ever is appropriate the direction of the cutter). Maximum bit would be 5-6mm diameter. 

 

 

 

If I was feeling brave I would consider machining 10 thou of the sides of the valances to allow the etched valances to sit at the correct overall width - although this may be easier with a few strokes of a file. 

[ozzyo]

Hello Down_Under,

 

as your going to use a single fluted cutter run it at about 900 rpm and feel how it's cutting.

 

Looking at the job you look to have two options for cutting it, mount it in a vice and cut across the ends and drop the cutter by about a millimetre at a time, BUT take it easy.

 

Or you could clamp it down onto the M/C table and side cut the metal off, you can do both end at the same time this way. But you will have to make sure that you get both sides in register.

 

For milling the sides not a big problem clamp it down to the M/C table and have the cutter running towards any open edges, you should be able to do it in two or three full depth passes starting at the open end ( bottom of you photos).

 

HTH

 

OzzyO.  

 

Having had a better look at the photos you only have got only one real option for milling the step opening and that is to clamp the casting to the M/C table.

Edited May 25, 2022 by ozzyo

[Down_Under]

On 25/05/2022 at 20:49, ozzyo said:

Hello Down_Under,

 

as your going to use a single fluted cutter run it at about 900 rpm and feel how it's cutting.

 

Looking at the job you look to have two options for cutting it, mount it in a vice and cut across the ends and drop the cutter by about a millimetre at a time, BUT take it easy.

 

Or you could clamp it down onto the M/C table and side cut the metal off, you can do both end at the same time this way. But you will have to make sure that you get both sides in register.

 

For milling the sides not a big problem clamp it down to the M/C table and have the cutter running towards any open edges, you should be able to do it in two or three full depth passes starting at the open end ( bottom of you photos).

 

HTH

 

OzzyO.  

 

Having had a better look at the photos you only have got only one real option for milling the step opening and that is to clamp the casting to the M/C table.

 

Thanks OzzyO,

 

I will clamp the diecast section to the table. Should not be too hard to ensure that it is square. to the slide. 

 

On the topic of collet / collet chucks - would anyone recommend the aftermarket brands that pop up Ebay, or should I keep my eyes out for a genuine set or ER16 collets? 

 

James

 

 

 

[Rob Pulham]

Although I bought my collet Chuck from Arc Euro to suit my lathe (SiegSC3), I had bought my collets (ER25) previously via eBay for the previous lathe and haven't had any issues with them. Although I let the collet chuck for the Unimat go, when I sold it. I kept the collets as I also use them on my mill.

 

Pretty much all such things are produced in China or India these days anyway, no matter who you ultimately buy them from.

[Down_Under]

On 31/05/2022 at 17:03, Rob Pulham said:

Although I bought my collet Chuck from Arc Euro to suit my lathe (SiegSC3), I had bought my collets (ER25) previously via eBay for the previous lathe and haven't had any issues with them. Although I let the collet chuck for the Unimat go, when I sold it. I kept the collets as I also use them on my mill.

 

Pretty much all such things are produced in China or India these days anyway, no matter who you ultimately buy them from.

Managed to pick up a genuine set with little use (some even came in packaging). 

 

Its hard picking stuff from overseas site unseen without any advise or experience, so advise much appreciated 

[Down_Under]

A questions for the brains trust. 

 

I am wanting to turn up (down?) some 2mm Avonside jig axles at the tip to 1mm tips for getting the correct axle spacing. 

 

However due to the length (nearly 40mm) of the stock 2mm jig axles the run out on the ends is quite alot (+/-0.5mm to 1mm) and I could not manage to accurately machine the 1mm tip. 

 

 

I cut one down to 15mm and tried to turn a 1mm tip again, however the tip is still slightly off - center (potentially I was too aggressive with the top slide?)

 

 

I had better success when starting from scratch (probably should have started with this as a test 😝) with a blank piece of 1/8 brass rod, turning a 1mm end and then reducing the 1/8 to 2mm. Run out basically 0 and all in all an much better product. 

 

So, would I be correct to surmise (and possibly answering my own question) that it is better place to start would be to use 1/8th jig axles as the 'stock' and turn these down to 2mm rather than try and turn a 1mm tip onto a 2mm axle? 

 

 

 

Secondly, should I be using the headstock when attempting to turn long relatively thin pieces? 

 

Ultimately, when my skills / knowledge progress I should be able to turn up a complete jig axle from scratch. But got to start somewhere.  

 

Thanks in advance,

 

J

[AndyID]

4 hours ago, Down_Under said:

A questions for the brains trust. 

 

I am wanting to turn up (down?) some 2mm Avonside jig axles at the tip to 1mm tips for getting the correct axle spacing. 

 

However due to the length (nearly 40mm) of the stock 2mm jig axles the run out on the ends is quite alot (+/-0.5mm to 1mm) and I could not manage to accurately machine the 1mm tip. 

 

 

I cut one down to 15mm and tried to turn a 1mm tip again, however the tip is still slightly off - center (potentially I was too aggressive with the top slide?)

 

 

I had better success when starting from scratch (probably should have started with this as a test 😝) with a blank piece of 1/8 brass rod, turning a 1mm end and then reducing the 1/8 to 2mm. Run out basically 0 and all in all an much better product. 

 

So, would I be correct to surmise (and possibly answering my own question) that it is better place to start would be to use 1/8th jig axles as the 'stock' and turn these down to 2mm rather than try and turn a 1mm tip onto a 2mm axle? 

 

 

 

Secondly, should I be using the headstock when attempting to turn long relatively thin pieces? 

 

Ultimately, when my skills / knowledge progress I should be able to turn up a complete jig axle from scratch. But got to start somewhere.  

 

Thanks in advance,

 

J

 

Can you post a dimensioned sketch of what the finished part should be?

[Vecchio]

In any case you need to use a fixed or travelling steady, otherwise the axle will never run true. Or even if it runs true, it will bend and/or vibrate while you machine it. 

Another possibility would be to hold it on a centre in the tailstock. As your pin is only 1mm it makes sense to manufacture an adaptor for the tailstock (having a 1mm bore to take the pin).

 

Not an easy project, as far as I know not many people own a steady for an Emco Unimat 3. And if yes there is probably not enough room available to use it.

 

Looking forward to your (hopefully success) story.

 

 

[2mm Dabbler]

Firstly, a three jaw chuck cannot be relied upon to hold items dead true, there will always be some run out and this will likely change according to the diameter of the material held. Use of a three jaw is normally for when all of the diameter is being machined or where concentricity of the maximum diameter is unimportant. Where something like these jig axles need to be held accurately you would either use collets or a four jaw chuck with the associated 'dialing in'.

 

However, for items such as these jig axles one can make a temporary or single use collet from scraps of round bar.  It's an old trick and there's a useful video here:

https://www.youtube.com/watch?v=Lj6HxUFUxdg

 

 

I would vary the collet slightly to be more of a top hat shape, the 'brim' resting outside the jaws and the inserted portion being the full depth of the jaws. Made with a little care this can be reused in the future to accurately hold any axle or shaft of the same diameter.

 

I'd also recommend the minimum length of the axle or shaft is projecting from the chuck or collet, this reduces flex and helps with  accuracy. If needs be you can drill a larger hole from the rear of the collet to allow for any collars or larger diameters required, inserting the jig axle from the rear of the collet.

 

Regards

 

Michael

 

 

[polybear]

An alternative may be to centre-drill the end of some 1/8th or 2mm rod (using a very small size 0 centre drill) and then drill 1mm & insert a piece of 1mm silver steel (or maybe the shank of a 1mm drill bit).

[2mm Dabbler]

1 hour ago, polybear said:

An alternative may be to centre-drill the end of some 1/8th or 2mm rod (using a very small size 0 centre drill) and then drill 1mm & insert a piece of 1mm silver steel (or maybe the shank of a 1mm drill bit).

True, but if the rod is held in a three jaw chuck then the insert will be eccentric to some extent which puts James back where he started.

[polybear]

7 minutes ago, 2mm Dabbler said:

True, but if the rod is held in a three jaw chuck then the insert will be eccentric to some extent which puts James back where he started.

 

Yes, but likely no worse (and possibly a lot better) than trying to turn a 1mm spigot without distortion; a steel 1mm spigot would be a lot stronger too.  The other option (if James has one) would be to hold the stock in a 4-jaw chuck and centre it using a DTI.