Lathes & M/C tools

[ozzyo]

Hello all, backofanenvelope,

 

one think that I would recommend is a quick change tool post with about four tool holders, Axminster tools do a few different ones starting at about £80.

 

Talking about lathes, when I was doing some turning a few weeks back I noticed that I was getting a lot of chatter on the job. So I got the D.T.I. out and did some checks. At about 5" out from the headstock I was getting about 0.006" play getting worse the more I moved along. This to me was a sign that the headstock bearings were in need of some T.L.C.. A phone call to Axminster about a workshop manual for the lathe (BV20M) did not help, but the fellow did know the bearings. Two part tapered roller bearing at the front and a cadged ball at the rear.

 

Looking at the tail of the headstock spindle I could see a thin nut that was held in place with a locking washer. Simple I thought, undo the locking washer and nip up the nut, job done. Not quite that simple! I couldn't move it by hand, so it was out with the rubber mallet so a few taps with it and bingo no play showing on the D.T.I. but the spindle was so tight I could hardly move it, it was a start. So a few taps to un-tighten it (only hit my thumb once) and I had a free running spindle and only about 0.001" play at about 5" out from the headstock.

 

All of this was done with the lathe cold so then ran it for about 15 mins. at different speeds and did some more checks. All now appears to be OK, but I'll find out better when I do some more turning. One thing that I did notice was the motor running warm but it may have done this before without me noticing it. Time will tell.

 

OzzyO.     

[halfwit]

Not books on lathework, but 'The 4mm Engine', and 'Model Locomotive Construction' both by Guy Williams cover turning boiler fittings, as does 'A Guide to Locomotive Building' by Mike Sharman. Both authers have differing ideas on approaching the job, which is no bad thing.

 

'The Amateur's Lathe' (L.H. Sparey) looks like a good starter on lathework, I have a copy but have yet to sit down and read it. David Fenner's 'The Mini-Lathe' is worthwhile if you either own or are thinking of owning a C3.

 

Most lathework books are aimed at model engineers rather than railway modellers. There is I feel a gap in the market.

[ozzyo]

Most lathework books are aimed at model engineers rather than railway modellers. There is I feel a gap in the market.

 

Hello halfwit, all,

 

I'm not sure why you would say that. I was taught to work with drawings that were 1;1, or down to1/4 scale when I was working at 12"; 1' scale. 

 

You can scale some of the drawings down to what we want 72;1 or 43.5;1 but something's don't scale down like a running fit of 0.00005"  on the real thing do work on a model.

 

So we have to compromise, that 0.00005" will still be 0.00005" in the the model, just for a running fit. You can not have a shaft of 0.125" running in a bearing of 0.125". Some will say you can, wrong.

 

Most of the reamers that you can buy are H7 that is that they cut under size so that they will cut to 0.1245"  That will give you a tight fit, If you want a good running fit for a 1/8 axle try and get an 3.2mm reamer.

For a running fit on an 3/16" axle use 4.8mm.

 

OzzYO     

[buffalo]

...Most lathework books are aimed at model engineers rather than railway modellers. There is I feel a gap in the market.

 

I'm not sure why you would say that. I was taught to work with drawings that were 1;1, or down to1/4 scale when I was working at 12"; 1' scale...

 

I read Paul's comment differently, rather than anything to do with scale, I thought in terms of materials. For example, you don't get to machine much in the way of cast iron when working in the smaller scales, and fewer of our parts are working parts, more just fiddly little bits of brass. As one without a professional machine shop background, just some short but useful introductions many years ago, I've certainly found the Williams and Sharman wrtings on making some of those fiddly bits very useful, but I'm not convinced there's a full book there.

 

Nick

[halfwit]

In hindsight I think that you're right Nick, a book would be too much. And as fewer modellers seem to be interested in making stuff these days it is doubtfull if one would sell anyway! But I have found it frustrating trying to track down info on turning boiler fittings in the smaller scales.

 

I spent 19 years working as a turner, on machines of various sizes (Colchester M300 to Binns & Berry long bed TB707) and there is a big difference between turning, for example, cast steel pump impellers and aluminium rollers to close tolerences on industrial machines and brass chimneys for OO9 locos on a little Unimat that sits on the dining table!

[Jon Fitness]

Ayup. Bit of a long shot is this but here goes.

I have been given/loaned a 1950's Unimat SL lathe as it was not working. The motor runs but slows after a minute and trips the circuit breaker for the mains. I've had someone look at the motor which apparently is electrically ok but the bearings are suspect. There appear to be several types of motor, the most common seems to be the KUS99 that has ball race type bearings. The one I have is a U70 (70watt) which has plain bearings which seem to have a bit of play. I have oiled these sparingly but the motor is quite noisy. It will run ok off the lathe but I'm wary of relying on it on the lathe now. Motors for these lathes seem hard to get and very expensive so does anyone know if the motor can be upgraded to ball bearing races or even if I can get some original spec replacement bearings?

Cheers

Jon F.

[John_Miles]

I bought some Glanze tools a couple of years ago - not cheap but they are really good and better than steel. I use a round nosed one for general shaping (really good for doing much of the work on chimneys and domes), a pointy one (as you can see I am no expert) and a patring off tool.

[decauville1126]

Ayup. Bit of a long shot is this but here goes.

I have been given/loaned a 1950's Unimat SL lathe as it was not working. The motor runs but slows after a minute and trips the circuit breaker for the mains. I've had someone look at the motor which apparently is electrically ok but the bearings are suspect. There appear to be several types of motor, the most common seems to be the KUS99 that has ball race type bearings. The one I have is a U70 (70watt) which has plain bearings which seem to have a bit of play. I have oiled these sparingly but the motor is quite noisy. It will run ok off the lathe but I'm wary of relying on it on the lathe now. Motors for these lathes seem hard to get and very expensive so does anyone know if the motor can be upgraded to ball bearing races or even if I can get some original spec replacement bearings?

Cheers

Jon F.

There's a Yahoo group for Unimats (and a separate one for Unimats 3 & 4) which might be worth a whirl:

https://groups.yahoo.com/neo/groups/UNIMAT/info

[Pebbles]

Check the yahoo group, if it's the one I believe it to be, it shows how a 24 volt motor off a motor buggy can be adapted. You will of course need an appropriate 24 volt Dc supply at something like 5 to 7 amps depending on the motor rating. One final point is that there are turning required for the adaption.

[Jon Fitness]

Thanks both, I'll take a look and see what that brings. Secretly of course, I'm hoping an occasional drop of oil will help it to carry on without expensive repairs or mods!! I know ball bearing races are available for the kus99 so I'm hoping I can find a source of plain (Oilite?) bushes for this one.

JF

[45609]

Jon,

 

Are you aware of this page?

 

http://unimat.homestead.com/motortips.html

 

This was my first strating point when recently repairing a Unimat 3 motor.  I didn't need to replace the bearings but it gave some useful tips on what to expect when stripping the motor down.

 

I'm not that familiar with the SL motor that you mention but given a careful strip down it might be possible to assess the condition and size of the Oilite bearings to see if replacements can but found.  A quick web search found plenty of hits for Oilite bearings in a variety of sizes.  Here are a couple of examples....

 

http://www.bowman.co.uk/products/oilite_flanged

 

http://www.bearingboys.co.uk/Oilite__Bearing_Bushes_-1011-c

 

Cheers....Morgan

Edited August 6, 2014 by mlgilbert30

[Jon Fitness]

Jon,

 

Are you aware of this page?

 

http://unimat.homestead.com/motortips.html

 

This was my first strating point when recently reparing a Unimat 3 motor.  I didn't need the replace to bearings but it gave some useful tips on what to expect when stripping the motor down.

 

I'm not that familiar with the SL motor that you mention but given a careful strip down it might be possible to assess the condition and size of the Oilite bearings to see if replacements can but found.  A quick web search found plenty of hits for Oilite bearings in a variety of sizes.  Here are a couple of examples....

 

http://www.bowman.co.uk/products/oilite_flanged

 

http://www.bearingboys.co.uk/Oilite__Bearing_Bushes_-1011-c

 

Cheers....Morgan

Hi Morgan

Many thanks for that!

I've seen the "motortips" one but the Oilite pages look very useful. I think the bearings are of the spherical type as they appear to be retained with a spring/cage within a carrier and can move about to help "self-align". I'll contact them to see if they have one specified for the job otherwise it's out with the digital verniers for some measurements.

Cheers

JF

[buffalo]

A mystery part question. On the top slide of my Sieg C3 (Warco model) there is a D shaped blackened steel object. It is 20mm high and about 33mm diameter and attached to the slide by two recessed screws.

 

 

It has a 10mm hole drilled right through and on the top face there are three slots about 2.5-3.0mm wide and of similar depth. The appearance is rather like a cartoon hand making an improper gesture. Not seen in the photo is a grup screw in the centre of the curved face opposite the flat, presumably to retain a 10mm shaft in the large hole.

 

It doesn't appear on most photos of other C3s, it's shown in the parts diagram but the entry in the parts list is blank. Any ideas?

 

Nick

[Guest Isambarduk]

Sorry I can't really help, Nick, but it would seem to me that the post retains some sort of tool (holder) in the 10mm hole that may be indexed into one of three positions.  David

[TheWeatheringMan]

Hello all, backofanenvelope,

 

one think that I would recommend is a quick change tool post with about four tool holders, Axminster tools do a few different ones starting at about £80.

 

Talking about lathes, when I was doing some turning a few weeks back I noticed that I was getting a lot of chatter on the job. So I got the D.T.I. out and did some checks. At about 5" out from the headstock I was getting about 0.006" play getting worse the more I moved along. This to me was a sign that the headstock bearings were in need of some T.L.C.. A phone call to Axminster about a workshop manual for the lathe (BV20M) did not help, but the fellow did know the bearings. Two part tapered roller bearing at the front and a cadged ball at the rear.

 

Looking at the tail of the headstock spindle I could see a thin nut that was held in place with a locking washer. Simple I thought, undo the locking washer and nip up the nut, job done. Not quite that simple! I couldn't move it by hand, so it was out with the rubber mallet so a few taps with it and bingo no play showing on the D.T.I. but the spindle was so tight I could hardly move it, it was a start. So a few taps to un-tighten it (only hit my thumb once) and I had a free running spindle and only about 0.001" play at about 5" out from the headstock.

 

All of this was done with the lathe cold so then ran it for about 15 mins. at different speeds and did some more checks. All now appears to be OK, but I'll find out better when I do some more turning. One thing that I did notice was the motor running warm but it may have done this before without me noticing it. Time will tell.

 

OzzyO.

Hi OzzyO,

 

Just a quick offer if its any help to you.

I too have an Axminster BV20M lathe (in my book a superb machine) and have both printed and downloaded manuals for the lathe.

If a copy would be useful to you let me know and i'll be pleased to arrange to get a copy to you.

Regards

[PatB]

I'm not sure about a tool holder but it could be a mount for a dial indicator I suppose.

[M Wright]

Hi, I just thought I would add my two pennies worth.  Lathes, I add these comments as a professional model engineer who builds  about 20 live steam engines a year.  I have in the workshop : A Myford super 7, fully tooled, A Seig C4, A Britan repitition lathe, A Pultra instrument lathe and last and still to be wired up an EMCOmat 17S.  The scales I work in are 7mm/foot, 16mm/foot, 1/3 scale.  Which lathe is essential to making money and a joy to use? My 1956 Myford super 7 rescued from a skip, rebuilt and recently (20070 fully reground and rebuilt by Myford before they hit the dust. It is a joy to use because it has a progressive clutch and it is fully tooled to do the work I need it to do.  When buying any lathe remember the lathe is small change compared to the cost of the tooling over the years.  With a good or new  Myford now being so saught after apart from chucks the only way to afford tooling it is e-bay or similar.  Is a Myford accurate and sturdy? Mine is not toolroom accurate , there is a run out of 0.0002inches on the spindle. Sturdy? NO, when parting off most Myford users use a back toolpost to get over the weak design of the saddle.

The Sieg C4 is a modern lathe design, I purchased it to keep going while my Myford was at Myford's. It is Chinese and well made. It is (my C4 lathe) very accurate, the run out is just detectable on my clock gauge, about 0.00008 inches i.e. a tremble of the needle between 0 and 1 of this ten thousanth Starett Clock. This is probably luck since this is unusually good in this class of lathe.  It is rugged, in an hour it produced 3Kg of swarf when machining a large chuck backplate from a 6 kilo lump of steel. (don't ask why) It is modern having a powerful DC drive with a delightful to use touch pad control panel.  The extra I puchased for it were digital gauges (Sieg accessory about £100) on the handwheels. They were hard to fit but it has made for a lathe that produces interchangable parts without the need for clock gauges mounted on magnetic stands (how the Myford does it) So today I would recommend a seig C4  with a stand, 3 jaw and 4 jaw self SC chucks, and good quality - Jabob's or Rhoem 3/8" tailstock chuck, Sieg quick change toolpost and holders (cheap quite well made), A set of Glanze insert cutting tools, and a 1/16" blade parting tool, plus a cheap bench grinder and some unground 1/4 square HSS tool bits as a good place to start. Cost about £1700(.Axminster sell C4s)  A similar new Myford set up - £12000, a lucky purchase off e-bay of similar set up Myford - £2500-£3000, but if you don't know what to look for buying an old Myford can be a sorry tale.

Your C3 can be purchased from Arc Euro and I think Warco, Get the latest version with the DC drive, It is a sensible choice and well supported by Arc Euro and a world wide user group (mini-lathe).You might out grow it as you get familiar with its use.  You won't unless you join me in 1/3 scale locomotives out grow a Seig C4 (or C6).Remember even the largest lathe can machine tiny parts but not vice versa. Size of lathe. larger equal mor ridigid equal geater accuracy.  Don't buy second hand unless you know what to look for (www. lathes.co. uk) is a useful to read archive of machine tools before purchase eg re-painted or owner altered lathes are always a worry. Regards.

[buffalo]

Sorry I can't really help, Nick, but it would seem to me that the post retains some sort of tool (holder) in the 10mm hole that may be indexed into one of three positions.  David

 

I was thinking along similar lines, David, but the hole centre is 100mm from the left hand end of the slide so, even with the normal toolpost removed, it wouldn't get very close to the chuck unless the cross slide was wound out to its limit.

 

I'm not sure about a tool holder but it could be a mount for a dial indicator I suppose.

 

Maybe, Pat, but 10mm seems a little on the large size for most dial indicator supports, and why the indexing slots? There's plenty of room on the machine for magnetic bases.

 

At least I now know that I'm not alone in wondering what it is

 

Nick

[Guest Isambarduk]

"I was thinking along similar lines, David, but the hole centre is 100mm from the left hand end of the slide so ..."

 

Yes, I had noticed that (sorry, I failed to comment!) but I was thinking that perhaps it was a toolpost for using behind a fixed steady - or perhaps it is for a travelling steady of some sort.  But, to be honest, I really don't know!  Do let us know if you find out.

 

I do 95% of my 7mm and clock repair work using my two Unimats (one set up as a lathe and one as a miller) but I also have a Myford ML7 that I inherited from my father; although I know what most of the attachments, jigs and fixtures that he made are for, there are a few that have defeated me (so far).

 

David

[ozzyo]

Hi OzzyO,

 

Just a quick offer if its any help to you.

I too have an Axminster BV20M lathe (in my book a superb machine) and have both printed and downloaded manuals for the lathe.

If a copy would be useful to you let me know and i'll be pleased to arrange to get a copy to you.

Regards

 

If you could do me a copy onto a CD that would be brilliant.

 

Thanks

OzzyO.

[Pebbles]

Having been to the Model Engineering Exhibition I can confirm that the mysterious item is for a protective screen holder. There is an associated  vertical shaft which locates into the holder and has two screws to hold a transparent shield. It appears that as the shields have all broken, and possibly no longer available, the item is largely redundant!

[buffalo]

Thanks Pebbles. I've just been out to the garage to have a look and that does seem to be the answer. In fact, the lathe came with two plastic screens and I'd assumed the second one was an alternative chuck screen with a fitting for a different type of hinged cutout switch so I'd never taken it out of its sealed bag. The pastic is already cracked around one of the mounting holes. The three indexing slots set the screen in some strange positions so it's difficult to imagine just what it is meant to screen from what. I'll take some photos later but it's too cold at the moment. Largely redundant seems to sum it up.

 

Nick

Edited January 17, 2015 by buffalo

[PatB]

Thanks Pebbles. I've just been out to the garage to have a look and that does seem to be the answer. In fact, the lathe came with two plastic screens and I'd assumed the second one was an alternative chuck screen with a fitting for a different type of hinged cutout switch so I'd never taken it out of its sealed bag. The pastic is already cracked around one of the mounting holes. The three indexing slots set the screen in some strange positions so it's difficult to imagine just what it is meant to screen from what. I'll take some photos later but it's too cold at the moment. Largely redundant seems to sum it up.

 

Nick

 

Might be useful if you ever rig a coolant system, either to mount the nozzle itself or to mount a screen to stop the goop from spraying everywhere.

[buffalo]

Herewith the promised photos of the guard as supplied in the three possible positions dictated by the pin and slot:

 

 

Even if it had been assembled the other way round, it's difficult to see most of the possible positions beinof much use. I think I can live without it

 

Nick

 

[ian@stenochs]

Hi,

 

I have been catching up on this thread and thought that the attached photo might be of some interest.  

 

I am making the parts for the inside motion on my latest build and the pictures how the blanks being parted off on my Myford.  The stock is mild steel filled to shape and drilled for axle and crank pin on the lathe while held in the 4 jaw chuck. Enough of the bar is shaped to allow 8 crank cheeks to be parted off, 2 locos worth.  The parting tool is held upside down in a home made rear tool post.  The lathe is run in normal direction at 300rpm with the saddle locked and cross slide fed slowly by hand. I use a little splash of Rocol cutting fluid as lubricant.

 

Also visible in the picture is my S7 wheel profiling tool which is mounted on the same toolpost.  It just requires the toolpost to be turned 180 degrees and the tool is ready for use.  For anyone who wants to copy. The toolpost is made from a piece of 40mm square bar.  Faced off while held in the 4 jaw and drilled at the same time.  The post was then mounted on the cross slide and the slot put in with an end mill held in the 3 jaw chuck.  The fixing for the form tool is an 8mm bolt.  The whole for which was drilled with the tapping drill in the chuck.  This ensures centre height. The thread was started with the tap in the chuck and the chuck turned by hand, it was finished with a plug tap by hand off the lathe.

 

I hope this is useful.

 

Happy modelling,

 

Ian.