Author Topic: A slightly belated Hello  (Read 562 times)

Offline andycarlson

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A slightly belated Hello
« on: September 01, 2019, 09:38:24 PM »
Hello all,

I joined a little while back but never quite got around to writing this post. I can't say that I've ever made a model engine of the sort that most of you would recognise. I've made a few 2mm scale locomotives but that's not quite the same thing. The real reason I joined was because of the postings I've seen here about Cowells lathes.

I've had a Cowells lathe for just over a year now. I think mine was made around 1978 and is in the old light blue hammered finish. I picked it up on eBay and have stripped it down, cleaned it and replaced some missing bits so that I could reassemble the power feed from the bits that came with it. I also improved the insulation and earthing of the electrics and added an NVR switch. Finally I picked up one of the old style Cowells hinged covers from a gent in the Netherlands. Err... finally?... no, I've bought more bits since then.

I've recently become the owner of a pre war Faircut lathe bought from an ad on lathes.co.uk so that's taking my time at the moment. Most of my photos seem to have been taken with some bits removed, but I've attached one from a couple of weeks back when it had all of its bits. It's now more fully instaleld on the workbench but work is ongoing on the circa 90 year old US made Century 1/4 HP motor that came with it.

I also have a circa 1961 Unimat DB/SL and picked up a watchmaker's lathe on the same day I bought the Faircut (I saved on the mileage by buying two lathes on one trip). I understand there may be support groups available for compulsive lathe buyers?

I only have one milling machine - a Proxxon MF70.

Offline b.lindsey

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Re: A slightly belated Hello
« Reply #1 on: September 01, 2019, 11:00:20 PM »
Hi and welcome Andy from another lathe junkie ( 4 at the moment and another being added soon but of a  larger size than the sherline, unimat and cowells).

So what sorts of projects are you interested in doing on your machines?

Bill

Offline andycarlson

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Re: A slightly belated Hello
« Reply #2 on: September 01, 2019, 11:34:18 PM »
Hi Bill,

Long story... the initial reason for buying the Unimat was to use it for 2mm scale work. For that I needed to fit a collet holder. I thought that Arc Euro did a collet holder backplate for the M12 x 1 thread but after buying the lathe I found I was wrong. I tried to figure out how to make a backplate myself on the Unimat but I think it was too much of an ask. Then the Cowells came up on eBay. It was pretty neglected and the bid price was low because it also seemed to be missing the tailstock. On the plus side the photos showed it had both 3 and 4 jaw chucks and a milling slide. I really wanted a Cowells so I thought I'd have a try. An hour before the end of the auction the seller messaged me to say he'd found the tailstock so I upped my bid and bought it. After 3 weeks getting the Cowells into shape I made the backplate for an ER16 collet holder to go on the Unimat.

So now I can upcycle N gauge wheels to 2mm finescale on the Unimat. I've used both the Unimat and the Cowells plenty since then but to be honest I've spent much more time making tooling than I have making stuff for 2mm scale models. My latest finished project is a graver honing guide because I've been dabbling with  some graver work and a friend who bought a cheap honing guide was not too impressed with it.

The MF70 has done a number of jobs, the most complex being making a set of frames for a 2mm scale model of a Weatherill L61 Wheeled Loader. I want to CNC the MF70 to make profiling loco frames etc less taxing which means more bits to make on the other machines.

So why buy a Faircut? Probably mainly because although I love using the Cowells and it can do a huge variety of work I do get a bit frustrated at the number of light cuts needed and the time taken. I doubt I will need the swing or between centres capacity of the Faircut very often but it's a lovely lathe and right now I'm just enjoying bringing it back into use after it has spent a long time out of use in the care of its previous owner.

Offline b.lindsey

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Re: A slightly belated Hello
« Reply #3 on: September 02, 2019, 12:39:29 AM »
They both look good Andy. So this 2mm scale is smaller than N scale. That gets pretty small  :o

Bill

Online Kim

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Re: A slightly belated Hello
« Reply #4 on: September 02, 2019, 06:15:56 AM »
Hi Andy,
Welcome to the forum.
I'd be interested to see some pictures of some of the 2mm models you've made!
Kim

Offline Roger B

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Re: A slightly belated Hello
« Reply #5 on: September 02, 2019, 07:12:41 AM »
Welcome to the Forum  :ThumbsUp:  :ThumbsUp: I also have an MF70 that I am thinking about converting to CNC.
Best regards

Roger

Offline andycarlson

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Re: A slightly belated Hello
« Reply #6 on: September 02, 2019, 08:11:31 AM »
They both look good Andy. So this 2mm scale is smaller than N scale. That gets pretty small  :o

It depends where you live really :) . 2mm scale (2FS) is 1:152 which is smaller than British 'N' at 1:148 but bigger than European and American 'N' which is 1:160. The Europeans also have FS160 and those folks have good ties with the UK 2mm folks.

In practice most of us are quite happy to run re-wheeled 'N' scale models when the donor model is of good quality and just build those items that can't be bought.

To be clear though, you dont need machine tools to do 2FS modelling - I've been working in 2mm Finescale since the 1980s and have only had machine tools for the past 3 years or so.

A couple of photos of the model with the most machining content so far - the Weatherill Loader (or in my case, shunting tractor). The frames were profile milled on the Proxxon. Much of the superstructure is fretted out by hand from 5 thou sheet after sticking a CAD printout onto it. The MF70 was also used to drill the holes and cut the main straight lines for the bucket arms... if it was up and running with CNC then I'd have been able to fully profile the arms too. The tractor is driven by rare earth magnets using a contraption below ground using stepper motors controlled by an Arduino.

Offline b.lindsey

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Re: A slightly belated Hello
« Reply #7 on: September 02, 2019, 01:42:31 PM »
Thanks for the info on the 2mm FS. Have you thought of adding a collet holder to the Cowells? I assume the one they offer would still fit you machine.

Bill
« Last Edit: September 02, 2019, 01:47:56 PM by b.lindsey »

Offline gerritv

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Re: A slightly belated Hello
« Reply #8 on: September 02, 2019, 03:56:40 PM »
For those wanting to CNC their MF70's there is a full set of parts available to print on Thingiverse.

I have printed all the parts for X and Y to CNC my KT70 which is very similar (the lower plates needed a slight modification due to leadscrew being in the centre, not offset.)
I just need to make some bushings/collars today and will then be able to connect to my GrblPanel/Grbl box for some testing.

gerrit
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Online Kim

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Re: A slightly belated Hello
« Reply #9 on: September 02, 2019, 04:53:13 PM »
That's a very nice little tractor, Andy! Thanks for the pic!
Kim

Offline andycarlson

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Re: A slightly belated Hello
« Reply #10 on: September 02, 2019, 05:06:54 PM »
Thanks for the info on the 2mm FS. Have you thought of adding a collet holder to the Cowells? I assume the one they offer would still fit you machine.
Thanks Bill.

My lathe has the old M14 x 1.5mm spindle nose thread so new chucks and so on won't fit but that doesn't matter because I have an older Cowells collet holder to fit the lathe. I've never used it because I have only a small number of Cowells collets.

Rather than spending on more Cowells collets I plan to fit an ER16 holder to the Cowells so that I can reuse the collet set that I've already bought for the Unimat. I also took a punt a few days back and ordered one of the cheapie Chinese ER16 MT1 holders to try on the Faircut. It may or may not turn out to be junk when it eventually arrives but it cost very little so I'm willing to take a chance.

Offline andycarlson

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Re: A slightly belated Hello
« Reply #11 on: September 02, 2019, 05:17:36 PM »
For those wanting to CNC their MF70's there is a full set of parts available to print on Thingiverse.

I have printed all the parts for X and Y to CNC my KT70 which is very similar (the lower plates needed a slight modification due to leadscrew being in the centre, not offset.)
I just need to make some bushings/collars today and will then be able to connect to my GrblPanel/Grbl box for some testing.

Thanks. My conversion has been a long time in the planning stage. I've looked at various items on Thingiverse and also at conversion kits made in Europe and the far east but none do quite what I want. When not in use my MF70 slots into a 500mm deep Ikea shelf in between the Cowells and the Unimat - they fit in there very nicely almost like I planned it that way :Lol: All of the conversions that I've seen would add some overhanging steppers and brackets to the footprint so it would no longer fit into the shelf. My plan is to do something similar but make it 'easy on and offable' so that the overhanging parts are only overhanging when I am using CNC. Hopefully that will also mean that I can use the MF70 manually when the job doesn't justify setting up for CNC. We will see how it goes once the conversion gets off the drawing board. I do have some metal for the job now, but I kinda distracted myself by buying more lathes  :ShakeHead:

Offline gerritv

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Re: A slightly belated Hello
« Reply #12 on: September 02, 2019, 06:51:03 PM »
You could drive the steppers using belts/pulleys. The rest of the brackets would still be of use, only replace the ones mounting steppers in present design? The new mounting plate could be made easily removable.
I have seen some coupling designs that use the original handwheels with pulleys instead of the dials. There was/is a Unimat SL kit that uses that method.

Gerrit
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Offline andycarlson

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Re: A slightly belated Hello
« Reply #13 on: September 02, 2019, 07:13:45 PM »
You could drive the steppers using belts/pulleys. The rest of the brackets would still be of use, only replace the ones mounting steppers in present design? The new mounting plate could be made easily removable.
I have seen some coupling designs that use the original handwheels with pulleys instead of the dials. There was/is a Unimat SL kit that uses that method.

I can see that would work for the Y axis but the X axis drive basically hangs off the end of the table. I dont have any better ideas for that than the ones I've seen - just try to minimise weight and overhang really.

Offline Roger B

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Re: A slightly belated Hello
« Reply #14 on: September 02, 2019, 07:53:35 PM »
I have been looking at this kit but am still not sure about which software to start with:

https://gocnc.de/shop/en/store/cnc-router/385/proxxon-mf-70-cnc-custom-kit?number=Go10126.1

Mike (Vixen) gave me some useful advice and support but I still haven't made the plunge  ::)

Best regards

Roger