Member postings for Andy Carlson

Interesting, thanks.

The eBay photo doesn't show the underside - would it have its own dovetail to mount to the bed or bolt on top of the cross slide? - I guess the former?

I wonder if it really belongs to the Faircut - I've never come across any production oriented gizmos on these lathes before.The most 'industrial' thing I've seen is the Trainer Lathe which has the belts all enclosed somewhat in the ML7 style.

I hope that posting a link to someone else's eBay item is not breaking any rules here. I have no connection with the sale...

https://www.ebay.co.uk/itm/313515899326

There is a long saddle type thing in photos 5 and 6 with what look like gib screws along one side and two tee slots for toolposts. Has anyone seen anything like this before?

I've never seen anything similar on any Faircut I've seen online in the past couple of years.

Nice work Roger.

FWIW I've also cut a 1mm screwdriver slot in a broken high tensile bolt using the MF70. TBH I wasnt expecting this to succeed but I really needed to get the broken part out. Anyway... it worked and I got the bolt out.

I have. It works.

If expect to be chewing away metal at a rate of knots then you will be disappointed. My jobs on steel have been mainly making pretty small fixings for the (similarly diminutive) Cowells lathe or making fine adjusting cuts to refine the fit of work done on bigger machines. Size-wise they vary but they are all small - think around 1/2 inch or less on each side.

I've mainly used the Proxxon cutters and they got the job done on steel with an excellent surface finish but more experienced contributors here have said that these cutters have a geometry better suited to non ferrous. More recently have bought an Arc Euro stub sized cutter which ought to be better suited to steel. I have only used this on brass so far so I can't report back on its performance on steel.

My most recent job was drilling a couple of 1/8 inch holes through some 5/8 aluminium. I'd had previous experience of the nasty noise that 3mm or 1/8 drills make when used at 5000 RPM in the MF70. I had thought that the noise was coming from the (usually pretty thin) workpiece but even with a 5/8 block I got the same awful screech. I switched to a stub length drill (maybe 2.8mm) for the first few mm of the hole and this ran tolerably quietly. I then went back to the 1/8 (standard length) drill and made sure that I stuffed it into the pre drilled hole as quickly as possible. Once it was a few mm deep the screeching didn't happen. My theory then is that the screeching happens because of resonance in the drill itself and my experience is that any standard length drill much over 2.5mm will protest in this way when used at 5000 RPM.

I have a 6mm Lorch. I think there are lots of variations, some arising from a lengthy production history and others from the sheer multitude of accessories that could be had for them. I'm curious to know when mine was made but have never found any reliable way to date them.

I thought it might be useful to write up my most recent job because it involved a lot of thinking and several different clamping arrangements. It is a 130mm long piece of dovetail bar to improve the attachment of my little 80mm telescope to my camera tripod. The dovetails are a 15 degree angle. Most of it was done on my 1930s Faircut lathe using my Tom Senior vertical slide. It would have been MUCH easier just to buy a short length of dovetail bar but in a fit of misguided enthusiasm last year I bought some 5/8 by 1 3/4 aluminium to make my own and then spent months agonizing over how to actually do the job.

Sorry no 'in progress' pictures because I didn't take any.

The first problem was the 15 degree angle. I have no tilting table and have never found one that I thought would be capable of useful work without also using up all of the available working space. Instead I decided to make two angle block fixtures that could attach using M6 Allen screws to the slots on the vertical slide.

They are made from the same bar stock. First I sawed a length off and then made a diagonal cut to achieve roughtly the right shape. A hacksaw is often much quicker than chewing metal off with a milling cutter.

Next the sawn ends needed to be tidied up. I did this on the vertical slide with the job overhanging the nearest edge and using the side of the cutter. I can't 100% remember but I think I used a steel strap over the job with a stud either side to engage with the 'T' nuts.

Next step was to drill the two 1/8 holes using XY coordinates to achieve an accurate 15 degrees. I could have done this on the vertical side but it has no dial so I used my little MF70 milling machine. The work was held down using step blocks and clamps... actually just one IIRC because there wasn't much room but I was only drilling so that was OK.

Then I milled the 15 degree faces. I attached a small vice (RDG Tools, no doubt from somewhere east of Suez) to the vertical slide, put 1/8 bar through the drilled holes so that the rods sat on the top of the vice jaws and clamped and milled both blocks together using the end of the 10mm cutter. Then remove them, mark and centre pop the middle of the 15 degree faces and return to the vice (still with the 1/8 bars), drill and tap M6. The final job was to mark out, drill and counterbore for the Allen screws (without the 15 degree tilt and overhanging the side of the vice to provide room for the drill to break through)

For the actual dovetails the first job was to mark and drill some M6 clearance holes - 1 3/4 will JUST fit in my vice on the slide. Then the angle blocks were attached to the slide, M6 studding screwed into the blocks and the embryo dovetail attached with nuts and washers. This was less than ideal because the dovetail bar prevented access to the Allen screws so it required some mucking about, clamping the blocks without fully tightening and then tapping them up or down to get the job level, checking level with a lever type DTI, then remove the job and tighten the screws... check again with the DTI to see if anything moved.

So now I could mill the angles using the side of the cutter on the top face. The big problem here is that even by winding the cross slide back (forward??) far anough to expose a short length of the cross slide dovetail at the rear I can get at most 4 1/2 inches of cross slide travel. I have a couple of 1 inch spacers that attach between the cross slide and the handwheel apron - those (and longer bolts) allow me to do the same trick in the other direction and get 5 1/2 inches of travel - theooretically enough for the job... if the job could be positioned to start and finish at exactly the limits... which it could not. I might have been able to arrange it if I had planned better but this is real life and that's not what happened.

My solution was to do each side in two operations, shifting the slide to another 'T' slot on the cross slide in between. This got the job done but there is a tiny step where the two cuts join - not an issue for what I needed but if I were making a dovetail whose main purpose was sliding then it would not be very good.

Job done. Telescope mounted. Naturally it has been cloudy and rainy ever since.

Edited By Andy Carlson on 03/05/2021 12:29:30

Milling clamps... how long is a piece of string? Really depends on the job and your ability to problem solve. Certainly sthe type with studs, 'T' nuts, step blocks and so on are useful on some occasions but they are not the answer to everything. Sometimes you need studs and a piece of thick enough bar drilled to clear the studs to form a strap across the job. Sometimes a vice is best. Harold Hall's site has several designs of low profile clamps fo you to make. As others have said, sometimes you can co-opt the toolpost stud to help with clamping. The general rule is probably that you never quite have what you want.

One of the challenges of milling in the lathe is that you have a lot less free 'T' slotted (or whatever) space in which to put your clamps. Quite often I find that this precludes the use of step blocks. Gravity as another challenge - on a mill you can set up on the table at your leisure. With a vertical slide or angle block everything will fall off so you need to set up off the machine.

TBH I think that the many piece clamping sets are overkill - yes you get lots of bits but they are all of a similar type.

Start simple, take things slowly, learn what a healthy milling cut sounds like and how much 'demand' your setup can cope with. Be careful - I generally assume that a milling machine (or lathe doing milling) is always trying to damage itself, the job and/or me. Try to figure out how many ways it will find to trip you up - for example apart from flinging the job across the workshop the cutter can work like a corkscrew and either pull itself out of the holder and into the job or else pull the job in towards itself.

Can't help with specific attachments for your lathe, but do consider HSS cutters - they are more forgiving of the lack of rigidity inherent in a lathe milling setup. After initially being blinded by the multiplicity of cutter options and then promptly snapping a tooth off a fancy specialist carbide one I decided to road test a 10mm stub length HSS cutter in the lathe. It works a treat. IIRC it was from Drill Service Horley.

If you lack a collet holder then chuck a pece of bar end roughly double the diameter of the cutter in the 3 jaw. Make a punch mark to align with No 1 jaw, tailstock drill to the cutter diameter and then remove and make a saw cut opposite the punch mark. Then your cutter will be repeatably concentric. Worked for me as a stop gap until I had a collet holder.

You will probably need something beyond a CNC shield for a 3.1A stepper, The CNC shield takes plug-in driver modules of various kinds (e.g. A4988, DRV8825). They do the same job but their current capability varies.I think 2A is about the max though - the form factor probably precludes anything more.

To source 3.1A you probably need a separate driver which will likely have screw terminals rather than little square pins.

Using a lower current driver won't fry anything - the driver will limit the current but it may not provide enough stepper torque to do the job,

Sorry I'm not au fait with the higher current drivers because my smaller machine is OK with the little ones but hopefully someone else will come along to advise,

Control-wise you indeed could go for a microcontroller running GRBL but I don't think GRBL can support much of a control panel because input/output pins on the Arduino Uno are mostly needed to talk to the steppers. Sorry I'm not sure what hobbyist controllers and firmware can do this but maybe someone else can suggest something.

EDIT: typo

Edited By Andy Carlson on 18/04/2021 18:16:15

I have one of these. It is not a sophisticated machine but I like it a lot.

Vintage wise, I think mine is just pre-WW2. The one in the pic appears to be later because it has vee belts but the Faircut 'Senior' is still a pre-war design. As you have no doubt read elsehere, 'condition is everything'. Check for backlash in the cross slide and leadscrew feeds. Expect some though - this lathe will be no spring chicken. The leadscrew is 8TPI and the cross slide 12TPI, so compare to that.

Compared with other lathes the big omission is a half nut. That doesn't stop you doing anything but can slow things down and does cause more wear over time on the leadscrew and nut. On the plus side the bed is longer than, say, a standard Drummond 'M' type of similar vintage and that is a good thing to have - even if the job isn't long it's nice to have some 'elbow room' to move the tailstock out of the way.

At best it only has a dial on the cross feed handwheel... which may or may not be resettable. Prewar lathes have fewer dials.

It is worth checking the exact height between the toolpost 'shelf' and centre height - this determines the size of the cutting tool that can be used. The compound design changed over time and the toolpost looks non original so measuring is the only way to tell - mine has 12mm. I don't think you'd want less than 3/8 inch.

To fit a new chuck you will need a backplate to mount it to the spindle, which means reclaiming one from another chuck or making one. The important bit is the spindle nose thread which is 7/8 BSF on mine and likely the same on the one in the pic. You are unlikely to find a backplate to buy like this so it's reclaim one or make one.

The asking price seems high. I bought mine 18 months ago in a superficially rusted state but with a hatful of accessories for south of 300 quid. I've seen plenty go for less but usually without a lot of tooling which does make a difference.

If you search for 'Faircut' on here you will find two threads about Faircut 'Senior's, one of them mine. There is also Brian Morehen's thread but he has a Junior which has quite a few differennces.

That's all I can think of for now. Happy to answer any other questions.

A very useful thing!

Dial Test Indicator, sometimes just Dial Indicator or Clock Gauge. Used for checking that work is parallel to the axis on a milling machine, concentric on a lathe and so on. I have a small lever style gauge on a magnetic base and adjustable stand. I use it all the time.

There is also the plunger style gauge. I have one of those too. I keep intending to arrange clamps to hold it parallel to my lathe axes but never got a round tuit.

The MF70 is not magnetic. I've added a couple of bits of 4mm steel plate between the XY table and base on mine so that the magnetic base has something to stick to. Other folks have made clamps to attach one to the spindle housing.

It's difficult to predict which jobs will come along but my experience has been that I have not found a need to use the MF70 for domestic projects. My Unimat, Cowells and the Faircut 3 1/2 inch lathe on the other hand have all been put to use in this way. Work has included a new brass button fur our old style doorbell push (maybe 3/4 dia), new buttons for the cooker hood (the old plastic ones disintegrated) and several things with threads on the end to adapt or extend various things.

Whatever machine you have you will find yourself making tooling on the machine, for the machine. I've probably spent more time making tooling than anything else, but with four small lathes and the MF70 that's probably my own fault.

Whatever machine you have you will also find that there are jobs which are too big for it. With 1mm sheet I would expect that Y travel will be a place where you will quickly find the limits. My own experience with small modelling jobs on brass sheet is that I quickly wanted CNC so that I could do accurate diagonals and curves etc. I've done this and it has been successful... but that's a whole other tangent.

I won't attempt to say much more on the subject of spindle speeds. I don't pay a lot of attention to what is 'correct'. I do pay attention to nasty noises. The MF70 speeds are OK for 1mm-3mm carbide milling cutters and drilling 2mm and below. The higher speeds are very handy with sub 1mm drills. Yesterday I was doing 0.3mm holes transversely in 0.5mm brass rod on the MF70...but there are plenty of occasions when I'd like to go lower than 5000 RPM but I can do that on the lathes.

Do consider a lathe but XY travel will not be a strong point there - the usable vertical travel of a milling slide may be less than half of the height of the work mounting face.

I've milled mild steel on the MF70 and would nave no concerns about doing it again. It won't chew metal off at a rate of knots but it will do it. The job needs to be small otherwise it will take ages. Steel swarf from carbide cutters is like thousands of tiny needles so bear that in mind if you plan to do this in a domestic setting.

In terms of drilling I don't think I've ever had a need to drill mild steel on the MF70 because I have other machines. When the MF70 was my only machine I did drill brass and aluminium with 2mm and 3mm holes. It coped with both but the noise was pretty nasty with a 3mm drill. A nice sharp drill and a slower speed machine is a much nicer experience.

3.2mm dia is the maximum the unmodified MF70 will hold. If converted to ER11 then it will go bigger but bigger drills are also longer and the high speed will be even more of an issue.

At the end of the day the MF70 is a small scale modelling machine and this is a model engineering forum so you won't find many folks expressing love for it here but like I said... within its limits (and those limits are small) it is OK.

But honestly, if you want to drill 6mm holes in steel then it's not the machine for the job.

Hi Mike. It's Vol 23 No 10 - March 2021. 5 and a bit pages on SDJR loco lettering, partly observations based on a drawing in the care of the HMRS, partly correspondence with one of the preservation folks and partly relying on photos which can be had in books like the old SDJR loco history (David and Charles).

Sorry I don't have a good answer short of joining... other than find a friend or else try contacting HMRS and asking nicely.

HMRS also do well regarded transfers in 4mm and 7mm. Not sure whether they cater for bigger scales TBH. I model in 2mm and they don't go smaller than 4mm.

Regards, Andy

The MF70 is fine within its capacity. I use mine for 2mm scale modelling and many other 2mm modellers do too.

It can be converted to use an ER11 spindle but the high minimum speed of the drive is another limitation. I know folks who have addressed that one too, but then you are getting quite far from the original machine. As you know, the axis travel is a further limitation. If you want to drill up to 6mm then I'd say it isn't for you. I can't speak from experience of the other options but rigidity is crucial to a mill so any increase in space for Y or Z travel should also be accompanied by an increase in the bulk of everything that keeps the head positioned with respect to the table.

Trouble is... the price point goes up pretty sharply too.

Try to get hold of the most recent HMRS Journal - there is an article on exactly this question.

IIRC he concludes that the main influence was the MR lettering from Derby... some new SDJR locos being painted there. He could not be definitive on the question of shading colours. There were also variations - most likely the lettering was done by signwriters working to written instructions or perhaps copying an example so variations may be down to the individual's interpretation of the instructions. The buffer beam lettering definitely varies considerably between locos.

I've used RS part 398-5279 . It is a panel mount NVR switch.

It has a connection for a second external E-Stop button - if this connection 'sees' a closed circuit then the NVR power can be switched on. If anything (like an E-Stop switch) breaks that circuit then the NVR switch will trip to off. You could (should you wish) wire multiple E-Stops in series on this cricuit and then any one of them would trip the NVR off.

Being panel mounted, you need to make sure there is no access to the gubbins at the back - including the E-stop circuit which also carries mains voltage.

There is a bunch of stuff going on to make use of more recent microcontrollers and/or drive more axes. No doubt a good deal of it is 'bleeding edge' but if you want more than 3 axes or capabilities that won't fit into the memory on an Uno then it's worth looking around to see if anything 'out there' suits. For example...

https://www.routerforums.com/threads/grbl-hal-what-ive-been-doing-lately.141693/

The above discussion seems to have a lot in common with the Cowells.

The Cowells set is 20T to 50T in steps of 5T, with two off 30T for achieving a 1:1 ratio.

The Cowells also has two permanently assembled compound gears - 16:32 and 20:56, mainly for slow feed although 16:32 has its uses for screw cutting.

The Cowells gears are 32DP. I'm not sure of the correct pressure angle but I've added some 20 degree PA delrin gears from HPC and they work OK once the centres are opened out to the right size and a keyway added.

If you want to make up your own compounds from the Cowells change gears then there is a challenge to overcome - you need a keyed idler bush and the 3/8 bore does not leave a lot of diameter to play with... essentially the key needs to be part of the bush because there isn't really room to cut a keyway in the outside of a bush.

The other limitation with the Cowells is the space available on the quadrant. This may make some of the higher numbers of teeth less useful than you might otherwise think.

I've added 37T and 47T (also from HPC) to mine for doing BA and imperial approximations. The inspiration came from this thread...

https://www.modelenginemaker.com/index.php/topic,1020.15.html

Hope this helps. Some of the above may apply to the Flexi but I know that some of them have a different drive arrangement for the feedscrew. The Cowells is a 1mm feed screw pitch, not sure if your Flexi feed screw is imperial or metric.