Member postings for Nigel Bennett

I've had a Boxford 280 for a while now. When I bought it, the tailstock 3MT bore was badly scored a little way down. There was a reasonable amount of surface left, but it annoyed me and I was concerned that it would not provide the grip for larger sized tools. I contacted Boxford a few days ago to see if they had a spare, but they don't any more. (If I'd wanted a new Myford one, it would have been a lot easier!)

One option would have been to fit a shortened 2-3MT sleeve and permanently batter it into the bore with Loctite, but I had a fair amount of 3MT tooling which would have then been useless.

(One interesting point was that when I had the barrel in my hand, part of the outside diameter hadn't cleaned up properly when it had been originally made. I realised then that the finish-ground taper bore must have been created first and then the barrel mounted on a special 3MT male spigot for the OD to be ground true to the bore. I imagine the keyway was then machined.)

I was therefore left with the option of leaving it or doing something. First attempt was to buy a 3MT finishing reamer. (It was a fairly inexpensive one, and probably made in an extremely well-populated country some miles away from here.) I tried it - and failed to remove any material at all as the barrel is hardened and the HSS reamer wouldn't touch it. My mind boggled at the imagined cost of a solid carbide 3MT reamer...

I did wonder about how I could grind the bore myself, but quite frankly I just didn't have the kit to stand a chance of obtaining a satisfactory result.

I searched on the net for local grinders and sent off several email enquiries. I only got two replies - one apologised and said it was beyond them, and the other said to bring it in and they'd probably be able to do it.

I went over on Monday and it was ready for collection the following day. Brilliant job; they showed me the 3MT test gauge they had used to check it and it blued up absolutely fine.

No connection at all with the company - B Kemp Grinders in Liversage, West Yorkshire - other than a satisfied customer.

**LINK**

Hope the information may help somebody out there with a (relatively) rare problem lathe.

On my Boxford 280 I have drilled a little dimple by one camlock mounting hole and corresponding dimples on the chucks so that they always go back in the same orientation.

Like Jon, I thought LNER too. It's similar to a Maisie, but with a different tube arrangement. The firebox is also quite a bit longer than Maisie, but overall boiler length is about the same. Maisie does have a sloping throatplate, It might therefore foul the trailing wheelset of a Maisie chassis. Good luck with whatever you do with it!

We used to make carriage door handles at work by casting the brass around a steel spindle with suitable chunks chewed out of it to provide a positive drive and location. The pattern was "handle plus spindle"; the pattern was removed and a steel spindle carefully positioned and aligned in the mould. Very simple bearings on most older carriage door locks; just a 3/4"BSW thread to provide axial and radial bearing surfaces.

To veer off-topic slightly, the handles on the BR Mk.3 doors were interesting; initially they were stainless steel, threaded 3/4"BSW, but they suffered misalignment problems. Later ones were fitted with plain journal bearings attached to the lock. Fitting the lock-plus-handle assembly involved first wangling the handle through the hole in the door, before securing the lock on the inside of the door with screws. Early handles - a lever type - suffered from twisting, due to the massive inertia caused by the handles whipping when the door slammed. (It is a rack-and-pinion arrangement which gives a positive visual clue to the door not being latched shut.) We had to change the material to a heat-treated grade normally used for turbine blades. The balanced dickie-bow type on Mk.2 and earlier stock didn't suffer from the problem, and a lower-spec stainless could be used.

And don't ask me about providing inside handles to slam door locks on Mk.3 stock...

With the wheel still in the chuck as you machined it, can you get a feeler gauge to slip between the back of the wheel and the face of any of the chuck jaws? It might just be that you haven’t seated it properly or perhaps there is a burr or piece of swarf trapped.

Hello Jon

It was I who described the Clayton 6-wheeler and I built it that way so there was more room on the back for me to sit on without making it an artic. If you’re going to run it, then you need the 2:1 reduction gearing to make it usable. If I was building another I would go for the taller boiler. When all’s said and done, it’s a small engine, and it has to be thrashed if you’re driving it on grass. You’re forever firing, injecting and steering as well, so you can’t leave it for ten minutes to have lunch! It would be a lot better in 3” or 4” scale...

I would check availability of rubber tyres for it at an early stage; I heard they were difficult to get hold of.

Good luck with the project; I had a lot of enjoyment building mine.

Just leave my shortened one in the chuck all the time, held in place with some duct tape so it doesn't fall out when the lathe's running.

No of course I don't. Two woodscrews into a piece of chipboard on the wall behind the lathe. Allen keys in a block of wood screwed to the chipboard. Two round-head screws carefully spaced allow QC toolholders to drop over them; a small chunk of wood stops them falling down.

Couple of points; using a small slot drill, you will need to take very small cuts to avoid expensive pinging noises. Don't expect to do it all in one pass. High speed is good.

A slitting saw would be better, but it needs to run slowly; you're not using a circular saw on wood. (I recall one chap asking what he was doing wrong with a slitting saw on steel as all he got was sparks and broken teeth hurtling about...)

Whatever you do, don't spread it in such a cavalier fashion that the top comes off the container and you splatter the entire contents over a very small area. If you do this, the grass dies and it takes a lot of effort to regrow it. Don't ask me how I know this....

I've got a set of 141, 142 & 143 Eclipse tap wrenches, circa 1975, so genuine, and well before the Chinese fakes. I find that there's a big gap in capacity between the 142 and 143; there's no way some taps (about M6 size IIRC) will go into the 142, but the 143 won't hold them properly. They won't enter the small part of the 143 jaws, and the large part won't close down as the threads disengage. Very irritating, so I have to rely on my apprentice skool made solid wrench for certain tap sizes!

Very impressive indeed. But what about those utter lunatics who were standing at the side of the runway within feet of the thing taking off and landing? It would have done a lot of severe damage indeed to the aircraft if it had crashed into one of those onlookers. At 1/6 full size, that Concorde is about the same size as a typical light aircraft...

I would never use brass in a boiler. I've had brass fittings dezincify and snap off! You say it will only be fired a few times, but what happens after you've gone and somebody else starts to use it?

Cost isn't really that different; it's just a bit more difficult to machine, so I would sternly advise bronze.

As a boiler inspector, I would refuse to certify a boiler with brass bushes in it.

I got some from Malcolm High at Model Engineers Laser. Obviously the current virus situation will affect any purchasing decision, and I don’t know if he is still able to supply.

I too had a car covered in paint spots - they were painting the car park where I'd left it. And where was this?

Paignton.

I scraped them off with a finger nail. Took a long time.

Are you actually twiddling the topslide handle rather than moving the carriage?

Hope I'm not teaching granny to suck eggs:

Don't forget that when cutting this thread, because it's metric and not Imperial - with the caveats about it causing high loadings as above - you must not disengage the clasp nuts until you've completed the thread to full depth. Hopefully, you can put in a decent undercut at the end of the thread so you can stop the lathe as soon as the tool reaches the undercut. (Hope you've got a clutch, but loosening the belt tension on a standard ML7 and stopping the motor should do it.)

Then you have to wind out the cross-slide, and leaving the clap-nuts engaged, reverse the lathe so that the tool goes back to the start of the thread, increase depth of cut, and ditto repeato until it's done.

Don't attempt it if you're tired - it needs a LOT of concentration.

Good luck!

If you're using T51 toolholders from RDG, (the ones I bought from them were made by HBM,) they may not fit an existing T51 toolpost! I had a Boxford 280 with an original Boxford T51-sized toolpost on it, but acquiring toolholders to fit it was not really an economic option. I bought a complete toolpost-and-holders set from RDG and I've been perfectly happy with the set-up. I usually bought a couple more holders each year at Doncaster. (Exhibitions... sigh. Remember them?)

The original Boxford toolpost is made to tight manufacturing tolerances, such that the eccentric cam only has a small (approx. 0,5mm) eccentricity, enabling it to get a good grip on the toolholders with a relatively light tightening torque on the clamp handle.

The RDG set-up, although apparently identical in size, has a greater eccentricity (Approx 1mm) so manufacturing tolerances (= cheaper to make) are relaxed. Hence the RDG clamp handle has to be given a bigger heave to tighten it than the Boxford one. So what?

I later modified my original Boxford toolholder cams by grinding bits off them to get the 1mm eccentricity, and was able to get the RDG holders to fit it OK.

(Before modifying the cam, I had originally modified the clamp head - the Tee-section bit that gets hold of the toolholder - on the Boxford toolpost by thinning it down so it gripped an RDG toolholder OK. Great! Unfortunately... the next toolholder I tried wouldn't clamp up at all - I'd taken too much off the thickness. Grinding the cam and using a putting-on tool on the clamp head sorted it, and I sometimes use the Boxford toolpost plus RDG holders on the Myford on a special mounting block directly on the cross-slide. I wrote about it in ME a while ago.)

Hence if you're wanting to buy inexpensive toolholders, you may need to modify your toolpost so they fit. Or buy the toolpost as well, like I did.

Hello David

In principle, there's no reason why you can't put the bypass valve on the right. Make sure there's a decent balance pipe between the two tanks.

The bypass valve needs to be connected to the axle pump only; if you connect it to the hand pump, you'll find that you'll be pumping away with the hand pump at some point, wondering why the water level isn't going up. And yes, I did, on one of my locos; I had to devise a Cunning Valve Affair so that it didn't happen again...

Hello David

The Chipmaster is a lovely machine, but as built, its Achilles' Heel was the variator used to change speeds. However, many folk have fitted inverters and discarded the Kopp variator. You'd probably need an inverter anyway as you're unlikely to have 3 phase power available.

Tony Griffiths has the following:

**LINK**

**LINK**

They're both elderly machines now, but if they've been looked after and not abused, they'll be just fine for your purposes.

Note that the Bantam is similarly-sized to the Chipmaster; in fact they share many components.

I don't think it was the pangolin's fault. If people left them alone and stopped converting them into "Traditional Chinese Medicine" we'd all have been fine.