Here is a list of all the postings William Chitham has made in our forums. Click on a thread name to jump to the thread.
|Thread: Boxford ?|
That's a Model A, looks nice. There should be a serial number on the right hand end of the bed where the tailstock is sitting in the photo. Have a look at lathes.co.uk for Boxford information, there is also a Boxford group on Facebook with lots of scanned documents and knowledge.
|Thread: Vfd and motor efficiency|
Happy to help Martin, here are a some photos of my motor's innards showing the star connection and the finished job before varnishing. I bought the red varnish expecting something translucent but it was actually opaque, more like paint. If I did it again I'd go for the clear. As Andrew said the connection was soft soldered, it did take quite a bit of scrubbing with fine emery to clean the insulation off the winding ends to get a good joint on to the new tails. There are a couple more photos in my Meddings album.
I've just rewired an old Newman motor as described by Andrew. First one I've done and a bit nerve racking but it went ok. I found the star point was tied in on the same side the existing 3 tails came out, not surprising I suppose but for some reason I'd convinced myself it would be the other side so I ended up undoing all the binding unnecessarily. The windings and insulation are rather brittle once untied but I read somewhere that the existing varnish can be softened with a hot air gun and that worked really well making it possible to squash the revised wiring back into place ready to tie. I failed to find any of the special binding string within my patience span so I used cotton string but I found a supplier called Brocott who have the special varnish in small quantities and various other winding related supplies including the glass fibre sleeving.
|Thread: I need to cut chamfers into x64 pieces of mild steel - any advice?|
I have skipped through this thread rather but if I have the gist of it correct then maybe this machine currently for sale on the Home Workshop **LINK**site might serve:
For Sale: Gravograph bevelling machine
Mon 6th Sep '21
Advert ID: 40428
Tools & Parts (Small tooling)
|Thread: Newman Motor Star To Delta?|
Well here are the windings:
and here are the instructions which emerged when I opened the case - these are the two sides of an oil soaked piece of paper so rather transparent but legible:
I wonder why they would make two versions of the motor, with and without dual voltage. Some small cost saving i suppose.
In a spirit of enquiry I think I will reassemble it and try at as is. If it is too feeble I'm pretty sure I'll be able to dig out the node and rewire it.
The Steinmetz circuit looks interesting but I do want the VFD extras (reversing, speed control, jog) to make power tapping easier.
Normal 3 phase is 400-440v. The "synthetic" 3 phase from a VFD is 230v. Most 3 phase motors can be configured to run on either voltage - star for 400v or delta for 230v ("dual voltage" motors) and this is usually made clear on the spec plate. Motors that are not intended as dual voltage, like this one, may or may not be easily converted depending on whether the node of the star is accessible or not.
However, I had a conversation with the fellow at the Inverter Supermarket who pointed out that it the motor may run satisfactoraly at the lower voltage as is. Here is a link to an explanation of how that works:
Basically the motor can be considered as a 230v 29Hz motor so will run at about 60% of normal RPM. Above 29Hz torque will drop off but that may not matter because one normally uses higher speeds for smaller drillbits which require less torque to turn. Definitely worth trying I think.
I have bought a 3 phase Meddings Driltru which I want to run on single phase. I'd like to use the original Newman motor with an inverter but unlike the motors on my lathe and mill which I have already converted the Newman is not marked as dual voltage and there are only three terminals under the plate. I have read that in such a case the necessary connections can sometimes be accomplished by dismantling the motor to get at the windings but sometimes this is not practical. Before I take mine to bits I thought I'd ask if anyone has experience of converting this particular type.
|Thread: Boxford BUD Tool Post|
Can't give you a dimension off hand but that 15mm seems very odd to me. On my CUD I regularly use 16mm shank tools so the top of the compound to centre height must be well over 20mm. I wonder if the compound or maybe the whole cross slide on your lathe is from a 5" model.
|Thread: Live Centre For A Boxford?|
In conclusion, I ordered a "Precision Live Centre Morse Taper 2 Extended Point Standard Series" from APT. Arrived next day and quite happy so far. Solved the chatter problem I was having and no runout I can measure. The body is quite chunky, 45mm diameter, but the long point gives good tool access.
|Thread: Power feeds for Chinese mills|
That's right, 230v 135lbin, still working six months on. Powerful enough to feed smoothly even if I forget to unlock the table properly which I never do of course. Powered through a normal 13A plug and since I fearlessly use mains voltage power tools all the time I'm not concerned about that. I can't say how accurate or repeatable the limit stops are, I have never tried them for cutting to a shoulder but the mechanism is simple so should be reliable I would think. I will do some experiments.
|Thread: Live Centre For A Boxford?|
I really like the look of the Heavy Duty one with the profiled point but will probably go for the standard series with the extended point.
I'm in the market for a new live centre for my Boxford. I have a big crusty old one that came with the lathe but it has a big body and a short point so it's always in the way of the tool. I have a slim body cheapy but I discovered that that is now all wibbly wobbly and causing chatter so I'm looking for something better. I quite fancy one with the long profiled nose, APT have a couple of contenders on sale at the moment but I'd welcome any recommendations before I spend.
|Thread: Chester 626 X axis backlash|
Hi Tom, I have a Chester 626 and the manual is pretty dismal. Grizzly sell essentially the same machine in America and they do a much better one, there is a link to it in this thread: 626 thread
|Thread: What Cutter For Big Cuts On A Small Mill?|
I wanted to do the job without spending a lot on tools so I cut a test thread using one of the old nuts to check it. It wasn't till I'd made the test thread a little undersized that I realized that the sample nut was distorted so at that point I chickened out and bought a second hand tap to finish off. My gorilla was off that day so I had to do it myself and even though the tap was only taking off a smidgin I still needed 12" of scaffold tube on the end of a 12" wrench to turn it. Not the sharpest tap maybe but still, I definitely wouldn't fancy my chances of doing that way from scratch or getting the Boxford to turn it even if I could hold such a tap in the tailstock.
All done now. Big cuts were to make big nuts for my brother in law's 1930s Ransome plough, 1 1/8" BSW 7tpi. He had some offcuts of 50mm x 25mm hot rolled (which were just too small to make 2 of course) so I started by rough cutting to length with an Aldi bandsaw. Then I milled to 41.5mm square 2 at a time using the aforementioned 60mm face mill. I did use the bandsaw to rough down the second side on some of them to see if it saved time on milling - it did. Final op on the mill was to centre drill then into the 4 jaw on the lathe to drill, bore and screwcut.
Getting more confident using my first mill, a Chester 626 and experimenting with heavier cuts now the novelty of it all is being overtaken by a desire to get the job done in reasonable time. I'm wondering what people would recommend for shifting metal fast on a small mill? For instance I've just been making big square nuts for an old plough and needed to take approx 8mm off the edge of some 25x50mm hot rolled steel bar. I found I could take a 1 mm cut with the big (60mm diameter maybe) brazed carbide tipped shell mill that came with the machine but once that is blunt I'm thinking to invest in something with replaceable inserts but would appreciate any advice on how big to go, how many inserts and what type will give the best performance?
|Thread: Myford VMC Mill new nuts|
Looks like a lovely job, is that made from silver steel, will you harden it? I'm a bit hazy about insert codes but does er22 denote an external thread insert intended for a 22mm bar, if so why not an internal NR type?
|Thread: What V belt cross section for use on a standard sized Picador pulley|
I happened to be looking at V belts on the Simply Bearings web site yesterday and they have teeny tiny ones down to 5mm width as well - "VB Classical".
|Thread: Myford VMC Mill new nuts|
I've just run into the same problem, can't get a big enough insert to cut a 7tpi BSW thread to fit my 16mm holder. A pre ground HSS tool solves my problem but don't suppose they are available for ACME profiles. To make one from scratch how about starting with a good size bar of silver steel and turn the thread profile on the end, instead of grinding. Then use the grinder to establish a cutting edge and reliefs and finally harden and hone. Hope this horrible sketch communicates the idea, not new I am sure.
|Thread: Is Liquid PTFE Any Good For Airlines?|
Now we are talking, that is definitely in my "take a punt" price range. Thanks to all for your thoughts.
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