Here is a list of all the postings old mart has made in our forums. Click on a thread name to jump to the thread.
|Thread: Ways to use your calipers|
I have 6 and12 inch digital Mitotoyos, from 1990 and 1993 and they are the only ones that are trusted to measure inside or out with accuracy. Most of the time I use the cheap Chinese ones from Lidl, and only use the Mits for precision work, I also have micrometers up to 150mm and a tube mic to 300mm, with the essential length bars. I often use the digital calipers as comparitors as it greatly simplifies measurements, which is impossible with mechanical instruments. I sold my digimatic mics as they weren't being used.
|Thread: ER 32 Collet Tightening Torque.|
I use er25 and have a ball bearing nut, which should allow a reduction of 1/3 of the torque. The torques quoted are for the maximum size cutters, so if using an 8mm one, you could use half of the maximum amount. I have put spanner flats on the er body, (the current ones seem to have them from new),and have milled the jaws of a foot long spanner to match. The nut wrench is pressed into a foot long steel tube, and together, they make tightening and loosening easy. With er, it is always a good idea to have a folded up old towel underneath to catch the cutter as you break the collet taper.
|Thread: Milling cutter advise|
If you want a shell mill, there are plenty of 40mm ones whick use 4 off APKT 11, or APMT 11 inserts. You will also need an arbor with a 22mm end which fits your spindle. You can use them with 2 or 4 inserts in them, or even 1 if you reduce the speed to allow for the out of balance forces. Inserts for steel and aluminium are freely available. I am not allowed to post a link on this forum.
|Thread: Cheap Milling Vice Question|
That ARC 5" vise which I bought is a copy of the Kurt, not in the same league for quality, but at 15% of the price what would you expect. It benifits from the Stevenson spherical improvement which does help to minimise the jaw lifting. The first Bison 6512 type 100mm vise came with the drill mill, and I was extremely lucky to get another complete with a swivel base in unused condition for 20% of the list price. The two Bisons make a useful pair, although they are of different ages, the height is matched within 0.0005". On one, I have removed the rear lug to allow more Y axis movement on the mills, but have made a bolt on lug for when the vise is used lengthways on the mill.
|Thread: How to create a hard edge to your steel.|
Thats exactly how stellite was used.
|Thread: Cheap Milling Vice Question|
We have two very good quality Bison 100mm vises which are a similar design as the Soba pictured, and even with hand stoning to tighten them up still exibit the design problems of lifting of the moving jaw. Its something you learn to live with.
|Thread: Removing bang in self tappers|
Some careful tapping with a wedge with a similar profile to a wood chisel between the head and the plate, not just in one place, but at several positions. Then as the head starts to lift, a blunter wedge and finally they should be high enough to turn. I would expect them to have a right handed helix.
|Thread: Cheap Milling Vice Question|
I bought a 5" model from ARC which opens 6". It is as big as I would ever want to use on the drill mill and too big for the Tom Senior. have used it recently on the TS clamped in line with the X axis. This type of vise is best used without the swivel base attached. The swivel base takes up Z axis space and is best left for those jobs which actually need it. However, it you have the choice between getting the vise with or without the swivel base, always get it as there are rare times when it is worth its weight in gold. They are prone to getting a lot of swarf in them, and need to be dismantled and cleaned regularly. I would think the 3" that you are interested in will work very well with a mini mill, when you get it, check that it is square and will hold your work properly.
Edited By old mart on 27/09/2020 14:10:33
|Thread: ER 40 Milling nose|
As long as the length of, say, 110mm from the end of the threads can be 30.5mm then that gives a decent choice of fitted lengths for the larger longer cutters. There needs to be room in the design for spanner flats directly above the nut. Some long spanners will be required as the recommended torque for larger cutters is 145 ftlbs.
I converted a Tom Senior spindle from MT2 to R8 last year and am very pleased with the results. R8 is still a very popular fitting and there is a wide variety of tooling. You would have to make special adaptors if you wanted to use shell mills with an er40 spindle, although there would be no need for a drawbar.
Since the range of collet sizes is from 3-30mm diameter, to utilise them all fully would need at least 4 diameters accomodated from the face of the nut. A much larger lower half of the spindle would be needed to take a 30.5mm bore. The size of the clamping range of these large collets is such that it is doubtful if cutters in the smaller sizes would be held accurately or tightly enough.
R8 cannot accomodate bigger than 20mm cutters and then only with very limited depth which means that standard length 20mm cutters project a long way.
Edited By old mart on 26/09/2020 19:29:24
|Thread: New member from the USA|
Welcome, Ronnie, this forum is a great place for model makers, there is so much expertese. I presume that you are already a member of The Home Shop Machinist forum on your side of the pond, many of their members are also into models.
|Thread: Vacuum Pump Advice Please!|
That Edwards pump is capable of going down to 133mB, which may not be enough for your requirements.
|Thread: Mounting a collet chuck.|
The backplate is drilled and tapped for three and four jaw chucks. If you would like to preserve the backplate just in case it is needed for a chuck in the future, then an adaptor plate for the collet holder could be made if it will not fit directly.
450rpm is rather high with that out of balance job hanging so far from the end of the spindle. It might be possible to secure a weight on the workpiece to reduce the out of balance forces.
|Thread: fly cutter wear|
Try a file on it, it if you can take anything off then its far too soft. Steel cutting steel always needs oil.
Edited By old mart on 24/09/2020 20:30:16
|Thread: Customs payment is it a scam|
If that happened to me, I would get in touch with the Royal Mail, and pass the details to their fraud department.
When I fitted the VFD controlled three phase motor to the Tom Senior, I first chose one with filters for interferance supression. The Vfd is in an earthed steel box, and all the cabling is screened, including the low voltage control wiring. We have not noticed any problems with VHF and DAB radio signals, and the wireless router in the workshop runs as expected.
I had been initially concerned by the manual mentioning an earth leakage when using the filters, but there has been no tripping of any RCD when the mill is in use.
Welcome, Mark, you will find lots of Myford experts and engine makers on this forum, so ask away.
|Thread: interest renewed|
That er32 collet chuck will also be very useful when holding work for turning as well as for milling cutters. In the dual function, I would recommend a full set of collets, but if just starting milling, then just buy 3-4-5-6-8-and 10 mm which should match the sizes of cutters likely to start you off with small jobs.
With the 920, you may find it difficult to just move the saddle with enough precision when milling. One way round this is a handle on the end of the leadscrew to move the saddle with the leadscrew nuts engaged, like a lot of Myfords have. Or even more outlandish, the tailstock. When we were refurbishing the apron of the museums Smart & Brown model A, I still needed to use the lathe for turning shafts and bushes with the apron sitting on a bench in bits. I just used the tailstock to push the saddle which saved using the compound which is difficult to use for precision parallel turning.
Edited By old mart on 21/09/2020 18:31:04
|Thread: Stuck SDS drill bit|
I cannot imagine just how an SDS drill bit could have turned once fitted, but if the drill is dismantled and the shaft with the chuck is removed and the pneumatic striker is taken out, where the striker fits is a bore right through to the rear of the drill bit. Every time I fit a bit in an SDS drill, I first pull it back and forth to ensure it is correctly fitted, it should slide freely about 10mm.
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