Member postings for old mart

Welcome, Keith, you will be amongst a huge number of steam experts. As for Vevor, you should put the name in the search box and read all the comments before committing yourself. I have just bought a Vevor 160mm lathe chuck for a very low price on ebay and initial examination suggests it is excellent value for money. You could start a thread asking advice on milling attachments for your model lathe, that will get the answers you want. If you have the room and funds, a mill would be a much better way to go.

If your spindle is the splined type rather than the keyed version, there is unlikely to be much rotary backlash as the forces are very light. You should check that the grub screw holding the pulley on the short shaft with the internal splines (next to the pic showing the needle roller bearings) is tight. I milled a second flat opposite the existing one so two grubscrews could be used. There are 20 splines with an internal angle of 90 degrees, so the wear would have to be terminal before rotary backlash was noticable.

Edited By old mart on 28/12/2022 20:58:38

Interesting process, I wondered how they worked. Are the bullets 9mm ?

My firm used to make large quantities of bushes for aircraft with beautiful internal grooves down to 1/2" bore on CNC machines. The last time I wanted a groove, I used a dremel, the oil will flow even in a shallow groove.

When the drawings were made, high tensile meant stronger than mild steel or wrought iron. 8.8 would have been classified as high tensile and now 10.9 and 12.9 would be even better choices if you can machine them satisfactorily. The advice about inside rads is excellent, it will greatly reduce the danger of stress cracking. Any washers should be thick and have an internal chamfer on the bolt head side to ensure thea the rad s not loaded. If you can, have at least 1 1/2 thread diameters in the threaded hole.

There are two types of drive between the front pulley and the spindle, I recon yours is like these pictures. You need to remove the front pulley and unscrew the 2BA screws which hold the bottom pulley/motor mount to inspect the needle roller bearings. They may be available from "Bearing Boys" or another bearing specialist. Ours were ok and just got a wash and new lithium grease. Check that the pulley is a good fit when re assembling.

Edited By old mart on 27/12/2022 13:43:08

I have a similar thing somewhere, it came with about 4 variations of plug, including the British standard one, it would work on dual voltage as it was a switched power supply intended for use in many parts of the world.

I modified the spindle to use R8 and chose a 6 pole 0.75 Kw TEC with a B14 end mount flange to use with a VFD and retain the 4 speed pulley system. The flange is different, so I bought an aluminium plate and copied the old mount with the B14 size hole and fixings. The motor spindle is bigger so the pulley was modified and twin grubscrews fit in the milled down motor shaft key. The reason for a 6 pole motor was to run up to the original motor speed, but also to retain more power at lower rpm. You still need the stepped pulleys to allow decent torque throughout the full range of speeds. For your MT2 spindle, a motor of 0.55Kw would be the best size. I checked the motor spindle sizes for the 0.55Kw and the 2 pole is 14mm and the 4 and 6 pole use 19mm.

Edited By old mart on 26/12/2022 15:38:57

Merry Christmas and a happy new year everyone, and best wishes to everyone who has other beliefs. And don't forget the suncream to all friends down under.

Edited By old mart on 24/12/2022 15:52:31

Good result, you should be able to check preload by running the spindle at max rpm and it should only get luke warm after 15 minutes.

If anyone is thinking of shortening their arbor to gain centre distance and quill stroke, here is the method I used. Hold the front of the chuck and use a centre to support the tang end. Using a carbide insert, turn the end down about 0.020", 0.5mm, having already decided exactly where the new end should be. Then you should be able to use a hacksaw to cut the end off, parting is not recommended as the work is not supported well enough. You may be able to face off the end if the lathe chuck gives enough support, otherwise grind, linish or file the end flat.

Not Evri, but Yodel, and the Christmas panic. I was expecting a box about 2 feet cube last Friday, the tracking shows it in transit, just as well it is not urgent, thankfully.

The carbon will migrate deeper if the time at temperature is extended. When I was working, the foreman gave me a very warped piece of steel, about 12 x 2 x 1/2 inches and asked me to straighten it. The end result was two pieces, and you could see the grain structure of the hard parts had penetrated at least 3/16". I couldn't help sniggering as I handed him the bits, and he stormed off in a huff.

The tangless arbor is the best of all worlds use with a drawbar, with a screwed in tang for the drill press, and a screwed in plug for self extractors. The first picture is of the 5/16" Kawasaki chuck used on my 7 X 12, the hole allows a greater length of MT while extracting about 1 1/2 turns before the leadscrew bottoms. The end for the Atlas is flat because the end of the leadscrew fills the small end of the MT socket. I already had the tanged arbors

A common drawback with smaller lathes is the length of the Morse taper if it has a tang. The tang was intended to be used for extraction with a wedge through a cross slot, but not all lathe tailstocks utilise this feature. Self extraction is common and both my 7 x 12 Chinese and the Atlas 12 x 24 at the museum have it and this limits the stroke of the quill by 1". Only an inch, but a handicap when the between centres is only 12" and even the Atlas only has 2" movement when it has 3" of graduations. The ansver is to shorten the MT by removing the tang and turning the end to allow just enough to break the taper. I have shortened both Chinese and genuine Jacobs MT's and drilled the ends. There will be some pictures when I get them added to my album.

Edited By old mart on 22/12/2022 17:00:39

Pat yourselves on the back, it must be nice to have the money to be able to invest on things like solar panels and electric cars, not everybody has anything left after paying the bills and eating.

I do it the simplest possible way. Just face off a bit of bar and see if the tool height requires adjusting up or down, and when the tool is on height the "tit" in the end of the work will be very small, or pretty near non existant. That tool is on height and the tip height can be used to adjust a simple gauge which sits on the bed or crosslide. No centres were harmed in the production of this work.

Good choice when you use cutters up to 12mm. My reasoning was slightly different when I chose er25 over er32, simply the cost of cutters over 16mm gets very high. For larger sizes using R8 collets, the straight shanked 12, 14, 16 and 20mm with APHT or APMT inserts are economic to use and do not overshadow the work like a collet can. APT sell this type.

With a DTI on the toolpost and your solid carbide bar in the chuck, you can run along the front of the bar to get a good idea whether the headstock is still aligned with the bed. There are better alignment bars about, but what you have already will get you 99% perfect even before taking a test cut. A length of aluminium bar that will just pass through the chuck bore would be good for a test cut. It would be as stiff as you can get and also be clamped by the full length of jaws. With a projection of about 150mm and a very light cut you can compare the diameters at both machined ends of the bar for final alignment. Allowing for flexure, the diameter furthest from the chuck would be plus 0.02mm or better than the chuck end.

Edited By old mart on 15/12/2022 17:49:00

Just in case it has been missed, this link could be useful to owners of the small Chinese lathes:

**LINK**