Member postings for old mart

For that size milling machine, a 4", 100mm would be the sweet size, with 5", 125mm being too big unless you have large work. ARC have a good range, and they also show the footprint if their products, you can cut out a piece of cardboard to lay on the mill bed to compare sizes.

That antirotation screw on the museum's Taiwanese round column drill mill is unusual in that it's thread is either Whitworth or UNC, not metric.

I notice that your spindle is Morse taper and there is an extraction slot for when larger drills are fitted directly to the spindle. That will prevent overpacking with grease alright.

Edited By old mart on 10/08/2021 15:45:59

There will be a joint between the base and the top half, this is where the 3/16" would be best removed from. This would be easy if a mill was available. The alternative might be to mount the base on a faceplate, square up the surface and turn off the surplace.

The tailstock of the museum Smart & Brown has shims between the halves to get the height and direction of the quill on the centre line. Actually it is set 0.001" high on purpose. I ought to set it up and mill it to take a decent thickness shim, but I'm too lazy.

On the other side of the pond, The Home Shop Machinist forum is well worth joining.

It is obviously made to fit in a coat pocket along with pens. What happens at the buisiness end when the scale is moved?

I was told that the more sophisticated kit with the foot pedal was worth the extra money.

I used to have one of those drill grinding attachments fitted to the bench just to the left of the grinder. The grinder in the picture, being right handed and not double ended would have difficulties mounting. When I sold my house, I left the grinder, drill sharpener and a 4" Paramo vise bolted to the bench. I miss the vise.

Smart & Brown used at least 3 gear tooth sizes on changewheels. Atlas have 12DP on the bull gear, I don't know what their change wheels are, though.

Edited By old mart on 09/08/2021 16:37:42

The model M Smart & Brown used 18DP gears, but they are only likely to be this side of the pond.

Another way to check the teeth is an online calculator.

https://www.technobotsonline.com/gear-size-calculator.html

Edited By old mart on 09/08/2021 14:32:32

That close up of the lower outer bearing race shows machining marks, not exactly an indicator of quality. I have only replaced the lower bearing in the drill mill, there was a delay in getting an SKF, so I took a chance on a Chinese one, and it was ok. I have been thinking of replacing both bearings in that machine, they are not too expensive and with the front of the head exposed, easy to fine adjust the preload without removing the quill to do it.

It would be difficult to use gears of different DP or MOD sizes if the shaft spacing was fixed. I have changed the hard to obtain British Smart & Brown gears for similar tooth size metric ones only because the changewheel positions are adjustable to accept many combinations of gear tooth numbers. If you are thinking of using your spare gears in this context, you may be lucky. These 16DP gears will be slightly bigger for the same tooth counts than your lathes 18DP ones. There would be some measuring to do before committing yourself to making them fit the lathe. You might not have enough combinations of gears to make the change viable.

I have never checked the surface of the window to see whether it is truly vertical, but have thought about a mirror to get a stronger reflection. I did try the laser on the front of the mill head pointing sideways at the other end of the building about 70 feet away, but it didn't seem to be an improvement. Those lasers come from ebay and include a number of mounting options as well as the remote squeeze switch for use with a rifle.

Terry, you have got your "upper and lower" quill bearing races the wrong way round.

Edited By old mart on 08/08/2021 20:59:54

Worry not Neil, the Evergiven docked in the UK the other day.

I would need training wheels on any motorcycle I rode with that engine in it.

This laser for a gun has been on the drill mill for years. The beam reflects off a window about ten feet away and back to the face of the laser. It can be easy to get 0.002" repeatability. An extension switch dangles from the rear of the laser and has to be squeezed to switch it on, there is never a danger of running the batteries down.

ACF50, as already advised, used liberally once every couple of months and be sure that no water gets through the tarp. If possible leave an air gap between the tarp and the lathe.

Our drill mill at the museum was left in a back garden for THREE years under a tarp, and was very rusty as a result. It was stripped right down, and I had to replace the lower spindle bearing. The rust was scraped carefully off the bed, which although stained, is none the worse for its treatment, as is the column. The motor was the only part which was kept in a dry place. There is a small ammount of pitting inside the R8 spindle, but not enough to seriously damage it.

If you are worried, why not reinforce the entire top with a single fitted piece of 19mm plywood.

Great to hear the good news, Terry. I would advise renewing both bearings, and use a common lithium high melting point grease. Be sure not to overpack with grease, leave at least 50% air within the quill. Hopefully, removing that label at the front of the head will allow fine tuning of the bearing preload. The correct preload is when running fast for 20 minutes only heats the quill/spindle lukewarm. If the preload is too great, the assembly will overheat very quickly. I have bought bearings from this firm several times and can recommend them. While you are at it, don't forget to check those pulley bearings, and see if that little screw is intended to hold them in place.

https://simplybearings.co.uk/shop/Products-Taper-Roller-Bearings/c4747_5262/index.html

Edited By old mart on 07/08/2021 20:30:50

Edited By old mart on 07/08/2021 20:34:50

A 10mm shank right handed lathe boring bar cut to the required length would be an option, there will be flats top and bottom which might be a problem. If the flats are at the wrong angle, a 12mm bar with the shank turned down to 10mm might be the answer. Tomorrow, I could measure a 12mm bar to see what the measurement across the flats is.

Edited By old mart on 06/08/2021 19:43:00

It is a bit time consuming, but making tee nuts yourself that fit the slots better and are 50% longer than bought ones is well worth it. They will last a lifetime.

No particular help, I recall having to rinse the probe under a jet of de ionised water and store it in water when not in use. Wiki has some info.

**LINK**