Member postings for old mart

You could try other floppies in the drive, which might, either clean the heads ,or prove that the drive was faulty. When you eventually get things running, it would be a good idea to copy the floppy contents onto a small USB stick as a backup.

If a MT is used with a self extracting device, like some lathe tailstocks, then the tang is nothing but a liability. I cut the tang off the chuck for my mini 7 x 12 tailstock, drilled a hole into the end after facing it off which was slightly bigger than the leadscrew size and put a thin brass plug down the hole for a bearing. I have gained 3/4" travel before the self extraction takes affect, which is a lot on a small machine. We will also be doing a similar mod to the 12 X 24 Atlas lathe to increase its travel also.

I do know that chrome plating and bronze do not mix well, so avoid stainless steel, just in case.

I'm always learning something on this forum, I thought fusees were little chains.

My father could have written a great book about his second world war, even though he never fired his rifle at anyone. He was captured by the Italians, a few days after reaching North Africa, and spent most of his war in Italy. He nearly died of dysentry and was saved by the Italian doctors, who were superb. He later escaped from the camp he was in and made his way north and lived with the Italians after the fall of Italy, but was captured by the germans and put in a cattle truck en route to Germany. One night he escaped from the cattle truck and ran for his life, his friend was shot as they ran. Luckily for his friend, it was a sympathetic German who shot him in the leg, and dad was surprised to meet him after the war, fit and well. Father walked into Switzerland and spent the last part of the war living with a family there. He spoke fluent Italian and German and got on well with his captors, who told him, as a British prisoner things that would have had them executed if their officers had found out. I have all the correspondence between him and my aunt during his captivity, and the certificates from the British Legation in Berne thanking his foster family on behalf of the government. He was one of those fortunate people who never held any grudge against his captors afterward.

Edited By old mart on 19/09/2020 21:20:23

Edited By old mart on 19/09/2020 21:20:56

i have tried to add a couple of the correct pictures to illustrate my last post:

Edited By old mart on 19/09/2020 21:24:19

Strange that this subject has cropped up just as I made one. I recently bought a NOS compound for a Smart & Brown model A. Of the two types that were made for this lathe, this is the one with the tee slot. The tee is part of the two way toolpost that I have made to fit on the compound. I made it out of 60mm diameter EN24T and the centre boss is 21mm diameter, drilled and tapped 12mm to just above the top of the compound. The 21mm projects 15mm and is the pivot for the toolpost. I increased the width of the slot on the compound to 14mm and the result is two flats on the 21mm part to fit the 14mm slot width. The toolpost has a spring loaded indexing plunger and there are two tapered holes in the teenut spaced 48mm apart. The indexing is not perfectly repeatable as the tee has a certain ammount of play in the slot. With a manual machine, this hardly matters. Also as the toolpost only locks at 180 degrees, using a boring bar would be a matter of lining up by eye.

Go ahead and buy the milling attachment, and hopefully in the next few years you will be in a position to add a mill to your tooling. Once you get a mill, you can sell the lathe milling attachment, which will certainly be surplace to your requirements.

The drill mill at the museum has handles at both ends of the X axis, so it depends which end you are standing at, (normally in the path of the least ammount of flying metal chips), and as soon as the Tom Senior was up and running, it had a second handle fitted at the left hand end.

The rear bearing is more likely to be damaged than the front, but if you can get the rear one to be a light fit on the spindle, so it can move without being tight, it would be best to give them a very good clean and regrease them and try again. The grease should not take up more than half the volume between the spindle and housing, this allows the grease to be displaced from the bearing races as they turn. If the grease has nowhere to go, as in overpacking, it will be churned around by the rollers and overheat. Having a DTI helps when adjusting the bearings, you can measure the end float on the spindle as the bearings are tightened, and know exactly the point where the preload begins. A tiny ammount of preload is all you want, and the standard method with taper rollers is to run the spindle at top speed. Check the housing temperature stays luke warm after 20 minutes. The DTI can then tell you if there is any radial play when you try lifting the front of the spindle. 0.01MM, or 0.0005" is a good ammount to start with, you have to understand that there will be some movement detectable even if the bearings are tight.

I would give the taper rollers another chance, unless there are visible indentations showing on the rear bearing outer ring.

You need to keep the Tizit bar flat horizontal while milling the bottom down to fit in your holders. This is to retain the correct angle of the insert when viewed from the end of the tool. It should dip slightly.

Fit the gib after fitting the table

I bought a 6" Soba RT which gets used regularly. It has 4 slots, which makes attaching the 6" four jaw independent front mount chuck very easy, using tee nuts which I made to fit the slots properly. Being able to mount a three jaw chuck is also handy, and I can mount a Pratt Burnerd 5" front mount using three 8mm tapped holes in the top. If you do that, beware of the lubrication drilling if there is one. I carefully drilled the holes and was somewhat annoyed with myself, as the third one broke into the lubrication drilling which I hadn't noticed. So this top has 6 holes in it. There is enough free play in the mountings of the three jaw chuck before the screws are tightened to put a MT test bar in the top and gently tighten the jaws on it before the chuck is secured. This will give at least 0.002" tir which is ok for all but demanding work.

I would vote for 4 slots, slightly more versatile.

As the application is not high speed, and the gears don't even move when the chair is going in a straight line, it would be a waste of money buying high quality gears. More importance should be addressed to keeping the gearbox sealed against ingress of dirt which will shorten the life severly.

Practice will make it second nature, I said as I tried to move the Y axis with the wheel on the rotary table.

I always recommend R8 above any Morse taper, if you are in the fortunate position to be able to choose. There again, the machine with speeds changed by belts or gears, rather than just motor rpm has the better torque.

It doesn't look exactly antique, maybe new blades can be obtained.

Using the same reamer with plenty of oil would be my first thought. It is very difficult to enlarge a hole that has already been reamed. Make a test piece first out of the same material if the original hole is critical.

I wonder if it could be sharpened by hand with a diamond lap of about 600 or 800 grit?

There will always be a centre in the tang used when the item was manufactured. Ihave taken advantage of this when machining the tapers of larger drills parallel, as we can only manage MT2. MT 2-3 reverse adaptors use up a lot of length.

I always use the same method as Hopper when fitting Morse tapers.

Edited By old mart on 15/09/2020 18:52:54