Member postings for old mart

A lathe with backgear can usually isolate the spindle from the leadscrew, and if you can lock the spindle, you're halfway there. A lot of Myfords have a handwheel on the right hand end of the leadscrew. The requirement for 19" between centres is more of a problem, I'm not sure about that.

Welcome Mike, there are plenty of people on the forum who are into machinery, both static and with two wheels.

I prefer to use a lever type indicator rather than a plunger. If the stock is square or rectangular, I just use the tool to touch the corners and see the marks made, or the gaps left.

There is nothing preventing you from very carefully putting a tiny bevel on the anvils with a fine diamond lap, say 800 grit. Make sure you don't spread the super fine abrasive particles about by using a little oil and cleaning afterward carefully.

This Rambaudi is iso50 fitting and built like a brick sh-----se

**LINK**

If I had a choice, I would always make backplates out of nodular (SG) cast iron. Why, it is easy to machine and doesn't make the mess of dust that ordinary cast iron does. The common blanks available, however, are the messy type, and having a magnet close to the tool tip can catch some of the dust. Steel is perfectly acceptable if your tooling works well with it. Having to make the register and thread without a gauge can be overcome quite easily. If the blank backplate has been faced off flat on the side which the new chuck will mount, and then turned round and clamped to a faceplate, the register can be bored to about 0.001" larger than the spindle register. The thread if Whitworth form will be 0.064" deep, so the starting bore will be 1.247" The thread if UNC form will be 0.065" deep, so the starting bore will be 1.245"

Just touching the threading tool in the bore and then cutting to a finish depth of 0.064", or 0.065" will give you the nominal size. Adding an extra 0.002" on a thread this coarse will not do any harm whatsoever. To check the fit on your spindle, just unscrew the faceplate with the backplate still clamped on and try it out. Should it prove to be too tight, just remount the faceplate, and with such a coarse thread, you can visually check the alignment of the tool in the thread in case it requires a slight adjustment.

Absolutely right about the chuck, one of the slimline chucks could save you 1 1/2" assuming that fitting it is feasible. A lot of the time you could make extra space by removing the tailstock.

If it was mine, I would think of the larger four jaw in the photo by S O D, it could be fixed to the faceplate easier. Also, a four jaw, while more difficult to set up, offers more versatility than a three jaw.  

A four jaw chuck can be drilled through from front to back without interfering with the mechanism if the holes are in the area between the jaws. this would make it easy to mount to the backplate.

Edited By old mart on 23/02/2020 21:52:50

Edited By old mart on 23/02/2020 21:57:33

I usually sit the dti on the cross slide if it needs to be moved about when setting up, and moving the saddle and cross slide speed up the rough adjustments, otherwise it sits on the bed.

Its easy to avoid flexing, just take your time with smaller cuts, or at least fine finishing cuts that will correct the problem. There are people who regard a Bridgeport as being too flexible, it is all a matter of scale.

I have been meaning to make two extra keys for the 6" and 160mm four jaw chucks for some time, having often heard of the improvement in dialing in. It pays to practice getting a four jaw chuck spot on, the work is held more securely, especially when parting off.

As for accuracy in setting up, it always depends, although, more than once, halfway through machining something, I have kicked myself for not getting the first chucking spot on when I had the chance.

Edited By old mart on 23/02/2020 20:43:20

I would look on the ARC site (link on this page), their range is good and they also publish the footprint of each one, which is most important. I always recommend one with an R8 fitting spindle if there is a choice, it was designed for milling, wheras the MT3 was designed for drilling, there is a difference.

Some time ago, I bought a set of brazed on carbide tools for the lathe. Even when sharpened on a diamond lapping wheel, they were still poor. They got binned and I have used nothing since but proper industrial inserts. The only time HSS goes near the lathe is in the form of drills. Getting the grades right can be a problem, inserts for steel are not sharp and are useless for finishing cuts, but excel with deep cuts. If you dare to make a finishing cut of 0.025" deep, then the finish will be good, but not so with a 0.002" pass. As already mentioned, there are sharp inserts made for aluminium, which are as sharp as HSS, but a much more sophisticated profile, they are capable of cuts on steel down to 0.0005" depth or less. Another advantage of using tooling with indexable inserts is the consistent tip height, so if your Bantam can use 20mm square tooling, with a shim, then that shim will be correct for all your tools except boring bars. I keep each size of boring bar in its own box with a shim to suit it.

I put a wad of paper or rag under the tool to catch it when the collet is slackened off. You can always tighten the collet with the fingers enough to hold it before tightening up.

Edited By old mart on 22/02/2020 15:11:05

Nicholas Wheeler's suggestion of the hose would work best. Don't forget, you are weakening the steel by drilling large holes in it.

I would look into milling flats on the collet chuck to use a spanner on. I did that with a 6mm solid carbide end mill on the er25 x R8 collets that I bought. I notice that the current Chinese ones already have the flat from new. If we want to change the cutter without removing the er25 from the spindle, we use spanners with specially long handles, at least 250mm long. On the Tom Senior with the R8 spindle, I had the luxury of being able to incorporate spanner flats near the spindle nose during the design phase and also another mill to carry out the work.

Have you got any ring gauges in that range to set it with?

I had to show an old lady how to drive one of the mini cart/trolleys when they first came out. You can push then, pull them or carry them.

That looks a likely use, the numbers would be the right way round as well.

I have several of the Parkside 20V tools, the combi drill, the drill without the percussion, the SDS hammer (excellent), the jigsaw, (not great) and the vacuum cleaner (very portable doesn't hold much, especially swarf off the mills, bags have to be ordered from Grizzley in Germany, but a boon for keeping all the batteries in good condition by using them rather than just storing them). These use the 20V Team batteries, not the very similar ones they sold with the brushless 20V tools.

I also have one of the 12V angle grinders which is very good for small jobs where a full size one would be too big. It uses the little 75mm discs and the second generation 12V batteries

This casting had been on ebay for several weeks with no interest, and when I looked at the pictures, I noticed the scale in degrees. That got me thinking of what it could be turned into. The round part is 6" in diameter. The start price was low so it was cheap without any bidding competition. The degree scale does not go right round, it is 90 - 0 - 90 and the correct attitude would be with the square part at the top. Could it be from a small milling machine?