Member postings for old mart

I've had a look at the Technology Supplies milling machine guards, and particularly the fitting at the ends of the bed, which may be the way to go. Tee slot mounting could be made very adjustable to suit different jobs.

Food for thought, they are all good, and if the health and safety people visit and see that we are making an effort, they can be remarkably helpful. The 6mm polycarbonate is pretty much bomb proof and it can be bent when a hot air gun is used. Some of my efforts at heating it have ended badly with a local overheating which makes it start to bubble up. The TS does not lend itself easily to a permanent guard, a small one might fix to the quill where a substantial aluminium ring is clamped on to connect to the Z axis digital readout.

I remember plunging a 1/4" slot drill about 1/4" deep and getting a hole 0.015" oversize. Changing the cutter resulted in a hole only 0.001" oversize, yet there didn't seem to be much difference in the sharpness.

The trouble with plunging two flute slot drills is that viewed end on they are asymmetric, so they drill like a badly sharpened twist drill. For cutting the actual slot, two and three fluted mills are much preferable to four fluted as the 90 degree separation of the cutting in the four flute interferes with the cutting.

Recently, I wanted to cut a quick flattish bottomed hole in a piece of 23mm square aluminium. The hole was 3/4" diameter, and 1/2" deep. The aluminium went in the lathe four jaw and a new Osborn slot drill went in the tailstock chuck. The tailstock was shaking at least 1/16" when I made the hole.

Edited By old mart on 09/10/2019 22:43:26

The T S light vertical we are working on at the museum is nearly finished, but there is one point I have so far failed to address, namely the fitting of some type of guard. This machine will be used by some of the volunteers at the museum, and must at least pay lip service to health and safety. I have never seen pictures of one of these mills with any type of guards. I have a supply of 6mm polycarbonate which has been used to make guards for the mill drill, and I would be pleased to hear from anyone who has any type on their machine.

I wouldn't be without my Shetack Monument thread reckoner. It has metric coarse, BA, UNF, UNC, BSF and Whitworth threads side by side. This makes it easy to compare sizes quickly.

**LINK**

Jason B's suggestion is best, leave less material for the slot drill to plunge into. A solid carbide four flute end cutting mill will plunge much better than a two flute slot drill, which is preferred for the actual slotting.

Good, you have the up to date inserts. You might try some of the cheap Chinese ones from ebay, they have improved a lot in recent years. For roughing steel surfaces, you cold get try and get tooling which uses round inserts, you can turn them a little at a time, and get up to 8 goes per set. I recently got a 40mm shell mill which uses 4 of the small APKT inserts, it had a 22mm arbor fitting.

15 years ago, a workmate was building a custom car, road legal, based on a Ford Pop which had a tuned small block Chevy engine with nitrous injection (9.75 quarter mile, that thing went well) and several of the special goodies bought from the USA had metric threads and fasteners.

Edited By old mart on 07/10/2019 21:45:26

You will find that the triangular 12V Parkside batteries have changed in the last year. at first glance they look the same, 12V, 2ah, but the new ones do not fit the older tools. The newer type are available at most Lidl shops and a range of tools including an SDS drill, angle grinder and drill driver are on sale especially in the larger shops.

Edited By old mart on 07/10/2019 21:33:30

They are a cost effective method of screwing directly into holes which are in castings of zinc or aluminium alloys and which have a draft angle, not being drilled. Generally, they are not intended to ever be unscrewed.

I would get indexable tools for your mill, this one is 12 mm for APMT11 inserts (1). The inserts are double ended and would be a lot cheaper to run than buying solid carbide end mills. The shank can be cut shorter if required with a hacksaw.

I have just seen that you are already using indexable inserts. I would be inclined to run at 4000rpm at least with these. The ones that you are using are first generation if they are TPUN and not exactly suitable for a cnc mill.

**LINK**

Edited By old mart on 07/10/2019 21:08:37

Edited By old mart on 07/10/2019 21:12:41

I would carefully measure the jaws and make a drawing including the teeth pitch, and keep checking the ads on ebay, sets do come up from time to time. Rotagrip sell soft jaws for your chuck, which could give it a new lease of life for special jobs, where perfect running is important.

The cardboard from a cereal packet or slightly thicker would be fine, you could cut a stock and change them every time a wheel is changed. As you are obviously aware of the importance of the soft interface, there is nothing more to say.

Welcome John, there are a lot of old motorcycle enthusiasts on this forum.

I used to live in Rusper and Lower Beeding about 60 years ago, I last went to Horsham about 12 years ago.

You would need a very strong Jubilee clip on the end!

One of the 25mm R8 collets is back on ebay, for sale by a reputable vendor. I would not dare to try one for fear of a disaster, has anyone used one?

https://www.ebay.co.uk/itm/R8-Collet-for-Bridgeport-Milling-Machine-etc-25-mm/372791941387?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

Edited By old mart on 05/10/2019 21:39:11

When we rewired the museums single phase 1 1/2 hp drill mill, we didn't bother with reverse, but kept the pulley lid safety microswitch, added a NVR switch, and added a standard emergency stop switch. The emergency stop switch is in the live incoming wire.

 Other things like DRO would benefit from their own separate power supply. Our lathe has a microswitch in the chuck guard which is linked to the stop button, which gets used all the time rather than bending down to reach the regular stop button.

Edited By old mart on 05/10/2019 21:20:41

Edited By old mart on 05/10/2019 21:25:17

That's what I thought, but the advertised one is just a tube with ends and fire tubes running through it, I cannot see that if it was double skinned, that there would be more than 1/8" gap between the plates. I had assumed that it was solid.

We were left the Tom Senior light vertical in a benefactors will. The Helicopter Museum at Weston Super Mare already has one of the larger drill mills, but I liked the thought of a knee mill so much that I have spent a lot of my own money to modify and restore it to working condition. It now is R8 instead of the MT2. It is close to start up now, just a few more bits of wiring to finish. I have a slow running thread going in the TS section of manual machine tools if you want to look at some of the pictures.

Please forgive me for knowing almost nothing about boilers, but as the firebox appears to be just a cavity with no water in it, where would the stays go?