Member postings for old mart

I was just browsing this old thread and noticed a question asked by Steve King 5 about his Smart & Brown model A. The answer was in error. His lathe has the revised apron, but the original cast iron stand. It is a Mk 1.5, not a Mk 2. The other improvement to the Mk 2 is the single control to engage the back gear, which cannot be identified in general pictures. The Mk 1 and 1.5 require a locking bolt retracting from the pulley before the back gear is engaged. The Mk 2 maximum speed is 1800 rpm, the older ones only 1425 rpm.

I believe there is a link between the collet lever and the lathe headstock or bed.

I remember back when I was a teenager, throwing a 1/4 full paint aerosol can on the bonfire in the back garden, and then shooting at it with my air rifle, a Webley Junior. Fortunately, I was twenty feet away, as the flamethrower like fireball reached about fifteen feet in my direction.

The only thing wrong with that er25 collet is the lack of spanner flats on the body. I put flats on the ones I use, and made a custom spanner, carbide endmills made the flats a doddle.

Later on you will be glad the X is a decent size, when some odd job comes up and you say "I can do that, fortunately". It will also be nice to have a DRO, and forget about the horrors of backlash, which is always there even if minimal. I always recommend R8 if there is a choice for middling machines when buying.

Good luck with the installing.

Could you post a pic of the plate on the drill?

There are plenty of ads on ebay for the linked belt to make your own custom belt. I bought a metre of it for the Light Vertical head, and made two belts, with three links left over. It comes in various widths.

Another popular way of dispensing the oil is to use a small cheap brush and one of the oil pots that do not leak when knocked over. I do up the er25 collets by using two spanners and using the bench top and tightening before fitting to the spindle. If tightening in situ, then 12" spanner extensions are a great help.

I've just noticed that Arc have an ISO30 X 25mm cutter which uses APHT style inserts, (060-282-00260). This is one piece and although not illustrated, should be quite short, and certainly save some valuable Z height.

Welcome, Gavin, I've looked at your collet chuck thread, but cannot help. I take it the anchor bracket is the pivot for the lever, I have not used one for at least 40 years, and that was on a Myford.                                                                What you need now the metal bug has started to bite is a mill.

Edited By old mart on 15/12/2019 15:23:05

It's a nice looking machine, be careful you get the plug wired correctly, the wire colours might be strange.

If the cutters are hss (steel and magnetic) rather than solid carbide (very weakly magnetic and heavy feeling) then some lubrication will extend their life considerably. You could get a small amount of water soluble cutting oil and dilute it to about 10% and put it in a squeezy bottle to dribble on as you cut.

The width is tight, I would look at the ARC site, I believe they give the dimensions and some of their fairly small mills have the preferred R8 taper.

The SX2P uses up 845mm width and only runs to 2500 rpm, but has R8. You have to factor in the full movement of the bed X axis when calculating the footprint. 

I missed your last post, good luck with the new mill.

Edited By old mart on 14/12/2019 22:41:07

Edited By old mart on 14/12/2019 22:42:38

I have some end mills with the flat, and they are generally put in a standard R8 collet. I make sure the flat in centralised in one of the three segments. With er25 collets, I would try to get the maximum amount of full diameter into the collet, even if that meant leaving only a small length of shank protruding. Just make sure the drawbar is tight.

Edited By old mart on 14/12/2019 22:23:59

My experiences with the cheap Chinese shell mills with APMT type inserts has been better than Jasons'. I have 5, two 40mm and three 50mm, they all fit snugly on their R8 arbors and run within 0.002" tir. One of the 50mm ones is not as good as the others, as it will not face and shoulder. The shoulders are sloping about 2 degrees. That one is labelled as such. They are cheap enough to have inserts for steel on some and for aluminium on others, saving the bother of changing inserts round. They all run on 22mm arbors, the 50mm size uses APMT/APHT16 and the 40mm use APMT/APHT11 inserts.

I also have Ceratizit, Maydown, Kennametal and Hertel shell mills, from 50mm to 80mm. 

Collets in an ISO30 fitting mill should work just as well as they do in R8, as the taper is the same within a few minutes of arc. The only difference is that the drawbar thread, 12 X 1.75mm is coarser than the 7/16 X 20 UNF of the R8. Slightly more torque will compensate.

Edited By old mart on 13/12/2019 21:57:33

As already mentioned, tin melts at a higher temperature than most tin lead solders. Using tin on its own is not free of problems:

**LINK**

You don't mention which mill you have, or its spindle fitting. If you cannot use a lathe to face the casting with carbide inserts, then maybe this isn't too big. Much smaller cutters from 10mm diameter are also available with carbide inserts.

**LINK**

Another way to hold that pinion more securely would be to turn up an aluminium tube to just fit on the pinion, with a reasonably thick wall. Make an axial cut with a hacksaw to make the tube into a custom collet. The three jaw chuck will hold the work better. Take the time to learn to set up a four jaw independent chuck, they are always better than anything else. If you only have one chuck, make sure it is a four jaw.

I have only used the rotary encoder to program the VFD, as I had already connected all the remote controls. The speed is controlled by a pot which has to be programmed and certainly always sets whatever speed the pot is at when the start switch is pressed. The encoder does not have travel limiting stops like a pot.

Here's a link: **LINK**