Member postings for Pete Rimmer

I saw this happen once before to a guy I know. He complained about the same problem and that the nut had come off but the drawbar wouldn't release. Bashed it for a day and a half before he realised there was a second nut on the drawbar which acted as a lock-nut for the longer first one.

He loosened that second nut and the collet popped out.

If it's a close copy of the Atlas then you could get an idea of the gearset from the threading chart.

Atlas 10

I would say that £150 is a very fair price if the machine is basically sound. I wouldn't pay much more than a couple of hundred no matter how nice it was.

I had one of those but for an older machine so it was in brass. Threw it out a few months ago along with all the other 540 bits.

TBH for the half-hour's work it would take to make one I would not bother sourcing a genuine part.

The reason is that it's a 10tpi pitch .200" lead 2-start thread.

There's a very good chance that if you can cut your screw with the tool running away from the chuck, your lathe leadscrew is probably barely worn (if any at all) in that direction.

Of course, the only way to know is to map the wear in the lathe leadscrew

Before attempting to effect any re-cutting I suggest that you map the condition of the screw in both directions to record the wear on each side. Set up a tenth-reading dial indicator and use it to record the actual travel at each turn or half-turn of the screw. Do this in both directions because if the flanks are worn in both directions and you only machine one flank you'll still have a loose spot where the other flank is.

A few things to note:

If your lathe leadscrew is worn you will create a screw that has the same wear characteristics as the lathe screw, so you need to use a lathe with a very good screw to make an accurate screw for your mill.

If you map the wear on the screw then machine both sides of the thread you'll have a screw with an asymmetric threadform and you'll need to produce a matching nut or some kind of backlash compensating system for the nut you have.

Yes that's what I meant. I actually fitted one of those Denford setups to my milling machine and whilst it gives great variable speed it also suffers vibration. It's common as the belt and sheaves get older as I understand.

I'd find a nice used 1.5kw motor and vfd if it were mine. The mount plate is large enough to be re-drilled for various sized motors as I recall.

Good point. It's not the year, but the spec but yes there were some heavy 10's with the smaller bore just like there were some other sizes with the larger. The larger bore are by far the more common and identified by the 2-1/4" spindle thread.

One of my lathes is Jarno 12. I wish I could find an adapter for it.

The smallest lathe I know of which qualifies is a South Bend Heavy 10 which passes 1-3/8" (34.925mm) through the spindle.

Edited By Pete Rimmer on 15/02/2019 16:49:22

Are you sure? I'm no Rachel Riley but I get 2.8664 degrees included angle.

Without drawing it up in CAD your adapter sound awfully close to #13 Jarno taper.

Since the VS has the variable speed belt and pulley setup which is a real power hog not to mention a source of vibration especially when they get old, I would give serious consideration to removing those pulleys, and the VS speed control, and fitting standard vee pulleys in it's place. You'll get smoother drive and more efficient power transmission to the spindle.

The CE compliance mark and the China Export mark are deliberately similar to fool unsuspecting people into thinking they have bought a CE-marked item. Once you know, it's easy to tell them apart. Quite simply if you continue the C around to make it an O, on the CE mark the edges will meet but on the China Export mark they cross over each other.

**LINK**

I would use Araldite 2013 and iron powder as a filler. It's not cheap but it's very good. Cures at room temperature (20deg nominal).

Edited By Pete Rimmer on 13/02/2019 06:22:01

I was experimenting with this today. The graduations on my HLV cross slide are rather faint and I wanted to make them stand out. I rubbed some fine magnetite powder into the surface and it brought the marks up beautifully. Unfortunately I have not managed to find a way of fixing it into the engraved markings.

The answer for you is to re-make the adjuster screw with a fatter head that fills the slot. If the slot sides are not properly parallel they will need filing or machining first and the new screw made to fit very closely. I had to do this with my own Warco milling machine.

Edited By Pete Rimmer on 09/02/2019 16:24:44

Edited By Pete Rimmer on 07/02/2019 09:34:39

More like a bed fitting for a HBM I'd say.

I would install GearDXF on your PC and use it to produce DXF of both pressure angles for a gear tooth count you already have. Open the DXF in Draftsight (or other CAD drawing program), print at 1:1 scale and simply put the gear on top of the printed DXF. Closest match wins.