Member postings for Fulmen

Pop! Goes the submarine.

100mm stick-out with no end support is asking for trouble. Start with a bull-nose adapter and tighten the gibs. Raising the tool slightly to compensate for deflection can also help.

Have you tried changing the tool height? There is no law demanding it be on center. Small tools flex, sometimes it helps to raise the tool slightly.

- Hey, let's take an experimental submarine called "Titan" to the wreck of the Titanic. What could possibly go wrong?

I make my own cutting oil by dissolving sulfur in rapeseed oil. Works surprisingly well, and smokes less than Rocol. It's about 5% sulfur by weight and then heated gently until everything dissolves and the oil darkens a bit. Too little heat and the sulfur just precipitates out again, too much and it becomes gummy and develops a ... funky... odor.

@Lee: All ICEs produce copious amounts of water, hydrogen fuel won't be any worse than petrol in that regard.

@Clive: Same here. I recently made a couple of 5mm deep grooves, 23/29mm dia in mild steel. I broke 3 cutters and was sh*tting bricks the whole time.

For holding reasonably thick stock larger than the chuck:

Tap it and screw it on a threaded rod or preferably long bolt with the head behind the jaws.

And remember: Usually the most efficient way to remove metal is sawing. Interrupted cuts isn't doing your machine any favors either.

Edited By Fulmen on 09/06/2023 21:16:56

Ouch, that sounds like a real oddball. For an external thread the obvious answer is to single point it.

Yes of course. The die is "screwed on" the stock as if it were a nut.

Turns out that's not as useful as one could imagine. From what I've learned about flow, most of the pressure loss comes from the change in cross section. Cross drilling the slot first to create a series of expansion chambers would probably make it much more effective.

Can you push it out hydraulically with grease?

...a little *brute force* later...

It is a thing of beauty. It is also worn out.

The inner shaft has a handful of very noticeable flat spots, maybe 0.01mm deep? I gave up on photographing them, but the worst was perhaps 1mm wide. The surface finish is bright and uniform, but it has a very slight "faceted" look to it even where it feels flat. The rollers look and feel fine.

It might be possible to regrind it, but I don't have the equipment. Hopefully the replacement will be good, but you never know with second hand parts.

Aw crud. I thought it was screwed together with a custom wrench, but it's just figured out it's a spline joint locked with a recessed snap ring. I'll have to compress two large belleville springs in order to get it apart. I'm sure that will be fun...

Pulled out the bendix on my old Madura today, it had seized up. A little bit of wrenching freed it up, but I still don't know why or if it's going to seize again. It's a non-servicable part, but that has never stopped me.

I also have a "new" on the way from Ebay just in case, but curiosity is getting the better of me. Problem is the 29 tooth "spline head":

It's 29 teeth, OD is appr 23.5mm ID 21.8 (or less, hard to measure). It looks like the teeth are rounded, but the chamfer makes it a bit hard to say for sure.

Is this based on anything remotely standard or completely proprietary? I don't mind making the tool, I just would like to get it right on the first try and it's impossible to measure properly.

Edited By Fulmen on 29/05/2023 22:15:30

Edited By Fulmen on 29/05/2023 22:26:27

I have a metric 2J from Adcock and Shipley. It was wired for 3ph, but all the electronics is 1ph. The VFD is simply powered by the original motor leads, and the switch rewired to control the VFD. Check the panel, it should be fairly obvious if it's wired the same way.

Edited By Fulmen on 27/05/2023 21:08:56

Edited By Fulmen on 27/05/2023 21:09:12

M14x1 isn't that uncommon, IIRC it's used on brake lines or something like that. I actually have a tap for it. Used it on a couple of silencers, the thin muzzles often require a fine pitch. Besides they stay put with hand torque.

Two measurements with different size wire should allow you to calculate the angle.

I use 10% nitric acid for the desmut / bright dip, but it's getting hard to get hold of these days. I'll have to try HCl and nitrates one of these days.

This is a very important aspect that is seldom mentioned. Some sort of temperature control is required for best results. I've had baths heat up so much it just ate the part without forming any coating.