Recent content by kelvin2164

It's a Weldmac 40. I bought it about 10 years ago. I spoke to BOC (not much help, but a little) and I now recall that there may have been a spacer under the nozzle, to keep it at the correct distance from the electrode. I seem to have lost that. I bought it from Queensland Welding Supplies...

Hi Dennis I think that the problem is with the electrode not seating and being too close to the cap, as the cap gouges out on the inside (see fuzzy pic). Cant find anything on the internet that states a clearance figure. I'm still working on it.

A couple more pics. I bought a packet of inner stainless tips, and you can see from that pic that it doesnt screw down flush. All of them do this and I have none of the old ones to compare. I imagine an arc must be generated somewhere to produce the heat and wondered if the gap between the...

Hi All I have a large 240v plasma cutter, which, when new, cut 4mm steel like a hacksaw cut, with very little slag under the cut. I can no longer get that quality cut and the tips need replacing very often. Like about one metre of cut and replace the tip. The copper part seems to gouge out on...

It's a 2hp machine and seems to handle a 20 thou, 3" wide cut ok. Well maybe not ok when I think about it. I'm just a self taught, home machinist, and maybe the shuddering is not normal, but I dont know, never having worked in a real machine shop, with real machines not toys. I used to run it at...

Wow, Bazmak. A lot of trouble to go to, but I can see the benefits. My 3" cutter with triangular inserts dulls off very quickly even at only 270 rpm. Very expensive in inserts, but this looks like a great idea. I will give it a try when time permits. What speed do you run your diamond head at?

Here's a better shot, sitting on a mirror

Hi Petertha Thanks for your input and you may be onto something here. See attached pic. The sides of the insert are parallel with the spindle, but bottom looks funny. Looks like 85 deg angle, but due to the funny shape, the outside corner isn't the first point to touch.

Attached are closups of the inserts. I dont mind buying name brand inserts, but not if I'm only wasting my money. The inserts are APMT1694. The problem seems to my uneducated opinion to be a back rack problem, as it just scrapes across the surface without cutting.

Thanks for the replies. The machine is a HM 48, 2HP, which I bought recently and am very dissapointed with. Not very rigid. But my other cutter works ok. I would like to get it working as it as many applications. I was thinking of replacing the Chinese inserts with name brand ones. Which would...

I bought a cheap 2", carbide tipped face cutter on Ebay from China. Most of my tools are Chinese and are fine, but this thing just does not cut. A light cut just squeals across the top without cutting, leaving a heavily scratched surface and quickly making the work piece too hot to touch. It...

Thanks guys, I'm getting there. I'm like a kid full of questions. If this is skull. Why has it solidified when it should have the same melting point as the rest of the cast iron. My last pour must have been a bit too cold as the iron didnt flow properly and left unfilled voids. Would this have...

I've been doing some more cast iron castings. Skim the slag off the top, ok, but after pouring, there is a huge amount of slag stuck to the bottom of the crucible. A few questions. Is this actually slag? Can I add something like borax to act as a flux. I thought all the slag would float to the...

I had another go using a watered down sodium silicate. Didnt really harden that much after gassing, so gave up and did it using green sand. Pic below. I would like to be able to do it though. I have some cylinders to cast using quite a few cores and I like the idea of being able to sand the...

Wow! Before reading this post I went out and put a wheel in a bath of hydrochloric acid overnight. I guess that was wrong. I'll remove that now! We can buy pure sodium hydroxide here in Australia, which I presume is the Drano? I'll mix up a strong batch and give it a go. Thanks.