cheap and simple flame and plasma circle/radius jigs.

[tattoomike68]

A 1/4" bolt ground flat on two sides a washer and some rod and bent rod,flat bar and you are making circles, it is just that simple.

Flame and plasma cutting is an art all to itself and I love cutting.

 

[Bogstandard]

Heavy stuff going on here, it is many years since I did flame cutting and plasma hadn't even been thought about then.
We used to use a very similar method but ours was a plate with a slot in it, and a spike with a wing nut on that could be slid up and down the slot to give us whatever radii we wanted, just like your plasma one but horizontal, we also had a little wheel on the flame cutter to keep it at the right height. This is the sort of thing I personally like to see, cheap and cheerful we call it in the UK. Easy to make but does a great job.
Nice post.

John

 

[tattoomike68]

The top picture is of the jigs sitting on a rotary table where its mounted on a bearing and had angle iron chunks 2" long tack welded on standing vertical to give the slag a place to pile while cutting. most of my torch work was from 1/4" to 1"+ plate.

I have built alot of farm machinery and heavy parts were common and getting it done good,fast and cheap was key. I was the guy who had to machine the circles and stuff so I learned to cut very nice circles and holes. Anyone else cutting them would slow me down.

My woman told me when cash allows I can buy a CNC plasma table, new plasma and air compresser. I just love that woman.

 

[Cedge]

Mike
When I was still working the fabrication shop, we had a similar rig, but it had a collar that the cutting tip fitted into. The pivot collar could be moved on the guide rod allowing adjustment. A good steady torch hand could cut to the line with it. I was not the owner of those hands...LOL

Steve