I want to use the air chisel in my HF planishing hammer to incise straight lines.

Anyone have any simple ideas, or perhaps you actually have made this mod, to prevent the chisel from rotating?

Thanks,

Dave

Why not build a slot (guide) for the air chisel to operate through. 

Just leave room for the full vertical stroke of the chisel. It would not need to be longer than the chisel blade in one direction so you could still see the placement of the chisel on the metal. A simple L shape with the short leg split and the long leg to attach the guide to something.

My old pneumatic hammer came with chisels and various other tools like the can opener bit. I haven't used one recently but seem to recall the locking spring did it. It fit through a notch in the chisel I THINK. Some bits were made to turn like the star drill, rock bit, every impact turned it about 1/8 turn.

Frosty The Lucky.

I have seen air hammers where the tool part had a handle out the side.  Easy enough to make a piece and clamp it onto the chisel to keep it straight.

Greetings Windancer, 

      The simple answer is use a leather chunk with the pictured vise grip to hold and turn your chisel. I have used this tool for treadle hammer work for years and it works great... I also have a fixture that I use in my fly press which accepts 401 air chisel bits . Works super there too,, Give it a try. 

Forge on and make beautiful things 

Jim

I modified an air chisel to do this quite a few years ago.  I drilled a 1/8" hole through the threaded area of the air chisel just cutting though edge of the hole for the chisel.   I then drove a roll pin though the hole.  The chisels then just need a small flat ground on them.  The first time I did it I drilled too close to the hole center, which meant I had to grind too big a flat.   Drilling so the flat is just under 1/4" seemed to be just right. 

To drill the hole on the edge of the air chisel without it skating off I made a drilling jig.  To make the drill jig I  bent a piece of square bar to fit snugly around the air chisel threads.  I then ground a flat on the outside of the jig.  I could then drill on a flat surface.  Then I just clamped the legs of the jig in a drill press vise with the air chisel in the jig and the hole was easy to drill.

Use a lighter duty chisel and it is just like drawing with the chisel.  It works amazingly well.  I used a princess auto air chisel and it worked so well I bought a better quality more powerful air chisel and it had too much power and tended to bounce out of the groove.

I've done the Vise grip trick as shown above..  Also made a handle out of a shaft collar welded to a round rod.. I think the Vise grip is better and actually easier to adjust.

 

If you find you like the air chisel.. You might want to get a rivet gun.  They have a "feather trigger" and you can control how hard/fast you hit with them.

 

Jeff Tice

@Jim Coke, I will definitely have to try that for the treadle hammer. Thanks.

I just weld a 3/8" round handle onto the side of the chisel.  The handles break off on very rare occasion, and I weld them back on.  Had best results tig welding with 309 filler rod.

Greetings JHCC, 

It will work the best with a 7LW Vise Grip.The jaws are off set at the right angle and it will pinch the leather better. 

Forge on and make beautiful things

Jim

I haven't done anything about this yet- will post back after a few tries. Thanks to all for posting their ideas. Whatever I come up with has to leave both my hands free to guide the work.

Dave

I guess I am in a brain-dead state!

I need to have both hands free to guide the work.

Tried several things to no avail.

Anyone have pictures [which even in my current state seem to work best for me] of your setup that works?

I am working on a project right now, many large feathers, and if I could get this to work it would save me a H U G E  amount of time.

Crossing my fingers that you guys can bail me out, here.....

Thanks,

Dave

Greetings Dave,

             Yep me again...  I did a lot of chase and repousse work .. I designed a special machine that works great. The air hammer is rigid mounted but the work table is hydraulic and movable by the foot pedal. I can control the chisel depth and air hammer speed at the same time.. The big wheel adjust the table up and down 6 inches and the foot pedal dual control 1/2 inch. I have also a old air hammer part set up to use chisels in my fly press that accepts air chisels. Lots of tools for different applications. The nice part is adjustable depth for different base media. 

Forge on and make beautiful things 

Jim

Jim, could I bother you for a couple of really close ups of the parts that stop the chisel from spinning? I am ready to start!

Thanks,

Dave

Greetings Dave, 

         My set ups are different. If you are going to use the HF planishing hammer I would first suggest an in line foot control air switch. To stop the chisels from turning I would make a steady hold for vise grip and use the leather to hold the chisel from turning.  You can grind the chisel square under the leather contact point and for sure it won’t rotate.  I hope this helps . 

 

Forge on and make beautiful things 

Jim

Jim, I need both hands free to manipulate the work.

But thanks for trying!

Dave

Greetings Dave,

         What I suggested would allow both hands to be free... Read it again .. Ya can pm me .

 

Forge on and make beautiful things 

Jim

 

 

 

Dave. I have not made this modification but thought about it a couple of times (not too much)

My little air chisel has a spring that screws around the body of the air-tool and at the other end the spring end is bent at 90 and pokes sideways a bit.

To stop the chisel from rotating you need a fixed point. the only two fixed point available are the body of the air tool or the spring itself.

To make a slotted flat bar attached to the body would be possible but a bit complicated. I thought that the easier way would be to weld a small flat bar to the shaft of the chisel, bent backwards and slotted to take the end of the spring. The spring should be flexible enough to force it back and into the slot and the chisel should stay there during work, if the slot is longer than the travel of the tool.

Of course is you mount the air chisel on a stand like Jim has, you can have a guide for the chisel attached to the stand and not the airgun. A sort of slotted arm that can be as long as you need it to be to stay away from your work.

Hope it makes sense