HF Planishing Hammer Modded w Hammer Drill?

[Dawai]

Well there comes a point where "noise" is hammer blows on metal.

Richard (you never call anymore) I have worked construction since I was young. I am no longer young. I never have saw a electric hammer drill that uses a air piston. they all were mechanical linkages.. Do you have a link so I can look at the parts break down?

I've ran them from 1/2", which the insides look like a star-fish.. to a 1" one where they look like a kick starter gear in a harley with a spring loaded ball bearing. The big ones have a lever to just "chisel" and that is what you are after I think.

I've dropped, broke, twisted in half more than most people have saw in a store. I had a young black female apprentice at a job in Chattanooga.. she was having trouble with a drill, keeping it steady, she said.. "COFA.. grab my hips and help steady me". I looked at her jiggling there and said.. "No dear.. if I do, we'll be here all day".

[Dawai]

http://www.harborfreight.com/3-in-1-...mer-97743.html

On Sale right now for $80.. 3/24/12 There is a parts breakdown there..

Okay.. this one has a pair of pistons, a crankshaft and connecting rod..
Can't say I have ever saw the guts of another one like it..
HOW long does that last thou not running in a crankcase full of oil?

ONE thing to note.. anyone could take a small engine drive it with a elec motor, remove the camshaft, plumb the spark plug out to a hyd cylinder, add a damper "pneumatic" cylinder in the circuit.. Oil on one side, regulated air on the other.. and each time the piston "rises" since the oil is non-compressible the cylinder will move.. It will generate heat. To hit harder, just add more air pressure. That would be "better" and simpler I think than trusting a "chinese" motor to not burn out after ten minutes.

BUT? why do that when a helve works so well. Kiss=Keep it Simple Stupid. (don't ask me.. I'm a rube goldberg fan)

[Richard K]

Most demolition hammers including Bosch and Milwaukee have been built with compressed air mechanisms for many years. Air is a compressible medium, hydraulic fluid is not. The compressible medium provides a cushion in the mechanism.

The Chicago Pneumatic Air hammer and all muffler chisels that are air operated take advantage of the same principal; the difference is the compressor (motor driven piston) is remotely located.

Although I've not seen plans or inside the Mechammer; I'd imagine it works in a similar fashion but runs slower.

The demo hammers all have brush type "universal AC motors. Universal motors can be speed controlled by dropping the voltage. Harbor Freight sells a "Router Speed Control" part No 43060 that will slow the motor on a demo hammer. It will then be quieter.

[marc111]

Thanks for the feedback everyone.
My thoughts.
1) I am a small shop and while the mechhammer is really nice I will have to wait a bit to build one.
2) Based on all of the feedback, your points on air vs fully mechanical were very good. I will stick with air for now.
3) now searching for a quiet oil type compressor that puts out at least 5 scfm at 90 psi.
4) I might just try the HF gun for curiosity with its cheap sale price.

I really was surprised when it comes to noise levels. Planishing both 16 ga and 20 ga steel the hammer and rivet gun really were much quieter than the oil free compressor I borrowed from a friend to try things out. Time to shop for compressor.

P.S. Check out my new thread showing off my modified HF unit.

Thanks,
Mark

[marc111]

Oh and thanks for the link to Richard K's build with the HF demolition hammer. I was really trying to find that thread and didn't have the right key word.

I appreciate the feedback Richard. Do you think your version with the demolition hammer is any noisier than the pure air hammers? Any things you do not like about it that you would change if you were redoing it?

Mark

[marc111]

Well I flipped on my choice. To get a decent compressor and hve some hope of lowered noise levels I was easily in the 400+ class. So I bought the HF Hammer Drill and am in the processs of fitting it onto a frame together with foot pedal control of up/down position. Once I get it worked out I will post some pics.

Mark