A Lawnmower Punch Press

[Robo_Pi]

Years ago I used to have quite a lot of reloading equipment including two presses. One single press and the other was a turret press.

You're right, they probably would work for this. I don't know. 1-ton isn't a lot of pressure actually. When the yard sales start opening up around here I'll be keeping my eyes out for possible hand-operated presses. I wouldn't mind having a small reloading press. I wish I would have hung on to my old ones. In fact, I would love to have about 99% of a lot of things I used to own.

My sister calls me a hoarder now because I refuse to throw anything out, no matter how useless it might appear to be at the moment. I learned my lesson the hard way.

I don't know if a reloading press could punch these gears out or not. It very well might. I trust that this lawnmower crank will do the job easily. With any luck we'll eventually find out the answer.

 

[kd4gij]

I say being hobbyist as most of us are Go Fore it. Sure there is other things that would work. I say use what you have at hand. Oh and in my last job I ran on occasions a coining press witch uses a large flywheel and punched out 100,000 parts in an 8hr shift.
Similar to this

 

[Robo_Pi]

,... and punched out 100,000 parts in an 8hr shift.

That's the attraction. I'd like to make at least 420 gears. Possibly a lot more than that. So the effort in building a punch press will pay off big time if it actually works.

 

[Robo_Pi]

Today's Progress

I'm not going to be working on this everyday to be sure. But I did take the crank out of the mower today,...

I had a heck of a time removing the block behind the mower blade. Had to heat it up and build a makeshift press out of cement blocks to get it off the shaft.




Then I had to wire brush all the rust off the shaft to get the bottom of the oil pan off.



Finally! We in!



At that point it was pretty easy to remove the crank and piston.



And then, after having done all that work I found another crankshaft laying around that I didn't even know I had.

Much BIGGER too.



Maybe I'll build two punch presses. A small one and a large one.

 

[rwm]

I confess I don't know much about punches but that seems like a lot of stroke lenght?
Robert

 

[Robo_Pi]

It is a much longer stroke than needed. But I don't think that will hurt. The actual punching operation wont start until the crankshaft is near bottom dead center. Everything previous to that will just be building up momentum. If anything it should be overkill. It also won't be real efficient in terms of rapid production because 90% of the stroke isn't doing anything. In other words, it's going to take it longer to go all the away back up and down again. In a production enviroment you wouldn't want all that extra unnecessary motion. But I think for a hobby press it's not going to matter much.

 

[rwm]

Makes sense, thanks
Robert

 

[Robo_Pi]

Makes sense to me too, but that doesn't mean I'm right.

Only time will tell. Maybe there's some magic in a short stroke that will come back to bite me later. I'll just keep plugging along here and see what happens.

 

[Superburban]

You could take that big crank shaft, and turn the two big diameters offset, to give a 1/2" to 1" throw, and run a setup like briggs did for their counter weight setups. Here is a good video that shows them. That would give you the small stroke for the power, and you could add some weight to the conecting rod area to balance the whole assembly, or even to work a power feed.

 

[Creativechipper]

Very interesting project going here.
Its always fun recycling things and seeing how others do it. Keep up the build photos!!