Tire size for power hammer?

oldanvilyoungsmith

oldanvilyoungsmith

Joined
Feb 7, 2011
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Alright, I'm starting to gather up the stuff needed for a power hammer build, and I'm fairly certain that I'll use the tire style clutch.

Most people I've seen used a spare tire, but I'm not certain if it's because of size, or just availability?


Anyone out there who m ade one that can weigh in?

Thanks ya'll, Stephen.
 
When i built my rusty style hammer, for the tire i used a mobile home tire and axle as i had one in my scrap pile (i have a big scrap pile), i cut off about a foot of the axle on the end with a tire on it, and just bolted the whole thing to a stand, and built a plate and hinge for the motor.

It works well. And my hammer is a 58 pound ram run with a 1 hp 1750 rpm motor with a 4" wheel on it.

I have no idea about how to calculate the perfect tire diameter to go with the motor u have to get the desired speed of the hammer. I just built mine out if scrap and "close enough".

Sure beats a 4 lb hand hammer for breaking down stock though!
 
I'll try to get measurements for you ere the weekend is over, Stephen. My hammer is a bit slow at approximately 200 bmp, but it's 100 lb ram and I think it might stress things a bit much whipping around faster.

I advocate using a shaft with an eccentric wheel on the opposite side of the tire rather than trying to attach your linkage directly to the tire rim. Keeps you from having to do any welding on the rim and causing problems from that. Safer, easier, and just a bit more material.
 
Storm Crow said:
I'll try to get measurements for you ere the weekend is over, Stephen. My hammer is a bit slow at approximately 200 bmp, but it's 100 lb ram and I think it might stress things a bit much whipping around faster.

I advocate using a shaft with an eccentric wheel on the opposite side of the tire rather than trying to attach your linkage directly to the tire rim. Keeps you from having to do any welding on the rim and causing problems from that. Safer, easier, and just a bit more material.
Click to expand...

Can you show a pic of what you mean ?
 
What he means it the round plate on the other end of the shaft from the tire. It should have a series of holes drilled on a spiral path from the axle. That allows the linkage to be tuned for how long a stroke it gets.

A smaller and solid ( spare) tire eliminates pressure problems, and will last forever (almost) against the wear of the motor on the tread.
It also gives a better gear ratio between the motor and the tire, making the hammer a bit faster.
 
Thanks guys, I'll start lookin around for what I need.

James, while I got you here, what did you use for the rollers on the top of your ram? I watched your vid but didn't notice any mention of it (could just be I wasn't payin attention).
I saw pics of one somewhere that used stacked up bearings (like 4-5 in a row on the rod) but that seems like it'd be more problem prone, and I'd have to use a smaller bar.
 
The best laid plans o' mice and men gang aft agley...

Didn't make it to the shop, and I'm about to go help a buddy move, so it'll have to be later.

In the meantime, the rollers are machined with a hole down the middle that fits over another rod. The middle rod has a grease channel and is threaded on the end for a grease zerk, though in operation those seem to vibrate loose so I leave them out unless I'm actively greasing them.

I'll try to get some photos.
 
No problem, I'm in absolutely no hurry, I'm slowly gathering pieces for this as I get the available cash. I'm expecting it to be in the next month or two before I really get going on this.

As for the rollers, thanks for the info, that's something I can make fairly easily at the college machine shop. I was thinking it needed to be smoother like a bearing.

Thanks alot man! :D
 
I took measurements and pics, but looks like my memory card reader has pooped out on me. Here are the dimensions at least; all *very* approximate. The contact wheel on the motor is built from oilfield pipe and is about 2 3/8" OD. The spare tire is about 19 1/2" OD. It hits at something on the order of 200 beats per minute, but that's a bit slow for a power hammer.
 
Ok, got a new memory card reader.

First, here's a side view of at least part of the hammer to give folks an idea of the basic design:



This is what I was talking about with having the tire clutch on one side of a shaft and your eccentric on the other so you aren't having to weld on the tire rim:



The same setup could be done on a hammer with a DuPont linkage, i.e. the Clay Spencer style tire hammer. I've seen a Youtube video with a partially completed hammer like that, but it was in a different language and I don't even remember which one.

And the rollers:

The grease zerk side, without the zerks:



T'other side:



The biggest change I need to make now is adding adjustment screws to the ram guide to be able to take up any slop.
 
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