Working out tire hammer build, need a car guys help.

[will52100]

Oh, and I'd see about setting it up to take dove tailed dies, the bolt on works, but I have had them back out once in a while, and there not exactly fast and easy to swap dies.  Also had a bottom die break the welds and had to fix it, not a huge deal and once in 6+ years of hard use isn't too bad.

[Charles R. Stevens]

Jerry, not a fan of the overhead tire clutch myself, but the tire clutch is a simple and effective setup. Using it as a flywheel also makes for a compact unit. Myself I would prefer a helve style hammer, and am waffling between tire clutch and belt clutch (riding lawnmower parts?)

but as a durable component, we are talking about something that holds up one corner of a 35-4500# automobile, that covers 15,000 miles a year for 10 years over wonderful city roads (honestly have you seen the potholes?! I will take Slick rock Moab over some city streets) with no maintenance. Tire clutches have been used to adapt flat belt farm implements to PTO for years. It really is a simple system, reliable and durable. I recomend drilling holes large enugh to reach the lug nuts threw the plate welded on as a flywheel. Off-roaders have been welding need locks to rims for years, welding the flywheel/crank plate in isn't an issue.  

[will52100]

The first power hammer I had was a rusty style I built.  It's now been cut up for scrap.  The flat belt clutch system doesn't have nowhere near the control of a tire clutch.  Also the helve didn't hit as hard as the toggle link.  And I really didn't like the spring flapping that close to my face.  It was better than a sledge hammer, but the tire hammer beat it hands down.  If I was to build a helve again I'd use a tire as the clutch, much finer control.

[Charles R. Stevens]

As the song goes, "when everything is spinning around it's bound to come undone..."

I think Frosty and I just find the fabricated toggle linkage scary. Educate us so we aren't scared  

[will52100]

Kinda the way I felt about the Rusty linkage.

On any toggle link hammer I highly recommend a shield.  The tire hammer's linkage has a rubber hose over the spring, but I've still got a shield over it.  Also it's good to inspect and lube before use.

The only mechanical hammer I know of that keeps everything away from you is the rocking beam hammer, the springs and such are further back.

A toggle link is more efficient and hits harder though, has to do with velocity and inertia, the faster you run it the harder it hits.

The ideal would be an air hammer, but I like being able to run a hammer off an extension cord and a 1 horse motor, air hammers take bit more power.

[JHCC]

3 hours ago, Charles R. Stevens said:

Jerry, not a fan of the overhead tire clutch myself, but the tire clutch is a simple and effective setup. Using it as a flywheel also makes for a compact unit. Myself I would prefer a helve style hammer, and am waffling between tire clutch and belt clutch (riding lawnmower parts?)

Charles, do you have links to the specific clutches you're considering?

(And it's not waffling if there's no syrup.)

[Frosty]

I'm not a fan of the home brew toggle linkage, double nor single. Double as in a Little Giant or single like a "rusty". Either way there's a lot of reciprocating mass, pivots and linkages. Where you put the springs and clutch mechanisms only determines where you put the linkages and how log they are.

While I prefer to have as much as possible low and behind the work position it just makes the connecting linkages between the crank, toggle and hammer a whole lot longer making the moment of leverage against everything greater.

Clutch is easy with a tire hammer, a primary or drive wheel on the motor and motor on a pivot with a lever linkage to the treadle. Press the treadle and the primary or drive wheel on the motor is pressed into the tire. Easy simple system minimum failure points and if something fails the primary drops away from the tire and it stops. I LOVE this set up, any failure mode and it just stops. Provided the builder uses gravity to disengage the clutch rather than springs.

If we're talking about the current thinking we can make a weld on or bolt on crank plate and crank pin for the tire. Okay, but I'd like to keep the wheel assembly as light as possible, it's on the wrong side of the clutch to make a flywheel with any positives for the hammer. A positive acting flywheel would have to be between the motor and clutch or it's just more mass for the motor to accelerate when the treadle engages the clutch. To do any good you want the flywheel mass turning with the motor to contribute it's momentum to the reciprocating mass when you engage the clutch.

I've been wondering if they make a space saver with aluminum wheels. The less mass the motor has to accelerate before it gets to the hammer weight the better.

I'm not crazy about the overhead lever arm either but like it a little better then the double link arm systems. Not a lot though.

You MUST have give between the crank and the ram and that's most commonly done with a spring between the toggle arms or a leaf spring single toggle lever. I'm leaning towards using a telescoping spring similar to a motor cycle shock WITHOUT a damper. No t really a shock, just operates like one. Then drive it with a "Scotch Yoke."

If I can get a scotch yoke drive winkled out it will eliminate ALL the lateral reciprocating mass a Little Giant type crank and linkage system has so the hammer won't want to rock back and forth or go walk about. There are two good points: first the hammer will stay where you put it. Secondly and this is the BIGGY, rocking a power hammer back and forth takes energy as does acccelerating all the laterally reciprocating mass.. That is a huge amount of wasted energy I'd really rather have driving the ram.

Anyway, that's what I've been kicking around for a tire hammer.

Frosty The Lucky.

 

[Frozenforge]

If anyone plans to weld on the rim this can be very dangerous with the tire inflated. As the steel heats up it can raise the internal air temperature to a point where the rubber begins to give off flammable gases. The pressure then begins to rise quickly in an exothermic reaction or continued welding can ignite the flammable gas in the tire. 

This is all happening unseen until there is a catastrophic explosion. While it may be rare it has happened. There is a safety video from Michelin and it is well worth watching and it is an OSHA (yes I did say a 4 letter word) voilation to apply heat or weld on a rim with an inflated tire.

I would think that deflating the tire and removing the valve core and welding small portions at a time with a cool down period would reduce risk or actually removing the tire from the rim, perform welding then reinstall tire to be 100%. 

Sorry if this has already covered previously, I didn't search the forum to see if it had.

[will52100]

If I was to do any welding of the rim it'd be with the tire removed.  If nothing else, even deflated you would soften and potentially damage the rubber, especially if its got a tube.

I remember where they tried shock absorbers on a junkyard hammer on anvil fire, it didn't work too well, though it did work.  Seems it absorbed too much of the energy instead of transmitting it to the ram and work piece.

Me, I like the simplicity of the X1's linkage, http://www.anvilfire.com/AnvilCAM-II/index.php?video=x1-test1  but I don't know how well it'd work with a lighter hammer, the X1 is a 110 pounder.  I would  consider putting the tire at the rear like this hammer, http://www.anvilfire.com/power/cr-jyh_index.htm  I may build an X1, or X2 as it were some day, but I'm still dreaming of an air hammer.  That said, my primary use for a power hammer as a knife maker is turning large stock into small stock, very little shaping under the hammer except for drawing the tang out.

Frankly, the Clay Spencer designed tire hammer is pretty much perfect as is.  It's simple and reliable, and easy to build and repair.  If I remember rite, the linkage is pretty much an exact copy of the little giant's linkages, center to center dimension wise.  I have had a couple of failures, but those were due to some seriously sub par welding, with decent welds it's been bullet proof.  Also I highly recommend something a bit thicker than 1/2" plate for the base plate, I welded mine down to two pieces of 3/4".  I welded around the perimeter and welded some plugs in 1" holes to tie everything together.  If I was building new I'd just go with 1" or thicker plate and save on time and effort.  I might would also add grease fittings to the bronze link bushings instead of oil holes, but haven't felt the need to change.

I'll tell you this, if I can't break the Spencer tire hammer with 6+ years of beating 52100 1 1/2" stock down to 1/4" at 1600 deg. F., I don't know what can break it.  52100 at 1500-1600 moves about like cold mild steel, very stiff, and makes the hammer ring like an anvil.  With any hammer I recommend some sort of guard or deflector.

[Charles R. Stevens]

Haven't saved any links, it's all in my head. Your welcome to poke around in there...

As to welding rims, breaking the beed on one side, and wedge it down with a couple of blocks of wood...

unlike a head lock, fully welding is not nessisary, as 1" welds spaced a few inches apart is plenty strong

[setlab]

I've been busy working on my hammer and am about ready to build the move-able ram portion. I'm figuring how much material I need to do it. You guys that followed Clay's plans, what is the distance between the back of the tire to the 5x5 frame post? I'll post more pictures of the build when I'm done but here is pretty much where I'm at now. 

 

[Charles R. Stevens]

Nice work