Tire Hammer

[Mainely,Bob]

Ted,I can see your mind is made up.
My experience with building foundations for large industrial equipment of various types and then installing them and test running them both on land and on the water has proven there`s more to it than that.

[Nakedanvil - Grant Sarver]

Some manufactured hammers had no counter-balance, many balanced the entire weight of the ram so they would lift smoothly. Little Giant played with many combinations over the years. I've seen 50's that would rock so bad they were in danger of tipping over. Not because they had no counterweight, but because they chose to balance nearly the whole weight of the hammer. So, ya bolt em down tight. And none of these hammers seemed any better or worse about transmitted vibration.

[peacock]

There are alot of tire hammers around this part of the country. Also several LGs. I have helped more than a few guys with this problem. In every case the problem with them moving around is the base is not flat then the bottom is not shimed enough to compensate for the round bottom. The next thing is anchors do not hold. I have not found any type of drop in anchors ( wedge, lead, red head, etc) that will hold. Cast in the base or good epoxy is all I have found that will not jack out of the concrete as the hammer runs. In another life I have balnced alot of motors and other rotating assemblies. Just not much chance of ever totaly balancing these hammers. Phil

[peacock]

Grant I totaly agree. I have rebuilt about 3 dozen LGs. Some of them Flopped sideways at idle(clutch pulley turning but not hammering) because the clutch and pulley assembly was out of balance mostly because the babitt was poured of center in a previous repair. Even these hammers would not dance if they were bolted down tight. Phil

[SGensh]

There are alot of tire hammers around this part of the country. Also several LGs. I have helped more than a few guys with this problem. In every case the problem with them moving around is the base is not flat then the bottom is not shimed enough to compensate for the round bottom. The next thing is anchors do not hold. I have not found any type of drop in anchors ( wedge, lead, red head, etc) that will hold. Cast in the base or good epoxy is all I have found that will not jack out of the concrete as the hammer runs. In another life I have balnced alot of motors and other rotating assemblies. Just not much chance of ever totaly balancing these hammers. Phil

Phil's got this right but not just about tire hammers or even hammers in general. Lots of guys will build a base for a hammer or a vise or something else out of what they think of as a "stiff" plate something like 1/2" or so and then weld a stalk (tube, I beam segment, or such somewherr near the middle on top of the plate. All of the weld distortion on the top of the plate results in a convex curved base plate almost garaunteed to rock eventually. (something likely to happen even if the plate stayed straight as most floors aren't flat either). I make a lot of stands for museum objects and it's been my practice for years to make any base in such a way that the stalk or shaft penetrates the base and is welded under rather than on top of the base so any distortion creates a very slightly conical base with it's outer edges lower than the center and therefore more stable. If you are going to weld to a relatively thin plate only on the top surface or work with any less than flat surface take Phil's very subtle advice and shim the mounting points so that the object can't rock. If your base plate is thin enough that it will deflect (say under a hammer's impact) shim the point directly under the upright first then shim the hold down points so that it will remain solid and steady. None of this of course addresses the issue of impact and a seperate foundation. Just my opinion of course- Steve G

[Nakedanvil - Grant Sarver]

Hey Phil! I did my last small hammer the same way we did big hammers. I used bolts that were about 1-1/2" extra long and put die springs under the heads and tightened them down about 3/4 of the way. Worked a treat! I don't think there is any kind of "solid" anchor that won't pull out after a time. Probably cast in "J" bolts will work for a long time, I still like the springs though, get too solid and you'll probably break something. Strains just move on down the line, till they find an outlet. Bold a cast hammer down too good and you'll probably break the flange. I like "give", the way a willow will stand in a storm that takes down the oak.

[twcoffey]

THAT is the first mention of "sideways movement" in this discussion. And has marginal affect on the foundation and isolation requirements. If the weight of the ram has "nothing to do with the hammer dancing problem" why do so many home made (and some manufactured) air hammers dance around? If sideways movement is the only consideration, why do we spend so much money on isolation and foundations for self-contained and air hammers?

OBTW: "Case closed" is just as irritating as "period, end of discussion" and means about the same. Only the group as a whole decides when the case is closed. One experience with one hammer is hardly definitive and is just anecdotal evidence. Although your analysis on rocking moment is correct.

Grant and others,
I apologize for making such an inappropriate comment. I think generally we are in agreement.
Ted

[wathomas]

I don't have experience enough to make any useful recomendations. FWIW I tried no weight and two different weights...for my tire hammer, the heavier made a big difference. I think it could be improved even more if I fooled with a bit more weight. As it backs up to a heavy lathe (approx 5000#) right now I have just looped a line around it ...that prevents it from slowly "walking". Its not bolted down..right now I am thinking next time I come across some scrap heavy rubber I will put it under the base see what that does.

Thats not why I posted. I want to say I am impressed with how everyone shared their experience in this discussion. Its a good group.

Kudos for Ted..class act to make a simple apology ,not take offense or stray off topic. And that was made easier I am sure because Grant was quite graceful in expressing his observation how a statement made for emphasis can prevent or have a tendancy to prevent everyone from expressing themselves. I will keep lurking always informative. thanks all.

[Sam Salvati]

Some manufactured hammers had no counter-balance, many balanced the entire weight of the ram so they would lift smoothly. Little Giant played with many combinations over the years. I've seen 50's that would rock so bad they were in danger of tipping over. Not because they had no counterweight, but because they chose to balance nearly the whole weight of the hammer. So, ya bolt em down tight. And none of these hammers seemed any better or worse about transmitted vibration.

All this spinning rotation blechhh, they got it right with the Bradley! They used the momentum to they're advantage, and kept it in an up down orientation and then used it to facilitate the whipping motion beneficial to a hammer.

[peacock]

Good point Sam even the current crop of self contained air hammers from Europe (Kuhn, Sayha, etc) have the rotation in line with the long foot print. These hammers have no counterweight. What they do have is a large flywheel compaired to the stroke. Short stroke large bore pump keeps volume up, out of balance to a minimum. Phil

[Sam Salvati]

Good point Sam even the current crop of self contained air hammers from Europe (Kuhn, Sayha, etc) have the rotation in line with the long foot print. These hammers have no counterweight. What they do have is a large flywheel compaired to the stroke. Short stroke large bore pump keeps volume up, out of balance to a minimum. Phil

I never thought of that Phil! I had a slight passing thought when I made my comment, about air hammers rocking (my Anyang is configured like a Nazel, flywheel perpendicular to the frame, and rocks slightly because I haven't tied it down yet).

[John Larson]

Floor anchor bolts have always pulled out for me. When I helped a friend with her 50 pound LG by bolting it to a 4'x8'x1" steel plate the machine was totally tamed and rebound seemed improved by a large amount.

Every hammer head pulled upwards correspondingly pulls the front of the hammer downwards and forward. Heavy anvil mass conquers that to large degree. I see it in my utility hammers as they have evolved over the past 14 years or so. Conquering that is step one.

I believe that the pump imbalance in a self-contained air hammer or the crank imbalance in a mechanical ought to be solved as a separate problem. Single cylinder engines cannot be totally balanced, so I'm sure that the same is true for air pumps. With the LG type of articulated linkage there is a really difficult physics problem associated with the off-loading of the springs at die contact and the reloading of the springs on the upstroke. As for a self-contained hammer with good pump balance I've mentally toyed with horizontally opposed twin cylinders--the so-called boxer configuration--to achieve balace and to render the pump set up more compact.

On another note:

Steve Gensheimer's comment about welding on the bottom of a base plate is brilliant. An old fabricator approach was to weld on both sides of the plate and the grind off the bottom. Uniting that with Steve G's idea seems immediately obvious.

I no longer weld base plates, even thick ones. I machine them flat and use bolted connections. In my opinion this is the only way to do it reliably.

[youngdylan]

.
Steve Gensheimer's comment about welding on the bottom of a base plate is brilliant. An old fabricator approach was to weld on both sides of the plate and the grind off the bottom. Uniting that with Steve G's idea seems immediately obvious.

I no longer weld base plates, even thick ones. I machine them flat and use bolted connections. In my opinion this is the only way to do it reliably.

This assumes the floor itself is flat. There could be a crown or high spot to the ground at just the wrong point. My hammers all use adjustable machine isolation feet at the four corners to make sure of good contact at these points. The "mass spring system" reduces inpact transmitted to the slab and the feet can be adjusted for contact one all four corners.

The inertia the bases I fabricated for my Anyang and "KA75ish" prevents them walking. The Kinyon doesn't have enough mass, so has a light angle iron frame around the feet to "pen it in". Its worth noted that the Anyang rocks considerably, almost diagonally, because the feet compress but hasn't walked a mm in a few years. This is inspite of the fact that it sometimes almost jumps in the air if I'm a bit heavy on the throttle at the start. The Kinyon rocks back and forth. The KA75ish doesn't rock at all, the tup and air cylinders are all on the centre axis

Air hammers rock !....... in more than one sense B)

[Nakedanvil - Grant Sarver]

When I was building the KA I had a 4-1/2" hole in the bottom and plug welded that first then welded around the 5" anvil. The base plate was 1" thick too. The extreme weight of John's hammers with a 20:1 anvil and massive construction pays off in many ways. Makes a nice solid hitting hammer and it don't take much to keep it in one place. I expect to just use a couple drop-in pins so never creeps.

[Senft]

As far as balancing the reciprocating and rotating assembly, normal way used on engines is to make up a weight which represents 100 percent of the rotating weight (crankpin bearing, and half of the toggle arms and spring) plus 50 percent (normally) of the reciprocating weight (the other half of toggle arms and hammer head, top die etc. Hang this weight on the crankpin and proceed to static balance by playing with counterweight until the crankshaft does not fall to a heavy spot in any position. Sometimes very slow moving assemblies are done at less than 50 percent of reciprocating weight. Perfect dynamic balance not practical due to fact that the weight spinning on the crankpin is not in exactly the same plane as where you can place the counterweight.

[KTB]

Wow, glad to see my hammer provoked some great discussion. I learn quite a bit from these topics. As far as my hammer goes it rocks but I know the wooden base isn't very flat either. I have a 3/4 in thick metal base plate through bolted to pine 4x4's that are in turn tied together with threaded rod. I would have preferred to use hardwood but I used materials I already had laying around. I am fairly confident that after I anchor it down with 5/8" or 3/4 in. wedge anchors it will hold up for a good period of time.

[John Michaels]

That's some nice equipment Keith, and yours too Mike.

[divermike]

Mine rocks a bit as well, so I made two straps coming off the top bolts and ran them up to a soffit, and tied them in there, that mellowed the machine out, just shimmies some stuff off shelves now and then when Big Red starts to really get goin, it's a fun beast to play on!!