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Dan O'Connor

Tire/Japanese Spring Power Hammer Build

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How many HP motor?

 

it'll be fine

 

My tendency is to go overboard but in this case I chose only a high torque 2HP. Hope it is enough.

 

Ooomm-Physics is my friend-Physics in my friend-Physics is my friend Ooommm.

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I have a few questions on this build. First I am not familiar with the design of this but why use a tire at the top? There should be plenty of better choices to use. What is going to happen when/if the tire looses air or pops during operation? How much damage is that going to cause? Also it does not look to be that easy to replace the tire when the threads are exposed.

 

The other notion that hit me is if the tire slips due to faulty traction. It may be me but this seems to have major design flaws in it.

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I have a few questions on this build. First I am not familiar with the design of this but why use a tire at the top? There should be plenty of better choices to use. What is going to happen when/if the tire looses air or pops during operation? How much damage is that going to cause? Also it does not look to be that easy to replace the tire when the threads are exposed.

 

The other notion that hit me is if the tire slips due to faulty traction. It may be me but this seems to have major design flaws in it.

 

OMG!!!!

 

I can't believe I didn't think of any of that. Thanks for pointing it out to me Ed. I guess I am doomed to failure :( . Wow! Three months of work for nothing.

 

Sorry for the sarcasm. :D

 

See Here

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Dan,

Great work so far. Can't wait to see it in action. Are you going to be using a coil spring and the dupont linkage, or a curved leaf spring?

I seriously doubt that you're going to have any problems moving the Tup with your setup, a 2 horse motor has alot more power than it would seem, espesially when you're multiplying the torque through your drive.

 

Zeb

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Dan,

Great work so far. Can't wait to see it in action. Are you going to be using a coil spring and the dupont linkage, or a curved leaf spring?

I seriously doubt that you're going to have any problems moving the Tup with your setup, a 2 horse motor has alot more power than it would seem, espesially when you're multiplying the torque through your drive.

 

Zeb

Thanks Zeb,

 

A curved leaf spring. That Dupont linkage looks inefficient to me. Not to mention scary

dsc_0530.jpg.

 

Cool-positive vibes on the motor

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So close I can hear it breathing.

 

breathe2.jpg

 

breath1.jpg

 

Breathe3.jpg

 

After all my layout and measuring Pitman arm is too long. :angry:

 

Cut and welded this evening. Paint is drying.

 

Only need to make spring guide and then it is

 

HAMMER TIME-Can't touch this :lol:

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Just make sure the neighbors know it's not automatic weapons fire before you crank her up! :lol:

 

You're gonna be one happy guy very soon, I predict. B)

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whoa there... you went with a strap hammer design ! ah now that is very cool... the vid's i've seen on the net, show that type of hammer has a sort of rhythm

 

2hp, will be plenty... for one thing, it'll be dependable

 

 

I've got a 3hp on my 50lbs mechanical, and that is way over kill... like putting a 3/4hp on your dremel B) the motor never even slows abit ...ever

 

 

Greg

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That is a seriously awesome undertaking. If I wasn't so happy for you I might be jealous. I really cant wait to see it go..

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Just make sure the neighbors know it's not automatic weapons fire before you crank her up! :lol:

 

 

But Alan,

 

All my neighbors have automatic weapons. I wanna play too.

 

You might be a redneck if------

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I really cant wait to see it go..

Yea me too. Fine tuning some alignments, making guides tomorrow. Figuring out the best way to attach the tup tightly to the strap.

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Damn it all and fire it up!!!!!

 

the time comes when you must guzzle a beer/drink and turn it on and go!

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Damn it all and fire it up!!!!!

 

 

Did!

Motor stalled. Tried using a lever and turning by hand. Tup was binding in the tup guide. Looks like spring guide is off center as well. Spent this evening realigning. Took tup guide off and centered and leveled everything so that everything moves in line with gravity.

photo 22.jpg

 

Tup is free hanging in this picture. Not touching at the bottom.

photo 12.jpg

 

If this 24" 110lb bar is not moving straight up and down it will bind up. I thought that with the strap and spring and all there would be enough give that any slight misalignment would be accounted for.

 

Wrong. Everything is really tight and pretty rigid except for the flex up and down. Plus I made the bore of the tup guide a slip fit without much play between the two. May have been a mistake.

 

Plus have not run my 220V yet and had the motor wired for 110V.

 

Have to wait until next weekend to get back to it.

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Dan,hi.I'll put in my 2 cents,hoping that it'll help rather than confuse...

 

You're dealing here with a situation that necessitates transmuting the rotary motion into the linear.

This was addressed in the design of the early piston-engines by means of a device known as a Cross-head(now,in an internal-combustion engine that job does the wrist-pin).

The actual point where it happens(or supposed to) is that pin mounted to the spring.

Frankly,i've never seen a cross-head where the guide was not directly affecting that very pin,i.e. the linear distance from the pivot point to the guide(s)was 0.

In other words,that pin is what,ideally,you'd want to be guiding.

IF i'm correct in that,then possibly a linear guide of some sort can be built, behind that pin,it's lengh equal to that of stroke.(As i've also noticed that the guided lengh of all crossheads that i've seen is equal,or greater than,the lengh of stroke of the crank.)

That difference in distance,between your pin and the guide MAY introduce those side-loads that you seem to suspect...Also,there's that extra joint at the lashing.I wonder if it,also,need to have some pivoting action there,as you yourself say that it's very rigid.I wonder if the lashing system shouldn't be centered on one point(lashed through the pin-hole,perhaps,as a test?),if that wouldn't allow it to flex enough?

The guide clearance,however,is proper that it's minimal,i do believe that's the idea(around 0.002,for most steam-engines,or just enough to hold a film of oil).The area of contact should,of course,be as large as possible,but here you're limited by the stroke of the tup.

But all these are idle thoughts at best,a mechanical engineer i'm not,alas.So again,hope that it'll not muddy your thinking further.

Meanwhile,great undertaking!It's a fantastic design,i've recently watched a short clip of a Japanese smith using one,and i turned green with envy watching him stick all sorts of tools under the tup-ALL this height travel!!!

I cannot drift,or do much tool-work at all under my old LG...

So,the very best of luck to ya,i'm sure that you'll figure this minor set-back out,and get to play with this great machine!

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Dan,hi.I'll put in my 2 cents,hoping that it'll help rather than confuse...

 

You're dealing here with a situation that necessitates transmuting the rotary motion into the linear.

This was addressed in the design of the early piston-engines by means of a device known as a Cross-head(now,in an internal-combustion engine that job does the wrist-pin).

The actual point where it happens(or supposed to) is that pin mounted to the spring.

Frankly,i've never seen a cross-head where the guide was not directly affecting that very pin,i.e. the linear distance from the pivot point to the guide(s)was 0.

In other words,that pin is what,ideally,you'd want to be guiding.

IF i'm correct in that,then possibly a linear guide of some sort can be built, behind that pin,it's lengh equal to that of stroke.(As i've also noticed that the guided lengh of all crossheads that i've seen is equal,or greater than,the lengh of stroke of the crank.)

That difference in distance,between your pin and the guide MAY introduce those side-loads that you seem to suspect...Also,there's that extra joint at the lashing.I wonder if it,also,need to have some pivoting action there,as you yourself say that it's very rigid.I wonder if the lashing system shouldn't be centered on one point(lashed through the pin-hole,perhaps,as a test?),if that wouldn't allow it to flex enough?

The guide clearance,however,is proper that it's minimal,i do believe that's the idea(around 0.002,for most steam-engines,or just enough to hold a film of oil).The area of contact should,of course,be as large as possible,but here you're limited by the stroke of the tup.

But all these are idle thoughts at best,a mechanical engineer i'm not,alas.So again,hope that it'll not muddy your thinking further.

Meanwhile,great undertaking!It's a fantastic design,i've recently watched a short clip of a Japanese smith using one,and i turned green with envy watching him stick all sorts of tools under the tup-ALL this height travel!!!

I cannot drift,or do much tool-work at all under my old LG...

So,the very best of luck to ya,i'm sure that you'll figure this minor set-back out,and get to play with this great machine!

 

Jake,

 

I think I understand what you are getting at. I do in fact have a linear guide for the pin that lifts the spring.

 

guide2.jpg

 

In this picture the tup is not cranked up all the way. The bottom of the pin guide ends up flush with the guide housing. The pin guide is 6" long and travels eight inches.

guide1.jpg

 

I think we are both on the same page in that the tup guide and the pin guide must be parallel and in alignment with each other

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if all looks good... then even a wee bit of lite oil may get things rollin abit.. .. i'm sure you thought of that ... .. maybe it'll take just abit of time before it sorta lap's itself

 

another thought.. a 2hp motor stalled ? i would not have expected that ... do you have the 1750 rpm motor ? i found the 3400rpm ones to be very weak... also i did notice abit of difference with 220v .... how many amp does this one draw

 

Greg

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One other thing that occurs to me: How long is the crank throw? That is, from the tire hub to the eccentric pin? On my 50lb Star it's about 1.5 inches. Any longer and it would strain the spring links too much.

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From the Brute Force and Bloody Ignorance workshop (Geoff Keyes sole proprietor), have you tried a larger motor? And what is the slop in the guides of a LG, or some other guided tup hammer?

 

I think my #50 runs on a 5 hp motor. I don't think it needs it, but the 1hp that we started with was too feeble, and the only other motor in the shop was a 220 V, 5 hp, so there you are.

 

BF&BI says, "Get a bigger hammer, and hit it harder!"

 

Just my .02

 

This is such a cool build, thanks for documenting it.

 

Geoff

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From the Brute Force and Bloody Ignorance workshop (Geoff Keyes sole proprietor), have you tried a larger motor? And what is the slop in the guides of a LG, or some other guided tup hammer?

 

I think my #50 runs on a 5 hp motor. I don't think it needs it, but the 1hp that we started with was too feeble, and the only other motor in the shop was a 220 V, 5 hp, so there you are.

 

BF&BI says, "Get a bigger hammer, and hit it harder!"

 

Just my .02

 

This is such a cool build, thanks for documenting it.

 

Geoff

 

Geoff,

My 50# LG runs on a 2 hp, 1ph, and the clutch wheel gets momentum before I engage the clutch..I am not sure the tire hammer has a flywheel effect (other than the mass of the motor). A larger motor will act as a larger flywheel. On the LG the 2 hp motor gets part of the load moving in one step then the other load ( movement of the tup and tup flywheel) kicks in. Have to run the tup guides very loose to avoid binding ( and lubricate the guides at every use ). I assume once Dan's knot finishes settling the hammer will settle down as well.

Jan

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Dan, I use a friend of mines tire hammer any time I need to move a major amount of metal. His is a 50#, and it runs just fine on a 1.5 hp 110v motor. He doesn't have the amount of mass that you have though.

 

The main problem he seems to have is the fact that the tire has become so "polished" from the contact wheel, that it often just spins on the tire. When that happens, he has been using a coarse scotch-brite type pad with a handle on it to scuff the surface of the tire (I think the pad is made to clean a BBQ grille).

 

That has been working well enough so far, but I think he is considering lightly knurling the contact wheel to try and remove the problem completely. You wouldn't want a deep/sharp knurl of course, because that could remove the built-in safety factor of the contact wheel slipping instead of breaking something. But a light knurling should keep it from polishing the tire, while still allowing it to slip if it gets in a bind.

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Apologies,Dan!(Can't believe that i've missed such a large aspect of your construction-duh!:).

 

Don't know how to calculate the power at all.

 

The only thing that comes to mind in regards to the lower guide is to leave its mounts slightly loose,if possible,to allow it to self-adjust (for the rotational forces,always present in any crank-hammer,to whatever degree?).

And/or maybe a smudge of prussian blue,especially if the assy. is not lubricated yet,to see where it may want to diverge from vertical?

 

Again,good luck,and i'm sure that it'll come together!

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Apologies,Dan!(Can't believe that i've missed such a large aspect of your construction-duh!:).

 

 

Actually Jake I just finished the pin guide this weekend and those are the first pictures of it.

 

Lots of good insights here guys-Thanks.

 

I think the key is to make sure all is moving freely and nothing is misaligned or binding up. Get the most out of the motor by running 220V to it.

 

Then it is a matter of whether the motor has enough OOMPH to get 175lbs of tup and spring over the initial hump.

Alan's comment about the throw is a big part of it. It is a 4" eccentric. And having no flywheel to add angular momentum doesn't help.

 

I can move it past the hump by hand using an 18" bar and applying roughly 40lbs of force. So that is what-about 60 ft/lbs of torque?

 

I have a 2" wheel driving a 21" wheel so I need 60/(21/2)=5.7ftlbs of torque from the motor

 

Motor torque should be (2(hp)*5252(constant))/1725 (rpm)=6.089ft/lbs.

Given that I am guessing at how much force I am apply by hand my guess is that I will be applying the principals set forth in Geoff's Brute Force and Bloody Workshop and there will be a bigger motor in my future. :(

Edited by Danocon

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