VFD on a Power Hammer?

[Bill Hubbell]

-Worked on my first damascus/pattern welded billet for the second 'session' Saturday. My son and I have worked on it twice now. But, my body keeps saying: build that power hammer now!
It's something I've been wanting to do, but have only rounded up a few materials and parts so far.

I searched the forum and didn't find my question addressed anywhere yet. The question I have is: I don't remember ever seeing a power hammer with a VFD and 3-phase motor. It seemed to me a good way to accomplish the speed reduction and control desirable. But, I have never even touched a power hammer, so I know there's a lot to learn. -and figure maybe there's a good reason for not going that route.
And, maybe I've seen some set up that way, but totally forgot it! My memory is pretty reliable (but my wife sometimes suffers from the illusion that she has told me something that I don't remember).

Is there a reason why not to use a VFD on a power hammer? I have located a 3 horse 3-phase (1,750 rpm) motor that I might be able to come by very reasonable. The other motor I have is a 2 hp single phase (3,600 rpm). It seems that the 3600 rpm motor might take a lot of reduction. True?

I know this project is going to stretch my budget when I get to buying steel and some of the components that I can't access cheap or through my scrounging around. Buying a factory-built unit is out of the question. And, I have skills and equipment to construct/assemble. But, I'm trying to save by utilizing what I have or can come by cheap, if I can do that without compromising safety or function.

So- three phase motor w/ VFD on a power hammer? What do you think? :confused2:

Thanks,
Bill

 

[Wayne Coe]

Bill, what style power hammer are you planning to build?
I doubt that a VFD would be advantageous.
Go to www.alaforge.org for some information about building the Tire Hammer.
They normally use a 1 hp single phase motor.
This hammer is a lot like a Little Giant and needs the whipping motion to deliver the blow.
The speed of the hammer is controlled by how hard you press the peddle as the drive wheel contacts the tire.
If you are talking about an air hammer the speed is controlled by how hard the peddle is pressed and the amount of air accessed.
You need to post more about the type hammer you plan to build to get good information back.

Let me know if I can help you.

 

[Bill Hubbell]

Thanks for your reply, Wayne. I don't know the correct terminology, I guess, but- I'm planning on a power hammer with either a tire drive, or a belt drive. I'm thinking around a 40 or 50 lb hammer, with a base/anvil of a few hundred pounds. I have a good sized 1" thick steel plate for a base plate.
I was thinking a 1 HP motor wouldn't be big enough,but apparently, I'm wrong on that, judging by the ones you showed me. I also saw a video tonight with one built with a 1 HP 3600 RPM motor and a tire drive, so I guess I was also off-track thinking a 1750 RPM motor would be more suitable. So maybe the 2HP 3600 RPM motor I have will work fine.
I looked at the link you attached for alaforge, but didn't see any power hammers there. I saw some interesting power hammer dies or tools, though.
I believe you helped me quite a bit when I was building my gas forge a couple of years ago. Thanks again for your help! I bought some of the supplies from you. It's still running strong. Your help was greatly appreciated.
Bill

 

[Wayne Coe]

Bill try the Trading Post page. http://www.alaforge.org/Trading_Post.html Clay has his plans listed there, there are several hammers listed there. Come to the Batson Blade Symposium in April to meet people there who build the hammers and to see hammers. If you want to buy a built hammer you could contact Raymond Head at e.m.forge@gmail.com. Raymond will probably be there and will probably have some parts for sale.

 

[Bill Hubbell]

I hope it's okay to pick up where I left off 6 months ago. A lot of my projects suffer from random interruptions. Part of that's probably my toddler sized attention span- the other part is just life! I've been building the anvil and base plate and gathering steel as I go.

My original question was the feasability of using a VFD on a power hammer. From what I've gathered, it sounds like if I wanted to pursue that, I should go with an over-sized motor to avoid overheating at low speeds. I also hear that increase in RPM would be slow. At any rate, I've already come up with a single phase 1 1/2 HP, 1750 RPM motor, and it's probably not in my budget to start looking for a different larger 3-phase one and a VFD now. So, I think I'm passing on the VFD idea.

I had planned to go with a slip/belt drive, but haven't purchased the pulleys, pillow blocks, or any of that yet. I hear that those tend to be pretty much 'in or out', will little speed variability. And, judging from other projects I've built, that sounds logical. I would think a tire would hold up to slippage better than a belt- but I'm just speculating (tires took a lot of abuse from my 400 ci 67 Firebird, 40-plus years ago!

So, I'm asking anyone out there: If you have (or have had), a tire-drive power hammer, does it seem to offer much variability in speed (strikes per minute)? Or, at least more variability than a belt drive might?
Thx,
Bill

 

[Rick Otts]

You are doing this all wrong.Just invite the football team over.Their test levels will take over.