Hakeye helve Hammer

[Chrispy]

I am currently constructing a power hammer very similar to the 1903 Hawkeye hammer. The only major difference is that I will be powering an open BMW diff (exposed axle type with flanges immediately out of the diff) with a 2 hp single phase electric motor. One side of the diff will be connected to a crank shaft offering a total lift of 5 inches, the other side has a modified disk brake rotor attached and when the caliper brake is applied to slow or stop this spinning rotor the input drive will transfer the drive to the other side of the diff, causing the hammer to start to operate. Controlling the speed and power is achieved by regulating the pressure on the brake mechanism. What I need to know is ... Are there any critical specifications to adhere to in making the pivoting, sprung arms that offer relief to the crank when hammering various thicknesses of steel? If this info is not available, can someone tell me the angles of the shackles when the crank is at the 3, 6, 9 and 12 o'clock positions. I think I have it worked out but not 100 % certain and really only want to build this once.
Regards, Chris csfuller@adam.com.au

[jeremy k]

Chris - The measurements you are talking about all depend on how you make the Dupont style toggle assembly. The rod up the middle has threads on it so the spring assembly can be raised or lowered to adjust for stock thicknesses. Also the spring assembly can be moved back and forth on the helve arm for adjustments for blows per minute. Here's a link to the picture of mine: Hawkeye Power Hammer - Blacksmith Photo Gallery

[Chrispy]

Thanks Jeremy, Now there's a tool that would make anyone proud. It is good to finally see a picture of it displaying the workings from this angle.
It is interesting that you say that the spring assembly can be moved along the hammer arm for hit speed variations as I figured to put it at 1/3 out from the pivit point (mechanical advantage) to relieve the workload on the diff and electric motor. I have already made the spring assembly except the shackles and threaded push shaft. It seems I may have to extend the length of the arms to accomodate the Harley Davidson rear shocker coil springs (halved). My construction material seems to be of equal proportions to your splendid machine.
Do you know how to determine the pound size of a hammer (without thumping the wife's bathroom scales)? My hammer arm [65mm sq solid mild steel] is 30 kg (approx 60 lb) without the spring assembly or hammer dies etc. In the calculations are all the components weights included or just specific parts? I'm quite green in this area.
I'm planning on nipping out for the 30 mm shafting and roller bearings today if I get a chance. Past experience has taught me that ball type bearing don't handle knocks or hits too well.
Thanks for the pictures and the valued information.
Cheers, Chris

[jeremy k]

Chris - There really is no comparison between inlines and helves as far as poundage. - This Hawkeye is supposedly rated for forging up to 2" round, therefor may be slightly compared to a 50lb Little Giant or another hammer make that can forge up to 2" stock. that's really the only way it can be compared as the working of it is different. The helve arm on mine is 2"x2" square roughly if I remember about 40" long(don't quote me on that)although I could measure it if needed. Good to hear your well on your way to completing your hammer...... how about some pics here???? - JK

[irnsrgn]

The only concern I have at this stage is the wear on the spider gear shafts as they were not designed for continuous operation.

[Chrispy]

Jeremy, thanks for the info. My hammer arm is 65 mm sq solid bar and the dupont spring action (which I have modified slightly is 25 mm [1"] milled out at the pivot point and built up to widen the pivot width). I have my own 36" lathe and access to a mill.
I just scrounged a metre of 30 mm shafting which I will reduce down to fit the 25mm hole in the spring guide and thread the 30 mm section a few inches past either side of the shackle / adjustment block also make a couple of locking nuts from some 50 mm hex bar for either side and keep the rest of the push rod at 30 mm. How does that compare with the shaft size on your Hawkeye? I picked out a few 30 mm nominal bore sealed ball bearings from by cousins scrap bin for the crank pivot but it dawned on me that I would need roller type bearings as ball types are short lived when subjected to blows. It wont be long now and I will add some pictures. Are there any rules on the size and or format of pictures when posting to this site? and should I stick them here or in the gallery?
Cheers Chris.

[Chrispy]

Irnsrgn,
Having never owned my own power hammer b4 but used a couple extensively I have found in most cases that the actual time hammering is somewhat less than I thought it would be. All be it, a xxxx of a saving in time, and certainly effort. I hope the spider gears will handle the constant load. I realize that I will have to wire the electric motor to run backwards because of the chosen mounting position, intentionally, to run the diff in a forward direction to prevent the diff from howling. If the spider gear or shafts fail I can easily modify my hammer to similate the Hawkeye's cam action. Possibly use a section of a crank shaft housed between it's big end and support bearings. Mind you it's a long time since I seriously looked at a crank shaft - possibly too much of an eccentric - Might even have to make one, shouldn't be too hard- time permitting. Not driving by a flat belt and idler pulley might pose a problem when activating the hammer from free wheel to hitting action. But then life is all about problem solving. Isn't It?
Cheers Chris.

[Chrispy]

Jeremy , Forget my queston re picture formats, I just read up on it and found the answer. Will post pics soon when things start looking more like a tool rather than A pile of scrap.
Chris