mfsbuell Posted December 24, 2011 Share Posted December 24, 2011 Hi, Mike here in Manteca CA. We have a power hammer working here, built off Krusty plans What speed motor do you all recomend? Currently we are using a 5 horse 3450 RPM Mike Quote Link to comment Share on other sites More sharing options...
macbruce Posted December 24, 2011 Share Posted December 24, 2011 A 3450 rpm mtr generally is too fast for any mechanical hammer. It will need to be drastically reduced via jack shaft or or motor and drive pulley ratio.........A 1725 is far easier to reduce in speed to the correct rpm for powering a hammer.... Quote Link to comment Share on other sites More sharing options...
mfsbuell Posted December 24, 2011 Author Share Posted December 24, 2011 Thanks for the reply, what RPM is generaly used or wanted? Mike Quote Link to comment Share on other sites More sharing options...
John B Posted December 24, 2011 Share Posted December 24, 2011 Are you asking RPM for the motor, or do you mean BPM for the hammer? RPM is immaterial theoretically as you gaer down the rpm to suit the BPM (beats per minute) of the striking head BPM to work towards is somewhere in the region of 240 or less as a general guide IMHO Quote Link to comment Share on other sites More sharing options...
mfsbuell Posted December 25, 2011 Author Share Posted December 25, 2011 Hi, Thank you. Yes I was looking for BPM, just a ruff number to shoot for. We will be installing a jack shaft to knock the speed of the motor down to around 1555 RPM or there abouts., then we can fine tune the BPM with pully size on the output side of the jack shaft. We are using a 5 hp compressor motor, with the hi rpm. When we first ran the hammer we were able to draw out a 3/4 sq bar to a distance of 6 inches to the point. But we smoked the motor pully as we were slipping the belt to much. Happy Christmas to All Mike Foley, in Manteca CA. Quote Link to comment Share on other sites More sharing options...
ptree Posted December 25, 2011 Share Posted December 25, 2011 I have a 70# version of the rusty. In acuality the Rusty and Krusty are both take offs of the 1870's Powell patent leaf spring guided helve hammer. Mine uses an odd ball motor, a 220Volt single phase of 5Hp and 1740 rpm. I have a 2" od steel wheel running on a roughly 21" compact spare tire. Gives a nice controllable rate. I get in the area of 166 BPM if slippage is ignored. At 70# that is pretty effective. Quote Link to comment Share on other sites More sharing options...
Stormcrow Posted December 27, 2011 Share Posted December 27, 2011 I'm running a 3hp 3 phase motor on mine with a 100 lb ram and a tire clutch and it is plenty of power to run it. How heavy is your ram, Mike? The tire clutch will give you better control than a slack belt from what I have heard, though with a fast motor like that you would want to put the clutch on the slow end of the jack shaft somehow. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted December 27, 2011 Share Posted December 27, 2011 The old motors that came with hammers tended to be about 900 rpm IIRC and so impossible to find direct replacements nowadays. As mentioned a speed reducer is pretty much a mandatory part of the design---how much tuning are you going to be able to do? Quote Link to comment Share on other sites More sharing options...
mfsbuell Posted December 28, 2011 Author Share Posted December 28, 2011 Hi all The Ram, which I think of as the Upper Die Hammer shaft. Weighs in at 85 pounds. My Partner has done the math so we are putting a jackshaft on the first tool, this with the pullys we will use will give us around 200 to 250 BPM depending . The motor I was going to use on tool #2 turns out to be frozen. So I will be shopping for a new or new to me 3ph 1 to 2 horse power motor. Have a Great New Year Mike Quote Link to comment Share on other sites More sharing options...
FieryFurnace Posted December 30, 2011 Share Posted December 30, 2011 I would recomend a lower horsepower motor like you mentiond. Generaly, 50 pound hammers are run successfully off of a 1 HP motor, so it might be good to use a 1.5 or 2 HP on yours. Like someone mentioned already, you can adjust the motor speed by use of pulleys and different gadgets. 1725 RPM on the motor is the norm though. BPM varries. My Kinyon air hammer runs a little slower. (Never timed it, but I'm guessing under 200 BPM.) The Clay Spencer Tire hammer runs about 220 BPM. A little giant runs faster but I'm not sure how much faster. (Maybe around 300 BPM.) I wouldn't worry about getting an exact number of BPM. Instead, work with it until you get an operating speed that the hammer works smoothly at. Any pics of your hammer? Quote Link to comment Share on other sites More sharing options...
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