Ted Ewert

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About Ted Ewert

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    Senior Member

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  • Location
    Mill Valley, CA
  • Interests
    Building stuff

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  1. Thanks Buzz, I'm looking forward to pounding some metal too. This design is a conglomeration of several different hammers. I'm still trying to decide if I want to use square tubing lined with plastic, or a T slot for the hammer guide. I'm leaning towards the T slot because it would be fun to build.
  2. Thank you all for the input. I'm sure I will make many changes once the thing is up and running. I just got through building the drive linkage. I had to build a turnbuckle since none are available in fine thread. I used a couple of pieces of 5/8" square stock and a couple of nuts welded together. Works good. The turnbuckle will allow me to adjust the height of the hammer, and the clamp on top will allow for stroke length adjustment. The core of the hammer is going to be four 12" pieces of 1-1/4" square stock which weigh 20 lbs. Adding the end plate, connecting rod and other pieces should make it close to 30 lbs. I can always add weight if desired.
  3. Well, thank you for the information. It's easy enough to swap pulleys if I need to. I'm still going to try it out at this speed to see how the whole mechanism works. I don't know how heavy the hammer is yet, so I'll have to see how all that pans out. Just for the sake of discussion, BPM does not necessarily dictate velocity. The velocity is dictated by the geometry of the lever times the BPM. The closer your drive arm is to the fulcrum, the more distance your hammer will travel. More distance equals more velocity at the same BPM. Also, raising the BPM rate requires more power for any set configuration, since more work is being done. So, I could shorten my stroke and raise my BPM, but the same amount of total force is being delivered to the work in any given time span. It comes down to a preference between big heavy thumps or a bunch of lighter thumps.
  4. About 180. If it's too fast I'll adjust the pulley sizes to slow it down. What difference does it make?
  5. I have had some difficulty trying to find heavy solid steel in my area. I don't own a truck, so whatever I get has to fit in my wife's minivan. Besides, I still think this anvil will work just fine. If I'm wrong you guys will be the first to know, and you can all take great satisfaction in telling me "I told you so". Until then, I'm moving on...
  6. Thanks for the vote of confidence, precious few here. I was watching a video of an old power hammer today and it also had hollow anvil. I'm not worried about it, but it seems to bother some folks.
  7. I got the "transmission" part of the build pretty much done. This includes the pulleys, belt tensioner (clutch), and cam. I'm not entirely happy with this belt tensioner, but I'll see how it works. Here's the Cam. I built it from two pieces of 3/4" square bar. The reason for this was so that I could mill a key slot in the 1" hole after I drilled it. I then pinned and welded the two halves back together. I'm using two of these 3/4" rod ends with a turnbuckle for the link to the spring. These things only come in fine thread (3/4-16) so I'll have to build a turnbuckle for them, as most turnbuckles are in course thread.
  8. I'm in the process of building the drive train for this hammer and was wondering how heavy of a hammer this motor can support, so I did some calculations. The 1.5 hp motor produces 2.2 ft /lbs of torque. Converted to inch pounds: 2.2 x 12 = 26.4 in / lbs The speed reducer is a 10:1 ratio. The speed is reduced by 10 and the torque is multiplied by 10. Therefore: 10 x 26.4 = 264 in / lbs on the output shaft. I will be using a 2" cam which will half the 264 in/lbs to 132. So, I have 132 lbs of force when the cam is at 90 degrees to the load, which represents the maximum load on the motor throughout the cycle. Then the ratio of the distance of the drive point on the leaf spring with respect to the fulcrum, and the distance of the drive point of the hammer need to be considered. A 2" cam will travel 4" vertically. If I want 8" of travel for the hammer, that represents a 2:1 distance differential which will cut my force in half. 132 / 2= 66 lbs In this configuration a 66 lb hammer is my theoretical maximum. In the real world we have mechanical losses and other inefficiencies, so I'm thinking a hammer around 30 lbs would be reasonable. I'm also thinking that the more travel I have on the hammer, the more velocity I can develop. I would rather have a lighter hammer with more potential velocity to play with. Discovering the properties of the spring (springs) will determine the best configuration. Just some thoughts...
  9. It's 34 inches high. That's a good working height for me. I figure another inch or two for the die.
  10. The way I built it I don't think I'll have any trouble with the concrete. As I mentioned above, the concrete is not load bearing and merely serves as a dampener and stiffener. Here is a picture of the rebar config. There is also a solid 1"square bar in the middle on each side to support the point of impact. Here it is after the pour: When I hit the top with a hammer there is no ring at all, just a thwack. Concrete is a wonderful noise suppressor.
  11. Me too! Thanks for your interest. Thanks, I'll look into it. I'm definitely putting horns on it. I'll make them as a first project on the hammer.
  12. I like the horn idea! Maybe a horned woodpecker motif. I don't know any smiths in my area, let alone one with a power hammer. Like everything else I do, I'm just going to build it and see if it smashes hot metal to my satisfaction. The hammer weight is a big question for me right now. I'm thinking of building a hollow structure where I can add or subtract weight (I know, hollow hammer bad). I want to keep the weight under 50 lbs for now.
  13. You can see the plates in this picture. I installed the two 1" bars from the bottom of the gusset to the base and also welded them to the web. I have another picture at home I'll post later which shows the column before pouring the concrete.
  14. I have zero experience with power hammers and I'm designing this based on what I have read and seen on YouTube. I've earned a masters degree in YouTube watching ya know. This is one of those "here, hold my beer while I build a power hammer" experiments. I'm sure I'll end up rebuilding it several times, but I like doing that. Nevertheless, you have inspired me to name the hammer Jack.