Gavj75 Posted June 21, 2020 Share Posted June 21, 2020 I got another 4 hours graft on my tyre hammer build today and I think it's coming on a treat. I finally got some 4mm welding rods and finished off the welding of the box sec. spine to the 50mm base plt. The result is approximately a 15mm fillet made up of 6 runs. With 3.25's, 1 in and 2 over then with the 4mm's, 3 over those The other thing I did today was drill and tap the 4 M16 holes in the corners of the 50mm, 140×140mm plt, which will then be welded to the top of the anvil post. This is how I'm going to fix the anvil dies or blocks(not sure what they're called)to the anvil post. So that was today's progress I'm getting close to attaching the drive motor so prior to that I need the drive wheel making but are not sure how big it should be? My motor is 2hp and runs at 1360rpm and the wheel is a 15" diameter. If anyone can advise me on this that would be cool. Thanks Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted June 22, 2020 Share Posted June 22, 2020 Is the outside diameter of the tire 15 inches? It looks bigger than that to me. I recently got my junkyard tire hammer operational, and the tire I used has a 21 inch outside diameter. All you really need is the the diameter of the tire, the motor rpm, and your desired beats per minute to determine the drive wheel diameter. Let's say you want 220 beats per minute. That means you need to reduce the revolutions of the motor by a factor of 6.18 (1360/220). Now you just need to know the diameter of the tire and you can figure out the correct diameter for the drive wheel. If we assume that the OD of the tire is 21 inches and divide that by 6.18, that would give you a drive wheel diameter of about 3.4 inches. If you design your system well, you should be able to use less foot pressure and slip the drive wheel a bit to create slower/lighter blows though. Your ram weight makes a difference here IMO. The heaver the ram, the fewer beats per minute you want. I'm using a very light ram/top die combination (around 15 pounds) and my maximum bpm is about 270. That actually feels a little too fast to me and I may decrease my drive wheel diameter a bit, but I'm going to use it as is for a little while before making any major changes. Quote Link to comment Share on other sites More sharing options...
Jason Fry Posted June 23, 2020 Share Posted June 23, 2020 Buzz is correct. For one, if that's a "15 inch" tire, that refers to the rim only. Actual diameter is probably 22-24. Formula is.... BPM= (motor RPM)/(tire diameter/drive wheel diameter) Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted June 24, 2020 Author Share Posted June 24, 2020 Thanks chaps 4 the info. My hammer weight will be around 45lb so I was thinking along the lines of 150 bpm. It's all guess work on my part so what do u reckon. Will that be ok? Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted June 24, 2020 Share Posted June 24, 2020 I would check to see what Champions or LG's in the 50 pound range have for max bpm and use that as a guideline. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 24, 2020 Share Posted June 24, 2020 According to the Little Giant Website 250-325 BPM for a 50# That would take a lot of trust for me! http://www.littlegianthammer.com/uploads/docs/2018-Useful-Information.pdf Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted June 24, 2020 Share Posted June 24, 2020 Agreed. That would be scary for a home built machine. 150 to 200 bpm is probably a better target to start with. The nice thing about building your own machine is you can alter it later if you want to make changes/improvements. Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted June 29, 2020 Author Share Posted June 29, 2020 After reading your reply's, I've decided to go with 180bpm which is 3 hits per second. I, also think that much more than this would be a bit scary considering my homemade hammer is as yet untested and its not like I've got experience building them. While I am confident in my fabrication skills, its defiantly wise to be cautious. The diameter of my tyre is 22.5" so, 1360(rpm) ÷ 180(bpm) = 7.55 22.5 ÷ 7.55 = 2.98 So my drive wheel will be 3 inch diameter. Thanks again 4 the help guys. I was in the shop again for 5 hours yesterday, but didn't really make any progress with the build. I did however solve the problem of moving it as i don't have use of a crane or forklift. This is what I came up with and it works a treat It's made from some old skate board wheels and a few bits of off-cut leftover steel. It lifts 1 edge of the base plate up about 5mm and allows you to push the hammer and manipulate it to where u want it. Next weekend I mite get the anvil post put together (Fingers crossed) and actually make some progress. Then it's onto the drive wheel and motor assembly. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted June 29, 2020 Share Posted June 29, 2020 I have a handful of pipe sections I use for rollers for "light" stuff and solid rods I use for heavy. Quote Link to comment Share on other sites More sharing options...
arftist Posted July 3, 2020 Share Posted July 3, 2020 Your slide area looks way too short. You want at least 10 inches. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted July 3, 2020 Share Posted July 3, 2020 For my Star 30 pounder, I have it set up for 120 BPM, that's plenty fast for me and what I do with it. Any faster and it gets scary. Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted July 8, 2020 Author Share Posted July 8, 2020 The contacting surfaces between the shaft of the hammer and the brass slides which are housed in the shaft sleeve have been a source of concern for me since I first put the assembly together. All my instincts have told me that I need to make it bigger so thanks, ''arftist'', for assuring me this is the case. I have an idea that I'm going to give a go, by adding some guiding rollers to the top and bottom of the sleeve, before I re-make the whole assembly. Who knows? you don't know until you give it a go, right? As for the bpm's, I was originally going to go for 150, 2.5 per second but decided to up it to 180 after reading the reply's I got. I'm now going to go with 150 again which is a 2.5inch diameter drive wheel. If this turns out to be too fast and possibly even scary, I can always drop it down some more by taking a bit more meat off my drive wheel. I can take more off but can't add more on. I didn't get much done in the shop again this week(I only get a few hours most sundays) apart from I built my anvil post. Its not fully welded yet and don't have any pics for you to see, but it's a bit more progress I spoze. Thanks again for everyone's feedback, untill next time Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 8, 2020 Share Posted July 8, 2020 Don't worry about a hammer that goes faster than you like, you can throttle the speed with the treadle. You don't drive your car by mashing the gas to the floor do you? 9 minutes ago, Gavj75 said: I have an idea that I'm going to give a go, by adding some guiding rollers to the top and bottom of the sleeve, before I re-make the whole assembly. Who knows? you don't know until you give it a go, right? Yes, we DO know, people have been putting guide rollers on home built power hammers for years and most seem to have reverted to slide guides. You know you can buy proven plans so you'll KNOW it will work if you follow them. Yes? The time to start experimenting with machinery is AFTER you understand them and can predict the probable outcomes of experiments. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted July 8, 2020 Author Share Posted July 8, 2020 Yep, got you, read u loud and clear. It's not that I'm ignoring your advice FTL, and I do appreciate your input and guidance, it's more a case of as I don't have money to throw at the issues I come up against,and even if I did, I wouldn't, as well as the fact that I'm a mechanical engineer with 20+ years experience using heavy machinery and the fact that I started doing this because I enjoy designing and building things, that I'll be trying out my ideas before reverting to an alternate altogether. I have no interest in buying proven plans to build something from. That is pretty much what I do at work every day. There is no fun in that 4 me and if there's no fun, what is the point in the first place. Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted July 16, 2020 Author Share Posted July 16, 2020 Just a couple of pic's of my anvil post (still not fully welded)for you all to check out. The hole in the middle is so I can weld it up and achieve, at least a small amount, of solid core material. With the equipment l have to work with, I think this is about as good as I can get. The pics Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted July 18, 2020 Author Share Posted July 18, 2020 As soon as the anvil post is finished I've got the small problem of making my drive wheel. Getting one turned is definitely not an option as I was laid off from work last Friday, along with 30 other lads, so I now have even less money to spend on it than before. My idea is to make one from 2 bits of hard wood glued together to make a block roughly 4" × 4". It's teak apparently.I'm going to grind a 25mm wood drill bit down to 23.9mm, ish(the motor shaft is 24mm)then drill and attach the block to the motor. Then build an improvised wood lathe around that to turn the block into my wheel. Thats the plan anyway. I'll let you all know how it goes. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 19, 2020 Share Posted July 19, 2020 That should work. Are you alternate the direction of the grain when you glue it up? It'll help prevent grain splitting out when you turn it. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted July 19, 2020 Author Share Posted July 19, 2020 Yeah, I lined up the 2 chunks of wood with the grains running roughly at 90° to each other. Used PVA wood glue and left them clamped up for 24hours. Just need my motor wiring up now so I can crack on with it. Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 19, 2020 Share Posted July 19, 2020 I made up a wood block to turn for a drive pully on my 2" x 72" from 5/4" hickory and used a hole saw to rough the blank before taking my turning chisels to it. Then I started coming into better motors than the original I was going to use but have to wait to bet the electrician out to connect power to the shop so I have 230v. The laminated block is piloted through the center with a 1/4" hole. It allowed me to align the hole through the entire block. I'll replace the pilot bit in my hole saw with a 1/4" rod so I can flip the block over and match the cuts. I used Weldwood water proof glue, it's what my Father used to laminate blocks to make metal spinning dies with. If it'll take the kind of forces a metal spinner applies with scissor tools in a production shop it'll take anything I'm going to do to it. And for those who are wondering, Yes I buttered the wood before gluing, for the same reason as for masonry. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted July 19, 2020 Author Share Posted July 19, 2020 I like the way you used a 1/4 rod to 180 your block over, so it lined up. I may well use this technique when I drill my block. I'll see how it goes. Gav P.s. What do u mean by "buttered the block" Sorry, " buttered the wood " Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 19, 2020 Share Posted July 19, 2020 Buttering is an old mason's technique for preparing the block, rock, etc. for the mortar. If you apply mortar to dry brick it flash dries on the contact surface and doesn't bond properly. Masons dip or brush water on a block or the wall before troweling the mortar on, this dilutes the mortar on the contact surface and allows it to penetrate deeply, the added moisture also maximizes the strength of the mortar, cement, etc. Buttering the ceramic wool refractory we use in forges promotes penetration and bonding of rigidizer as well as what water setting hard refractory, and kiln wash if you use one. Buttering wood before gluing does the same thing though a wet and sponge is plenty of buttering for most woods. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted July 19, 2020 Author Share Posted July 19, 2020 I kind of had an idea that that's what it was but wasn't sure so thanks 4 the explanation. Like the saying goes "you learn something everyday" Gav Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 20, 2020 Share Posted July 20, 2020 20 hours ago, Gavj75 said: Like the saying goes "you learn something everyday" If you're paying attention. Sometimes I learn something so uninteresting or icky I wish I could delete. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Buzzkill Posted July 20, 2020 Share Posted July 20, 2020 On 7/17/2020 at 8:22 PM, Gavj75 said: My idea is to make one from 2 bits of hard wood glued together to make a block roughly 4" × 4". It's teak apparently.I'm going to grind a 25mm wood drill bit down to 23.9mm, ish(the motor shaft is 24mm)then drill and attach the block to the motor. Then build an improvised wood lathe around that to turn the block into my wheel. That's pretty much what I did for my drive wheel as well. I clamped the motor to a work bench (with the correct amount of shims for height) and used a piece of RR track as the tool rest. My motor runs faster by a few hundred rpm, but it worked fine and the drive wheel is still doing fine after several hours of use. Quote Link to comment Share on other sites More sharing options...
Gavj75 Posted July 20, 2020 Author Share Posted July 20, 2020 Thats good to know"Buzz". Gives me a bit more confidence in my plan of attack. Just need the motor wiring problem sorting and I'll be at it. U any good with 240v electrics Buzz? Quote Link to comment Share on other sites More sharing options...
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