Bruno C. Posted June 12, 2012 Share Posted June 12, 2012 Greetings everybody, Long time troller, don't post much, but much enjoy the benefits of this forum. I was wondering, I'm building a Rusty style Power Hammer, and after a few duh moment's, and a long pause in the build, I've decided to rebuild my ram guide using UHMW plastic. It appears mcmaster-carr is a good source for the material, but they have several varieties including, Ultra-Abrasion-Resistant UHMW Polyethylene, Impact-Resistant Slippery UHMW Polyethylene, and oil filled UHMW polyethylene amongst others.... My question is to anyone with experience with JYH or UHMW, which would be better for the ram guide of the Power hammer ? What material or source have other builders used (asking you builders out there)? And what is a good thickness to use ? As in how fast does UHMW wear and degrade? I was thinking a good 1/4" would be sufficient all the way around a square iron tube, but if it wears pretty fast then maybe 1/2" thickness would be better ? I dunno, just trying to make the best purchase for my limited funds, unlike those danged bearing I bought attempting to make rollers. The rollers work fine, I just decided not to trust them for the like of my facial and cranial features I've grown accustomed to. Would hate to have one hit me in the face... A little background on my working environment: I'm working in a small garage where I do all of my grinding, cutting, torching and the like. So particulate dust is usually floating around, and I imagine will find it's way into all the tight places of the power hammer and the like. Also, as it stands right now my Ram weighs about 65 pounds, and I hope I have enough anvil for it. All bolted together to a 1" plate, bolted to 5 18" railroad tracks , bolted to two railroad ties buried in good hard desert ground. My primary purpose for this hammer will be for Pattern welding, I'm hoping to be able to get a 4" long x 3" tall stack welded together and flatish in 10 minutes as opposed to 3 hours. So, there will also be lots of scale and flux floating around, likely getting into the UHMW I'm sure. Also, as a side note I have one 1/2 horsepower washing machine motor, and one 3/4 horsepower old (30+ year, 3450 rpm) motor which I think works. I imagine neither or these are strong enough for my 65 Lbs ram, but I will see. I'm more interested in hard,solid consistent hits at less than 100bpm. Not that interested in a high BPM at the moment. But if anyone could recommend a good motor to use for the ram weight, I'll keep a look out. I'm limited to 220v 100amp max in my fuse box. Anyways, any input would be much appreciated. Thanks in advance. :) -R.D. Quote Link to comment Share on other sites More sharing options...
MOblacksmith0530 Posted June 13, 2012 Share Posted June 13, 2012 The spare tire I have has 1/8" nylon sheet guides and I have had to add one 22 guage sheet metal shim in 5 years of use. I keep it well oiled and I have not noticed any wear other than fine polishing. It will smoke a bit as the oil drips on teh dies and hot metal but that is not really an issue. I don't know why UHMW would not work. I would try it in no more than 1/4 inch in the high abrasion variety if it were my choice. Quote Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted June 13, 2012 Share Posted June 13, 2012 UHMW can squish, and move around on you. I used it for wear strips on winery conveyors, and the old UHMW strips that was only pop riveted down in a few places was a mess after a few years. The stuff I got had a fiberglass type mat molded onto the back, so that it could be glued down the entire length. I only had to screw down the ends after glueing it down with contact cement. A lot of plastics will absorb moisture, and swell, shift, and do things that you don't want it to. If you can contain it, it should work fine, but if it is not contained it will move on you. Be careful of abrasives getting imbedded into th eplastic, and creating something akin to Cratex. Quote Link to comment Share on other sites More sharing options...
ptree Posted June 13, 2012 Share Posted June 13, 2012 UHMWPE does not asorb water. One of the reasons it is used in replacemnt human body joints. I have a rusty style if you can call it that. Mine has been much modified and so I call it a Palmer patent style since Palmer first patented this type hammer in about 1870 I think. I used the basic slide nd ram design from the Clay Spencer prints for the tire hammer, but modified to adapt to the spring helve. I went with 1/4" UHMWPE. I use a generic equiv of Tri-flow as an oil, and have been using this hammer about a year now with a 70# ram. No issues yet, and my experience with UHMWPE tells me that I will probably get many years service. I bought my UHMWPE from a local plastics supplier in Louisville KY, General rubber. They sawed a hunk off a sheet big enough to make the 4 slide surfaces 3 times over for about $25, and since I picked up, no shipping. If you are near a city of any size there is probably a local place as well. Having used UHMWPE for over 30 years in industry, I see two ways to make it ripple or warp. Mount it to steel and let the temp change and it will ripple as it expands and contracts at a greatly different rate. Heavy impact will mush it and if contained it will ripple. Quote Link to comment Share on other sites More sharing options...
Bruno C. Posted June 15, 2012 Author Share Posted June 15, 2012 Thank you for the info Gentleman, I can't wait to order some up. Seems like the ideal material. I'm hoping I can complete my long stalled JYH soon and get back to forging. Dunno why I thought I could improve a simple design with overly complicated rollers, live and learn I guess. I welcome anymore information or tips, as it does a good job keeping me up nights :) Back to riffling through the forums again... Thanks Again... -R.D. Quote Link to comment Share on other sites More sharing options...
DonS Posted June 15, 2012 Share Posted June 15, 2012 I used 1/4 inch UHMW on my Rusty hammer. I had to adjust it a bit after the first couple of hours of breaking in, but it has no noticeable wear in 6 years of hobby use. Ram is 34 lb. Main part of ram is 2 inch heavy wall square tubing (smooth, not rusty).. I have a band of UHMW 2 inches wide around the top of the guide and 2 inches wide around the bottom, so that there is no contact or excess friction in the middle. Using material that is thicker than necessary could result in more expansion with heat and require it to be a bit loose at low temperatures and too tight at high temperature. A drawing of the guide assembly is here: http://www.wcbg.ca/wcbgsite_015.htm Don Quote Link to comment Share on other sites More sharing options...
Bruno C. Posted June 15, 2012 Author Share Posted June 15, 2012 Don, Thanks very much for the images, they are a great help. Also, it never occurred to me to use less UHMW. WOW, just makes sense. My current plan was, using material I already have, to use a 9 inch piece of 4" x 1/4" thick wall square tubing, which when my ram is inserted which is made up of 3" x 1/4" thick square tubing, leaves me about 1/4" on all side with the ram in the center. works out about perfect for some 1/4" UHMW. might be a little tight though. I was gonna use 3"x9" long piece of uhmw on all sides, but your suggestion makes sense. Using a 3"x3" or a 2"x3" piece of uhmw on all sides top and bottom seems like it would create a lot less friction which is a good thing. My ram is currently contains about 18" of 3" square tubing as a usable slide area, and with a 9" ram guide, in theory I can get a maximum of of a 9" stroke, there is a little wiggle room, and I can gain another inch or two usable slide, if I shorten the die bolts I currently have on it. Do you use any lubricant, oil or otherwise with this type of setup ? Also, a question slightly off topic... The rollers on top of the ram, or the ram to spring linkage I guess, what is typically used ? A bolt/sleeve setup seems a bit to frictiony, to make up words. From my previous failure with a roller system for the ram, I purchased a bunch of 3/8" x 1" bearings from ebay. That is a 1" long bearing, with a 3/8" center whole for bolts and whatnot. These rollers happened to fit perfectly in some 1 and 5/16" pipe (1-5/16", 1-1/8" center diameter) I had laying around. with a little bit of electrical tape, the bearings made a perfect fit. So the roller is basically, a 3/8" threaded rod, with some washers and nuts in the center, and 2 of these bearings on the outsides wrapped in a light layer of electrical tape, and an end cap on both ends made up of plastic cutting board material cut with a whole saw. They are functional rollers. However, being that my ram currently weighs 65 lbs with the die attached, probably will be cut down to 55 or 60 pounds after I cut the excess off the top, I wonder if I use two of my created rollers for the linkage, how are the bearings liable to hold up ? With lifting 60+ lbs, then smacking it down on some hot metal repeatedly, I wonder if I would just eat these bearings up in short order. So, again, what do you guys typically use ? Again, thanks for the info.. tis much appreciated. This project is long overdue. -R.D. Quote Link to comment Share on other sites More sharing options...
DonS Posted June 17, 2012 Share Posted June 17, 2012 Hello R.D. Holding 3x3 inch pieces of UHMW inside the square tube might be a bit difficult. Your original plan to use a long strip might be simpler and has been done before. You could use the long strip and route, file or sand 1/32 or 1/16 inch off the center portion to reduce drag. I lubricate the ram with some silicone spray. It seems to help, and it reduces the chance of rust developing on the ram. I am not sure if the silicone does any harm to the UHMW, but so far so good. Maybe someone else knows about the compatibility of silicone and UHMW. For rollers I used 1/2 inch bolts and some close-fitting pieces of pipe. I always save odd sizes of pipe for simple bushings and bearings. I drilled a hole in the center of the pipe for oil, and apply oil regularly. The spacing of the bolts will depend on the thickness of the pipe and the leaf spring. You might have to file out the holes to add a bit of clearance so that the spring still fits between the rollers at an angle at maximum travel. I gave it a bit too much space and it made an annoying click-clack noise. (about 1/4 inch too much space) I temporarily taped a pair of 1/8 inch oak strips to the leaf spring to quiet it down. That's about 5 years ago, and I only had to replace the tape once. If you plan to use a 3/8 inch bolt with a 60 lb ram, that might be a bit light for that kind of abuse. Regards, -Don Quote Link to comment Share on other sites More sharing options...
ptree Posted June 17, 2012 Share Posted June 17, 2012 On my hammer I used 3/4" bolts, with pipe rollers. Had to ream the pipe some. I also drilled the bolts from the hex head to center of the roller and then cross drilled to allow grease to be pumped in from a zerk fitting in the hax head. Allows easy lube'ing and I use moly grease. I also drilled one corner of the hex head for safety wire to prevent the roller bolts backing out. I pretty much safety wired all the fastners on this machine as i hate bolts backing out from vibration:) Quote Link to comment Share on other sites More sharing options...
Bruno C. Posted June 19, 2012 Author Share Posted June 19, 2012 Hi Again, Changed my display name since my previous one seems to raise Moderator eyebrows, so hopefully I can get off Mod Queue. DonS, Ptree, thank you for the suggestions. 3/8" does seem a little light, and I just don't think those ebay bearing would last a few hours under all that stress. So once again my plan is being modified again and going back towards simple. Waiting on some UHMW now, and hoping I can get back working on it soon. Thanks again for the info and suggestions, -Bruno C. Formerly R.D. :) Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.