twcoffey

If your hammer is static balanced(dynamic balance is impossible) then it should be able to run on a rebar re-enforced 5" concrete slab without slab isolation. My hammer is proof of this. The slab is part of the shop floor(nothing special except for rebar). Most slab concrete jobs with mesh wire re-enforcing will not suffice and require isolation. Ted

You probably know this but I thought I would add that concrete needs about 30 days to cure before applying stresses. Ted

Mark, You don't sound like you are experienced in heat treatment and tempering so don't try to do this without experienced help being present. This is not a beginner's project. You could take the trap to a truck spring repair shop and pay them do the job if they will. Some can be quite contrary about doing work outside their normal routine. You won't get a guarantee I am certain. Ted

All things being equal which they never are: In poor but usable condition around $1.00 per pound. In pristine like new condition about $3.00 per pound. Ted

I agree with Keith. Clay(who is a mechanical engineer) along with the spring company engineers worked out the design. I think Clay has the springs for sale for around $30 to $40 + shipping. Trial and error is going to take significant time and money to achieve the best results. Ted

Doing this cold with a power hammer is no different that doing on your anvil with a hand sledge. Most of us would not think of doing this cold at the anvil. Doing it on the power hammer will take its toll on the hammer heads. Add that cost to your project and reconsider. I would never do this in the quantity of footage in question cold. Ted

Keith, Go to local auto repair shops especially those that repair or scrap wrecks and inquire. I found mine that way and the guy was happy to give it to me because he said he has to pay to have them disposed of. One scrap yard I went to puts them on the ground and sets the junkers on them to keep the cars out of the mud. You may ask them to save you one if they will. Not all scrap dealers are friendly and easy to deal with. Sometimes $25 to $50 might bring them around. Ted

Keith, I haven't found anything that needs to be changed at this point. Hammer works just fine from my perspective. Good luck on the project. Lay persons coming into the shop always want to know what that is. I think the tire mounted at six feet is puzzling. When I say its a power hammer they always say "I get it". Ted

Jeff, I use 4140 hardened to about RC40. Easy to machine when annealed easy to harden and welds fine with 7018 rod. Ted

I find it interesting that there is no evidence of the rubber actually burning(no black smoke) so it must be a gas burn which is so rapid that the rubber does not reach its ignition point before the whole thing blows. Ted

Worked fine. I have had the tire off and on a few times. I haven't run it a lot because of cold weather has kept me out of the shop. It also could be done other ways such as using a thicker plate like 3/8" or 7/16" instead of going with the spokes and a 1/4" plate and my backup plate. That would eliminate some of the welding. At that point of the hammer there are not a lot of force but you don't want a thin plate flexing. Another point to be aware is the balancing. In this thread I discuss my experience and method of balancing. Also read this thread: about welding on the rim. Hope this helps. Ted

Ralph, If you read the thread ( ) you can find what I did to get around the problem of lug nut removal. Another advantage of this is that the tire can easily be demounted for welding of rim. Ted

Since I started the thread, I thought I would pipe in with my understanding of the process. I came across this video yesterday and have since been doing some study. If you had a non-organic pressurized vessel such as steel this would not happen. Pressure would increase slightly. The tire is an organic compound containing many elements and trapped gases in the rubber. There is a critical temperature(not very high probably around 300 to 400F) at which the gases trapped within the rubber (such as methane)are released and may ignite. What follows is a runaway self fueling ignition creating very high temperatures. The gases of combustion causes very high pressure in a contained vessel(the tire). In the video you will notice that comment is made that removing the valve stem and even breaking the bead will not prevent an explosion and that the rapid gas production will re-seat the tire and the valve stem is too small to allow the large volume of gas to safely escape. I imagine that a chunk of rubber placed in a closed steel container would explode if the container was moderately heated to around 300+ F. When I built my tire I completely demounted the tire from the rim for welding. At the time I was unaware of this danger but just based on intuition I thought it was better not to have the rubber near the heat. Clay Spencer's plans shows a procedure of a loose tire on the rim using spacers and wet rags between the rim and rubber. This has been done hundreds of times apparently without incident. Remember to keep the rags wet I thought that builders and owners should see this video so they would not weld or burn on the tire rim without knowing a possible danger. If a weld or something breaks on the rim it is temping to grab the welder and fix it.(Take your time and do it safely). Ted

The video claims otherwise. Ted

Applying heat to a tire rim with a tire mounted can be deadly. Tire should be totally removed from rim when welding on rim. Watch this amazing Bridgestone Tire safety video. Ted

http://www.scribd.com/doc/26525150/Just-See-the-Works-of-Cal-Lane

go to: http://www.appaltree.net/aba/adpad.htm scroll down to "Ray Clontz" for details on getting plans. Ted

Industrial companies are using UHMW plastics extensively for sliding surfaces. An example is the sliding rotating water screens for power plant water inlets. The most important factor is that the sliding metal surface must be smooth to prevent accelerated wear of the plastic. Ted

Try searching on "electro-etching" or "touch marks" Your design is a little two complicated or intricate for a touch mark stamp. The electro-etch approach looks more suitable for your application. Ted

Yes, that helps. What you say makes sense to me. The tire hammer is essentially a little giant with a different drive system. Thanks Ted

Can anyone give a clear explanation of the effect of tightening and/or loosening the spring and when do you know it is correct? Ted

Woody, If you go to the thread in this section titled "Tire Hammer Construction Changes" and scroll down near the bottom you will find a photo of a tire hammer with a three phase motor and in the background a portable TECO VFD setup. Note the labeling on the switch and receptacle. "240 Volt single Phase" and "240 volt three phase". This particular VFD has a horse power capacity up to 2 HP. In this photo it is controlling a 1 HP motor. I can move it to a nearby drill press with a 3/4 HP three phase motor. I have another unit set up for a Fay-Scott Lathe (2HP) and a Bridgeport mill 1/2 HP and a old Garvin Horizontal mill 2HP. These units provide an exceptional flexibility for three phase and can be bought with much larger HP ratings (100 HP plus) if you have the current capacity to handle that. They can also be bought for three phase input and three phase output. In the later case they provide all of the flexible control features as mentioned before. There are in excess of 100 programmable control functions available in these units(Speed, Acceleration, Braking, Motor protection, current limiting, etc.) . Ted

Your best bet is to use a VFD (Variable Frequency Drive). They are available to create 3 phase power from single phase and provide numerous control options such as variable speed(50% under and 150% over rated speed depending on motor and load), dynamic braking, jogging, etc. I have used them for years and wouldn't be without one now. I would use them even if three phase power was available. Ted

I have the parts to add remote on/off pushbutton and speed control for each VFD but haven't got that done yet.

I normally use the VFD on a drill press but it is a simple matter to share it with the hammer(by swapping twist-lock plugs). I have a second VFD that is shared between a lathe and milling machine. The speed range should be from about 1/2 to 2X normal speed(1800rpm) but my interest is to slow it down at times. I have not experimented much as the shop is tooooo cold right now. The adjustable toolrest is for holding dies and other special tooling with vise grips as a clamp. Ted