arftist

I disconect batteries on cars with computers for the same reason I unplugged this computer from the wall outlet during the huge lightning storm we had here last week. Electrical isolation. Not connected, can't be harmed.

Afraid I have to agree with irnsrgn of this one. If the time it takes to undue one battery cable is too much to spend, then I guess you can readily afford to repair whatever damage may occur. Just because you have done something without ill effect, in no way garrantees that you will always get away with it. There is a concept that is a bar to all knowlegde; that concept is contempt prior to investigation.

Jose, thankyou for your exellent explantion of tungsten selection.

Draw out end to a point to suit your taste. Cut to lenght plus extra for head. Drop in header and peen til satisfied. If you don't have a nail header, a vise can hold the nail while you peen (upset) the head. This exercise teaches drawing out, upsetting, and hammer control.

Reading your responce gave me some more insight or posibly another idea. One thing that makes me wonder, is after you burned away the 1/8 electrode, how did changing to a smaller electrode help? Aside form that, Al welds differently from other metals. Al's rate of thermal conductivity is second only to copper. This is why so much more heat is required to establish a puddle. However, as the welding progesses, less heat is required to maintain said puddle. I have to second hillbillysmiths suggestion that you use a higher heat setting at the machine. Stomp the petal to get the puddle started, then back off the heat to just enough to maintain the puddle. As the work heats up you will need less pedal. The phenomenon of the side of the weld pulling away is usualy caused by the fact that the melting temp of aluminum oxide(which continuously forms on the surface)has a MUCH higher melting temp than Al, so by the time you burn through the oxide, the Al under the oxide has melted away. Hence the need to vigorously wire brush the work with a new s.s wire brush. Also, if possible, practice some on some Al srap, just to get a feel for the heat input needed for fusion. Lastly, it is perfectly ok to weld over your previous beads and melt the lumps together. But then I've only been welding Al for 30 years so take it with a grain of salt.

Along these lines, it may be worth mentioning that many modern vehicles have computers on board, if welding to a vehicle with a computer, at least disconnect the battery leads.

None of your problems sound unusual for cast Al. Aluminum is difficult to weld at best, and casting alloys contain many impurities. Start with a new stainless steel wire brush. Brush the work severely, imediately before welding, and between passes. Only use pure tungsten, and check the alloy of your filler rod. Be very careful grinding Al, unless you have a disc made for Al. The main problem with welding Al is aluminum oxide, which has a much higher melting point than Al. I think your amp setting is rather low, but I wasn't there either. Some cast weld well, some do not. Remember that Al is a very good conductor of heat.

I am sure you will get a lot of different good answers to this question, but I like the rathole, for a few reasons.

Good Luck. Your initial design looks promising in its simplicity and small foot print. Acomodation for height change can also be acomplished through stacking removable plates on the sow block. As for the 1/2 spring helve, sounds like a project to engineer, but probably a worthwhile task. I spent about year deciding exactly what I wanted, then about 4 months to build. What I am trying to say, is try to look at every design possible. For example your roller guide tup. Research this design thoroughly.

Also, you have to get past the idea that the shock is going to compensate for the thickness of the iron. This would be fine if all you were making were a mechanical flatter. In no time at all, you are going to want to strike hand held top tools, place bottom dies with varios thickness, etc. You MUST have an adjustable tup height or you severely limit the usefulness of your hammer.

Yes, I am quite familar with the construction and opperation.Actualy, the sping should not be compressed at all when the hammer hits, quite the oposite, it should be extended if set for maximun power. The reason for this, is that the crank throw is only seven inches, the maximun stroke is about eleven inches. The tup height is adjustable, maximun impact is achieved when the tup height at rest is set one inch above the work, this increases the available throw, the spring is compressed on the up-stroke, hurling the tup down on the down stroke and extending the spring. If the spring were to be compressed with the crank in the lowest position, it(the spring) would have had to absorb energy that should have gone into the work, which is part of the problem with using shocks: you don't want to lose any energy from the tup. Shocks ABSORB energy!

Have you seen designs for apalacian style hammers?

This is very interesting. I had no idea rounds were so hard to get in places. The reason I use elm, is that it resists splitting, so much so that it is not considered good firewood.

Another good reason to let the weld cool, is that hot chips of slag landing on your eyelid hurt more than cool chips. The slag also serves to protect hot metal from oxidation.

You can also cut some serious holes with a holesaw, even with a hand held drill-motor

A short chain, two washers, and two lag bolts will quickly secure an anvil

This is good advice. Longer belts last longer, and even with 1800 of them, why not have a lifetime supply. Also, there is nothing standard about 2" wide belts. Common, maybe, but the more surface area available, the more versatile your machine will be. Also you will never be able to splice them as well as the factory, if at all. Two of your pulleys will need to be crowned, and one of the crowned pulleys should have angular adjustment. You can weld most of the framework, but try to design mounts for moving parts which can be shimmed if needed. There are whole websites on shop built belt grinders.

LDW, Not to be a wise guy at all, But I adjust my regulators almost any time I use my torch. The thicker the metal, the more pressure and vice versa. Even If your average pressure only went to 30 psi, you would save 25% on your oxy bill alone. If you don't cut much it probably will not matter much.

Shocks have been tried and proven to not work well. However, all power hammers use springs in one form or another. While most mechanisms can be improved in some way, there is no need to reinvent the wheel. For more info on shocks, check anvilfire.com. In my opinon, a flat belt clucth is the way to go, but a lot of people like the spare tire clutch method.

LDW, So do you use 40 psi of oxygen for all your cutting needs? Just curious.

If something must be movable, make it the hammer, not the anvil.

So I guess your question is whether or not you can build your own power staightener with 5 wheels. I don't see why not, provided you have access to machine tools, machinist skills, time to build it, money for all the parts and stock, and can justify the amount of time it will take. Do you need help designing the drive system? Bear in mind, you will need either adjustable dies or interchangable dies. As someone else mentioned, much straightening can be done during texturing.

First things I forged were nails, in blacksmith school. This exercise teaches drawing out, upsetting, and hammer controll. Next was hooks, which taught twisting and bending.Still have most of them and still teach forging in this order.

Frosty just in time.

If you are worried about damaging the textured finnish, use a wood block as an anvil, and a large wood mallet to straighten, even if hot. If not, use anvil and hammer. Find the low spot on the anvil,and strike over it. For radical bending, a hardy tool can be made; plate 1/2"x3"x6" long, with a 3" long rd. bar welded across each end, and a prong to fit hardy hole on underside. Place stock on rods and hit inbetween.