ciladog

Youngdylan,

I built a digital control for my propane forge from plans posted on the internet by Whitney Potter. This was a few years ago and they were downloaded as a pdf file. Well, Mr. Potter has now published a book on the subject and the pdf file is no longer found for download. This is the link to the book.

I’m posting a pic of one of the pages from the file with the assumption that what I have posted was not copyright protected since it was available before Mr. Potter published his book and nothing in the document says it is copyright. ADMINISTRATOR: Please delete the pic if my assumption is incorrect.

Now with that being said, I have replaced the blower in the diagram with a power relay (both 120 V and 220 V) that I can either plug my forge blower or my kiln into. The connection to the thermocouple has a plug connector so I just unplug the forge thermocouple and plug in the kiln thermocouple. It works very well for both.

A type “k” thermocouple will take you up to 2300 F. If you use it in a forge, I suggest it be 8 gauge. I don’t think it matters what gauge you use in a kiln. And be suspicious of used thermocouples; they wear out.

I have recently purchased and refurbished a logan /monkey wards 10x24" lathe and am looking for a taper attachment to fit.
Logan Actuator Co. is awfully proud of their new ones and I dont have a milling machine yet to make one. Anyone out there seen or heard of one for sale or trade or gimme for shipping cost ??? Thank you,

Clifford

When I got my first metal cutting lathe back in 1976, I was in the process of building a large woodturning lathe for columns and needed to cut some internal Morse tapers in the spindle and tailstock. I couldn’t find a taper attachment for the lathe I had so I built one. It was simple to make and worked so well that I put a set of plans together and sold them along with the blank stock as kits. I sold quite a few mostly to prison inmates, surprisingly.

I attached a pic of the ad that appeared in the April, 1977, edition of Popular Mechanics just for fun. I also attached part of the plans with the exploded diagram so if you want to make one, you could see just how simple it is. Sizing it for your lathe is a matter of calculation once you understand how it functions.

I have a set of construction plans that I bought from Clay last year at a class I took with him. I decided not to build his hammer and the plans are of no use to me. If anyone wants them, just PM me with an address to send them to and they are yours.

Sorry ladies and gentlemen, the plans are spoken for.

I see a lot of the argument going on here as about the same discussion as if we where talking about Bush or Obama and who has helped or hurt the country more ( Im my opinion they are both a cog in the same machine out to destroy us, but hey)

Monstermetal

I was wondering when someone was going to interject politics and the current administration into this thread.

Without getting into a political debate or bashing anyone I will give you my brief opinion and observation.

I have been self-employed doing high-end architectural woodwork for the last 35 years and up until last year; I was making a good living. I wasn’t getting rich but I kept pace with the rising cost of everything and was able to put something away for my retirement. I have never seen things this bad in those 35 years. Now I’m living out of the bank watching the saving dwindle. I can’t collect unemployment and I’m not yet retirement age.

I haven’t seen one dime of the Stimulus money nor do I expect too but I’m paying for it. Much of the money went to union jobs in the public sector and to infrastructure improvements also mostly unionized workers. It’s a good time to be in a union. I will say that if I had it to do all over again, I would have taken a public sector union job. I would be collecting a pension, on my second career with money to spend by now.

It is the disposable income of the wealthy that has kept me in business and I would guess it kept most artisans and craftspeople that work for them in business as well. Well, they’re not spending like they used to because of the uncertainty of what is to come. I know that what was good for the wealthy in this country was good for my little business; something I fear is a thing of the past for the foreseeable future.
****, soon we will all be surfs giving everything to the government, owning nothing and letting them take of us. Not where I want to be. And if you think things are bad in the economy now, just wait until next year.

The function of a circuit breaker is to protect the wiring in the building not to protect the device plugged in to an outlet. The sizing of a breaker is determined by the gauge of the wire used. For example, if you use 12 gauge wire to run a branch circuit then you would use a 20 amp breaker. If you use 15 gauge wire you would use a 15 amp breaker. If the breaker is sized larger than the wire, you create a fire hazard in that the wire could burn if overloaded before the breaker trips. A smaller breaker on larger gauge wire is no hazard at all.

Here in the USA, we use single phase 240 volt service in most residential buildings. It comes into the house on two legs, each is 120 volts. The third leg is the neutral. If you connect a circuit using one 120 leg and the neutral, you have get a 120 volt circuit. If you use two 120 legs for the circuit, you get 240 volt and the neutral is used only as a ground.

Chances are that you somehow created a 240 volt circuit and blew the small windings in the dermal.

Turn the breaker off and call someone who knows electricity. If you don’t know what you’re doing it will not only kill you but burn down your house.

This may help.

Glenn, I'm trying to get my hands on a blueprint posted by Dick Sargent on rethreading a post vise. He has given permission to use his photos in an article. Any chance you could send me a link or post it? Thanks

check your pm

Keith,

I built a hammer that needed 16 CFM at 120 PSI to run continuously but the compressor that ran my woodshop for the last 35 years (a big old Dayton two stage, 2 HP) only put out 7 CFM at 120 PSI and was 75 feet from the hammer. I ran ½ inch black pipe to the hammer. The hammer ran fine for about 30 seconds each cycle and then the pressure would drop below 120.

The Dayton runs the woodshop (which is my bread and butter) and I didn’t want to replace it and I didn’t have the room anywhere inside for a much larger compressor. I wanted to keep the cost down.

I bought a 3HP Harbor Freight compressor (11 CFM at 120 PSI) for under $400 and hung it on a bracket outside on the wall of the shop with a little shed roof over it to keep the rain off it. I ran a ½ inch pipe through the wall and connected it to the existing system with a ball valve. I set the pressure switch to come on at 120 and off at 150. The Dayton comes on at 140 and off at 165.

So here is how it works. The 60 gallon tank on the HF acts as a receiver for the Dayton and the pressure goes up to 165 in the entire system. When I use the hammer, I have 60 gallons of compressed air just a few foot away from the hammer and 80 gallons of air in the Dayton and the hammer runs fine. The Dayton can charge the entire system between heats and the HF doesn’t come on until the pressure drops to 120 which is not very often. When I’m not using the hammer, I turn off the ball valve to isolate the HF and its back to business as usual.

So I end up with 18 CFM to run the hammer on a 2 HP compressor and occasionally its 5 HP for a minute or two. Cheap air.

Working thru the calculations for screw force and the yield strength of babbitt, it does indeed look like babbitt would not be a good idea. Makes one wonder if the author ever actually did it.

Pretty interesting, putting 200 pounds on a 20" handle going through a 4 pitch thread yields a force of 50 tons! That's disregarding friction which is a big factor with the poor thrust bearing and all, but still! Checked my calculations three times.

Good post ciladog! Glad to see someone who has actually done it. Practice beats theory any day!

Apologies to dablacksmith too!

Thank you Grant.

Most tasks we do are a process of orderly steps. The task, as a whole, can seem overwhelming or beyond one’s ability. But broken down into the steps, and we have already accomplished it.

Here are a few more tips for those who will actually try to re-thread a vise box.

The box I re-threaded was cast so I had to cut out the old threads on a lathe. You need to use a stead-rest when you cut the threads out. Chuck the box in the lathe as true as you can and put the stead-rest about an inch back from the end. It will be a bumpy ride at this point. Then cut the first ¼ inch of the box on the OD to true up the end. Then reposition the stead-rest and cut out the threads.

Leave the box in the lathe until you have made your threads so you can do some final sizing. The threads (on the screw) should just slide into the box with a few thousands clearance. If you need any force to insert them, you will most likely distort them when the screw isn’t supporting them.

Before you insert the threads for brazing, put the empty box in the forge and burn out any old grease and scale from the back. Grease vapor will contaminate your weld. You can clean the inside of the box using a brake cylinder hone, works very well. Use brake cleaner for a final cleaning.

To make the brazing power, I put a sheet to wax paper under my belt grinder and just collected dust from grinding up brazing rods. I added borax as flux and ground it up into a fine power. I added this mix to the box cold and then put it in the forge. You can add more brass as short lengths of rod once the box is up to heat by laying them across the threads. But if you try to add flux, you will most likely end up with brass on the threads.

When the brazing is finished let the box cool completely before you attempt threading in the screw (the metal contracts when it cools you know) and you don’t want it contracting around the screw. The first time you try to thread the screw it will seem like it just won’t go but it will. I sharpened the end of the thread on the screw to a chisel point with a cutoff wheel to cut the flux and excess brass as it threaded in, in a little then out (you know the drill) and use some muscle.

Use some valve grinding compound on the screw once you have the flux and brass cleaned out to cut a few thousands clearance and it will work like a new vise. Remember to wash out the grinding compound or you will be re-threading again in short order.

I absolutely 100% guarantee that welding nuts together will jam due to shrinkage and distortion. Heck, welding on one nut is usually enough no prevent a bolt from going in. Don't ask me how I know! You can get Acme all thread and nuts from ENCO, MSC and others.

Actually, babbitt works very well for this kind of thing. A steel nut requires about 1 diameter of length to have full strength. Babbitt, at 1/4 the strength requires at least 4X diameter thread engagement for full strength. Split nut on a lathe is often babbitt and seems to follow the 4X rule.

I have to disagree with using babbitt to repair the treads in a vise box. They just won’t hold up to the abuse. Some vises boxes were made by forging material into a tube and threads were then brazed into it. Some later vises were made as cast with threads cut into the box. There is a proper way to repair a leg vise box. Dick Sargent posted a blueprint on the process but since the blueprints are not currently available I’ll tell you what it said.

I know this process works because I just repaired a vise using it.

If the threads are brazed into the box (you will know if you see brass between the threads and the tube) then remove them by putting the box in a forge and heating and pulling the threads out. Or, you could turn them out on a lathe. If the threads are cut or cast, you will have to turn them out in a lathe.

Then make new threads by wrapping stock (say 1/8 X1/8) around a good part of your screw. You really only need about 2 inches of thread. An OA torch works well for this. If you don’t have a lathe, you will need to size the stock to fit into the box.

Take the threads you made and put them in the box, add flux and brass and put it into a forge, either coal or propane. Bring it up to temperature and rotate to let gravity and capillary action do it thing. That is the way vises were made before there were screw cutting lathes.

Then start working the screw into the box to break up the flux. Use grinding compound to cut clearance for easy use.

I make slack tubs. They are not hard to make but the labor that goes into making them prices them higher than people what to pay. So I don’t do it for profit anymore. It takes about 5 hours to make the tub and the bands. I have three left from the last run and I would like to get rid of them. If you are somewhat local to northern New Jersey and can pick it up, message me and make me an offer. The worst that will happen is I’ll turn you down.

They are made from 5/4 hickory, 16 inches diameter, 20 inches tall. They come with a steel base to keep them off the ground and have an OSB lid.

If you want to calculate the true cfm your compressor is putting out at a given pressure, this is how you do it.

The time it takes to pump the receiving tank of a know volume from a known starting pressure to a known ending pressure will measure the cfm using the Ideal Gas Law with isothermal compression where we ignore temperature (adds some error in the calculation) and change the pressure and the volume.

First, determine the tank size in cubic feet. You can take some measurements and calculate it to confirm say if you have a sixty gallon tank (divide the tank volume in gallons by 7.48 cu-ft/ gallon). So a sixty gallon tank contains 8.02 cubic feet.

Second, slowly bleed off pressure from your tank until the compressor cuts in, start a stopwatch, and note the pressure in the tank before any regulators. When the compressor cuts out, stop the watch and note the tank pressure. Subtract the starting pressure from the ending pressure and you get psi increase for a given period of time.

I’ll use a compressor I recently added to my system as an example. It has a 60 gallon tank and the label says it delivers 12.35 CFM at 100 psi. The cut in pressure was 120 psi and the cut out pressure was 148 psi and it took exactly 60 seconds (that was convenient). So I get a 28 psi rise in 60 seconds.

Next, convert the psi rise to atmospheres of pressure (1 atm=14.7 psi). So 28 psi/14.7=1.904 atm of pressure added in 60 seconds.

The rate air is being pumped into the tank is the pressure rise X the volume of the tank (8.02 cu-ft X 1.904 atm = 15.27 cubic feet) in 1 minute at 120psi (cut in pressure). The error range in these calculations could be minus 30% because we are not accounting for temperature rise or a gradual pressure rise so the range is somewhere around 11 CFM at 120 psi. To my surprise, the label on the compressor is probable pretty close to what it puts out.

Depending on the time it takes your compressor to cut out you will have to convert to minutes to get the CFM. Example: it takes 50 seconds, 60/50 X 15.27 cu-ft or if it takes 90 seconds, .666 X 15.27 cu-ft.

I hope this helps.

Here are some interestiing links to info on modern day press and hammer installations.

The first link has two videos on the page. First is installation of 24,000 ton press and the second is about hammer installation.
videos

This link is pictures of a massive fondation for a 12,000 ton press.

pictures

Enjoy

Youngdylan,

I like that KA75ish hammer you made, real nice.

I’m not so sure that I like the spring shock absorbers though. They may help save your tup to cylinder connections but don’t they take away some if not most of the striking force the cylinders produce? There can’t be much acceleration with such a short stroke so it seems to me that you are relying on the weight of the tup for all the force. I’ll have to think about this some more.

I suggest working with the throttle valve so the hammer starts off more slowly and is almost in a closed position when you take your foot of the treadle. That would eliminate some of the slamming. I can’t see all the controls in your pic so I don’t know what kind of spool valve you have. If it is a spring loaded spool with only one pilot valve, you may want to consider going to a 5 port 2 way valve using 2 pilot controls for more control.

When I first considered building the Bull, I too was concerned about what looked like an unbalanced force. I thought there would be too much torque on the connections of the cylinder and would require more force to move the tup. But it turns out that much of that concern was unfounded because of the way the head (tup) slides on the column. The cylinder doesn’t “see” an unbalanced force as long as the bearings are adjusted to keep the head perpendicular to the column. Doc’s Bull has been in production use for 10 years with no cylinder problems at all.

Check out my reply to Finn for some more info on the throttle and using larger cylinders.

Finn,

If you have ever watched the demo video by Tom Troxzak on the Pheonix website, there is a subtitle that says, “Always snap foot off treadle to allow cushion at top of stroke when finished.” The reason for this is it closes the throttle down so the last upstroke is slowed down and the ram doesn’t slam up.
Video

The throttle adjustment (connected to the treadle) is critical on the Bull. You want the hammer to start slowly when you first depress the treadle and gradually increase speed as the treadle is depressed further and the throttle opens further. If the throttle isn’t adjusted correctly, the ram will just keep slamming up hard until you get the stroke far enough down the column.

Obviously, the pilot control valves also need to be adjusted correctly. This is a matter of trial and error. You want to start out so the up and down valves are both contacting the control rod when the ram is in the up position and treadle is up. The up valve is pressurized and the down valve is almost pressurized. Be sure that the valve pivot stops are contacted for this first adjustment. Then it’s a matter of tweaking the adjustment until the hammer runs the way you want it to.

They call it a 75# hammer but the ram weighs more than that. It starts as a 6” X 9” ram (72#) add the die and die plate (14#) add the bearing plates and housing (20#). So the 75# ram weights 106#. Mine weights 120# because the housing is larger because of the bearings I’m using.

A 2” cylinder produces 377 pounds of force at 120 PSI. That’s more than enough to overcome gravity and raise the ram at a good speed. For a 12” stroke, the acceleration on the down fall is only about .27 plus the weight of the ram (106.27) feet/sec. x sec. Meaning, the force when the dies hit is about equal to the force the cylinder produces. Inertia is a story for another day.

The 2” X 12”cylinder requires 37.692 cubic inches to fill once. A 3” cylinder will produce 848 pounds of force at 120 PSI but requires 84.816 cubic inches to fill once. Depending on the strokes per minute and the length of the actual strokes once the hammer is running will determine the CFM needed to run the hammer. A Bull should run on 16 CFM but change to a 3” cylinder and you would need more than twice that.

When you get your hammer fixed make sure the bearings are adjusted so the head stays perpendicular to the column but allows for easy movement. Consider stabilizing the cylinder by making a stabilizer to eliminate torque at the top of the cylinder (see the pic).

Good luck and get that Bull running.

Youngdylan/Senft,

I have posted a CAD drawings that might help explain how the controls work. I suggest you print the pic so you can look at it while you read this explanation.

The “control rod” is telescoping. It is made of 16 gauge ½ inch square tubing with a 3/8 inch rod sliding in and out of the tubing as the ram moves.

The red line on the drawing represents the alignment of the control rod when the ram is at its upper most position and the treadle is not depressed. The blue line represents the alignment of the rod when the ram is down and the treadle is depressed all the way. At any given position of the ram and treadle, the line will be somewhere between the red and blue lines.

Let’s start with the ram up and the treadle up. As you depress the treadle the bottom of the rod moves to the right changing its angle and moving it away from the up pilot control valve, on the left of the rod. The rod then begins to contact the down pilot valve and the ram begins to move down. Depending on the treadle position, the rod will move to the left at the top as the ram moves down contacting the up pilot valve and reversing the ram. The further the treadle is depressed, the further the ram has to travel before the up pilot valve is contacted.


Youngdylan, Anyone that has a Bull knows how violent the ram moves to the top of the column when you supply air. Research of available posts on the Bull indicates that if the cylinder is going to break it will do so on the up stroke. So what you see on the top of the column is a shock absorber. The cylinder has air cushions but it’s not enough. Since I can adjust the hammer for a full stoke, I put that up there to save the cylinder. It does nothing during normal hammer operation.

My dad has a 125lb Bull... the more conventional looking machine. I borrowed it for a year or so and really fell in love with the thing. Its such a universal machine. Ive tried to buy it from him but I guess I am just going to have to build my own.

Thanks for sharing you hammer build and info... Looks like it was a great success!

Hello monstermetal, Yes, the hammer came out better than I expected. It was not hard to build with minimal skills in machining and welding. It cost me under $1,900.00 in material in the new market. No salvage. It took about 4 ½ weeks to build.

There are several other changes I made on this hammer that is different then the original Bull. First, is that I can move the cylinder up 3 inches and down 2 inches to accommodate different dies or tooling (check the pic). Second, the distance between the column and the anvil is 2 inches not one to allow for larger forgings. Third, the anvil is taller than the original. And the column is made of 2 ½ cold rolled welded into 3 inch X ¼ inch tubing. I think it makes the more ridged. The bearings are made of 3/8 inch HMW oil impregnated polyethylene and should last a long time (see the pic).

The Bull is a controversial looking machine compared to what most think of as a forging hammer. But I like radical especially when it works

Doc is correct in his explanation. I could not have built my hammer without his knowledge, support, and collaboration. I now have this hammer thanks to Doc.

So let’s take this a step farther. We, Doc and I, talked about the workings of all the hammers we could find and with Doc’s long experience in the art, when he told me that his Bull hammer was so versatile, controllable, and dependable I decided that it was the one I would build. But like a lot of Kinyon style hammer, stroke controllability causes the stroke to shorten when doing hard forging (I think). Could you get a full 11 inch stroke at full power and still control it when you needed it? Could you get a full single blow like a striker, have clamping ability; does controlled chisel or repousse work? Could you build a hammer that could it all without sacrificing any one element? We think we did.

Subtle changes in the control valve positions cause great differences in the ram’s movement. The polygonal motion of the control rod also has great influence on the ram’s movement. So I decided that on this hammer I would be able to adjust the valve position and the control rod position while the hammer was under power (so to speak).

By moving the position of the control rod where it attaches to the ram changes the length of the stroke. If you move it forward, the stroke gets longer and moving it backwards makes the strokes shorter. See the pic of how this is achieved.

The spool control valves are mounted to plates that have arms that extend through the top of the control box so their position and relationship to each other can be adjusted without having to open the control box. See the pic.

Something that we discovered after the hammer was built could help anyone trying to adjust or time a Bull or other hammer is that it is NOT an all or nothing situation with the spool control valves: Meaning that you can have two control valves in the pressure state at the same time. The spool can’t move with equal pressure on both sides. Which ever valve is pressurized first controls until one of the valves goes into the exhaust state.

I hope this further explains the working of this hammer.

I recently completed building and new forging hammer. It’s in the style of the Bull but with many modifications in the controls that allow for on the fly changing of the length of stroke, intensity of the strike, position of the stroke, and it will even run without touching the treadle at any given stroke. But this post is about increased controllability for all pneumatic hammers (not self contained).

I have a pressure gauge on the supply line just before the hammer and I noticed that each time the tup changed direction; there was a pressure spike of about 10-15% PSI. This happens because at the very instant that the tup changes direction (when the spool in the control valve changes position), the pneumatic cylinder becomes a pump while the inertia of the present tup direction is overcome. The intensity of the spike varies since air can be compressed and it is unpredictable.

I installed a directional air control valve (inline spring type control valve) just ahead of the spool valve as an experiment and although the effect was subtle it was noticeable. The control became more exact.

I got the valve from McMaster-Carr for under $14.00. You may want to see if adding a check valve adds to your hammer’s control. Place it as close to the spool valve as possible.

I know you’ve seen a pic of the paperclip before on the Phoenix hammer website but I just had to try it so I post if for your amusement. I also posted a pic of my hammer, it's control box, and one of the original Bull control box.

Thank you Tom Troszak for designing the Bull. It is the best hammer pound for pound.