View Full Version : E-Wheel Building Tutorial - by Kerry Pinkerton
09-07-2005, 08:27 AM
Part 1 - Frames
Part 2 - Anvils
Part 3 - Adjusters
09-07-2005, 08:28 AM
Original content supplied by Kerry Pinkerton
I've been fortunate to have worked with Wray Schelin on a wheel design. I've just finished it and it is build from 8x2x1/4" tubing. It will be unveiled late in August 2003. During this two month build process I began to consider holding a 'WheelMeet' similar to what Tom Lipton did early in 2002.
Hopefully some readers will follow along using these photos and measurements as instruction. You will need some way to cut the material, weld the material, grind and finish. Some work could easily be farmed out.
I literally stumbled across a large quanity of 10x2x1/4" wall rectangular tubing that just looks like it could be Ewheel frames. I got enough to build 8 frames very reasonably.
I also found a 8'8" length of 3" cold roll suitable for anvils at 20 cents a pound (40 bucks)
When I found all this stuff, I talked with Wray about doing a design that worked with the material. This sketch started the process.
Wray got busy with work and other projects so I went ahead and modeled his sketch in full size using full size cardboard in dimensions of 20"x3' which is the size of the scrap material.
This design has a 31" throat and had 24" between the arms.
As I laid the template out, I realized that the distance between arms was a little too much and proposed the following modification to Wray which he approved:
This version has two fewer parts and only 18" between the arms.
NOTE: This is no longer a Wray Schelin designed frame. Wray never sent me his layout so I went ahead. Wray had envisioned different angle cuts so that the material ends were all the same length. I opted for the same angle and one small filler. Wray thinks this may weaken the frame so at this point I guess it's accurate to say this is a Wray Schelin "inspired" frame.
This frame is designed for ease of BUILDING. I am not a machinist, I am a brute force fabricator. If you are sharp eyed, you may notice part #3 and Part #2 don't line up perfectly. This is intentional to keep all the angle cuts the same. The short distance will be easily filled with scrap.
With the modified layout, there are only 3 unique parts: The backbone (#1), four angles (#2), two straights with a 90 degree on one side (#3). All angle cuts are the same. They are 67 1/2 degrees (or 22 1/2 degrees depending on how you look at it. Half of 45 degrees) While most larger bandsaws can easily cut this angle, it is not marked or easy to lay out. This is easily solved by doing some simple trig. Please note that I did not do the math but simply asked an engineer friend. It's been 40 years since I opened a trig book. :D
If you simply lay out a right triangle with the two legs of 12 1/4 and 29 3/4, the resulting angles will be 22 1/2 and 67 1/2. The hyponuse will be 32" even. I laid mine out on a piece of 1/8" luan and cut it with a box cutter. You can use most any stable material.
Before you start cutting the material, it's helpful to know how much you will need and what pieces you will cut from each. When you lay all the pieces in a row it takes 100" of material not including the base.
Because my material is only 3' long, I had to lay it out into 3' increments. It will take 4 pieces which includes a 16" piece of scrap which will be used on part of the base.
Using the triangle to set the angle on the saw is as simple as laying it even with the side of the metal and marking the appropriate cut.
Lets' talk about material and sizes. My material is, as mentioned previously, 2x10 rectangular tubing 1/4" wall in 3' lengths. If you are building along, you can use a variety of 1/4" wall (or thicker) material. 2x8, 3x8, 4x8, 3x6, 3x6, etc. Anything smaller will probably be too light for the sizes described here and you will want to scale down the porportions.
The dimensions of each part are described below and are the INSIDE dimensions. This way, regardless of the material you choose, the measurements are the same:
#1 = 19" One each
#2 = 8 1/4" Four each
#3 = 14" Two each
Check with local salvage yards and fab/welding shops for cuts and drops. Frequently you can find material for next to nothing. One of my sources let's me get stuff out of their scrap metal dumpster for SEVEN CENTS per pound. This is where I found most the adjuster tubing. I got the 40 pieces of 2x10 for $14.13/lb. Here is a single piece of the tubing I found.
It weights 53 lbs so this is going to be a heavy frame. I'd expect final weight without wheel or anvil will be around 275lbs.
As I said, you can cut this with a variety of ways. I'm using my $50 bandsaw (long story but it pays to get friendly with your used machinery guys).
You can also cut it with a torch or pay a local shop to make the 8 cuts for Wrays design. My fixed lower mod will be a little more complicated because the long lower arm must be cut lengthwise.
When I first cut the angle it took 18 minutes for one cut. This was with a 20 tpi 3/4" blade. I changed to a 1" bimetal blade with 8-12tpi and the time dropped to 13 minutes. Figure 15 minutes for each cut to include setup. I also realized the saw cuts better at a high angle than it does when it gets flat so I double stacked the material. This also saves on setup between cuts. I was able to cut an entire frame in 4 hours including taking a break for lunch. This is a start and walk away saw that shuts off when it finishes the cut so other things can be done while the saw is grinding away.
Once the metal was all cut, I laid it out on the floor. I noticed that the metal is slightly bowed on the seam side so I laid all the seams on the same side and tack welded it together. It's nice that all but the #3 parts are symetrical so they can simply be flipped over. I chose the 1/8" gap method instead of grinding bevels in all the joints. I just stuck a couple paint sticks between the joints, laid the metal tight and tacked. It was possible to see the inside of some of the welds and I'm confident there was full penetration. I'm no professional welder but if one of these welds break, I'll donate $100 to MetalMeet03.
Then I welded it solid by going from side to side and joint to joint so it would not warp. It didn't.
Here it is all welded except for the two #3 pieces. It's ready for a base and adjusters tomorrow. Sorry about the shadow.
I spent some time thinking about what kind of stand I wanted. It's a little too big for a bench mount <grin>. Not wanting to use any more material than I had to, I welded up a few pieces and came up with this. The legs were a piece of 4' long angle I had in my scrap pile.
And here it is standing in the yard waiting for grinding. The level on the front is 4' long. The working height will be about 54 inches if you put it on 4" casters. For now it is pretty easy to walk around the shop without casters.
This frame is very stiff and has no indications there will be any flex in any direction.
Here is a shot of the 4 pieces that made up the trapazoid base.
I've also decided to make a modified frame for my personal use. This one will have a fixed lower arm with space under it and an upper adjuster. Wray was not that excited about this design but what the heck, it's my steel. <grin>
This version has the same 4 part #2s and one part #5 but part #1 is longer and the long lower arm is different.
Sharp eyed readers may notice the stand is shorter. That is because the main upright (part #1) is longer than in the other version. Working height will be about the same. The long lower arm was made by cutting the taper lengthwise with a torch and welding the two pieces together. Took about 45 minutes.
Both these frames were made with 12' of the tubing with not much scrap left over.
Ok, it took me about 8 hours total to get to this point (16 for both frames), including time to cut the steel.
Now it's time to build the adjusters. I'll start with the modified frame but they will all be similar. I first cut a piece of 3 1/2 tube and 4"x1/2 plate the depth of the upper arm. The plate will be welded to the arm and the tube bolted to it. Four 4 holes were drilled for boltiing it to the tube.
Four pieces of 1/2" thick Polyethene were cut for bearing material. Pressure on the sliding tube will be adjusted by set screws so there will be NO play in the upper wheel. All these holes were drilled.
Then tapped for 1/4x20tpi screws. The big bolts to the frame are 1/2" allen screws.
I can tell already that this adjuster is too time consuming for the wheel meet. I have 3 hours in this one so far and don't see many ways to cut the time. Drilling and tapping the holes with any precision is just time consuming. I still have to cut the slot in the screw, weld in the bolts, build and mount the yoke and pivot.
Once I put the adjuster and wheel on the frame, I noticed it was a little front heavy so I added the front 'foot'.
My yoke is pretty simple. A base plate with a hole and bolt sticking up. The head of the bolt is welded on the backside and the plate welded to the arm.
I wanted the upper adjuster to be removable so it bolts on to a plate.
And here is my designed frame all welded up. The point of contact is about my belly button.
Now for a reality check. This frame is VERY still in the up and down dimension and also in side to side. However, I noticed that if you slap the upper frame hard, it kind of 'quivers' for a minute. I could not tell it while wheeling but did not want to put up with it so I cut some braces and welded them in to both the front angle arm and the main upright. This made a HUGE difference but the frame now weights at least 300 lbs without the upper wheel.
http://www.metalmeet.com/members/pinkertonk/WheelMeet03/Kframe1.jpg http://www.metalmeet.com/members/pinkertonk/WheelMeet03/kframe2.jpg http://www.metalmeet.com/members/pinkertonk/WheelMeet03/kframe3.jpg http://www.metalmeet.com/members/pinkertonk/WheelMeet03/kframe4.jpg http://www.metalmeet.com/members/pinkertonk/WheelMeet03/kframe5.jpg
In addition, I like the looks of the frame with the braces. I may add something across the top but first I need to grind the welds. While I had the front end loader on my little John Deere to unload a new 1930 vintage drill press, I managed to get the frame outside so the grinding won't trash the shop.
As mentioned in the email to Metalshaping, I've decided to postpone the wheelmeet. This is just too complex a machine to do in a three day build. I only had two people sign up anyway. John Staincamp is going to wait until after MM03 and the Bennett Chapman is going to come over for a few days before MM and we will build his wheel.
Bennett will probably do is modify the other "C" frame to something more to his liking rather than start from scratch. Bennett is a very experienced fabricator so between the two of us this should be no problem.
While Bennett was here, I realized the frame would look much better WITHOUT the center post. Bennett grabbed my torch and had at it, teaching me a few torch tips along the way. A little body filler and some rustoleum hammertone paint and here is the final result.
http://www.metalmeet.com/members/pinkertonk/WheelMeet03/Model1_1.jpg http://www.metalmeet.com/members/pinkertonk/WheelMeet03/Model1_2.jpg http://www.metalmeet.com/members/pinkertonk/WheelMeet03/model1_3.jpg
http://www.metalmeet.com/members/pinkertonk/WheelMeet03/model1_4.jpg http://www.metalmeet.com/members/pinkertonk/WheelMeet03/model1_5.jpg http://www.metalmeet.com/members/pinkertonk/WheelMeet03/Model1_6.jpg
With the casters on the frame, the contact point is 49"
I like this design so much more that the original, I decided to modify the original to the same basic design (with of course a few improvements) I cut the base off the frame, stretched the backbone to 3' and cut off the lower arm. The new arm will be built to fit a modified lower anvil holder I'm thinking about.
Original content supplied by Kerry Pinkerton
09-07-2005, 08:30 AM
Original content supplied by Kerry Pinkerton
Here is how I build anvils. I don't pretend to be an expert. I am not a master machinist. I'm probably not even an apprentice machinist. I don't know what I'm doing so I'm expecting lots of good advice and improvements to my process.
My process is based on things that Wray told me and stuff gleaned from the emails. To make anvils, you will need a lathe, a grinder, sandpaper, metal, the anvil profiles posted below, and some time. A drill press is nice but not required. For the lathe, you will need some drill bits and a reamer. Oh, you will also need some bearings. I found 1/2" ID 3/4" OD needle bearings at a local surplus store for 50 cents each. Roller bearings can be ordered from Skatebearings@aol.com very reasonably.
I start out with a blank of CR 3" (or whatever). I found an eight foot piece of CR for 40 bucks at my local scrapyard. These are cut into 3" lengths on the bandsaw, actually you should cut them a little oversize and face to 3" in the lathe.
THIS IS NOT A TUTORIAL ON HOW TO RUN A LATHE. If you don't know how, get help. These things can hurt you bad! On smaller lathes, you might slip the belt if you get something wrapped up or jam the tool. On larger lathes, you will most likely have some part of your body rotating with the work until someone comes over and shuts off the machine.
I find it's easier to make them in 'batch' mode rather than changing tooling between each step. That is, I cut them all, then face them all, then center drill them all, etc.
After everthing is faced, I center drill them all. I'm using a 3 jaw self centering chuck. This is on an antique Monarch Model A lathe, made about 1910. Lathes are pretty simple machines and as long as it is not loose, you can turn out decent work. My first anvils were made on a Craftsman toy lathe after the blanks were drilled on a friends Atlas. SLOW but got the job done.
Since my bearing bore is 3/4, I first drill all the blanks all the way through with a 1/2" bit, then with a 11/16". The next step is to ream it to 3/4. I guess you could bore it to 3/4 if you know more about machining than I do (wouldn't be hard to know more than me) but I had the reamer and it's easy. The bearings are a press fit.
This is a stack of blanks with the ends faced, and the holes reamed for the bearings. I ream all the way through. Some folks only go in deep enough for the bearing. Since it's a press fit I don't see the issue either way. Going all the way through eliminates having to stop and swap ends of the blank. It's one less step in the process that way.
OK, now to the hard part. My lathe is old and while a very good lathe I want the anvils to be as perfect as I can make them which means that I need to be turning between perfectly aligned centers. After trying several different methods over the years, here is what I'm doing (TODAY :) ) That is, I make a one time use arbor.
I cut a piece of CR about 8 inches long and face off one end and about 4" of the outside (could do it all but I'm lazy). I remove the piece from the lathe and on the drill press drill a 1/4" hole 1" from the center. This will contain the drive pin (more later) The piece is then reversed and chucked up tight with about 4" protruding and the faced end out. This is then drilled 3" deep and reamed for a bearing. A 1/4" pin about 1" long goes in the drive pin hole.
One step not shown is drilling a drive pin hole in one side of each of the anvil blanks. I use a drill press but it could be done with a hand drill.
A 6" piece of 1/2 drill rod (axle material) goes in my tailstock chuck and through the bearings. Because the arbor was machined in the chuck and NEVER REMOVED, it is true to the tailstock and there blanks will be true also. If you remove it orchange the tightness on the chuck, you are introducing inaccuracies. A bearing is pressed into the arbor.
If the arbor is removed, you need to make a new one as it will not longer be accurate.
You then put a blank with bearings pressed in on the axle and using the tailstock shove it onto the drive pin. The drive pin holes are about 1/2" deep. It does not have to be a tight fit.
Now as the chuck rotates, the arbor rotates, the drive pin rotates driving the anvil blank. The AXLE DOES NOT ROTATE because it is held in the tailstock chuck and the arbor rotates AROUND it. On your wheel your axle is fixed and the anvil rotates.
If your lathe is accurate enough, you can put the axle in the chuck and have a drive pin that 'catches' on the chuck jaw. The axle has to be center drilled and a live center placed in the tailstock. This approach rotates the axle WITH the blank.
So now you have the blanks read to cut profiles. Profiles, ah, the $64,000 question. (anyone remember that show??) There are as many opinions about profiles as there are bellybuttons. Master Wray came up with a set that is below. Works for him, worked for me, and will work for you also. If you have a CNC lathe or DRO's you probably aren't reading this because you can accurately cut the steps. Tom Lipton has published a very nice step chart for anvils.
You can save this image and dink with the image and your printer until the profiles are the width of your actual anvils. You then cut them carefully out and trace them on a thin sheet of plastic and then cut them out with sissors. I use some 1/16" Melamine from Home Depot left over from when we remodeled the kitchen.
If you are going much smaller than 3" you probably want to modify the profiles. The important thing is the flat, the relief, and the radiused edges so you won't mark the metal.
When you get through, drill a hole in one corner and string them together so they don't get lost and out of order.
Now to make some chips. Face the outside of the part and using a sharpie mark the center. I stop the lathe and put a dot at the center. Spinning the lathe and resting my hand on the tailstock, I touch the sharpie to the mark and it makes a line all the way around as a reference part.
Since I don't have digital readouts or CNC, I use a manual eyeball process.
I always start out with the flatter profiles. That way if I mess up and cut too deep, I can always convert it to a deeper profile. With this approach, I've never lost a blank.
Basically the approach is to take off material until it comes close to the profile guage. I do this with manual control instead of power feed and do steps but try and not get the steps over 1/16" deep.
Once the blanks is roughed to the profile, it's time to grind out the steps. You can do this on your lathe but the grinding dust is nasty and not good for the machine. Kent White posted that he puts an axle in a vise and lets the grinder spin the axle. I tried this and it works very nice for roughing it off.
Once you have all the steps out and it more or less matches the profile, I put it back on the arbor and take a cut across the flat. Then I blend the flat to the profile with a DA sander.
According to Wray, the flat is about all that is important, the relief just supports the metal and doesn't let it sag.
After you have it where you want it, it's time to polish. DON'T DO LIKE I DID! In the photo I'm wearing a glove. As Jacin pointed out this is a BAD BAD idea around rotating machinery. Hold a strip of emery cloth or sandpaper by both ends and pull against the work. Metal dust will quickly come off and the polish on the wheel get's better and better. Start with 180 grit and go until you want to stop. I usually end about 320 but have gone to 600.
Good enough for me!
One word of caution. One the anvils I made for Wheelasarus and Bennett at MM we noticed the 1 1/2" flat anvils and the 1" anvils actually had a low spot across the flat. I guess I did this during final polish with the DA sander. It's easy to fix but was embarrasing non-the-less. If you put the anvil up to the upper wheel and just kiss the contact, with a bright light behind it, you can see any problems.
Original content supplied by Kerry Pinkerton
09-07-2005, 08:31 AM
Original content supplied by Kerry Pinkerton
Part 1 of this series showed how the adjusters were made on WheelASarus. Wray Schelin described the basic format to me over the phone and the first version of this was the one put on RoboWheel. Bennett Chapman improved my original implementation and at MM and Wray, Bennett, and I later discussed further improvements in the design. These are shown here and this approach is how I am now making the adjusters for the machines we're selling.
This adjuster approach can be used for lower or upper adjusters. Lower adjusters are somewhat simplier because you don't necessarily need to attach the feed screw to the quill since gravity will lower the anvil for you. In that case you can have the screw simply push up on the quill.
Some terminology is in order. The screw that the handwheel turns I call the feedscrew. It drives a rectangular piece of metal that I call the quill. The quill is boxed in by Polypropolene (UHMW) pieces I call gibs. This terminology comes from machine tools and seems to make more sense than calling them plastic thingies or up and down tube things.
You can use this same basic approach in different scales. For my larger wheels I use a 4x4" square tube for the housing and 2x2 stock for the quill. On Randy's RoboWheel, I used smaller components and for our benchwheels the outer housing will be 3" tubing with a 1 1/2" quill. (Note, I never did go to 3x3 tubing for the smaller machines. The 4x4 1/4 and 2x2 quills works VERY nice 9/10/04)
The following photo shows all the components of the adjuster. The dark things beside the plastic gibs are steel backing plates for the gibs. The goal of them is to evenly spread the load of the adjusting screws and keep the gibs square. Wheelasarus and Bennett's frame had just straight UHMW 1/2" gibs and I think that would work fine, probably forever. I'm using the backing plates because these are machines being sold and I don't want any problems to come back to me (or more importantly the owner) down the road. For this reason, this design is as bullet proof as I can make it.
Note the thin bolt on the top of the feedscrew. We'll discuss that later.
You might note the gibs are different sizes. The 3" wide ones go on the front and back and the 2" ones on the side. That keeps things tight.
One thing to note is that tubing has a welded seam. If you don't account for this, your gib could 'rock'. Here is the backing plate for the seam side which I always put at the back, toward the frame. It is the only side that does not adjust. I choose material that spaces the material out so the quill is centered and let the other three sides be the adjustments. The backing plate is milled so it will straddle the weld. This could be ground out with a hand grinder easily. If you wanted to put adjusters on the back plate just drill holes, and tap for them.
My adjusters start with a 11" piece of the square tubing. A 3/4" 4x4" plate is welded to the top and is drilled and tapped for 1", 8 threads per inch (tpi) rod which is what I use for a feedscrew. Holes are drilled and tapped on three sides for the gib adjusting screws. On the sides I put 2 3/8" allen head cap screws (regular bolts work fine) with lock nuts. These are centered in the housing and I normally put one 1" up from the bottom and about 3/2 of the way up. On the front I use 4 screws.
I design the frames so at least 75% of the quill is within the adjuster under use. That ensures the assembly stays tight and has no play.
Our quills are made from 2x2" pieces of 6061 Aluminum. This is done for weight, ease of machining, and looks. You can get a foot of this for about 10 bucks on Ebay. You could also make your quill from 2" square tubing and weld a plate over the end for the feedscrew attachment and weld a nut in the other for the yoke to bolt onto.
I drill a hole through the quill and square it off with the mill, leaving 1/4" on two sides and 1/2" at the top. The top is drilled for a 5/8" hole in the center. Alignment is important!
The feedscrew is turned down to 1/2" 1 1/2" long. This goes into the 5/8" hole in the top of the quill and a 1/2" shaft collar is tightened on it with the set screw. The next step is important, the set screw will NOT hold the assemblies weight. Drill through the collar AND the shaft and press in a spring pin. This pin will carry the weight of the yoke, wheel, etc and NOT come out until driven out.
There are other ways to accomplish the same thing but this one works for me. It's relatively simple, with a minimum of machining processes, and most importantly, is a 'forever' solution.
The steel locking collar rides against the inside of the machined opening and carries the weight of the assembly when in the 'up' position. Steel on aluminum makes a good bearing surface. White lube helps keep things smooth..
To apply the downforce, we use a NYLOC locking nut. This is run down the feedscrew and adjusted until the feedscrew turns freely but has minimal play. The NYLOC will ensure the nut will not back out. Alternatively, you could drill and tap for set screws to hold a regular nut in place. This works fine but boogers the threads should any adjustment ever be needed.
The bottom of the quill is drilled and tapped for a bolt that holds on the adjuster. It is important to drill and tap these square.
The photo below shows how the gibs fit inside the adjuster. To keep them from falling out for the upper version, two pieces of 18ga (or whatever) are welded across the sides. This retains all 4 sides and you can still get the gibs out.
About now, some of you are wondering how the thing is assembled since the threaded shaft has to be fit to the quill. Bennett came up with this. He drilled and tapped a hole in the top of the feedscrew. Into this he screws a 4" long bolt and locks it in place with a locknut. This can be seen on the component photo. To assemble, simply insert the threaded shaft into the adjuster with the gibs installed and grab the bolt as it comes through the threaded hole in the top. You can then turn the bolt and the feedscrew will feed through the threaded hole. A little white lube helps. Once assembled, you can adjust the gibs for desired tightness (white lube works well to keep thing smooth). Lock nuts on the adjusting bolts keeps things in place. I use regular 3/8" bolts for mockup and switch over to socket heads when complete because they look better.
Once you have some type of handwheel in place, you can remove the temporary bolt and nut.
Speaking of handwheels, I found a few cast iron valve wheels that work well because the weight makes a flywheel effect and minimizes the effort to spin up/down. I've seen these at salvage places for cheap.
Neat idea, thanks Bennett. The alternative would be to have the feed screw 3-4 inches longer than the housing so it could be fed from the bottom or assembled after the screw was in place. All thread is not cheap and you don't need a foot of it sticking above the adjuster.
And this is what it looks like hung on the frame.
I prefer a bolt on approach so as technology evolves the frame could be upgraded to hydraulic adjusters or whatever. A 1/2" plate is drilled for 4 bolts that go into holes drilled and tapped in the adjuster housing. On future machines, I'm going to a plate that has 4 bolts ABOVE AND BELOW the frame rather than on the sides. This is because of appearance only.
Here is a version made with a tubing quill and no steel backing plates. I think this one is the one on Robowheel. The top of the adjuster was a plate with a nut welded on it. Since this was a lower adjuster, a plate was welded on the bottom of the quill that the feed screw pushed against. Gravity provided the 'down'. For the yoke attachment, a nut was welding inside the quill tube.
And this is what a version looks like with the yoke and wheel mounted
My thanks to Wray Schelin for the basic design and to Bennett Chapman for his enhancements and assistance in developing a robust, manufacturable version.
Different designs will work as well but this one is simple, easy to build, provides positive up/down, is adjustable, and is TIGHT yet free.
Original content supplied by Kerry Pinkerton
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