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Building the mini-H The mini-H took about 4 months (part time work) to build although it seems to be a continuous process to change and modify different parts and characteristics. I don’t know that it will ever be exactly the way that I want it. The beginning of the project involved looking at as many H’s as I could find and taking pictures from various angles. These were used to determine the overall look of the final product as well as approximating the lengths of various sections of the tractor. The mini-H wasn’t built to any scale, but wherever possible, I tried to get the correct proportions. Also, I'm not real good about taking pictures as I build. I get anxious to finish something and don't take the time to stop and take pictures. Therefore, you'll notice that a lot of pictures in this description were taken "after the fact." Sometimes it's a little harder to illustrate or show after something has been completed and painted, but I hope you can get the idea as you read through the description. Both the Mini-560 and the Mini-H began life as Cub Cadet Model 100's. When I made the mini-560, I’d simply used the front grille housing and rear pedestal support to hold the sheet metal in place. The H has a much longer, narrower appearance then the 560. It seemed that using the housing and pedestal to make the H would produce a tractor that would appear too wide. I wanted to avoid having to produce a new frame but so I just removed the front housing and the pedestal support and kept the main fram intact. I began the project by making a card board mockup of what the finished project would look like. I had done a lot of experimenting with tires and wheels on the Mini-560 to get the "proportional look" that I wanted. Since I didn't want to go through that process again, I used the same size on the Mini-H. The front tires are 3.50 X 8 and the rear tires are 7.50 X 18. I purchased the front tires new and mounted them on the Cub Cadet rims. I purchased the rear tires and wheels from a tractor salvage. The guy there told me they came off a corn planter, but a different salvage yard where I purchased the ones for the Mini-560 told me they came off a manure spreader. They could both be correct; I don't know.
It’s hard to tell in the picture, but the rear wheels are supported off the ground, and the two front tires are leaning against one another for support. From the mockup it seemed that the tractor was going to need every bit of length I could get using the original frame. The seat seemed to be in the correct position with respect to the rear wheels and the rear end of the tractor. The location of the seat dictated the location of the steering wheel and all the sheet metal had to sat forward of the post supporting the steering wheel. I began by mounting the vertical support for the front axle. I knew from my experience with the mini-560 that this would be a 1 1/4" diameter shaft. Calculations had shown that the shaft didn’t have to be that large, but a smaller shaft just didn’t look right. The rear wheels probably should’ve been completed first, but,again, I already had the mini-560 completed and could get any height measurements I needed from it. And, since I’d had that experience, I knew that would be fairly easy to do. I cut off a piece of 3/8" thick by 6" wide flat that would fit across under the front frame of the tractor. I cut out out a 1 ˝"+ diameter hole in the center of this piece to allow for clearance around the 1 1/4" vertical shaft that the front wheels would connect to. I moved the 3/8" plate as far forward as I could get it and still have the centerline of the vertical shaft behind the front end of the frame. Notice in the picture how the centerline of the front wheels is right under the end of the original frame. Adding this extra length also allowed me to build a front end housing below the grill that better simulated an H front end. The front end extension is made of 1/4" X 4" flat iron sections welded together to approximate the shape of the front end of an H. Each side piece butts up against the original cub cadet frame with pieces welded to the inside that extend back into the frame of the tractor and bolt to the sides. These extensions provide some support, but the front wheels are supported mainly by the original tractor frame. I mounted a 4-bolt, 1 1/4" flange bearing to the bottom of the plate centered on the 1 ˝" diameter hole. I welded together a metal “box” on top of the plate to support a 1" diameter 2-bolt flange bearing centered over the 1 ˝" diameter hole. I turned down the top of the 1 1/4" diameter shaft to a 1" diameter for about 2 inches and turned down the top one inch of the shaft to a 3/4" diameter. The shaft extends up through the bottom bearing and through the top bearing with the 3/4" diameter section on the very top. A locking collar around the 1" diameter portion of the shaft prevents it from dropping back out. A longer collar added to the 3/4" diameter section of the shaft connects to an extension to reach to the top of the tractor. Eventually, after I had everything assembled and at the correct height, I slid a 1/4" thick washer up against the bottom bearing and welded it in place. That prevents the shafting from sliding up through the bottom bearing. I drilled a 3/4" diameter hole horizontally through the 1 1/4" diameter shaft about an inch from the bottom. I pushed a 3/4" diameter shaft through the hole and welded it in place. I bent each side of the shaft down at a slight angle to toe the front wheels in at the bottom. I slid a 1/4" thick washer over each shaft and welded them in place about 3/4" out from the center shaft (for the inside wheel bearing to rest against). I placed the front wheels on the shaft, determined the proper length, cut off the 3/4" shafts, drilled and tapped the ends for a 3/8" bolt, replaced the wheels and bolted them on. The front end was done!!!!! Well, at least except for the steering.... After completing the front end, I was anxious to get the tractor on wheels so I could move it around – even without the steering attached. The only difficult part for the rear end was making the wheel adapter and extension. The inside hub (that bolts to the original Cub Cadet axle is 5.375 inches with 5 equally spaced holes located on a 4.5 inch diameter. The outside hub is 7.0 inches in diameter with 6 holes located on a 6 inch diameter. Both hubs were milled from 3/8 inch plate. The inner hole for each hub has a 1.9 inch diameter that fits over a piece of thick wall tubing that I had. The hubs were all cut on a CNC milling machine.
 I pressed the hubs over a 6 inch long piece of the thick wall tubing. I took three 3/8" coupler nuts and screwed bolts in until there length was the correct inside dimension for the spacing between the two hubs. I used a nut to lock them at the correct length. The three coupler nuts and attached bolts were spaced equally around the hubs and a C-clamp was used to pull the hubs in tight against them. (Unfortunately, I didn’t take any pictures of the assembly before welding.) That assured that the two hubs were parallel. The center tube was then welded to each hub. After the hubs were welded, I tapped the holes. The inner hub just had to have clearance for a 3/8" bolt; the bolts just go through the hub and screw into the original cub cadet hub. The outer hub had to be tapped for a ˝-20 NF thread. The hubs and wheels were installed on the tractor. The tractor was now completely on it’s own wheels!!! Since I’d removed the pedestal there was no support for the upper pivot point for the clutch arm. I bolted an angle arm to the frame and added the pivot for attachment of the clutch arm. It was one of the easiest changes I had to make. Next, I had planned to work on just the steering. But it soon became evident that the framework to hold the steering would be the same framework that held the sheetmetal. So I decided to make the sheetmetal and build the framework along with the steering. I bent the center section of the hood out of a piece of 16 gage metal using a homemade roll bender. (The roll bender was made for me by two students as a project when I was building the mini-560.) The roll bender was designed to produce a 2 inch diameter bend. I experimented with several pieces of scrap to determine the correct location of the bends to just fit the width of the original frame. After the central hood section was bent, I could determine where it had to to supported.
It was a simple matter to build up a framework in the front to support the front section of the hood. But the rear section also had to support the front of the steering shaft as well as the back of the hood. I didn’t want to connect supports extending up from the engine, so the supports to hold the front of the steering shaft had to angle forward and upward from a connection on the frame behind the engine. I bolted two 1/4 by 2" pieces of flat iron to the inside portion of the frame just outside the angle holding the upper clutch pivot point and angled them forward to a point that would support the front of the steering shaft. I ran a piece of 1/4 by 2" piece of flat from the front support rearward to the location in the back where the hood would attach. It required a spacer between these pieces and the angled pieces I had previously installed. The hood now had a good support system as well as providing a support for the end of the shaft that held the steering wheel. I used a section of 3/4" pipe and the home made roll bender to bend the center section of the hood – the section the steering shaft extends through. I cut a slot in the main hood section and welded this piece over the slot. I used Bondo to make a smooth transition. (I don't know what I did to make the picture look so "stretched out", but you can see the sections containing the Bondo.) The front grill was made on a CNC mill. It was milled out of a piece of flat 16 gage sheet metal and then rolled and bent into the final configuration. I made the entire grill one piece rather then leaving the cut out that an H has that allows for “steering” cultivators. With all the supports in place for the grill and hood, I could work on installing the steering. My first attempt involved using two bevel gears. Although the bevel gears worked, and I used them as the steering setup for about a year, the steering was too quick, and the tractor was no fun to drive. You were continually making steering corrections and couldn't just relax and drive the tractor. I have since replaced the bevel gears with a steering gear from a Cub Cadet. Since I had limited space available, it wasn’t an easy fit, but I managed to fit everything in. I mounted the Cub Cadet steering gearbox offset to the right of the front steering shaft. It required two u-joints to get from the steering shaft in the center of the tractor to the gear box. (It also required cutting off some of the steering gear housing to shorten it and allow enough space.)
I took the "steering arm" out of the gear box, chucked the bolt that's welded to it into a lathe and turned down the section of the bolt and weld that protrudes out of the steering arm to a 1/2" diameter. The 1/2" diameter was used to "accurately" center a 18 tooth sprocket over the turned down section. I welded that sprocket in place and mounted an 12 tooth sprocket on top of the vertical steering shaft that runs up from the front wheels. Since the steering gearbox from the Cub Cadet didn’t give me as sharp a turning radius as I wanted, a chain drive from the Cub Cadet steering gearbox to the top of the Mini-H steering shaft gave me a larger ratio. That also allowed the offset steering gearbox for a little more room to work. With the current setup, I get about a 160 degree steering angle -- didn't measure it so I'm not sure of the exact angle. It's hard to believe, but one of the most difficult and time consuming things I encountered was trying to find room for a gas tank. I tried several different locations and several different gas tanks. I think at one time or another I've had at least 4 different gas tanks on the tractor in at least 4 different locations and orientations. I finally found a gas tank from an 8 hp Briggs and Stratton engine that fit almost perfectly in the space I had available. I say almost perfectly because I had to do a little bending (hammering) on the front bottom lip of the gas tank to get it into position. It does fit very nicely and looks like it was designed to go in the current location.
The finishing touches for the Mini-H included making a panel to hold the ammeter, a support to hold the starter button and the headlight panel. I didn’t place “backs” on any of the instrument panels because of the limited space that was available. To make these panels, I simply modeled the parts in Pro/E and machined them on a CNC mill. They're machined from 1/4" steel. It's not obvious in the picture, but the panel holding the starter button is welded on angling slightly bacwards as the original would have been mounted on an H. The throttle support is one of those things that still needs to be made. Currently, there is just a piece of rectangular metal bolted to the top of the rear steering wheel support with a friction disk to supply a holding torque to keep it in the correct position. While I don't plan to make a "toothed" section like the H has, I do want to cut out a circular disk to replace the rectangular section to give it a more authentic look.
The headlights are from an International combine. It was a simple matter to cut out a piece of sheet metal, weld it to a 1/2" diameter pipe and use a muffler bracket to connect it to the rear steering wheel support.
The very front of the hood and what would be the gas tank on a "real" H are still made of wood, bondo and plaster. For the front section I made a rough model out of wood, made a steel template with a 2" diameter cutout and used it to shape plaster to give it the right curvature. For the gas tank, I modeled and assembled several elliptical sections in Pro/E to get the look that I wanted. I then traced those sections on 1" boards and cut them out on a band saw. I glued all the sections together, sanded them to approximate the shape I wanted, applied plaster and some Bondo, and smoothed and sanded it to get the final shape. I've used those sections that way for over a year, but I'm afraid to leave the tractor outside during a rain. I'm currently in the process of using those sections for patterns to make a mold. I plan on using the mold to make fiberglas sections to replace the wood, Bondo and plaster. I still have a few things to do besides replacing the front hood and gas tank before I will consider the Mini-H complete – although I think I will forever be making changes. The main addition is to add a “swinging drawbar” in place of the fixed drawbar that’s currently on it. I also need to add the "H" emblem to each side of the hood. I’ll add those details ‘if and when’ I get the time and ambition. I hope you enjoyed reading about my experiences building the Mini-H. The Mini-560 had been so easy to build, that I was not expecting the Mini-H to be any problem at all. The Mini-H turned out to be a lot more complicated and took a lot longer then I had originally intended. But it was truly an enjoyable experience.
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