CASE Garden Tractor Cab Design
Over the last few years, I have owned a couple of factory Case garden tractor cabs, but I have found them to be unwieldy to keep on year round, unwieldy to put on and take off, proportionally incorrect for the tractor, and worse of all, they have really TERRIBLE visibility.
On and off I started drawing a few cab ideas, but this season, I figured I better get something going. I am getting too old to sit there and just accept that no matter where your blowing, its always INTO the wind. So, I set out to build a prototype cab that I can use for a season and then build the next one with any adjustments or changes. Some of these photos are a little out of order, but hey, I never said I was a website creation expert now did I.
For the main frame, I felt there was no product more worthy to use that of common off the shelf aluminum extrusions. I have used such extrusions over the years for building machinery and machinery gaurds. One thing that always intrigued me about them, was how rigid they were once you screwed a few together. This cab is super rigid. Even in the beginning when I had only 4 mounting points, pushing the cab rocked the whole tractor. I ended up with 2 additional mounting points as I buttoned up the door entry/footrest areas. Using extrusions also made sense when one figures that the T-Slots in them would be exceptionally handy when it came to mounting lights, mirrors, door hinges, etc. I might even try the black anodized ones for the final cab so it looks more modern.
I'm not quite done with this thing yet, but I feel that I will have it done before snow starts falling. I am waiting for a fab shop to tell me they have finished my roof, and, I also need to hunt down a proper wiper system. I wish I even had the factory manual one laying around at this point, because I am not sure I will have time to build the right thing, which essentially will require a parallel linkage to keep the blade straight and vertical with each swipe... then there is that "degree" thing to figure out. How many degree sweep will I need ? I dont know because I did not get there yet!
Those two things are the crucial parts, the wiper and the roof, but I will also need to find time to add wiring and lights, a more pointed defroster system, and probably sound control and a few speakers to plug in a portable device.
The above photo shows the beginnings. I figured I would put this prototype on the 446 that will eventually be my backup tractor when I restore a 448 that is waiting for me. It is hard to come to conclusions about proper height and width, so you have to just start clamping things up and see what falls out. I did have the original cab dimensions to go by, but again, I felt the original looks like it does not belong on the tractor being so tall.
Running out of time for this year, I thought it might be fastest for me to build the doors out of 1/4" waterproof underlayment panel. The photo above is the door design I ended up with. One thing I learned along the way, was that NEXT TIME, I will adjust the window sizes to match a little better the sizes of acrylic sheets that are available off the shelf, OR, map out all my windows such that I would be able to cut them all from one 4x8 sheet. I was surprised at the price of acrylic at the home builder type stores. I am sure if I would have run to one of the local plastic suppliers, it would have been cheaper to get a whole sheet.
The inside of each door is framed out with some clear pine to strengthen it and give some bounderies to the windows. I ended up just covering these doors with black vinyl on the outside and stapling on the inside. The correct way is to make an inner and outer door for each side then put them together with the plastic between them. I think I will completely re-think the doors on the next cab because I think I want some sort of sliding/opening windows and probably will go for real glass in the final cab..... real glass is more permanent... we all know what plastic looks like after 10 years of use.
I used some stainless hinges I had laying around to hang the doors. Searching the local hardware stores did not offer me very many hinge options that seemed any better. The doors open fully just like the factory cab swing doors, but inside mine, there is nothing in the way. No lips, flanges or mounting brackets to slide over ar fight with while fueling. You'll note that I have installed a piece of safety glass for a windshield. The glass was cut to fit inside the T-Slot of the extrusion and then held in place with a bead of caulk. The company that makes the extrusions offers a panel liner, but I did not want to order that and wait for it.
Another interesting note is how the cab is mounted. I really hated how the factory cab was mounted. First, they had that huge sheet steel angle bracket that sat on top of the fender. You could not slide over it easily, and it required you to drill holes in the top of the fenders. Uck ! My cab is mounted up front right under the case logo on the hood and thats it up front. I use the existing lower holes of the battery seperator panel. In the back of the tractor, I have 4 neatly located holes that will not look terrible if the cab is ever removed, and there is an additional 2 holes in each footrest, but also very small and inconspicuous. I will point out the rear mount location in following photos.
Again, you can see that I simply covered the doors with black vinyl, wrapping the vinyl around the backside and stapling it with an air stapler. Then, I set the clear acrylic "windows" over the openings from the backside and caulked them into place. The latch I used is a plastic southco slam latch, and like the name says, you just slam the door and it catches. The only thing I dont like is the latch handle is a little small for glove use.
Here is what it looks like out in the sunshine. I am sure the neighbor in the house behind the tractor is plenty happy to see that I am near to being prepared to blow their snow. <G> Again, I do not have the roof yet, but the roof will be VERY similar to the factory roof with the radiused outer edges and drip gutters. It will be fastened with a few holes on each side, and stainless button head bolts going into T-nuts in the top slots of each side rail. The roof could be slid off towards the front just by loosening the screws. The top will pretty much rest on the forward top crossmember, but will ride above the rear crossmember by 1". I want to make n vent in that 1" area that can be opened or closed as necessary. The roof should give the cab a finished look. You might be interested in the size of the cab. It is 34" wide, a little longer than the factory up front (because I dont need the vinyl boot extensions for foot clearance like the factory has), and a little longer in the back too. I have my seat moved quite a ways back, and I did not want to be banging up against the back wall. Even so, comparing dimensions with my 448 that has the rear PTO on it, it looks like this cab would clear the handle for the PTO, but as it is designed currently, you could not activate it from inside (a minor issue).
You can see here that I have a sliding panel for underhood access. Loosen the plastic knobs and slide the plastic panel up to open the hood. That yellow strap is temporarily holding that right side door shut as I did not make the strike plate for that side yet.
Visibility is fantastic ! You can see that there is room for my big feet and my foot control. Also, note the 2" wide extrusion laying flat ouside of the footrests. It is the back edge of this extrusion that mounts into the back of the footrest.
ALL forward looking panels are CLEAR, the top of course glass and the rest are acrylic. I have some basic handles inside to pull the doors shut, but I am concerned about wind grabbig the doors when you open them and flinging them.... Maybe I need some sort of door closer or stops ? Not sure yet.
Visibility out back is also stunning. The whole rear panel is clear, as well as the section under and around the seat and behind each fender. The longer more vertical extrusion is the one that is mounted to the fender. Studs are in the end of the extrusion so that I can simply locate nuts underneath the fender. The outer, shorter extrusion is simply there for closure. Without it, there would be a big hole in the back corner. The outer extrusion on the near side is not quite finished in this photo. A plastic cover will go between the fender and the end of the extrusion... the other side is done, but you might not make things out in the photo without zooming in.
I filled the unused T-Slots with some 1/2" diameter round foam caulk filler strips. This will keep dirt out of them and make for a more finished look. The extrusion suppliers offer a similar cap system, but this is just as effective and less expensive. Interestingly, I used/jammed a 5/8" section of the same foam in the edges that seal the doors. It will work very well to close all the gaps around the doors. The doors are removable with 4 bolts on each side.
Here you can see what it looks like with the seat flipped up. The plastic is cut around the seat shape. It cant fall out because it is captured by the t-Slots. It is cut such that there is about a 1/2" gap between the edges of the plastic and the seat. One thing I do wonder about, is whether I will desire to have a removeable rear window someday. This one is tight inside the t-slots, but I can change that easy enough on the next cab.
Note that I will not have to jump over the top of anything on each side by the doors when entering the cab. Just SLIDE right in !
If you study this photo long enough to see where it is taken (left side above footrest), you will see that I made and welded in some defroster "ports" to the factory air deflector tins. You can see that my cab does not currently allow the engine air to all come into the cab. I decided to not build it that far forward for the fact that most guys have reported that it gets almost too hot in the factory cab. I will utilize these ports (there is one on each side) to direct warm air where I want it, like via a short defroster strip across the inside of the windshield, and that can be made to also blow air on each side window. Test running the engine to find out how much air comes thru the ports proved successful. There is more wind there than I think I will need. If in the end I need more heat, I can always divert more engine air into the cab, or block more by closing these ports off and making my plastic tighter to the chassis.
Above, you can see that I had a roof made. This is just a sheet metal roof with drip gutters and rolled outer edges very similar to the factory roof. The rolled side edges do make it look a lot more factory made than just square corners would.
From the side, you can see that the whole cab is a lot lower profile than factory. It is 68" from the ground to the top of the roof. This helps me clear many low branches on newly planted trees along sidewalks. I am about 5' 11 1/2" tall, and my seat is mounted up on 1.5" rubber blocks to give me a little more legroom. With the current roof profile, I have 4" above my head. My neighbor is about the same height, though when he sits in it, he comes within 2" of the roof. If one needed or wanted a whole lot more height, it would be easy enough to just have the sides of the roof made longer so it sits higher on the extrusions.
And sure, the tractor I have the cab mounted to is far from spectacular, but with the 18hp Onan transplant, it sure will blow snow. Even a crappy looking Case is better than most of the other GT's out there... we all know that, right ? <G> I used this tractor last year and had hopes to use a different 448 I picked up this summer, but the engine in that one will need a complete overhaul first.
This view probably gives you the best look at visibility. You couldnt get much more visibility than I got !
The photos above do not show the Flashing LED lights nor the radio and dome light I added inside. It has since snowed and I am enjoying the cab very much. A great friend and fellow Case enthusiast that many know as "Bart" graciously let me use his factory windshield wiper mechanism for this winter. So far, I am not quite sure the fuss over having an electric wiper because I only have found it necessary to do an occassional wipe when conditions demand. I might find it more difficult to switch one on and off. If I do decide to install anything regarding an electric action to the wiper, it will be something that will allow a single swipe to one side and then the other with a simple button push. Sure, I probably will install more than just a momentary in case I have to blow snow in the rain... I guess.
Regarding heat ? Wow ! Plenty, PLENTY warm. Too warm actually. I never did spend any time closing up the bottom under the foot rests, and since I dont make a habit of blowing in my pajamas and slippers, I have not even remotely noticed any annoying wind coming in from under there. However, the next one I build will have sliding side windows so I can let a little fresh air in, and allow a small amount of cross wind to take moisture from breathing out when you first get started.
Those "defroster" tubes I put in the heat shields are nice at first, but eventually I have to plug them with some paper towel or something.... I still need to connect them to some sort of tube to direct the heat to the windshield, but no matter what, I will need to put dampers in them to stop some of the heat !
I do hope to draw the cab with all the dimensions so others can duplicate it. When that happens, I will announce it in the Yahoo group. Extrusions from the company I use (8020inc) are available on ebay from their "garage sale" at a discounted rate. Since most of these parts are under 40" it is easy to find those sizes in their store reasonably priced. The only ones that one will likely need to purchase new are the two front extrusions.... But you can get those from Mcmaster along with all the T-nuts and bolts you will use to fasten everything.
You can see more of the stuff I have done to a few of my tractors here: