sounds like you have a good plan here. industrial computer cases are good HD metal boxes, the right size for the application, and are available for small amounts of $$$.. check with GT_80 and see if he has any extras kicking around
MF12 rear weight box
With snow season upon us, I figured I should start to plan and build the weight box for my tractor. I plan to melt down the lead to fill a shop-built steel box for the back. My plan is to have it attach to the trailer hitch and use the two bolt holes in place for the tiller bracket.
So a few measurements give me an ideal box size of 14" wide and 9" tall. I dropped my depth down to 4" deep because even at 4" deep, that's just a hair under 200 pounds! :fing32: I figure I will have to install an eye-bolt on the top so I can lift it with my chain hoist to mount it. I also plan to install a rear flood light on it with a plug so I can use it when plowing. I might slap one of those reflective triangles on the box too.
So I guess I need to cut myself a sheet of metal and get it bent in a U shape to start the box. I will take some photos and update as I go.
PS, is there a chance someone with a hitch can take some measurements for me?? I need to find out the space required by the lift arm. Ideally, measured from the bottom side of the seat pan.
a) The top height with the lever up (measured from the seat pan)
b) The top height with the lever down (Measured from the seat pan)
c) The max depth the lever sticks out in any given position.
I want to add a hitch and better planning will allow me to weld in a slot for the hitch arm to have full movement "inside" the weight box. That way I can just remove the lower hitch and leave the upper arm in place. In fact, I want to redesign the plow to mount to the same brackets the sleeve hitch uses. (beefed up, and redesigned a little so it's a slot and not a tab. Simple pins will install through the bracket and attachments to make swapping them nice and easy.) That will free up the stock trailer hitch of the plow bracket so the weight box mount's easier.
The other use this weight box will get, is that I want to design it in such a way that I can attach it to the front bumper when running the single bottom plow. This may be done with a bolt on bracket / adapter. :fing32:
So a few measurements give me an ideal box size of 14" wide and 9" tall. I dropped my depth down to 4" deep because even at 4" deep, that's just a hair under 200 pounds! :fing32: I figure I will have to install an eye-bolt on the top so I can lift it with my chain hoist to mount it. I also plan to install a rear flood light on it with a plug so I can use it when plowing. I might slap one of those reflective triangles on the box too.
So I guess I need to cut myself a sheet of metal and get it bent in a U shape to start the box. I will take some photos and update as I go.
PS, is there a chance someone with a hitch can take some measurements for me?? I need to find out the space required by the lift arm. Ideally, measured from the bottom side of the seat pan.
a) The top height with the lever up (measured from the seat pan)
b) The top height with the lever down (Measured from the seat pan)
c) The max depth the lever sticks out in any given position.
I want to add a hitch and better planning will allow me to weld in a slot for the hitch arm to have full movement "inside" the weight box. That way I can just remove the lower hitch and leave the upper arm in place. In fact, I want to redesign the plow to mount to the same brackets the sleeve hitch uses. (beefed up, and redesigned a little so it's a slot and not a tab. Simple pins will install through the bracket and attachments to make swapping them nice and easy.) That will free up the stock trailer hitch of the plow bracket so the weight box mount's easier.
The other use this weight box will get, is that I want to design it in such a way that I can attach it to the front bumper when running the single bottom plow. This may be done with a bolt on bracket / adapter. :fing32:
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Nawh, I have some heavy gauge sheet metal here. I just need to cut to size and have a friend bend it at his shop seeing as he owns a 12 foot press break! That will allow me to build it to the exact size I need and customize as I will.
awesome! i am looking forward to pictures. you do high quality work
I take it that your talking about the rear lift bar that sticks out the slot.
The lift bar sticks out no more than 3" and is never higher or lower than the slot on the rear plate.
Hope this helps.
Maybe you could somehow smaller removable weights that fit inside the box???
The lift bar sticks out no more than 3" and is never higher or lower than the slot on the rear plate.
Hope this helps.
Maybe you could somehow smaller removable weights that fit inside the box???
Thanks Doug! So even at the very tip of the lift arm, it is still below that slot? If you get a chance and double check, it's much easier to adjust before it's welded and filled!
I really thought about making some lead filled bars and loading them into the box, but this is where the sleeve hitch get's in the way. With melted lead filling the box, I can get the max weight for plowing and make it fit the tractor. I can always make some lead bars down the road... I did get the wheel weights for free, and can find more if needed. Oh, the other thing is that I have a bunch of lead melted already and everything melted and every shape can be loaded into the box and the newly melted lead poured around it. It will save a lot of re-melting as I have about 50lbs melted down already!
I really thought about making some lead filled bars and loading them into the box, but this is where the sleeve hitch get's in the way. With melted lead filling the box, I can get the max weight for plowing and make it fit the tractor. I can always make some lead bars down the road... I did get the wheel weights for free, and can find more if needed. Oh, the other thing is that I have a bunch of lead melted already and everything melted and every shape can be loaded into the box and the newly melted lead poured around it. It will save a lot of re-melting as I have about 50lbs melted down already!
The lift arm itself without any thing attached to it.
When it's all the way down, sticks out the most 2 7/8", is horizontal and the bottom of the arm does not go below the bottom of the slot.
When the arm is all the way up sticks out less and the top of the arm is lower than the top of the slot.
I have 2 tractors with rear lift both the same.
The sleeve hitch hooks on to the lift arm.
When it's all the way down, sticks out the most 2 7/8", is horizontal and the bottom of the arm does not go below the bottom of the slot.
When the arm is all the way up sticks out less and the top of the arm is lower than the top of the slot.
I have 2 tractors with rear lift both the same.
The sleeve hitch hooks on to the lift arm.
Ummm. Static load rating on that axle is 750 lb. Double the weight of the lead filled box, add your weight and the weight of the tractor carried by the axle to figure out how much load you're putting on the axle.
I mention this because I broke an axle trumpet going over a bump in a field with a lot less weight in my weight box and a FEL on my MF12H. I used 65 lb. of calcium in each tire plus 40 lb. MF wheel weights and about 125 - 150 lb. in the weight box. (Thirty + years ago there was no RimGuard.) The tires and wheels don't count for axle static load and at 175 lb., I think my weight put it very close to maxing out the axle.
If you are planning on an implement on the sleeve hitch with that weight in place, you will be over the axle limit.
I mention this because I broke an axle trumpet going over a bump in a field with a lot less weight in my weight box and a FEL on my MF12H. I used 65 lb. of calcium in each tire plus 40 lb. MF wheel weights and about 125 - 150 lb. in the weight box. (Thirty + years ago there was no RimGuard.) The tires and wheels don't count for axle static load and at 175 lb., I think my weight put it very close to maxing out the axle.
If you are planning on an implement on the sleeve hitch with that weight in place, you will be over the axle limit.
I will not be running anything but the snow plow with the weight in the rear. The tires are filled and I have some plastic cement wheel weights. Your front end loaded would of shifted load front to back pretty hard hitting a bump which may of been a big factor in the breakage too. I ran about this much weight last year when I had the entire seat pan filled with loose wheel weights, this will just kind of consolidate them and not mess up that nice bed liner in my seat pan this year! This can't be that much more weight and stress than the roto-tiller puts on it when hanging that far out, right?
You lost me a bit on the math of how much load is on the axle though... How did that formula work?
You lost me a bit on the math of how much load is on the axle though... How did that formula work?
If you could make lead wheel weights??? That would be nice.
I have lead wheel weights that are around 75-80 pounds each, and the tiller is around 200 and it sticks out pretty far beyond axle centerline so that probably doubles its weight on the axle. the tires are full as well. the only breakage has been a stripped hub that was shot anyway, and the tiller is real abusive to the rear at times. Maybe i have been lucky but i would say the load rating is more for the bearings long term use. I have also had the front wheels come off the ground while pulling a small log, and that was with a 100 pound front weight, now that puts all the tractor weight on the rear, and i have no idea how to figure the leverage factor, but its alot of weight! The tires were at a decent pressure, and still wrinkled ALOT. The rear axle in my book is pretty tough.
That was my thought.... I figure if it can hold up to a tiller, my 200 lb weight bolted close to the rear frame should be just fine.
Doug... I have many times wondered just how hard it would be to use an old wheel as a mold (welded up holes) and pour some lead weights. At 10" I could even mount them in my lathe to turn the edges clean (Granted, I don't think I would want to be close to the lathe when the switch was turned on!) It's just so much work to do, and the lead is exposed. This way the lead is a bit "safer" as it will be inside a box and not open and something you must handle all the time.
Doug... I have many times wondered just how hard it would be to use an old wheel as a mold (welded up holes) and pour some lead weights. At 10" I could even mount them in my lathe to turn the edges clean (Granted, I don't think I would want to be close to the lathe when the switch was turned on!) It's just so much work to do, and the lead is exposed. This way the lead is a bit "safer" as it will be inside a box and not open and something you must handle all the time.
The math, yeah. Think of the rear axle as a teeter- totter pivot. Weight placed on one side of the pivot must be balanced by an equal weight on the other side. Think foot pounds of torque. Even close in to the axle requires an effectively equal weight on the other side, so the weight load on the axle is double what you put behind it, whether it's the tiller far behind or the weight box close in.
There is no doubt that these axle ratings are somewhat low for safety. I mentioned the breakage as a warning of what part that you may want to have available to cover the "weak link" on the axle. I still cautiously drove the tractor, but only far enough to get it to the shop to change out the trumpet. Like you, I've stood that tractor on the rear axle pulling something, and that's with the loader on it. That puts the entire weight of the tractor and operator on the rear axle plus suffficient counter weight (torque) to rotate the rest of tractor (the weight normally carried by the front axle). In my case that was something close to 1500 lb. with the loader.
The axles are strong, but the trumpets are cast iron and do not like impact loads. As you realized, the added rock and roll with the momentum from the loader contributed to the demise of the trumpet. Speed also contributed. :duh:
There is no doubt that these axle ratings are somewhat low for safety. I mentioned the breakage as a warning of what part that you may want to have available to cover the "weak link" on the axle. I still cautiously drove the tractor, but only far enough to get it to the shop to change out the trumpet. Like you, I've stood that tractor on the rear axle pulling something, and that's with the loader on it. That puts the entire weight of the tractor and operator on the rear axle plus suffficient counter weight (torque) to rotate the rest of tractor (the weight normally carried by the front axle). In my case that was something close to 1500 lb. with the loader.
The axles are strong, but the trumpets are cast iron and do not like impact loads. As you realized, the added rock and roll with the momentum from the loader contributed to the demise of the trumpet. Speed also contributed. :duh:
I have an operators manual that I got with my 1970 MF10 and in there it say's
"do not exceed 800lbs. rear axle load, total weight including operator"
"do not exceed 800lbs. rear axle load, total weight including operator"
The math, yeah. Think of the rear axle as a teeter- totter pivot. Weight placed on one side of the pivot must be balanced by an equal weight on the other side. Think foot pounds of torque. Even close in to the axle requires an effectively equal weight on the other side, so the weight load on the axle is double what you put behind it, whether it's the tiller far behind or the weight box close in.
But...200lbs close to axle is less than 200 two feet back. the further back it is, the less weight is on the front wheels, therefore more load on the rear end. I had to put 100 lbs on the front so i could come up out of my back yard with the tiller on. If the tiller were another foot or so rearward it would probably need more weight in front. Also, as im sure everyone knows, the wheel weight shouldn't be factored in with the load carrying limit of the rear. that should leave it safe with 200 lbs in a box. still easier on parts than the tiller.
Plus... even if I do break one of those cast iron housings. I have spares! LOL
Teeter totter effect. A 50 lb. child can lever a 200 lb. adult up in the air by being a tiny bit over 4 times the distance from the pivot (fulcrum) as the adult, but the actual load on the fulcrum is 400 lb., not 250 lb.The math, yeah. Think of the rear axle as a teeter- totter pivot. Weight placed on one side of the pivot must be balanced by an equal weight on the other side. Think foot pounds of torque. Even close in to the axle requires an effectively equal weight on the other side, so the weight load on the axle is double what you put behind it, whether it's the tiller far behind or the weight box close in.
But...200lbs close to axle is less than 200 two feet back. the further back it is, the less weight is on the front wheels, therefore more load on the rear end. I had to put 100 lbs on the front so i could come up out of my back yard with the tiller on. If the tiller were another foot or so rearward it would probably need more weight in front. Also, as im sure everyone knows, the wheel weight shouldn't be factored in with the load carrying limit of the rear. that should leave it safe with 200 lbs in a box. still easier on parts than the tiller.
The actual distance behind the axle means nothing as far as the weight carried by the axle is concerned. It will be double whatever is hooked up, whether it be a 200 lb. weight box bolted to the back of the tractor or a 200 lb. tiller 3' behind the axle, the extra load on the axle is 400 lb.
Due to the longer lever from the fulcrum (rear axle) to the front of the tractor, less weight is required at the front of the tractor to counterbalance the weight box close to the axle than the tiller which is quite a bit further back. If you put an extension on the front end, as is sometimes done with field tractors, less counter weight woud be required for the same effect resulting in a slightly lower weight for the tractor overall, but still the same load on the rear axle.
I dont mean to argue, but lets say my tractor weighs 600lbs, and assume perfect balance 300 ft and 300 rear, now i add 200 to the rear and adjust it rearward until it picks the front tires up slightly.. i then have 800 lbs rear axle weight and 0 front. therefore my 200 lb tiller 3ft behind axle centerline places more weight on the rear than his 200lb box just one ft behind.
You're right! I was trying to keep it simple since a lot of guys think they are only adding 200 lb. to the rear axle in this scenario. In actual fact what we should be talking about is the torque load placed on the rear axle by this added weight and the resulting torque load coming from the front of the tractor to counterbalance the load. These things don't steer worth a darn with the front wheels in the air so we add weight to the front to help with the counterbalancing.I dont mean to argue, but lets say my tractor weighs 600lbs, and assume perfect balance 300 ft and 300 rear, now i add 200 to the rear and adjust it rearward until it picks the front tires up slightly.. i then have 800 lbs rear axle weight and 0 front. therefore my 200 lb tiller 3ft behind axle centerline places more weight on the rear than his 200lb box just one ft behind.
At 1' back from axle centerline, a 200 lb. weight box will add 400 lb. to the rear axle. At 2' back the load increases to 800 lb. At 3' back we are now looking at 1200 lb. and that MF12 isn't going to steer worth a darn.
One 6" concrete block is just enough to lift the front wheels of my GC2310 off the ground, if I take the FEL off first and fully extend the back hoe and put the block on the back hoe bucket. Ordinarily, I would lift the front wheels with the FEL, but on that occassion I needed to work on the FEL subframe and I don't bend very well anymore as well as being too lazy to drag out the jack and the stands. The hoe weighs 800 lb. and is all behind the axle.
Further to your comment about not including the weight of loaded tires, rims and wheel weights to the rear axle loading, add the cast iron hubs to the list. If you're looking at bearing loading, discount that portion of the axle shaft outboard of the axle bearing as well. I know, I know. Nitpicking.
I love these discussions. Makes me think and I realize that sometimes I know something deep down, but not off the top of my head.
Thanks.
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