My son spends far too much time on the Playstation, he likes Farming Simulator amongst other things so, when he said he wanted a tractor I had an idea. I've seen the various lawn tractors on here and thought with a few mods he ought to be able to drive one. I had a bit of a search on ebay and this turned up locally.
It was a runner but had an odd wheel which was smaller and the mower deck was full of holes. The seller still had the original but the tyre wouldn't stay pumped up. I stripped the deck off plus any other bits it didn't really need and then had to cover it up so he didn't see it before Christmas !
I wasn't sure about the clutch mechanism being very easy to use. It certainly was a bit heavy and the pedal needed moving back a bit so with a couple of bits of flat bar taken from the mower deck mounts I added a second pedal with a bit more leverage built in. This is the Mk1 version, I have cut off the extra bits and fitted a better pedal but it got too dark to take a decent picture of it.
It's let him have a drive around today but it doesn't allow for very smooth starts, more a case of stop or go. This isn't much of a problem in first gear but if you put it in 5th it is a bit exciting even when I really tried to let it engage slowly. I was asking on here about using a centrifugal clutch, and I think this might be a good plan. Thats providing they don't mind hanging down underneath. I really need to fit a proper brake on it as well. The transmission brake it has doesn't work at the moment so I will have to see if I can fix it or if I need to find a small drum brake or disc to use on it.
Right, finally took some pictures. This is the clutch I got hold of. It's a bit of a lump of a thing but it seems to work quite well. The outside diameter of the pulley is 128mm so it's about twice the size of the original. There is a smaller version available but it's out of stock at the moment. I pinched a spacer tube from the PTO and turned it down lengthwise a bit so the crank was a couple of mm shorter than the clutch when fitted. I had to adjust the keyway and key slightly as it was a bit tight and find a shorter bolt.
The tensioner is left as standard but the pedal has been separated from it. I will probably be changing the brake but for testing purposes this was OK.
The brake is on in these pictures and with the rod adjusted as shown there isn't much travel needed on the pedal anyway.
A slightly revised version of the brake pedal extension. Again this is on with the handbrake engaged and by moving the pivot forward (no holes drilled) there is somewhere for the spring. Finding something suitable took a while until I remembered I had some old exhaust springs from my kart.
This shows the 86" belt fitted and the reason why it was easier to keep the two tensioner pulleys. If I didn't the belt would have been rubbing against the gear selector.
I gave the mower a try out to see how it goes and unfortunately it's too fast. Normally this wouldn't be a problem but it seems that reverse is actually a bit faster then 1st so I need to have a re-think. I've got nothing to loose by trying it so I turned the clutch pulley down as small as I dared today. Not sure what it was made from but it was a bit of a struggle on my little lathe.
The before and after. I've ended up with the smaller of the two pulleys I found for sale, if they had any in stock. It was 128mm OD and is now about 110mm. If I do decide to get a bigger pulley for the gearbox it won't need to be quite as big now.
Todays other modification, or rather quick lash up to see how it worked was to fit a foot throttle. I've seen people have fitted bike brake levers so for now I have done similar using an old racer lever I straightened up a bit. The hole in the bit of wood isn't a clever design feature it just happened to be lying about. The good thing is it actually allows more gentle take offs so I will give it a try tomorrow to see if it's any more driveable now.
When I have sorted out what does and doesn't work I will make up better pedals and might move the brake to the other side. Not sure if I will have to go back to the standard style clutch so don't want to go drilling lots of holes in it.