"Don't Weld Your Toys To The Tractor!" I know it seems like a great way to keep things solid and in place, but toys welded in place must stay in place. Two years ago I purchased a new tractor. The fellow that purchased my old one did not want any of the toys I had (Snow Blade, Landscape Bucket, Sprayer, Etc.). I have now modified them all to fit my new tractor and am glad to have them!
I will 2nd that...I made a FEL for a lawn tractor, despite advice not to. Once I had rebuilt the steering, front axle, and front spindles, then the transaxle, I began to see the light. I found a garden tractor with a cast iron transaxle and moved my toys over. Now, I still had to do a bunch of cutting and welding, but my approach was to weld up to a mounting plate, and then bolt that to the tractor. My mounting plates got a bit long...you could call them frame doublers and not be too far off. But being able to unbolt all the parts from the old tractor without having to cut welds was a big help.
I spent about 4 or 5x what it would have cost me to buy a garden tractor with a loader from a local ad (and several came up while I was building), even scrounging "hard", just by buying stuff that in the end didn't work, having to remake stuff, or breaking stuff. Developing your own design is harder than it looks, even if you have a good idea of what you are doing. Buying plans is very good. Starting with a complete unit and adapting it to your needs is even better.
I have a metal lathe, and a pile of scrap from a friend, so made my own bushings. If I had to buy it, I would look for DOM with maybe a 1/4" wall on ebay and/or onlinemetals.com (there are a couple of other reputable metal dealers online too, I will at least vouch for these guys because I have used them and gotten good service).
Some of my pins are drilled from one end to a cross hole, and the outside end tapped 1/4-28 for a grease fitting. Other pins are solid and the side of the bushing is drilled and threaded. I used whichever approach seemed to best fit the situation at the time. For pins and bushings, as long as you keep it greased, I very much doubt you will wear out mild steel on a homeowner use machine. If you want you could sleeve your bushings with brass or bonze/oilite, or bearing nylon, but as long as you keep it greased I am not sure the return is there. If you had work for it for 8 hours a day you could afford a real machine you could buy parts for so you could focus on making money, and that machine would have those features, but for an occasional weekend machine, not so much.
For main structural, I used 2x2x1/4" and some 1-1/2" pipe. Probably more than sufficient for your stated needs...but I will also say that weight of dirt and gravel add up quick. At about 2 tons a cubic yard, 350 lbs. is only about 3 cu ft. That means 9 trips to get that cubic yard of material moved. If you look at videos of people working with a tractor-loader-backhoe with a one yard bucket, and how many trips they make to get a job done, you can really start to see it add up.
Which is not to say that this isn't worth doing, 350 lbs. a loader picks up is that much less on your back with a shovel. Just have reasonable expectations on how much work you can get done.
To get back to materials, I also used more of that scrap pile, which had a bunch of trailer hitches and things in it. Would have all come out looking a lot neater and more professional had I just forked over the cash up front to get "real" materials. I probably would have used 2x3 or 2x4 for the uprights were I to do it again. Also, longer main lift cylinders (but the small ones I have are not necessarily a bad idea...they run out of lift right about when I run out of traction on my tractor, so it all works out).
If you haven't found it already, look at the front spindle upgrade on
Spindle Upgrade
And maybe consider buying and building his plans, too, they look fairly well thought out.
And another vote for the Cadplans.com guy, he has also been around for a while, and is also a member of these forums.
Here's my little mongrel:
