building a bandsaw mill

[Groo]

bigger tire = less severe bend on the blade every rotation, and permit a bigger vertical chunk of wood to be cut per pass.
smaller tire = less "wasted" blade length = larger throat area for any given blade length

seams like most medium sized mills use 18 - 19" wheels.

Tires strike me as the easy way to build it, not necessarily the easiest or the best in the long run. all the filling and emptying, plus you have to make sure the 2 tires were comparable and comparably filled. I'd avoid a mini-donut spare type tire since I think those are often (if not always) bias ply and those tend to go out of round, especially when cold. I love the mini-donuts as trailer tires, and hadn't noticed that being a problem then, but anything off like that on the mill will show up in the lumber. You'll get enough crap like that with a band mill in general. I'd not want do anything to make it worse

 

[EastBerkshireCustoms]

Bar far, the biggest advantage to larger wheels is blade life. A .042" blade on an 18" bandwheel has a bending stress of 70,000 psi, while on a 25" wheel, the stress drops to 50,000 psi. The bending stress is the main cause to eventual band breakage. The larger wheels also offer the possibility of a deeper cut and the 'carry through' momentum once spinning. FYI, I'm using 26" wheels. Yes, they are pricey
I think you need to go larger on your main frame rails. True, hobby mills use angle iron (the 2"x4" tubing would be a great improvement over this), but they must be carefully leveled each time they are set up. The big mills mostly use 3"x6" tubing- either 3/16" or 1/4" wall, depending on manufacturer.
Since you are in the design phase, I suggest you build for a wide cut. I didn't realize that there was such a large wide slab market until recently. I have 36" between the guides with a log capacity of 40"(ish) and wish I had built a little wider, say 40-44" between guides, to take advantage of this market. Of course if you are just shootin' for framing lumber, then this point is moot.
If you are interested, here is a link to my build: Bandsaw Sawmill forums :: View topic - A Few Progress Pics

 

[muddstopper]

EBC, Nice fab work. I dont have anything planned quite so nice.

I have located a used WM mill that i will be checking out. Dont know model# or capacity yet. The machine is supposed to have some broken part the owner cant afford to fix. I dont know what that could be unless its the engine, but anyways, I have a friend thats going to get me a little more information on the machine. It might be that I buy and repair instead of build.

 

[EastBerkshireCustoms]

If it's in the setworks or some of the other control boards that the WM has, th price to repair can be quite expensive. However, buying a used machine (at a decent price) that needs repair would still be cheaper than building from scratch.

 

[pfatz]

Look around for inexpensive Axles with tires & wheels for such a build. One possibility might be a mobile home axle with tires & wheels. Be sure to true the mount of the tire & wheel (if it is the old style with no center in the wheel ) before cutting the axle anywhere that suits you. Usual cost is $100 to $125. for one. they are everywhere. They take them out of new MH anywhere from 4 to 6 at a time. They left 6 under my new MH laying on the ground. You can also buy axle stubs with hubs and bearings at Farm stores, trailer places and other supply houses. A hub with 5 lugs on a 4.5" circles is common. Then go to the salvage yard for an old ford {Falcon}or other make wheel (sometimes with usuable tires for cheap. A quick search online will yield a chart of which Autos use which # of lugs & on which bolt pattern (circle size). You could find tire/wheel combos first, determine the # of Lugs and the Bolt pattern(Circle from such a chart online then find suitable Hub Bearing setups. pfatz

 

[Groo]

Cooks has several packages. Here is the 25" package
25" Performance Band Wheel Package

 

[muddstopper]

I have a couple of 5lug 3500lb trailer hubs with the wheels and tires that fit them, if I decide to go the tire route. Havent measured the dia. of the tires yet. Spindles to fit I can get most anywhere. I can pretty much fab up everything and have a lot of b-belt pullies, shaft material, hydraulic pumps and motors, a engine, and probably some other things once I start looking, to start a build with. I have done the ruff math on steel and figure new would be around $700-$800. Buying rollers and guides, lead screws, sprockets and such, a couple or three more hundred dollars. I could probably build the complete mill for $2grand. This is what put me in the build my own mode to start with. Now I have a lead on a factory built mill supposely for less than $2grand, (which remains to be seen if its fact or fiction), It's making me rethink doing all that cutting and welding, not to mention the mistakes along the way.

Now just because I might buy a used mill doesnt mean I have bought it yet. I appreciate all the comments and advice and hope everyone will keep adding to the discussion any thoughts or ideal they might have.