The basic idea would work, but I would go up to 3/4" plate, 5hp motor, and something like a yard of concrete cast into the base. And yes, you absolutely have to machine the wheels, which should, together, probably weigh about half what you are thinking for this entire saw.
I dont get the point. This is furniture design, not usuable tool design.
Using the Ellis 1600 as an example; Has a total weight of about 520lbs(counting drive unit), has a frame pretty similar to what I'm doing(1/4 or 3/16" angle perimeter over plate, with addition of some flatbar along the spine), pushes a 1" blade with a 1hp motor, and cuts pretty well. The cast Chinesium saws that you reference are even less substantial than that.
I'll take your plywood and concrete suggestion into consideration if I'm feeling like I'm in a Bob Vila kind of mood.
Just because you can doodle it on your CAD....don't mean you should build it.
Recall the engine "Designer" that was here a few years ago ?
Oh man you've got to see some of my other projects.
I'm not usually one to be the voice of patience here, but I think the dumping has gotten out of hand.
We complain that nobody makes tools here anymore, and then when someone wants to start noodling in that direction, we shit all over it. He's working on it, he's improving the design, he's listening and learning.
Maybe we ease up on the "this is pointless crap" talk? Worst case, he learns how not to make a band saw.
But really, you do need machined wheels.
Thanks. Yeah, I certainly anticipated these types of replies. This is the internet, afterall. I actually just had surgery and ended up selling my Ellis, among other stuff. This is something I'm doing to maintain what little is left of my sanity. I definitely appreciate the more constructive replies, even if they're blunt.
My fiber laser guy assures me he can hold +/- 0.001" on smaller parts. Is that adequate for the wheels if one were to do crowned urethane tires over the flat geometry? Or does it absolutely positively have to be balanced and machined? Im just not ready to give up on them just yet.
I ran static loading sims and observed about 1/16" of lateral deflection over the length of the head. There's a simple technique I've used building ramps, and that's using the weld stress and fixturing to create a precise camber. One could "pre-load" the saw head the anticipated amount. Or integrate something like a guitar neck truss rod. Going to explore this further.
But maybe it's more the dynamic stresses that get you, I don't know. It seems like maintaining planarity between the blade wheels is the most crucial aspect to getting good tracking.
For the work you are describing most people would seek out a used older USA made Porter Cable Portaband and make a stand with downfeed, limit switches etc. I have one of the old 2-speed models and it will cut 4 x 4 solid steel with the right blade.
Not to dump on your project but a DIY wood cutting bandsaw is one thing whereas IMO your design is too elaborate for the average "maker".
And I 100% agree with DDoug that It is often far easier to imagine something in CAD or on paper than to actually build it.
I like the idea of a motorized portaband stand. It's actually a pretty cool and attainable thing. I agree, the average maker doesn't have a laser cutter. Final assembly would be within the purview of a decently handy person, ideally.
I think a 3/4 inch vertical (rollin size) and small horizontal would be better made out a wooden beam design. Not the whole saw, the saw frame back out of laminated oak. Strong and has vibration dampening. Not a box frame, solid oak. Also would have better torsion resistance than smaller saws tend to have. If you really got into the design you could get tensioning with frame flex and cables.
Said before, say again: buy the wheels finished- machined/balanced and made out of cast iron. The commercial wood saw wheels are plenty stout enough for this level of saw.
From machined wheels to press bearings, op has a lot of things to address in details. And the frame, and sub frame...vice...
I think it is worthy; a saw is an extremely complicated machine- a lathe is easier and cheaper to prototype out.
Automating an existing saw is more what he shows ability at. A portaband on trick tools stand with the old marvel dial feed? Or a Klucth horizontal frankenfeed... btw the Klucth is a good canvas to start with.
That's an interesting thought. An Oak tool in a welding shop might be frowned upon though. xD
I have scrapped the pillowblock idea once I talked to my laser guy. He says his laser can hold 0.001" on smaller parts, which makes me think that transition fit tolerances are attainable. I do like the idea of using tensile cables or rods.
I don't think I'll do a vise at all. Thinking rather a backing plate with slots cut to accommodate a stronghand clamp(less frame stress this way). Can rapidly reposition and clamp wide variety of stuff, and it doesn't impart as much stress on the platen/subframe as a vise.
This design would necessitate laser cutting, so I anticipate around $500 there. $500 for the plate. $500 for chibay gearbox and motor. Probably $200 in bearings and misc hardware. Full day of welding and assy time. Nice options: $300 for powdercoat, $100 for a VFD.