Talk:Sawmill
The page is kind of a mess, it needs to be cleaned up some more. Anyone should feel free to help out. We should make some kind of template for development. Jeremy 13:47, 14 January 2009 (PST)
A sawmill would also be able to cut wooden pieces that have been rescued from elsewhere, right? I mean, in places like Detroit where there's an almost post-civilisation setting with reuse of previous stuff. Interesting if we could make http://www.gridbeamers.com/ which looks like a project doable by others in any setting. http://www.globalswadeshi.net/forum/topics/any-recent-news-about LucasG 23 March 2009
modularization
Let's modularize this design by by:
- x axis space frame and rollers
- z axis mounting
- z axis raising - need to consider log location
- log holding
- blade attachment to axis
- Blade selection and maintenance
- y axis motion
- motor speed control
Bandsaw
I apologize if this has already been discussed elsewhere. Also, I know these talk pages aren't visited much. But in my meager woodcutting experience, and in watching Darren Doherty's videos, and also from "Saviors of the Rainforest" and the related content there, it seems like a chainsaw would be the best place to start, whereas a double-bladed circular saw (here's something though) would perhaps be more of a niche product.
The evolution:
- Chainsaw for freehand cutting: http://www.turtleislandpreserve.com/internships
- Alaskan mill on your chainsaw for dimensional lumber: [1], [2]
- A track for your Alaskan mill so you don't need to hold the thing: [3], [4]
- Then actually make a bandsaw: http://woodgears.ca/bandsaw/homemade.html
- Then put the bandsaw on a track: bandsaw mill! [5], [6]
Where I am outside of Detroit, there are two machine shops that toss their huge metal bandsaw blades into their open scrap metal dumpsters on a weekly basis, still perfectly good for woodcutting. Bandsaw blades are probably a more straightforward open-source/scrap option than chainsaw blades.
This kind of implies a weedwhip/lawnmower size "power cube"... which again, I apologize for not watching OSE more closely, you all may be onto that already. But, then again, open-source weedwhip and lawnmower (then, chainsaw, snowblower, ice auger, jackhammer, hedgetrimmer, etc etc), that's a hell of a business model, the "low hanging fruit" perhaps.
I absolutely love this guy, though unlike FeF he's using wood as his basic structural material, not metal: http://woodgears.ca/
A.J. 20:17, 27 January 2011 (PST)
Just some points that occur to me or may be present elsewhere on the wiki already, no harm in copying them here :
against bandsaws: The blades are usually made of 2 different materials, welded together which coudl be added complexity. Maybe they can be made with just one at some acceptable performance hit using only a single material.
Larger machine, and steel is more expensive than it looks.
Heavier to move around?
How often do bands break?
For bandsaws/mitigation of downsides:
An automatic device could be made relatively easily to sharpen the blades, this could be built right in to the saw. A grinding surface and a diamond truing device could last a very long time.
Deep cut depth possible. Maybe a sawmill could be designed with an array of many blades which could be adjusted such that they could convert a log completely to lumber in a single pass?
Against circular saws:
Cut depth more limited. Blades can oscillate or get bent.
Less teeth means more frequent sharpening for a given tooth material (but a wider choice of material may compensate).
for circular saws: The stuff about needing to weld or otherwise attach teeth to the blade is I think of low validity. The reason blade teeth are attached is obviously to make them last longer since they can be from a harder material than the rest of the blade. You would do this for a bandsaw blade too if you could. Indeed as mentioned some bandsaw blades are dual material. Circular saw blades could be made with high solid carbon steel if desired for instance. But there would be little sense I would think as performance would be low due to risk of cracking the blade etc. and relatively short tooth life compared with a more flexible core and carbide tips.
Clearly difficulties in making relatively high performance stuff is a very common theme in OSE's development work. All the more reason for the importance of a decent fab lab, from whence relatively high performance parts can be made practically. Or the equipment to make said parts. For example, a modela like mini mill with a diamond bit can sharpen carbide teeth. The teeth themselves may be a challenge to make but carbide may be meltable with induction (it is a bit conductive at higher temps, as is glass I think).
Also a laser direct sintering machine can make the bits from powder additively albeit slowly. Being a dark color maybe the laser head of the laser cutter could work here with minor changes to the optics.... 40 watts doesn't sound like much but if it's focused to a spot 20 microns across that's pretty intense. The calculations should be done to determine if this can melt carbide.
Related pages
http://openfarmtech.org/wiki/Sawmill_Questions There is also information in the forum on bandsaw vs. circular
"Edwardian Farm" circular ripsaw
Just watched episode 3 of "Edwardian Farm", included a bit with a huge circular saw for ripping logs. Mollison wrote of a similar steam-powered machine that he used in Tasmania in the 1940s, which he said was even quieter.
Most interesting bit might be what looks like half-moon (screw-in?) blade teeth.
