40"x21' Conway Bandsaw Mill Build

[bconway]

Well, it has been a few months since I started this project, but I wanted to post some details for future builders. I know how much I learned from reading over past builds.

I designed this to be heavy duty and hopefully reliable. It needed to be portable and easy to upgrade in the future (to everyone that suggested hydraulics, I get it now). A big thank you for all the help it took to get here. The mill did very well during its test run and I look forward to putting many more hours on it. This is what I came up with-







I'll break this up into a few different sections. More to come

[OldSmoke]

That is a nice looking mill you have there!

[thecfarm]

Looks like some thought and planning and work went onto that!!!
Looks good!!!
Let the sawing begin.
What's the plan for the lumber?

[fluidpowerpro]

That looks great. You do nice work. Looking forward to more pictures.

[cook]

very nice first class build alot of time and thought put into that project and yes your right first class forum lots of skilled people here willing to share their knowledge

[fluidpowerpro]

I see a chain on the side so I assume you have power feed. I would love to see more pictures of that set up.

[bconway]

Thank you all. I'll start with some of the carriage features and my thought process behind them.

It is 36" deep and 6' tall built with 2x2x1/4" tube. Having the saw mast in front of any vertical supports makes blade changes easier and keeps the center of gravity right in the middle of the carriage. The top of the carriage extends past the front of the wheels, allowing the engine and battery to raise past the top of the carriage frame. I have about 50" of vertical cut capacity this way.



The mast is made from 4x4x3/8 tube (I got a deal- way overkill). My fixed wheel is a plate bolted to the bottom of the mast with four adjustment bolts. The tensioned wheel is a plate welded to a 5x5 tube with UHMW slides inside of it. 18.75" pulley wheels on 1.5" shafts. I would suggest USA pillow bearings for the main wheels. The Chinese ones were not impressive and were swapped out.  A Vanguard 35hp engine and Group 31 battery are bolted on plates to the top of the mast




The lift system took some thinking to figure out. The mast slides up and down on 1.5" solid round bar. Two pieces of dom tube house flanged bronze bushings which are kept in place with set screws. I thought about acme rods or linear rails, but this seemed like the most reliable. The 1.5" rounds are adjustable in 4 directions on both the top and bottom. A jack shaft runs across the top of the carriage for the chain lift. #40 chain lifts directly on the mast and snakes back to the bottom of the mast. I had to keep the jack shaft further back so that the engine doesn't hit it when it is raised up high. There is some mechanical advantage gained through the sprocket gearing. A 24v wheelchair motor drives this up/down and a handwheel brake keeps it locked. The handwheel lets me run it manually if the lift motor were to ever fail. A laser level shines on a magnetic quarter scale to set the height, so no parallax error.





The tensioner is pretty simple. It's just 1" acme rod pulling the tensioner bracket against a fixed angle bracket. The die spring is green strength 2" OD x 1" ID x 2-1/2" OAL. 9 half turns gives me proper tension with about 4 more turns possible before the spring bottoms out.



All of the stuff that I didn't want in my way is on the other side of the track from the operator - gas and lubrication tanks, sawdust chute, and the power feed chain. The power feed works well on only one side even with a probably 800lb carriage, but I wish I would have driven it from both sides. A board drag back system down the road would be pushing a one side driven carriage. The chain is fixed at both ends of the track, goes around two idler sprockets on a plate, and another wheelchair motor drives it.



All of the controls are kept in one corner for the operator. An over-centering handle for belt tension to engage the blade and a throttle handle are mounted on the mast. Everything else is contained in the operator's box - a solenoid actuates the lubrication wiper, two controls for the up/down and power feed with resettable fuses, and the engine ignition. The whole system is 24v. A dc transformer steps up the 12v battery which makes the wheelchair motors move a lot faster.





That's plenty for one post. I'll plan on doing another to breakdown the track and trailer. Let me know if there is anything at all I can explain further. Happy to help

[47sawdust]

Beautiful.
Welcome to the Forum.
First time I have ever seen a vegetable grater on a sawmill!

[Peter Drouin]

Nice job.

[Old Timer]

I'm here to say, my friend that is some high quality fabrication work! Not too many people can fabricate something...dial it in...take it all apart...

paint each of the parts then reassemble. As a CNC machinist-fabricator myself that take dedication right there... 

Great Job 

[RAYAR]

Very nice mill build, looking forward to more pics and details. That 4X4X3/8 tube is not overkill, there is a lot of blade tension pulling off center on it and you need rigidity on that part to keep everything properly aligned.

[RetiredTech]

 That looks to be very well thought out and built. I hope you enjoy it for a long time. Happy sawing!

[rusticretreater]

Quite impressive.  You are well skilled, talented and patient.  I was thinking how expensive the metal was while looking at it.

I agree with you on needing a double chain drive for the head.  That  jumped out at me while looking at the pictures.  A big change as the operators controls need to be redesigned to provide room for the driveline components. 

I also agree with centering the lifting mechanism to keep cranking forces even on both sides. That is easier on the motor I think, instead of heavy torque twist when the motor is at one end of the drive shaft.  The weight of everything should keep it hanging even though.

[customsawyer]

Nice build.

[jpassardi]

Nice work - I can see some Cooks mill design influence there.
You were wise to incorporate a spring to maintain band tension. Having the chute on the side opposite the operator is sharp as well, that's one thing I don't like on my Woodmizer.

[fluidpowerpro]

If you would please, share the details on what motor / gearbox you used for your power feed. Brand, P/N etc. 
Thanks,
Tom