Sawmill building advice

Xnight · April 03, 2018, 05:44:15 AM

Hi Guys,

I've been reading a lot of interesting threads on sawmill builds on this forum.
Since I live in Europe (Belgium) things are a little bit different.
Parts are very hard to find and if they are available you pay high dollar.

The plan is to build a (very) portable bandsaw sawmill that I can use in the forest but also at home.
I'll be using v-pulleys for the wheels but it seems that wheels taller than 315mm (12.5 inch) are not available for a type B belt around here. Pulleys for type A belt are plenty available and are cheap.
So my question is, can I use type A pulleys and type A belts? Will this give tracking issues?
The size will be 400mm (16 inch) diameter. For the sawblade I'm thinking about using the ripper37 blade in size 27mm (1-1/16) or 32mm (1-1/4) because of the type A combination.

The power source will be a lightweight 6.5 honda gasoline engine.
Wood will be mainly oak.

Thanks for your opinion

justallan1 · April 03, 2018, 08:12:15 AM

Welcome to the Forestry Forum Xnight.
If at all possible I would try to get bigger wheels. From reading on here and my own experience, the smaller wheels are harder on blades. Your blades can develop stress cracks in the bottom of the gullet and the smaller wheels will be bending your blades more, possibly causing them to snap.
Just a heads up on the smaller engine, you will find that it will bog down on anything less than good sharp blades and you will need to change them more than if you had more power. If you can get a blade grinder or have a re-sharp service and keep a bunch of blades on hand this shouldn't be a problem.
My first mill was about what you are describing, 16" wheels and a 6.5HP engine. The mill did work fine, I just wanted something to saw bigger logs.

longframe200 · April 03, 2018, 11:31:37 AM

Hello and welcome!

I have recently finished my saw mill My DIY bandsaw mill in Sawmills and Milling and encountered the same problem, could not find SPB pulleys in the 500 mm size anywhere in the EU. That's why I chose to use SPA pulleys with SPB belt, because the saw is newly manufactured I have only done a few test runs, but so fare so good. The SPA pulleys with SPB belt also makes the distance from the underneath of the saw band to the upper of the pulleys a bit bigger, so less risk of the band eventually coming into contact with the pulleys and jumping off.

You can also use two tracked SPB pulleys, slightly heavier, but there is nothing negative in this context. One track may also be used for the belt to the engine.

Then, as mentioned above, I recommend the 500 mm pulleys.

Xnight · April 04, 2018, 07:35:51 AM

Ok, so I will consider to go with bigger wheels.
How much hours can you do with one blade without sharpening?

I really like the simplicity from the Lumber smith sawmills, how do the blades keep up with such a small wheel diameter?
Thanks for the tip with SPB belts on SPA wheels! Longframe200, keep me posted on this subject.

I was thinking to get 2 steel plates CNC'd and bolted parallel together to form the "frame" and use flange bearings on both sides of the wheels. On the non driven side I would have "long" holes to permit adjustment of the wheel. Disadvantage of this system that I'll have to remove all the bolts and front plate to change the blade. Advantage is that because everything is CNC'd, it should be perfectly straight and pretty simple to assemble.
Any thoughts here?

Crusarius · April 04, 2018, 08:31:23 AM

With how often you will need to change blades I would not make a system that you have to tear it apart to change them.

Even if the plates are cnc'd there is still some slop so alignment would also be a pain every time you tear it apart to change blade.

Xnight · April 09, 2018, 11:37:26 AM

What shaft size is advisable when the wheel is supported on both sides? I have 4 1" bearings laying around but think these are to small.

longframe200 · April 09, 2018, 04:58:45 PM

I would not use an shaft under 40mm (1,5") on any band saw mill construction.

boscojmb · April 09, 2018, 07:40:35 PM

Quote from: Xnight on April 04, 2018, 07:35:51 AM
.
How much hours can you do with one blade without sharpening?

I was thinking to get 2 steel plates CNC'd and bolted parallel together to form the "frame" and use flange bearings on both sides of the wheels. On the non driven side I would have "long" holes to permit adjustment of the wheel. Disadvantage of this system that I'll have to remove all the bolts and front plate to change the blade. Advantage is that because everything is CNC'd, it should be perfectly straight and pretty simple to assemble.
Any thoughts here?

There are many factors that effect blade life.
Blades can become dull in as little as one cut.
It would be very unusual to get more than four hours between blade changes.
My opinion is that a design that has to be disassembled several times a day to change blades would be frustrating at best.
I hope this helps.
John B