Portable Log Mill

[scottbrrtt72]

Hi All,

It has been a long time since I have posted progress on my sawmill. This project has taken a while for me to build and I’m not done yet. I am at a point where I need some of your help. The attached photos should help explain what I am trying to do. I will post individual photos along with the questions I hope you all can answer. The first photo is a general picture of the frame and the cutting part of the sawmill.

 

[scottbrrtt72]

This second photo is where I am having the problem. As you can see from the first photo I am using a winch and pulley to lift the cutting part of the sawmill. The cutting part slides up and down the tube steel to the required height. The frame is 2-inch tube steel and the cutting part frame is 2-½ tube steel. The problem is when I want to lift the cutting part of the mill the 2-1/2 tube steel kinks on one side of the 2 inch frame. When it does this it will not lift at all. I have tried numerous things to try and correct this problem. I even added casters to the sides to keep it from torquing to one side. This seemed to work for a little while. When it did work, it seemed like there was a lot of resistance. The whole cutting part, including a 100 lb motor, shouldn’t weight more than 225 lbs. The lifting capacity of the winch is 1500 lbs. Anyway, is there a way to add additional pulleys to make the cutting part lift level and smoothly? Any ideas would be greatly appreciated.

 

[scottbrrtt72]

Here is another photo.

 

[scottbrrtt72]

Another photo.

 

[scottbrrtt72]

This is the old saw mill. I will be using the same log carriage but different cutting head.

Hope you guys have some good ideas! I am getting fustrated with this part of the project....

 

[RobS]

Kind of hard to tell from your pictures Scott. Are all the various square tube pieces square and parallel where they need to be? Can you get it in a gravity-neutral position and try to slide it by hand to feel for binds? Is your lift mechanism lifting evenly or is one side/end being favored? How about grease?

Looks like a neat project. Maybe a wider angle photo would help us picture it better /forums/images/graemlins/smile.gif

 

[rockinmywaypa]

like Robs says it's hard to see but I think the problem may lie in your lifting point being off the centre of gravity.Consider where the motor is and all weights and then sort of think in terms of a piece of plywood hanging on a rope with the rope coming up through the centre of the disc. You have to find that centre point in relation to the spread of weight or counter balance the platform to balance it out, then you will have very little twist on the sliders as it goes up and down. in your case I think your cable may have to move farther back towards the motor pulleys to do the lifting and maybe closer to the motor end.

 

[scottbrrtt72]

I think that is the problem. When the winch starts to pull up, it binds on the left hand side all the time. That is why I tried putting in the casters to reduce the binding on sides of the frame. Like I said, it worked for a little while but there was a lot of resistance. Everything is level and parallel. I know the side where the axle resides is heaver than the other. That said I don’t think it is well balanced. Do you think adding additional pulleys would help? Or does the weight on both side have to be equal for the pulleys to work?

/forums/images/graemlins/confused.gif

 

[missourihick]

check out bakers sawmill. You might get some ideas there. I am buying one. Baker wood buddy sawmill Send for their info and video,it's free and it shows some very good details.

 

[wroughtn_harv]

Grease will make a ton of difference. You can buy grease zerts that you just pound in. You drill a quarter inch hole. Then, I use a socket over the zert, hammer it in place.

But with the sawdust grease presents a myriad of problems, staining, collecting sawdust, etc.

When you look at the amount of bearing--resistance surface you have a ton, buku square inches of it, two inch times four sides times height. There's plenty of room for trouble. Also your bind is always doubled because it happens at each end.

A viable alternative would be to limit the bearing--restance surface area. If you went up in size to three inch for the outside and put bearings on the top of your outside and the bottom of your inside piece. Then your contact patch would be cut by umpteen percent and it would be converted to a rolling resistance instead of a rubbing one.

Good sealed bearings aren't that much. Plus with your resistance cut down times hundreds everything else, winch etc, will live longer too.

I like your concept and attention to detail.