Great idea Al! If you’re going to make one, may as well make 6.
4 Likes
We should start a new thread, ‘‘Hard time fixes’’. You can also use a piece of leather belt, soaked in oil to replace engine bearings. Will get you home, and maybe more.
6 Likes
But what about the bearing behind the blade? This is the one that toast… wood will probably not last or am l wrong?
Al, l totaly agree on that topic idea!
4 Likes
You could try to make it round with a center hole, and keep it oiled, or bronze. With either one I would make an oil drip of used oil. The first bandmill I built, I used white oak blocks top, and bottom of the blade as guides.
5 Likes
Ha, l failed to mention why the bearing broke in the first place.
I havent yet got a water drip. It was a hot day, did some sawing and blade got warm and expanded. It kicked off the push bearing and scrached its bolt a bit, but l tightened it and went back sawing. But it seems the litle burr must of held the bearing in place just enough that it stayed still. After half a plank l sas smoke at the bearing and l saw the back of the blace allready licked its way halw way trugh the still bearing! Quite amazing actualy…
So yeah, time for installing that water drip…
10 Likes
Also, the back bearings should be set so they only touch when the blade is pushed hard. The tracking should be set so the blade idles roughly 1/8" away normally at full tension. I’m not sure how using inflated tires for wheels will affect blade tracking, but if it slips back too easy, increasing air pressure may help. If the blade rides too long against a back guide it will wear and burr the back of the blade. Moving back too much against the guide could also indicate insufficient blade tension, but excessive blade tension will lead to faster blade failure. Deflection measurements as would be used for vee belts would be the surest check.
4 Likes
My dad was a ship’s engineer. He told of using wood bearings for ship propeller shafts. These were made in sections like a wood barrel and wedge shaped so that they could be driven into the bearing housing to adjust shaft clearance. Old water powered grain mills used wood bearings as does an old farm disc that I have.
I’ve used Osage Orange for a water lubricated bearing on an aggregate washer. This is an Archimedes screw made of cast ni-hard flights bolted to an 8" diameter pipe 14 ft long. The screw probably weighs 2000 - 2300 lbs. One end is under water and the other above water. It turns at about 120 rpm. The underwater end bearing is a stub shaft that is 8" long x 3" diameter. I clad it with 308 stainless weld and turned smooth. The wood bearing is simply a chunk of Osage log turned round to fit inside a housing and bored to fit the shaft. Pressurized water is supplied to the end of the housing to flush the bearing with clean water and exclude sand from entering the bearing. Originally we only gave the bearing .015 clearance. This was not enough as the wood swelled and squeezed onto the shaft so hard it squealed. I ended up boring the bearing out twice and finally ended up with about .050 clearance along with a few axial grooves. I ran the same bearing for 8 years and roughly 100 - 120 hours a year. It definitely still has life left in it.
18 Likes
I understand that the ships bearings were made from lignum vitae, a super hard wood. I didnt know about the wedged segments though. I will have to remeber that for future projects. Another place wood bearings are used is on combine grain heads,The big paddle ? Thingy.
8 Likes
Wood bushing type bearings used in grain augers as hanger bearings no friction or wear on shafts…
7 Likes
Information I did not see in this thread:
Seems to me, and I do not know where I read or picked up this thought…
Wood bearings if you cook a wooden block in oil at the right temperature and I would assume this is in the 100-150C range you can cook the water out and impregnate the wood with enough oil to act as lubricant.
In this way you can make a wooden bearing simple for application like a water wheel.
I could be wrong because this is off the top of my head but such a bearing would need water.
But it might work just fine if you just keep it wet with oil.
This is really worth tinkering with and learning more I think…
9 Likes
Wallace,
Your procedure with boiling wood in oil reminded me of the days when I was building spark radio transmitters. The copper coils of the oscillation transformer were wound around wooden supports. In order to boost the electrical insulating properties of the wood, I boiled the wood in paraffin before assembling the transformer.
10 Likes
I have never tried this, but its one of those things that stirs in your mind when you think about things you would like to build.
I must have read some micro hydro story someplace, I think it might have been from a sustainable development paper.
I did a quick search and found reference to using wax like said you were doing with your oscillator coils…
http://www.woodexbearing.com/history
Very interesting bit for idea cross pollination here.
One of the many reasons I like reading at this site.
More interesting bits:
John Harrison, I remember this name he designed clocks so accurate they cold be used for navigation.
Also wood bearings gears and self lubricating parts…
7 Likes
Here, spruice knots used to be the material of choice for horse wagon axle bearings.
Been clearing the brush last 2 days. Slow process digging out each stump but finaly we did it.
It was not in first plan to clear so much but a neighbour offered to plow the ground for me so l took advantige of that.
Some pics of what we were up to
We made a hot bed for seedlings
Kids learning how to milk
21 Likes
You live in a very nice place, looks like in some places in Norway.
6 Likes
Wonderful pics Kristijan!
You’re lucky to have such a nice place.
I can see Neza is no city girl - milking goats and swinging the axe 
9 Likes
Lookss like you’re on the right path K, with getting the younguns trained.
6 Likes
Neža is sometimes more hard core thain her brother funny things those genetics…
Billy, belive it or not, this is your fault. Staying with you and Erika last yeat was eye opening. Since that l focused way less energy in geting things done and way more in teaching kids how to get things done.
Just one example of this one year focusing all the time to tiching kids… Son will be 5 in a couple of days. Yesterday l asked him what he wants for his birthday. He sayd “l want us to plant corn”. Hard to hide a tear of joy after that…
15 Likes
Wow, that’s quite a compliment. keep up the good work.
9 Likes
That’s wonderful. Way to go Billy and Kristijan.
4 Likes
How is the ram pump working for you these days Kristijan?
6 Likes