Wood bearings

[RB211]

This is a type of high speed linear bearing, and one I created for a special purpose, it's an arrow rest and far as i know never seen one used in this way, I did not build the black outer structure --- that's pre-fab and is supposed to contain cheesy little brushes, but i did incorporate the little white UHMW pucks...



I pretty much tried every plastic going - delrin AF *teflon delrin and ceramic delrin along with some other choices - but my first choice actually worked out the best - UHMW was capable of over 1500 shots without a "puck change" and may have gone as high as 2500...

I cannot imagine a wood holding up to that but you never know, I do know it would not be as chip resistant and the way you load an arrow into this rest is to press it into the center two top pucks and they flex and let the arrow in - then a spring loaded lower UHMW puck provides constant guided tension - yet it's so slippery the drag is near non-existent...

The UHMW is ultra quite - especially when loading - I think wood would be like delrin - very loud... (not good if your a hunter) It's funny - I thought teflon delrin was going to be the thing to use - one days shooting and it was gone...

ceramic delrin did not fair any better....



BTW - this last pic is of 3 numbers barely readable --- they are of my easton match grades --- that number is .001"

that is --- + or - .001" for over 30 inches of arrow length,,, all high density ultra grade carbon fiber... that's pretty incredible - I could use them as a straight edge to measure cylinder heads lol

Had no idea you could source CF with that straightness and diameter precision.

[A.K. Boomer]

Had no idea you could source CF with that straightness and diameter precision.

They cost a little extra - they are just the best of the batches - most come out between .003 and .005" still damn good for a 30" .293" diameter shaft...

[JRouche]

Lignum vitae was used to the point of extinction during WWII- the US Navy spec'd it for all their ship propeller shaft bearings.
]

Yeah, he is correct. I bought some blocks of Lignum vitae, I collect woods and I was overseas.. Pass port, piece of paper as what I want to decree.
Naw, I was in the Navy. No pass port required.

You cant find real lignum anymore. And yes, a great line shaft bearing. FYI No grease needed. JR

[Tundra Twin Track]

For a number of years grain auger or screw conveyors manufacturers used ball bearing on power shaft on top drive models.It was a total plunder when a bearing failed all the paint on shaft had to be removed as all other bearing that were in the way to do the repair.Thankfully most all use wood again that john hobedeclipe &Ringo mentioned in post #40&41.The pic with yellow auger shows wood bearing.

The maple bearing on auger I built have stood up well,6 of the 14 are original from 1990 on 50’ power shaft as pic shows.

[A.K. Boomer]

That's a rough life out in the elements like that and i can see why ball bearings would fail, even sealed units would get penetrated by moisture and then it's all over, I guess in places where loose tolerances does not matter much I can see where wood would work but am surprised certain plastics are not incorporated into the build for the same reason -

and they both could have the advantage of just being a split bearing to where you do not have to take the entire shaft down just remove a cap and install a new set - really can't do that with B.bearings...

[A.K. Boomer]

This is just one company of hundreds out there producing plastic bearings for specific applications (including shipping and agriculture)

this particular company has over 55 different types of plastics for various purposes and needs,

at the very least very informative young lady speaking and showing different designs most of which wood could not even be considered - only about 5 minutes...

https://youtu.be/KblADSqgvf8

[A.K. Boomer]

More on wood VS plastic, these guys say plastic holds the edge and yes even in propeller shafts and hydro plants...

https://www.tstar.com/blog/comparison-of-underwater-bearings-wood-vs.-plastic

[Tom S]

Not a fan of whisker-biscuits AK? Have you ever had those UHMW pads destroy the fletching on an arrow?

This is just one company of hundreds out there producing plastic bearings for specific applications (including shipping and agriculture)

this particular company has over 55 different types of plastics for various purposes and needs,

at the very least very informative young lady speaking and showing different designs most of which wood could not even be considered - only about 5 minutes...

https://youtu.be/KblADSqgvf8

I've dealt a bit with Igus and have been provided samples by them in the past. Great company to work with and they know their stuff when it comes to plastic bearing applications. They also do many small machine components such as gears, linear bearings, cable carriers, actuators, lead screws, and stepper motors all based around their bearing technology. You can even purchase bar stock and 3D printing filament of their plastic offerings to make your own designs.

[A.K. Boomer]

Not a fan of whisker-biscuits AK? Have you ever had those UHMW pads destroy the fletching on an arrow?

LOL necessity is the mother of invention - bisker wiscuits are one of the worst idea's ever created, the first compound bow I bought came with one and could not believe people actually try to shoot and be accurate with them,
within about a week I had my new design up and running and yes one arrow got the tail end of the fletch slightly "disconnected" in fact it's this one down below - I simply glued it back on and readusted the knock, as you can see the arrows fletching has a radical spiral to it,

that's what got me - - you have to have this one adjusted perfect for clearance.... there was a slight possible advantage to it - you could just catch all three tails and instead of having to wait for the arrows flight to rifle it down it's path the rotation was instant right out of the gate lol

that in itself could be an invention within the invention, I find stuff like this out all the time with inventing as it leads to other avenues that I did not initially see....

[A.K. Boomer]

This is an interesting topic and don't get me wrong I applaud Ma Nature in every way esp. when she still can give us a run for our money with stuff to this very day, until of course it's counter productive to her and almost makes a certain species of tree extinct....

Topic reminds me of the perfume industry --- is stinky old Ambergris (Wale poop/vomit lubricant) still the best damn thing to attach a perfume note too? even though synthetics have taken over much of the task? wanna get the perfume people all up and arms bring that one up on their site and stand back with some popcorn...

well just checked on e-bay and looks like it's going for about 25 to 30 bucks a gram,,,

their are people who have found 10 lb chunks washed up on the beach and then retired lol

and of course im sure allot of Whales killed just to dig the stuff out of their guts... in that case - im all for the synthetics, even if it don't work quite as well...

[A.K. Boomer]

or 60+ lbs is way better

https://www.scmp.com/video/asia/3150820/thai-fisherman-finds-whale-vomit-worth-over-us1-million

[brian Rupnow]

I will tell you an interesting story about wooden bearings. My grandfather, who was born in the late 1800's spent his entire life in a small village about 60 miles south of Algonquin Park in Ontario. His grandfather, who was one of the pioneers to that area in Ontario told my grandfather this story. In my great, great grandfathers youth, there was very little finished metal available. Finished metal products were made in England, came up the St. Lawrence Seaway, up Lake Ontario, and was shipped north by horse and wagon from Belleville. Belleville was a port on the north shore of Lake Ontario. A man wanted to build a sawmill in a very small village called St. Ola near where my great grandfather lived. A 48" circular saw blade and shaft were sent from England, and eventually made it's way north to St Ola. The bearings were wooden blocks, and they were greased with ---wait for it----bear grease. The river that provided a power source for the sawmill was shut off by "stop-logs" when the mill was not in use, the water being diverted away from the mill and over a dam. On Halloween night, my evil minded great great grandfather and some cronies (who were all about 14 at the time) decided it would be great fun to open the stop-logs and let the mill run as a Halloween prank. Not a good move!! The bear grease man was not in attendance, the turning metal shaft ran dry and set the bearing blocks on fire from friction, and the sawmill burned to the ground.---Brian

[RB211]

I will tell you an interesting story about wooden bearings. My grandfather, who was born in the late 1800's spent his entire life in a small village about 60 miles south of Algonquin Park in Ontario. His grandfather, who was one of the pioneers to that area in Ontario told my grandfather this story. In my great, great grandfathers youth, there was very little finished metal available. Finished metal products were made in England, came up the St. Lawrence Seaway, up Lake Ontario, and was shipped north by horse and wagon from Belleville. Belleville was a port on the north shore of Lake Ontario. A man wanted to build a sawmill in a very small village called St. Ola near where my great grandfather lived. A 48" circular saw blade and shaft were sent from England, and eventually made it's way north to St Ola. The bearings were wooden blocks, and they were greased with ---wait for it----bear grease. The river that provided a power source for the sawmill was shut off by "stop-logs" when the mill was not in use, the water being diverted away from the mill and over a dam. On Halloween night, my evil minded great great grandfather and some cronies (who were all about 14 at the time) decided it would be great fun to open the stop-logs and let the mill run as a Halloween prank. Not a good move!! The bear grease man was not in attendance, the turning metal shaft ran dry and set the bearing blocks on fire from friction, and the sawmill burned to the ground.---Brian

That's horrible!

[SVS]

Sorta proves that “stupid damn kids” were stupid BEFORE the smart phone was invented…..

[boslab]

Reminds me of a visit the the Greenwich royal observatory when I lived in London, I’d spent weeks trudging round museums, science was my favourite, anyway the Harrison clocks were on display, beautiful things but what I didn’t know was all the predecessors to H1, etc were made by mr Harrison out of wood
quite a feat to make accurate clocks , and apparently they were ( but not as reliable as he wanted) the bearings were our old friend, Lignum.
there’s a good book about it it’s called Longitude by dava sobel, it’s on Amazon, there’s a video dramatisation done by the bbc I think also worth a watch ( pun)
all his prototypes were wood, not surprising as he was a cabinet maker and joiner.
chatting to a mate he reckoned that most of the big clocks like the one up the Big Ben clock tower have lots of wooden bits too.
oh and carvers mallets were traditionally lignum as it’s the densest wood on earth
( 1.25 tons per cubic meter, my favourite metal fact, osmium is 22.5 tons per cubic metre fascinatingly)
it makes me think, there is so much wonder in the world, I sometimes think it’s wasted on us, I told a guy that once and he said so fing what, who cares enough to make you cry,
mark