anti friction material for bushing

[AndreaNSR125]

Good morning to all, I must realize very long bushings and especially that they are economic, with a somewhat particular technique.
in practice I have of the classic round rectified from 16,00mm, on which I made a quarry of 3mm width and 6mm depth for anchoring (in practice I made a supported tree).
on this tree I have to run a bushing as long as the tree (200mm) with the least possible tolerance and of course with the least possible friction.
everything is necessary to move now a cross table and in the future a cnc machine.

the bushing is currently made in this way: I sprinkle the tree with epoxy resin strongly loaded with bronze powder (which I always get) and then wrap it in multiple layers of carbon fiber (to have structural stiffness).
At the moment I find myself having a not very low friction coefficient, and especially when I extract the laminate, it has a diameter of a few cents lower than the 16,00 of the tree, I think because of the thickness of the loaded resin layer that causes this deformation in the polymerization phase.
this precarious in reality would not be so bad (it contributes to stiffness altogether, for a more precise handling), the problem is that then the tree remains well tightened inside the bushing and to move it needs a lot of strength.

I therefore wanted to replace the layer of charged resin, with a thin sheet of non-stick material, which therefore still manages to take the precise shape of the piece, but with a much better friction coefficient. . .
What can I use?
I natually thought of a sheet of bronze or teflon, but with the bronze I don't know how much they can find thin sheets in a low friction alloy, while for the teflon I have some doubt about the duration and actual friction coefficient (I took the classic teflon tape to seal the threads, and flowed on the metal is not that it was very slippery. . . )

 

[linch]

and commercial balls recirculation of spheres not?

 

[AndreaNSR125]

and commercial balls recirculation of spheres not?

too expensive, still for a future cnc, but now it is definitely too high expenditure...
I had also thought of using more standard polymer bushings (that of igus) but are still 35mm wide and I need 6... 6 for almost 4€ per one, and I have at least 4 guides to make = 100€ not worth it.

 

[cacciatorino]

If I understand correctly, use the aberino d16 as a soul to make the mouthpiece.

Could you make a male d16,05 (more or less) to use only to make the bushing to then rotate on the real aber d16?

 

[MBT]

too expensive, still for a future cnc, but now it is definitely too high expenditure...
I had also thought of using more standard polymer bushings (that of igus) but are still 35mm wide and I need 6... 6 for almost 4€ per one, and I have at least 4 guides to make = 100€ not worth it.

Goddamn world:
if 100€ worry you... We're wrong.

and really do compass with bronze powder and carbon fiber cost you less?? ? ?
when you took them and threw them away because too much "hard", you already spent the 100€ needed to take igus and keep them because they work well!

 

[cacciatorino]

Goddamn world:
if 100€ worry you... We're wrong.

and really do compass with bronze powder and carbon fiber cost you less?? ? ?
when you took them and threw them away because too much "hard", you already spent the 100€ needed to take igus and keep them because they work well!

He's a student, maybe to buy igus he has to go to the department chief to get himself signed the commitment of spending after deliberation of the academic senate, instead maybe the bronze powder loaded with elephant ivory of the zambia has available to us in the lab...

 

[MBT]

He's a student, maybe to buy igus he has to go to the department chief to get himself signed the commitment of spending after deliberation of the academic senate, instead maybe the bronze powder loaded with elephant ivory of the zambia has available to us in the lab...

Oh, right. :smile:
In fact, I remember that at the beginning the bronze dust bowls and the carbon fiber pencils abounded!

 

[Il marangon]

return polyzene?

 

[linch]

If you're good at the lathe, build self-lubricating bronzes by stealing the raw material somewhere, it's not the same thing, but the effect looks like it, and you don't spend anything.

 

[vale61]

Maybe I don't understand well but a 200-long compass (I also think cut because under the tree there are the supports) that must flow on a 200-long tree, but that loads must support ? or on the wheelbase works as a swing?
Perhaps a sketch with some size and weight to move could direct to the best solution.
Bye-bye.

 

[AndreaNSR125]

100 euros are so many for me, even because to pay them is me, not polytechnic
the bronze powder I got it with the flexible and a fine-grained disk, starting from a full bar,while the carbon I have it in the house without problems, are small pieces and I can recover them quietly from the spherical.
so in fact the cost is practically null if not in material time (time that discards him too, but at least I do not put hand to the wallet and gain us in knowhow)

I do not have drawings to show you, but the thing is extremely simple: there is a plate 200x200mm on which two supported trees,paralleles,lungos like the plate.
above this there is another equal dish that must flow along the two trees, with an excursion of 100mm per part (then the upper plate goes to protrude than the lower one)
this regarding the x axis, but the same thing is repeated for the y axis.
trees and guides will be bound to the plates along the entire length of the plate, distributing well the loads.

the table will be mounted on the plane of a column drill that I will also use to mill (aluminum, bronze. . light robetta, and in any case if it happens to make steel, it will go very carefully, the drill bearings would not be very happy), so the loads will not be high (I think that already '50n of lateral force on the tool will be many), and for more ' distributed on a wide surface of the guides.

overall weight of all a dozen kg plus you and no a couple of kg of piece to say so, possibly you could mount the swivel table with spindle and there are about ten kg.
all however would be fixed on the lower plane of the drill and certainly not on the scaffolding plan, unless to remake it a little more rigid and robust

 

[zeigs]

it seems to me that you want to build a moving plan for braking (presumption controlled by two flyers and coupling screw-lives on the two axes)

Don't you look around first and recover that of a cutter?

 

[AndreaNSR125]

yes exactly, the idea is that (

)

but finding it recovery is a nice daff, because they are usually too big for my drill, also often precision leaves much to desire. . .

a thing that I forgot to say, that is perhaps the most important thing of everything, is that the work was originally thought to be able to get some bushings for vines trapezie to zero tolerance, so as to avoid the expensive bronze bushings, to be taken double to make the right precarious... then for convenience I carried out the experimentation on the rectified bar.

in any case, a small update: I tried to laminate without the bronze layer, and actually the piece keeps the size of the bar, without shrinking, sign that therefore it is just that layer to pull and make it shrink everything.
Now I want to try to make a very thin stratelle, or to increase the number of carbon layers, so as to stiffen everything (with the flaw however that at that point even the slightest interference will provoke great loads).

I also have another idea, especially with regard to the mothervite tpn:I could make a single layer of resin+bronze without fiber, detach it and then cut it into 8 parts.
reassembling the 8 pieces on the screw then lamino normally. . .

 

[zeigs]

If you want zero game you should do the same in two pieces the mothers, so you can recover the game that inevitably creates over time

 

[PaoloColombani]

Goddamn world:
if 100€ worry you... We're wrong.

and really do compass with bronze powder and carbon fiber cost you less?? ? ?
when you took them and threw them away because too much "hard", you already spent the 100€ needed to take igus and keep them because they work well!

A positive twist could be, in a while we will be able to compete with the Chinese.

 

[AndreaNSR125]

If you want zero game you should do the same in two pieces the mothers, so you can recover the game that inevitably creates over time

yes this is true, but my use is certainly not intensive, for the cross table of the drill only one kilo is sufficient. . At most when I see it takes a bit of play I replace it.

 

[PaoloColombani]

Now I want to try to make a very thin stratelle, or to increase the number of carbon layers, so as to stiffen everything (with the flaw however that at that point even the slightest interference will provoke great loads).

You may also perform a longitudinal cut, interpose in the cut an elastic separator and adjust the preload through a preload screw.

 

[AndreaNSR125]

You may also perform a longitudinal cut, interpose in the cut an elastic separator and adjust the preload through a preload screw.

good idea, if I can't do one shot like I say, I will definitely use this system