Loading ...
Sorry, an error occurred while loading the content.

Re: Nylon-12 Sintered bearing?

Expand Messages
  • ipeerbhai@ymail.com
    Each corner piece weighs about 250g when printed at 80% infill. The plastic costs about $50/KG. So, all 4 pieces cost about $50 to print on a MakerBot. That s
    Message 1 of 5 , Apr 29, 2013
    • 0 Attachment
      Each corner piece weighs about 250g when printed at 80% infill.
      The plastic costs about $50/KG.
      So, all 4 pieces cost about $50 to print on a MakerBot.

      That's $12.50 a piece. ( Let's toss in some fudge factor to cover bad math, tax, shipping, etc... So, let's add another $10 to each piece. 'Cause hey, why not? ) -- $22.50/part. The printed material can be tapped. Undersize the holes, add extra shells, tap the holes, insert helicoil, and you've got a part stronger than the original -- for about $25. With .008" tolerances...

      That's nearing the cost of HDPE raw bars. That gantry though -- that's a different problem. Looks like no-one has tried reaming sintered nylon into a bearing...

      Also -- the Lumen domain is dead. It is now domain parked by some scammer. Looks like any vestige of the company is officially over.



      --- In micRo-cnc@yahoogroups.com, Dan Andersson <dan@...> wrote:
      >
      >
      > Do you have any numbers on the cost of printing yet?
      >
      > Say four corner posts an the gantry parts?
      >
      > The original micRO can produce spare parts with enough quality and by using hand reamers, you achieve good enough bearing quality holes.
      >
      > But that require you to have a micRO at hand and these are a bit difficult to get as we know...
      >
      >
      > //Dan
      >
      >
      > On Mon, 29 Apr 2013 20:45:53 -0000
      > "ipeerbhai@..." <ipeerbhai@...> wrote:
      >
      > > Nylon-12 as the gantry, since the part can be monolithic. If I can make a bearing surface out of the nylon, then I have no need for added parts/complexity. Laser sintering makes the micRo design slightly more practical to produce.
      > >
      > > If I wanted a separate bearing, I've already found good pre-manufactured, affordable, plain bearings and rolling bearings. I also have designed a new carriage that can be 3d printed or 3-axis milled to mount those existing bearings, and already have that designed to mount to T-Slot. Here's one of my prototype plain bearing test videos:
      > > http://peerbhairobotics.com/2012/11/02/bearing-experiment-results/
      > >
      > > As you can see -- T-Slot + added bearings just doesn't match the look and feel of the micRo. T-Slot can look nice. Bearings can look nice. But for now, for purely aesthetic purposes, I prefer the micRo's look. My target is to figure out how to make it affordable and to good quality. Nylon-12 sinters at 80% density. Nylon is inherently stronger than HDPE. So, 80% density nylon should match HDPE characteristics in almost everything but color, surface quality, and water resistance. Color is better -- HDPE has a more "cream" color than Nylon. Surface quality -- not so much. But -- nylon can be polished and dyed to create a very nice surface. ( Hot pink CNC mill, anyone? ) Water resistance is pretty bad, but nylon can be sealed. With a good hand-reamer, I think it might be bearing grade. But again, the test is expensive... I'd rather find if someone has already done it...
      > >
      > >
      > > --- In micRo-cnc@yahoogroups.com, Dan Andersson <dan@> wrote:
      > > >
      > > >
      > > > Njae...
      > > >
      > > > Why not make a bearing out of a chunk of Delrin or HPDE? It's the same material as the micRO is made of. I suggest touser the cermaic coated aluminium rods as the original micRO as they are cheap and very(!) good.
      > > >
      > > > Also, do not fall into the size matters trap! Go for a M2 design. The M3 is to big and the base flexes. By using a more rigid base, most of the flex problem will go away. And another lesson learned! T-slot base! Don't even consider the cheapo hole solution we have now.
      > > >
      > > > You might need to re design the support parts, especially the corners. They take a lot of load and a sintered part will flex. Possibly adding a metal support part.
      > > >
      > > > Alternatively, use steel rods and get copper bronxe besarings to sacrew on the gantry parts.
      > > >
      > > > Hmm, I might need to get me some kind of 3D printer for xmas this year?
      > > > I'm not sure for what reason but I still have a few months left :)
      > > >
      > > > My list of "upgrades" for the micRO is:
      > > >
      > > > More rigid base. Possible scale down to M2 by buying new and shorter rods and screws.
      > > >
      > > > The base designed as a full sized vacuum table with T-slot blocks add ons.
      > > >
      > > > A new spindle with tapered contact bearing at bottom. ( working on it )
      > > >
      > > >
      > > > //Dan, M0DFI
      > > >
      > > > On Mon, 29 Apr 2013 18:52:36 -0000
      > > > "ipeerbhai@" <ipeerbhai@> wrote:
      > > >
      > > > > Hi All,
      > > > >
      > > > > I recently came to own a used MakerBot. It can print a part that visibly meets tolerance requirements for the micRo. This means the support stanchions might function when 3d printed. Might.
      > > > >
      > > > > Next up is the Gantry. I've been wondering about laser sintered nylon-12 -- like you can get from Ponoko. It costs $300 a part to get a laser-sintered gantry component from there ( so about $900 USD ) using nylon-12. I know nylon makes a good bearing -- but sintering makes a bad bearing. I'm thinking using the MakerBot to make all the non-moving parts, and then using Ponoko to make the moving parts. I've been really impressed with the Replicator 2. By and far, a very good 3d printer. All tolerances from a MakerBot part seem to be around .2mm -- around .008". Moreover, error seems consistent -- you can characterize it. This is awesome -- I can characterize it well enough to compensate in my CAD models, and with a hair of work, get a part that is more accurate than the stated error.
      > > > >
      > > > > My question -- anyone have any experience sintering nylon-12 then reaming it into a bearing? I'd hate to risk $300+ ream + shipping just to find out what the answer to that question is...
      > > > >
      > > > > Thanks!
      > > > >
      > > > >
      > > >
      > >
      >
    Your message has been successfully submitted and would be delivered to recipients shortly.