<![CDATA[SoliForum - 3D Printing Community — Fixing initial mis-alignment]]> https://www.soliforum.com/topic/5298/fixing-initial-misalignment/ Mon, 27 Jan 2014 01:01:39 +0000 PunBB <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47822/#p47822 Fair enough. I meant a standard 1x6, 21 inches long. I didn't anticipate people using other lumber. Good point about the spacing, I'll add it to the next revision.

]]> Mon, 27 Jan 2014 01:01:39 +0000 https://www.soliforum.com/post/47822/#p47822 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47818/#p47818 I probably should have known better, especially about the hole spacing, but those are both things that should probably go in the instructions.  It doesn't say anywhere in there how far apart to space the holes, and given that you specify the dimensions of the board as 1"x6"x21" it isn't at all obvious that you mean standard 1" lumber which is 3/4" thick, rather than a board that is actually 1" thick.

]]> Mon, 27 Jan 2014 00:42:57 +0000 https://www.soliforum.com/post/47818/#p47818 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47817/#p47817 Ah - that makes sense. Two problems afoot:

1.) not spaced far enough apart. Torque = r x F. The closer the screws are, the more force is on them. I usually space them 2.5" apart.
2.) 1" lumber is actually 0.75" thick. You lost 1/4" of engagement.

]]> Mon, 27 Jan 2014 00:33:18 +0000 https://www.soliforum.com/post/47817/#p47817 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47816/#p47816 Pre-drilled with 1/16th bit.  Each screw was 1" from the side of the mount board, so there was 1.5" in between them.  The holes were drilled in the center of the width of the board -- I measured the board width at 3/4" so that would be 3/8" from the edge.

One slight quirk, but shouldn't make a difference: The base board I used is thicker than what was called for, 1.5" vs 1" BUT I took a large bit (can't recall the exact size, but it was bigger than the head of the screws I was putting in, I can measure if you want), and drilled 1/2" deep holes centered on the holes drilled with the 1/16 bit in the relevant spots under the base, where the motor mount screws went in. I've double checked and these holes are at least 1/2" deep. The screws went in so that the heads of the screws were 1/2" up into the 1.5" board, so the screws went up at least as far into the motor mount as they should go.  The screws did NOT pull out of the base board, the motor mount board pulled up off of the screws that were in the base board.

]]> Mon, 27 Jan 2014 00:27:28 +0000 https://www.soliforum.com/post/47816/#p47816 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47814/#p47814 ericpaulbishop wrote:

I did pre-drill, and the wood didn't crack in front of/behind/beside the screws. The wood was pulled partway *UP* off of the screws, and then the screws were bent at a weird angle as the motor was trying to turn. Sorry, but I didn't think to take a picture when I initially saw what had happened.

So the screws pulled out? What size did you pre drill? How far apart were they?

]]> Mon, 27 Jan 2014 00:16:09 +0000 https://www.soliforum.com/post/47814/#p47814 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47813/#p47813 I wonder if somehow it was grinding against the support due to an initial misalignment long before the motor mount got pulled out from the base.  I was checking on it (and not noticing any obvious problems) during the initial couple hours of runtime, but it may be that the problem was there even though the block hadn't yet been pulled away from the base.

]]> Mon, 27 Jan 2014 00:04:41 +0000 https://www.soliforum.com/post/47813/#p47813 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47809/#p47809 I think you are right that the steel bearing hit the flange -- I can see that the threading on the back flange is partly stripped now that I look at it.

Worth noting: this thing did not run for hours unattended -- it happened in at most 30 minutes of run time.  I was checking at least once every 15 minutes when I noted the initial misalignment, and I ran it for at most 15 minutes after I got everything re-mounted. I'm not sure how it managed to happen so fast, but it did.

I did pre-drill, and the wood didn't crack in front of/behind/beside the screws. The wood was pulled partway *UP* off of the screws, and then the screws were bent at a weird angle as the motor was trying to turn. Sorry, but I didn't think to take a picture when I initially saw what had happened.

I'd like to order all the parts you mention including another auger and barrel -- it's going to be much easier for me to just spend $40 on a new auger/barrel then to soak it in acetone for 2 days, and maybe then discover it's bent. Yes, I know I'll have to regrind the barrel but that's going to be easier than procuring a lot of acetone and soaking for 2 days.  I don't at all mind spending a (reasonable) amount of money just to re-order the broken parts and avoid hassle.   Can you sell me another flange (so 2 flanges) too?  That way I don't have to unscrew the barrel from the flange it's currently attached to -- it is in there really, really tightly.   

Not sure how you want me to handle the bill, but I'm happy to pay for the replacement parts.  Just send a paypal (or any other payment service) invoice to my email (which you should have on file -- pm me if you need me to update you) and I'll pay it right away. I'd like to get the replacement parts as soon as possible.

]]> Sun, 26 Jan 2014 23:54:04 +0000 https://www.soliforum.com/post/47809/#p47809 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47805/#p47805 Whew! That thing ran for a LONG time in bad shape. Here's what I think happened:

  • The motor support/upright came off the base, resulting in a bad misalignment, one the thrust plate couldn't cope with. (I use the HDF composite since it has a little give to it, meaning that things don't have to be perfectly aligned for the bearing to be relatively evenly loaded)

  • The misalignment was so bad that it started to wear the HDF thrust plate, enlarging the hole significantly to the point the auger/collar/bearing assembly slid backwards

  • At this point the steel bearing came to rest on the flange. The auger has slid 0.25" backwards, further worsening misalignment due to axial translation. The steel bearing is now not supported evenly across its face, and it is destroyed quickly, dropping out of the assembly. This results in another 0.25" of backwards translation.

  • The shaft collar now rests against the flange, wearing the profile you see on the collar into it. By now the auger is far enough out of the melt zone that you're not getting very much extrusion.

New parts needed:

Minimum:
Thrust bearing
Shaft collar
HDF thrust plate
Flange

Other possible parts to check:
Auger
Barrel
(inspect both for being bent. you will need to clean the plastic out and ensure the auger can still rotate freely. Pull the nozzle off at temperature and soak the whole thing in acetone for a day or two)

Steps to prevent this happening in the future:

  • Ensure uprights are fastened to the base securely

  • Post a picture of the final assembly before running it in case there's anything that was missed during assembly that I can't figure out from the above pictures

  • Check on it at LEAST hourly during initial startup

I do have to say - I've never seen anything like this before. It's very interesting. How did the support come loose from the base? Did you pre drill? Did you observe the wood splitting?

]]> Sun, 26 Jan 2014 23:25:33 +0000 https://www.soliforum.com/post/47805/#p47805 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47799/#p47799 Since the first picture is a bit fuzzy, here are a few more pictures.  Again, this is after i took the bolts off to get a better look, it's not as if I ran the filastruder disassembled like this. I also initially forgot in my last post that the thrust bearing wasn't just one washer shaped piece, but several -- it looks like they are all destroyed. All that was left is a thin circular piece shown in the picture below.  The wooden plate (I think it's called the thrust plate in the instructions), looks chewed up around the edges of the large central hole.  A piece of the thrust bearing is lodged in one corner of it as shown in the picture.  I notice that now the hole in the center of the thrust plate is large enough for the auger (with the shaft collar on) to slide easily through it -- I can't remember if this was initially the case.

I'm guessing I need a new thrust bearing (all 3 parts), and likely a new thrust plate and/or shaft collar. 

Also, can you comment/confirm on whether the initial misalignment could have caused this?  I'd like to make sure that when I fix this there isn't a dumb mistake I've made that will cause this problem all over again.

]]> Sun, 26 Jan 2014 22:01:00 +0000 https://www.soliforum.com/post/47799/#p47799 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47698/#p47698 Here is a picture.

]]> Sat, 25 Jan 2014 17:19:47 +0000 https://www.soliforum.com/post/47698/#p47698 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47696/#p47696 I took off the bolts that hold the central column assembly to get a better look at what got destroyed, and you're right it looks like the thrust bearing got destroyed.  One washer is completely gone and it looks like the back part of the shaft collar (I think that's the right name for it) got chewed up.

]]> Sat, 25 Jan 2014 17:17:17 +0000 https://www.soliforum.com/post/47696/#p47696 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47642/#p47642 Sounds like the thrust bearing was destroyed. Can you upload some pictures of what you've got so far? Again - we'll work out replacement parts - just want to figure out what's happened and the extent of the damage.

]]> Fri, 24 Jan 2014 21:44:08 +0000 https://www.soliforum.com/post/47642/#p47642 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47625/#p47625 A small butane torch is a good tool to have on hand.  If you ever need to take the hot end apart, including the coupler, you will need a source of heat other than the band.  I usually use the heater band to heat it up enough to at least take off the nozzle.  If the wires are long enough, you can take the barrel/flange/auger off while the heater band is attached and powered up, then twist the auger out by hand.  Then turn it off, pull off the heater band and try to get the coupler unscrewed before the plastic goes solid again.  Or once the nozzle is off you can remove the band, take off the barrel/flange/coupler and use a torch to melt the plastic inside until you can twist the auger out.

Once you have the barrel clear, roll it on the edge of a table to see if it got twisted.

]]> Fri, 24 Jan 2014 17:47:56 +0000 https://www.soliforum.com/post/47625/#p47625 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47623/#p47623 hmm, looking closer, the flakes aren't part of the auger, but rather a washer that was attached to the auger. I'm going to have to take apart the central block to see exactly what got destroyed and how.

]]> Fri, 24 Jan 2014 17:23:13 +0000 https://www.soliforum.com/post/47623/#p47623 <![CDATA[Re: Fixing initial mis-alignment]]> https://www.soliforum.com/post/47622/#p47622 Actually, just measured instead of estimating.  The metal flakes are clearly part of the auger and are over 1cm in length.  You can see the curvature where they were attached to the auger.

]]> Fri, 24 Jan 2014 16:47:45 +0000 https://www.soliforum.com/post/47622/#p47622