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jkarnacki's MKIII

Discussion in 'General Phlatprinter 3 Chat' started by jkarnacki, Nov 6, 2010.

  1. jkarnacki

    jkarnacki Member

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    Reserved for showing off my MKIII and it's first meal. It's not too early, is it? muahahahahaha

    - Jeff
     
  2. jkarnacki

    jkarnacki Member

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    Well I checked the UPS tracking for the tenth time today, hoping it would bring good news but knowing full well that it would still tell me my MKIII was stuck in a sort facility just an hour's drive from my house. I'm here to say I had a pleasant surprise. Originally it had a rescheduled delivery date of 11/30, and it has said that since this past Wednesday. But tonight (12:30 AM, tomorrow really :shock: ) it gave me ANOTHER rescheduled delivery date of 11/29. So I will will my MKIII in my hands tomorrow afternoon :D .

    First thing I'll do is inspect ALL of the wood parts (while keeping them separated into steps!) to make sure UPS didn't do a number on the boxes. Hopefully I'll have some good news to report as opposed to, IIRC, to kits with damaged pieces. Fortunately IF anything is broken I know Mark and Trish will send new ones out in a hurry :D

    Just noticed my avatar changed to "Level 1 MKIII". WOOHOO! Not fair though - I could never be level 3 because the MKI and MKII aren't sold anymore, lol.

    I'll see if I can get past the excitement and remember to take some pics during the build.

    - Jeff
     
  3. jkarnacki

    jkarnacki Member

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    I've ran into my first problem. I'm on step three, inserting the acme rod into the the two bearings. Problem is, it doesn't fit! I've tried filing down the ends of the rods in case there were some burs, but i can't get the bearings more than 3/4 of the way on the rod...

    - Jeff
     
  4. jkarnacki

    jkarnacki Member

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    Just tried filing the rods a little more, and now I'm able to get the bearings all the way on so that the rod sticks about a 1/4" out of the end of the bearing, but they still won't go any further. :?

    - Jeff
     
  5. 3DMON

    3DMON Moderator Staff Member

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    I think Larry mentioned in his build about sanding the inside of the bearing.
     
  6. Flashsolutions

    Flashsolutions Active Member

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    Not the inside of the bearing! Just sand the outside of the Acme threaded rod! It will remove burrs which are preventing the threaded rod from slipping into the bearing.

    Use a fine sandpaper grit like 400 and wrap the rod while running it back and forth a few times.



     
  7. jkarnacki

    jkarnacki Member

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    Thanks guyz, I'll give that a try. It was frustrating as I was sure they were mismatched parts :roll:

    - Jeff
     
  8. jkarnacki

    jkarnacki Member

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    I'm using some 320 grit (finest I have) to gently sand the threads down and it seems to be working...just a few more strokes and the bearing should slide freely.

    One more question so far. While working on step three I I developed a small crack in the MDF, looks just like a surface crack and it doesn't go all the way through. The wood does not flex at all at the crack. I didn't force it on the tabs any harder than the rest of the pieces, I guess I just pushed it at the right place to induce a crack. I've included a picture (hopefully the macro setting on my camera worked well enough for you to see it) of the crack. Let me know if you guyz think it will be okay. I would think so, as there will be plenty of support from other pieces around it, but what do I know!

    - Jeff Attached files .jpg][​IMG]
     
  9. kram242

    kram242 Administrator Staff Member

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    Jeff if you will PM us the part number we will send a new one out to you so you can have it for the future should you need it.
    I Know that part and I do not think you will need it but you never know :)
    Thanks
    Mark and Trish
     
  10. jkarnacki

    jkarnacki Member

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    Thank you for the offer, Mark! I think I'm going to wait until I'm done with the build though, just in case there's anything else I need it could be done all at once. After my more recent problem I think there may be many more :D

    The acme thread now slide smoothly onto the bearings. I slide the acme thread through one bearing, then screw it into the anti-backlash nut on the assembly with the four bearings, then through the other bearing and tighten the stop collars. One side of u-groove bearings fits nicely on the rod, but the other side is near a quarter inch off, and in order to get in on the track, the acme thread is must be bent quite a bit. I've tried tightening the nuts on the u-groove bearings first so that it is completely on the tracks and then screwing the acme rod through the second bearing, but it doesn't even come close to straight. What do you guyz suggest I try?

    - Jeff[attachment=1]IMG_1049[1].jpg[/attachment][attachment=0]IMG_1050[1].jpg[/attachment] Attached files .jpg][​IMG] .jpg][​IMG]
     
  11. Flashsolutions

    Flashsolutions Active Member

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    Go back to the build video and watch it again closely... I think there are supposed to be two washers there instead of one.

    I'm not in my shop to verify this, but I am pretty sure that is the case.
     
  12. kram242

    kram242 Administrator Staff Member

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    I am building a gantry system today to see what is happening with the acme rod
    Thanks guys
    Mark and Trish
     
  13. jkarnacki

    jkarnacki Member

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    If it helps, I could take some video of the specific problem I'm having. I know it's kinda hard to understand my words, especially when I don't have the right terminology.

    - Jeff
     
  14. jkarnacki

    jkarnacki Member

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    I watched the build videos again and there's only supposed to be one washer on either side of the bearing. You are right, though, on a different assembly the washer setup is one washer on one side and two on the other. On the assembly concerning me, two washers would the problem worse, anyway :D

    For now I've moved on in the build and am currently on step 6, gluing the rods for the Y axis in place. Hopefully the acme rod deal will be sorted out soon and there will be an easy fix...

    - Jeff
     
  15. jkarnacki

    jkarnacki Member

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    ooohhh yeaaaaaa, it's lookin pretty sweet already :D

    So nobody else has had any problems with the acme rod feeding straight through the anti-backlash nut?

    - Jeff Attached files .jpg][​IMG]
     
  16. rcav8r

    rcav8r Moderator Staff Member

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    Gee it seemed like just last week mine looked like that :)

    I didn't have any problems with alignment with the Acme rod, Ant-backlash nut and bearings, straight an an arrow. But my Anti-backlash nut is REALLY tight. With the pulleys swapped (small on stepper) it is working Great.
     
  17. Gefahren

    Gefahren Member

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    With my Acme rod thru the lower bearing and the anti-backlash nut it didn't naturaly line up with the top bearing, but it was close. I didn't have to try very hard to get it into the top bearing, it felt like there was enough play in it to go there and it "looks" as straight as an arrow now.
     
  18. Crash

    Crash Moderator Staff Member

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    During my build, I encountered a similar issue, though not so bad as to create any binding. It's as if the ABN is too close to the sliding Z mount. I thought about taking the assembly back apart and putting a couple of washers between the ABN and the Z mount to space it away and make the bearings line up better with the rail. However, I went ahead with the assembly first just to see how much bind there would be.

    As it turned out, even though it seemed like there would be a binding issue, there was actually not an issue at all, so I never put in the washers.

    Of course, yours could be different, but mine ended up working out just fine.
     
  19. jkarnacki

    jkarnacki Member

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    I guess I might have to just try it out. Maybe even with a slight bow in the acme rod it will still screw in and out of the assembly freely. We'll see. It's just that I kinda need to get the assembly on in order to move on in the build :D

    - Jeff
     
  20. jkarnacki

    jkarnacki Member

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    I'm on step 11 right now but I just couldn't sleep without knowing whether or not I had too much binding on my Z axis. First off, Crash, your video tutorials are excellent! Like you mentioned, you DO have a knack for these things. My y axis jogged around just fine, but the Z would only move a fraction of an inch before it the belt started slipping or the motor stalled. I tried tightening the belt a little more but still the same problem. So, I need to fix my Z...somehow. It's been a couple days since I last looked at it, so maybe tomorrow I'll take it off the rails and have a "fresh" look at it to see what's going on.

    Apparently swapping the two gears (small gear on stepper, big on gantry) may help, but this will give me more torque at the expense of speed, correct? Even if swapping the gears worked, I'd rather figure out what's going on than apply a bandaid.

    Thank you, guyz, for all your input so far. I'm sure I'll get through this with your help :D

    - Jeff
     
  21. kram242

    kram242 Administrator Staff Member

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    Jeff I did not get a chance to build the gantry yesterday, but I have time this afternoon to build one and see what what may be happening here. I should have something to tell you guys tonight.
    Thanks guys
    Mark and Trish
     
  22. kram242

    kram242 Administrator Staff Member

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    Ok guys I have built another gantry system and have not found this issue yet. However I did find a possible solution or at least the reason while the acme thread does not seem to line up left to right of the zplate. What I have found is a 3/32 movement in the holes vs. the bolts on the non-adjustment side of the zplate. Not sure how this could have happened but it seem to be that the hole is slightly larger then the bearing bolts and that could be creating the slight misalignment. If you loosen the bearing bolts for the z plate and push the ones that are the non-adjustable ones (the ones without the slots) over to the side, away from the center of the gantry then tighten the down then move the adjustable ones in place this keeps the holes in line and seems to work a little better. The Tee nut is tight to spin (even in hand) and that is something that should work its way in over time.
    As for the front to back alignment as shown in the pics above. To be honest I cannot replicate this so far. I will be building another gantry separate from this last one to see if there was something I have overlooked.
    we will keep you posted on any findings
    Thanks again
    Mark and Trish
     
  23. jkarnacki

    jkarnacki Member

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    Thank you for checking this out Mark. I'll take the gantry off tonight and try what you suggested.

    As for the handle being locked in the upright position, I have to knock one end down at a time with my fist...that's how tight it is. The left side has worked it's way loose a little bit, but the right side must be smacked pretty hard. Hopefully things will work in over time. I have everything done so far except for the cabinet door. I'm missing two square nuts for the hinges but I should be able to find some in the garage or at Home Depot.

    - Jeff
     
  24. Flashsolutions

    Flashsolutions Active Member

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    I had similar issues... I attributed it to having painted my MDF but what I did to solve it could work for you if you have a Dremel with a round sanding bit.

    I think I used the half inch sanding bit but it may have been the 1/4" one, not sure now. In any event, I lightly sanded the tracks where the pivot arm bearings run up and down.

    Then I added lithium grease to the bearing tracks and to the insides of the pivot arms.

    It made a huge improvement and now my pivot arms raise and lower with little effort. You still have to exert some force to lower it, but it raises into position and locks very nicely now.


     
  25. SlowBipe

    SlowBipe Member

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    Mark,

    I ran into the same problem that jkarnacki had where my bearings that position the zplate appear to be too high on the blocks and washes. When I assembled it yesterday, it went together causing a slight bow (about 1/16 inch at the center) in the acme rod. My solution will be to go out and find a set of washers that are about half the thickness of the ones supplied to go under the 4 bearings. This should work if I can find them. It appears that there may be some variation in the way all of these parts are going together. I don't know if it's because there may be an opportunity to snug some plate down more than you might, or if it could be caused by the paint on the two blocks that support the bearings that is raising them more.

    Maybe a possible solution to those who are finding this variation would be to supply additional washers of varying thicknesses to allow the builder to fine tune.

    I supplied a picture of my z axis block. The hight of those two bearings seems to be the issue for me. I am not having any problem with the alignment from left to right.

    SlowBipe Attached files [​IMG]
     

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