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shiremog

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Posts posted by shiremog

  1. IRobertl, any chance of posting step files for the feeder? I fancy trying lost wax castings in alli & the process needs slight differences from 3d printing.

     

    Well,

    a/ It's finished :-P

    b/ It works :-P :-P

    A few pictures of the process:

    Waxes ready for the flask

    IMG 2027a

    Waxes mounted on sprue

    IMG 2029a

    Magically converted to aluminium

    IMG 2030a

    Finished parts

    IMG 2036a

    Assembly

    IMG 2039a

     

    I made a few minor changes to allow for different processes & material. I also made some changes which don't strictly conform to the requirement to re-use existing parts:

    Added a spigot to the end of the yoke and fitted a washer with a similar spigot to keep the spring central.

     

    Used a stud with knurled nut to allow adjustment of spring tension without tools.

     

    Included the snap-on guide as part of the body ( couldn't see any reason to leave it off). There's a ptfe insert at the lower end of the guide.

     

    Added a ptfe bush where the filament feeds in. This is screwed into the body.

     

    Used studs with nuts to hold the assembly on. This was primarily to give the latch & the arm a smooth surface to rotate on, rather than a thread ( I couldn't find any M3 screws with a plain shank). This has an extra advantage in that the motor stays in place with the feeder off, hanging on the studs.

     

  2. My theory is as follows:

    The printer give it's best finish on vertical and horizontal surfaces. By tilting the model, I'm bringing the sides of the raised sections closer to vertical/horizontal and minimizing peaks which often result in blobs.

    I did get some blobs, but far fewer than when printing flat.

     

  3. I printed this crest from a picture. First I printed it flat:

    flat.png

    I you look close, there are plenty of flaws on the top edges.

     

    I then printed it tilted to 30 degrees and rotated by 30 degrees:

    angled

    It needed a raft & support. Most of the un-wanted artifacts have gone.

     

     

     

    print

     

  4. There's about a 50% increase in weight. The effect on the shafts & bearings should be minimal. The potential problem would be the end load on the stepper motor. I've not been able to find that value in the specifications for the motor, but if the worst happens & the bearings die, I'll fit a thrust bearing to take the load.

    The increase in weight has an advantage: greater mass damps any vibration, result: better finish!

     

  5. I'm new to 3D printing. This has dis-advantages ( I don't know what I'm doing :???: ) and advantages ( no pre-conceived ideas of how things should be done ).

    Having played with the new UM2 for a month or so, it seems a well thought out & put together machine which produces good results ( when you've worked out how to use it!)

    The one weak point to my mind, is the bed. It's too flimsy. It narrows at the back edge where maximum leverage can be applied. This is made worse by two cut-outs at the weakest point. I'm sure we've all had prints which self-destruct when the bed judders as the nozzle crosses the fill...So I decided to play:

    Original bed

    First I tried these two aluminium tee strips. They were fixed with double-sided tape, not ideal but it worked. Before fitting them, I measured the deflection on the outside edge of the table when a weight was added, then measured the deflection after fitting the strips. The deflection was reduced from 0.018" to 0.012". I found a significant improvement, with noticeably less judder. Encouraged, I decided to go for it & make a complete new bed:

    New bed

    Top face. Note the integral bearing brackets with strengthening buttresses.

    New bed

    Underside. Strengthening ribs all around. The deflection test showed a reduction to 0.004". So far I've not managed to get any judder, even at high speed. It might be my imagination, but the surface finish also seems better.

    The new bed was cast in aluminium, using a pattern printed on the UM2. It had to be made in 6 pieces, which were glued together. This may be a bit extreme, but it shows that anything which stiffens the bed is an improvement!

     

  6. A couple of suggestions ( from a beginer! )

    The spiraling may be less noticable on the face ( it will tend to get lost in the other detail. It will always stand out more on a smooth surface). Try printing face up.

    As Nallath says, the roughness on the overhang on the bottom is unavoidable. I've overcome this by cutting the model in 2, then gluing the prints together. This way, both halves can be printed without overhangs.

     

  7. I'm in the UK, so can't comment about US points.

    I've had my UM2 for a few weeks now, my first go at 3D printing,although I've had some experience of CNC.

    I found the UM2 well packed, no problems at all. The only problem I've had with the machine is with a number of the pulleys coming loose, just needs a quick tighten of the grub screws.

    The only slightly negative comment I have about the machine is that the bed is rather flimsy which allows it to judder while printing.

    Hope this helps.

     

  8. For Ultimaker2, it's best to use "ultigcode" mode which allows you to control the temperature on the machine itself.

    For Ultimaker Original you *must* use normal gcode mode which allows you to control the temperature in Cura.

    Switching between machine types in Cura makes the temperature appear and disappear in the gui.

    Even for UMO prints I set temperature to 0C and controll it on the machine instead.

     

    Yes, I can change the setting on the machine, but having found setting which suit me & the machine, it would be nice to have Cura set them automagically. The only way I can set the temperature is by adding an M104 to the gcode. I can use TweekAt but only after layer 0, so I still have to edit the gcode :-|

     

  9. Your basic tab should have 5 headlines marked in bold:

    - Quality

    - Fill

    - Speed & Temperature

    - Support

    - Filament

    Speed and Temperature should have settings for... Well... Speed and temperature...

    It sounds like maybe you are in basic settings mode... Which you shouldn't use... Do you have a button somewhere that says "Switch to full settings"?

     

    I'm in Full Settings.

    I have Quality, Fill, Speed & Temperature & Support. Speed & Temperature only has an option for speed.

     

  10. While printing a number of items, I paused the print after the first item was complete & the second started. The print head collided with the first item, knocking it off the bed & shifting the Y axis setting. Shouldn't the bed drop right down in a pause to avoid this?

     

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