mastory

Out of curiosity, what do you feel is a reasonable price for a purpose specific dust cover? I have been thinking of making one for myself. I have a sewing machine and it would be a pretty simple thing to make. Maybe worth making 50 of them and peddling them...

Somehow the H-bot prior art claim should be brought to the attention of the patent office before this applied for patent is official. I have no idea how this should be done. Perhaps someone with skin in that game should take it up.

This on the lead product page would seem to confirm it; "The valve may be controlled using DC current, open or closed-loop control, and even PWM (Pulse Width Modulation) to cover a broad range of applications."

Gr5, http://umforum.ultimaker.com/index.php?/gallery/image/1970-pwm-flyback-diode-here/

On reading your comment above, I gather you do mean to suggest that I could connect the valve directly to the fan output (plus diode) I'd really like to know what the parameters are for the fan output. Where could I find those?

Gr5, I think your suggesting that I use both units from Clippard which would allow using the fan output as is (plus a diode). If so, that was what I was thinking. Just wondering if the UM fan output could somehow be changed to avoid the control unit. My familiarity with the UM electronics is not very good and my overall electronics knowledge is mediocre at best.

I am frustrated with fans for print cooling. The stock setup with a single fan neglects the opposite side of the nozzle. Adding more fans can help, but at a cost to the gantry size and mass. I have tried a couple different printable air ducts with mixed success. I have a custom hot end which limits those options for me. So, I built a mod to cool with compressed air instead. I have the capacity for much more intense cooling with more consistent coverage and it can be consistently throttled down to nothing. It also reduced the print head footprint substantially and reduce the inertia of the print head. I put up a couple pics of the manifold in a gallery. The only negatives are; you need a compressor, and controlling the intensity has to be handled differently. I have the first part covered. Control is my issue that I am trying to figure out. The set-up; I built an air manifold from a bent & soldered piece of brass hobby tubing. I plumbed it to an air compressor with a 1/4" nylon tube added to the bowden tube. I placed a manual needle valve inline to control the air flow. The manual needle valve is the problem. It requires user intervention to keep it adjusted properly. I want to replace it with something I can drive from the existing fan controls. I found a couple of products made by Clippard Pneumatics that I think offer the control I need. The first one is a proportionally controlled flow control ($58). It runs on up to 20vdc and varies its output according to input current 0-.09A. I gather that the speed of the stock fans are controlled by a PWM voltage level, not current. Can someone tell me the specs/ranges for the stock fan control output? Can it be programmed to vary the output current instead of voltage? Can the control range be altered? Clippard also offers a control module (bottom of page) that accepts a 0-5 or 0-10VDC control input (or 0-20mA control input) and converts it to the current signal that the valve needs. The input and output control ranges are programmable. If I can't alter the stock fan output to run the above valve, I think I could make it all work with the addition of the control module. Any thoughts? Can anyone expand on this in a direction that wasn't obvious to me? I'll add a picture to the post shortly. Thanks, Matt

I an idea I had last week from another post about bridging. To keep subsequent bridge lines from destroying the prior lines, how about lowering the print bed slightly after starting the bridge, then dropping back down at the other side to make the connection. This would help keep the nozzle away from the prior laid lines. Also, why doesn't the first bridging layer always pick the shortest possible unsupported span?

Ive been wondering for a while why printing with the platform standing vertical isn't done to improve overhangs.

If the slicer is working correctly, it could be that the motor cable has a phase pair reversed. At one of my former employers, it was the first thing to look for when troubleshooting a reversed stepper motor. Don't know if its the case here, but it might be worth checking.

Just an idea here. May be foolish, but might also might inspire something else. If bridging subsequent lines, maybe the bed could drop a mm for the bulk of the travel, and then go back to the normal Z height to connect the bridge at the other end??

The bed needs to be 'level' in respect to the print nozzle. More specifically, it needs to be parallel to x and y axis gantry guide rods.

I have been lurking on this discussion. I made a similar boot for my homemade hot end. I did try mixing in some corn flour to hasten the cure. Actually, in the states corn flour is a bit hard to come by so I used "corn meal" and turned it into flour in my coffee grinder. I'd say I mixed it at 1:3 to 1:4 flour to silicone. Probably a more saturated mix than necessary, but didn't seem to hurt any. I then mixed it well on a paper plate with an old credit card. I designed a fill port and opposing vent port into the mold. Used a 50cc utility syringe to fill the mold. It cured in about 20-30 minutes

As Owen stated, parts in an assy cannot be merged into a contiguous body. It is possible to insert one part file into another. You may then be able to merge them into one body.

You might just edit the fourth line from the bottom with your preferred priming distance. You can choose if want to keep the higher f200 speed or substitute f90 like your example. May not matter, but I think i would use the 90. The existing line extrudes 3mm at 200 speed. Idont know what the speed units are. May be just relative to max or something....

No problem. My initial answers were a bit vague, but I think correct if interpreted carefully. Peace

MIC6 is the common name for a type of aluminum tooling plate. It is manufactured to be very flat and to tolerate machining without warping from subsequent machining operations. I am no metallurgist, but I have been using MIC6 in my work over my career. It is produced by a casting process (to eliminate internal stresses that are common in roll formed metals) and a secondary machining of both sides to produce a flat, smooth and parallel final product. It is sometimes generically called "cast aluminum tooling plate". Unfortunately, the thinnest is is manufactured is 1/4" or 6.4mm. It should be sawed to size and not sheared. My heated bed is made from MIC6. I believe if it were available in 4mm it would be preferable for our purpose. If someone had access to a press room with high tonnage presses, (like the kind that press car bodies) it would be possible to coin a roll formed sheet to have a similar flatness. It would be preferred to do the machining first. Matt

Your prints are looking pretty good. I rarely use alcohol for adhesion. Most of the time it makes the print stick too much, like you have experienced. I would use alcohol when printing something larger that would tend to warp and pull off the tape. For most parts, starting with the nozzle primed and adjusting the Z height on the fly while printing the first layer gets them sticking well. If this is hard to do, you could specify a thicker bottom layer in Curas Advanced tab under Quality. I usually reuse the tape for multiple prints before replacing. A good thing about narrower tape is that when a strips gets damaged, you an replace smaller areas. I usually print the tops and bottoms at 4x or more of the layer thickness to get a nice finish on the top. The larger the flat areas, the more important this will be. 220 is a very safe temperature to print at for most any PLA. There are trade-offs between temp/speed/quality. At 220, you should be able to easily print these parts at 100mm/s without much loss of quality. Personally, I go for lower speeds and temps for better quality and less warping. I usually print around 200-210 and generally below 75mm/s. Every roll of filament seems to print differently.

I hesitate to respond because I have no experience with UM2. It looks like typical under extrusion. Could be caused by a bunch of things. Can you try some different filament? Maybe the hot end is not actually hot enough? Too much friction in the filament path? Filament diameter too large or oblong? Bad filament? Incorrect and too low extrusion constant in your firmware or Gcode. Because you have noted that the extruder drive is reversing every few seconds, that probably means it is not slipping. It could mean that the extruder motor is not operating at high enough current (torque). Probably some others that aren't coming to mind. I don't know what manual control options you have with the UM2. You could test for the first couple failure modes above by the following: If possible, I would preheat the nozzle, run the bed down, release the extruder drive and try to extrude some filament by pushing it through by hand. If you've done this with UM1, it should be about the same resistance - maybe a couple pounds of force. You could try an even higher temperature. As I said, I have no direct experience with the UM2. Hopefully one of these tips will lead you in the right direction. Someone from UM with hands on experience should be along in a few hours to elaborate and help narrow it down. Best of luck Matt

For mine, I am using a piece of heavy thread that's wound tightly filling the groove and tied off.

You need one of these. It will also help your results when using retraction since it takes the play out of the bowden tube. http://www.thingiverse.com/thing:22851 I tried to see if there was a version of it on Youmagine, but I went to the home page - and there is no search button! edit- I didnt want to link to Thingiverse again. I went to the YM home page and I was surprised to find no search button on the home page. I guess I was too easily discouraged so I went and found the link on Thingiverse. I did later find search from one of the secondary pages. It might be better you could search from the main page

You can prime the print head manually before starting a print by turning the big gear by hand until you get a consistent extrusion. When I do this, I try to cut the oozing stringer off at the nozzle as the print head traverses to the start point of the print. I use an opened scissor or screw driver or exacto knife - whatever is handy. Just stay out of the way. Another thing you could try is to enable the skirt function. If you have skirt turned on, priming the extruder manually is maybe redundant. Skirt will print a single layer thickness 'border' around the bottom of your print at width you define. This will normally be 6 or more concentric loops starting away from and ending at the outside shape of your part. Since its the first layer, it prints the skirt on slow speed and give ample time to establish a properly primed head (and properly adjusted Z screw) before the part is started.

For sure!

You need to depress the collar toward the fitting. Then a firm pull should remove the tube.

For about $2 you could pick up a piece of 3/32" window glass cut to fit on your acrylic bed. Mask it up with blue tape and binder clip it to the acrylic. Bump your Z switch up and level to the new surface. Better, get 2 or more panes so you can swap them out. As noted, the acrylic isn't really flat, so there might be some risk of breaking the glass - but hey, its cheap. Worse, the glass may teater, but it should be easy to shim it up with something. In the states, Lowes will cut glass to size for you. No need for tempered glass. I'm running plain wndow glas on my HBP.