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People building or using RepRaps.
Re: Closed-loop stepper controller progress - 11 years ago
Let me get this straight: This is a bolt-on closed loop control upgrade for any Pololu driven machine with steppers that have a shaft out the back? Higher speed and acceleration with position errors continuously corrected? Can the encoder be mounted elsewhere, for steppers that don't have a shaft out the back? I think most people have single-shaft steppers. Any chance we could print our own housby Dale Dunn - General
Re: Prints with ABS have a corner curling, same corner every time - 11 years ago
If it always makes a layer change in the same place, ooze will cause an overextrusion problem there. Retract will help, as well as other anti-ooze strategies.by Dale Dunn - Printing
Re: Introducing the ramps 10 - "Ramps10" an open source multi-configurable stepper controller shield based on the Ramps 1.4 design. - 11 years ago
Very interesting, and looking great. Just what is needed for researching more hardware permutations. Sorry if this has been asked already (I looked but didn't see it), why develop for Sprinter and not Marlin?by Dale Dunn - Developers
Re: Can I use a different z axis threaded bar finer than 1.25 pitch - 11 years ago
M5 has been common to Prusa designs for some time now. It's a much finer pitch, but the nice part is that it's the same diameter as the motor shaft. You can make a coupler with just some tubing and zip ties. Being thinner, it's also less likely to contribute to wobble.by Dale Dunn - General
Re: Motor Screeches - 11 years ago
My Prusa with M8 Z axis threaded rods is using F7800 from Slic3r, but I'm not sure if my firmware is really allowing that. I used to go a lot slower, but I put some effort into removing all binding and drag. Try going slower anyway, or see what happens without a load on the Z axis. Going slower won't hurt anything other than giving your nozzle more time to ooze. Hmm... I can't seem to find the seby Dale Dunn - Printing
Re: Z-Axis Homing difficulties - 11 years ago
The rule is to think of the tool's motions from the perspective of the table. If you don't keep that perspective, it can seem that some machines move opposite from others, depending on whether it is the tool or the table that is actually moving. Sitting on the table, Y+ is the tool moving to the back of the machine, and so on. That would be the table moving forward in the machine, or the tool movby Dale Dunn - Firmware - mainstream and related support
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
I'm not sure I understand your concern with the number of contact points. Do you mean that there will probably not be significant saving in rotating mass do to the number of bearings?by Dale Dunn - Tantillus
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
Dale Dunn Wrote: ------------------------------------------------------- > My brain seems to have been integrating the last > couple weeks during this morning's shower. It > occurred to me that the pen plotter's Y axis (the > travelling beam) would be a viable Z axis drive > that wouldn't have required the shaft across the > bottom of the machine. I imagine you already > thouby Dale Dunn - Tantillus
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
Well, this is awesome. Just drop an idea, and watch you all amplement it for me. Oh wait, I'm missing all the fun! I need to get started on my own build.by Dale Dunn - Tantillus
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
My brain seems to have been integrating the last couple weeks during this morning's shower. It occurred to me that the pen plotter's Y axis (the travelling beam) would be a viable Z axis drive that wouldn't have required the shaft across the bottom of the machine. I imagine you already thought of that, but I wanted to record the idea here.by Dale Dunn - Tantillus
Re: Newbie with a lot of problems on repstrap - 11 years ago
What do you have, and what's working so far?by Dale Dunn - Printing
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
I didn't get at first that the two cables are for X and Y separately. I didn't take the time to carefully trace out where the cables ran. Plain as day, now. The only thing I don't like about it is the fact that the Y axis has to move more mass than the X, and I don't think it can be made lighter than either axis of the Ultimaker arrangement. However, acrux's arrangement could much more easily aby Dale Dunn - Tantillus
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
Nicely triangulated frame... It looks like one cable is used by the two steppers to control X/Y movement, with the second cable preventing skew of the moving beam. Nice. I don't really trust CoreXY to get that done. Do you find that position is repeatable over extended periods without having the cable anchored to the spools?by Dale Dunn - Tantillus
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
Sublime Wrote: ------------------------------------------------------- .... > If you are talking about it dropping when the > power is turned off you could go to a worm drive. Some brainstorming on that in his G+ post.by Dale Dunn - Tantillus
Re: Smooth rod straightness requirement, how straight ? - 11 years ago
The rods need need to be straighter than the minimum clearance between the bushings and rods for each pair of rods on an axis. If the rods are bent beyond that, you can at least try to make the bends parallel to get the curvature Traumflug describes. After that, the straightness requirement is a matter of what you can tolerate in your builds. Keep in mind, bent X and Y axes will cause bed levelliby Dale Dunn - Mechanics
Re: Holes and gaps on top! - 11 years ago
You need more solid layers on top, or a slicer that can recognize the need automatically.by Dale Dunn - Printing
Re: Print Head bouncing over previous print on the same level - 11 years ago
My first thoughts are lost steps during the Z move, or extruding far too much plastic on the first layer.by Dale Dunn - Slic3r
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
No flex. Excellent. I'm looking forward to seeing this thing moving.by Dale Dunn - Tantillus
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
jimjimma Wrote: ------------------------------------------------------- ... > Greatly appreciate the feedback btw, thanks! You're very welcome. Until I get the time to do this myself, I can only indulge in armchair engineering and telling other people what I think they should do! I'm envious of you, actually getting it done. This arrangement of bearings looks pretty good. Short of some expenby Dale Dunn - Tantillus
Re: Upward curling corners / sides? - 11 years ago
Looks like you're extruding too much plastic. I've forgotten how to adjust this in Skeinforge. After you've done E steps/mm calibration for the firmware, there is an extrusion multiplier that is basically a fudge factor for whatever it is that causes the calculated flow rate to be different from what's deposited. I'm currently using Slic3r, which is much easier to use than Skeinforge (and enormoby Dale Dunn - Printing
Re: Printing large slablike pieces in ABS - 11 years ago
I don't have FreeCAD handy right now (a screen grab would help), but ABS is going to warp. If you get it to stick to the bed, sometimes it even pulls layers apart. A heated chamber is the only universal cure. For individual parts you can try printing other orientations, or design in features that break up the layers. Or print the part in PLA if that material is acceptable.by Dale Dunn - Printing
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
Well, that certainly gets rid of the cantilever loads on the bearings. I don't trust a single bearing per shaft to keep the platform level though. I think it would work better with 2 rods and 2 bearings per rod, separated some to help them resist the forces of offset loads on the platform. If you think about a moment load on a single LM10, the forces on the shaft are sort of focussed* on the ballby Dale Dunn - Tantillus
Re: ProtoForge printer - 11 years ago
It will only move in a negative direction? That's usually inverted end stop logic. Change the wiring to the end stops, or find the relevant setting in the firmware. I know Marlin is capable of inverting endstop logic.by Dale Dunn - Developers
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
I just read about a new design in another post with a Z axis similar to what I was proposing. The ProtoForge uses screws instead of belts, but the idea is very similar. He links to a video with a demonstration of the Z axis, and it looks quite solid.by Dale Dunn - Tantillus
Re: New machine build - block and tackle style belt drive for z axis? - 11 years ago
I see a combination of two problems. This will exert more force (by a factor of 3:2) on the end of the gantry to which the belt attaches, and it relies on bearings that may be widely separated to keep the gantry level. So, I think it will pull one side of the gantry higher and bind the bearings. Have you seen the belt arrangements on some of the Tantillus variants?by Dale Dunn - Mechanics
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
jimjimma Wrote: ------------------------------------------------------- > Took me a while to work out those diagrams but I > get you and it's not too dissimilar than an > approach I was considering. The problem with > separating the belts to either side of the chassis > the that I’m only using a 5mm shaft between the > pulleys and at a 450mm span, I suspect it might > have toby Dale Dunn - Tantillus
Re: Y slip but then again not - 11 years ago
You need to turn up the current on your steppers a bit. The frequency response of the printer's frame sometimes creates higher loads on the steppers than the programmed acceleration limit.by Dale Dunn - Printing
Re: 3 bushing configuration formula - 11 years ago
If the rods are spaced correctly and parallel, it shouldn't matter much where the belt is relative to the bushings. Near the rod with 2 bushings is best because it minimizes the loads on the bearings.by Dale Dunn - Mechanics
Re: golemD released! - 11 years ago
Is there any difficulty holding temperature in the chamber with the slots down the sides?by Dale Dunn - General New Machines Topics
Re: Variant of Goopyplastic's Tantillus Variant - 11 years ago
What if the Z belts and rods were moved to opposite sides of the platform? Instead of being at the back edge of the platform, they could be 1/4 or 1/3 of the platform depth away from the rear. The weight of the platform should still keep it hanging on the same side of the rods, but the bending moment on the rods would be immensely reduced. Attempted ASCII art follows. Belts are ":", and rods areby Dale Dunn - Tantillus