Show all posts by user
Discuss any sort of mechanical stuff here: positioning systems, gears, extruding methods, etc.
Re: Missing corner - 10 years ago
Why isn't the M400 in the end code by default? Seems bizarre.by JamesK - Printing
Re: Can't start up an ATX PSU... please help - 10 years ago
Someone should make a board like that but with more pins broken out - both rails for 12v, 5sb and the ps_on pin would cover most rep-raps I guess. +5 and +3.3 to round things out, plus blade fuse holders for each line.by JamesK - General
Re: Uneven circles - 10 years ago
Sounds good, but I'd start by checking the axis moves freely. What micro-stepping are you using? This would be the classic case were the reduced per step torque could cause problems.by JamesK - Printing
Re: Uneven circles - 10 years ago
Sounds like the x axis motor is having trouble with small reversals. If you take the belt off does the x-axis move freely? Does the x idler turn freely? If yes to both of those, it might be time to try a new motor on the x axis.by JamesK - Printing
Re: 1 Meter bot project - 10 years ago
Looks amazing. Dumb question - what's the purpose of the block and triangle at the top of the printhead?by JamesK - General
Re: 1 Meter bot project - 10 years ago
QuoteSubsequent layers generally have similar toolpaths so deflection will have the same effect on each layer (effectively making it invisible unless you are getting resonance/ringing). That's exactly the question I was trying to thrash around in my head - thanks for expressing it better than I could. It's not clear that there's any fixed answer to what the accuracy should be as it's evidently gby JamesK - General
Re: Filament suppliers for Canada? - 10 years ago
Many thanks, that's good to know.by JamesK - General
Filament suppliers for Canada? - 10 years ago
Hi, the vague possibility that I might one day finish building my printer and start using it has made me consider where to get some filament. My current thought is to go with and I was wondering if any one has any experience to share? Any other places that are recommended?by JamesK - General
Re: I don't think Marlin is optimally coded.. and here's why - 10 years ago
What's the status of the RAMPS-FD boards? I seem to remember reading that there were problems with them - or maybe I'm confusing it with a different board. Is there an LCD+SD that works with it to give a complete replacement for a mega2560/ramps/lcd+sd setup?by JamesK - Reprappers
Re: 1 Meter bot project - 10 years ago
What's the thermal expansion across a bed that size? Will you need to allow for movement in the mounting hardware?by JamesK - General
Re: Top layer issues - 10 years ago
Oh - good catch, I missed that. Layer height should always be less than nozzle diameter.by JamesK - Printing
Re: Top layer issues - 10 years ago
Seems a bit unlikely doesn't it, but I guess if things are right on the edge them small changes can make a difference. The different filament is probably still the most likely explanation.by JamesK - Printing
Re: Top layer issues - 10 years ago
Quite a bit from what I've heard. I've even seen posts where people just used a desk fan pointing at the print to help with PLA overhangs and bridging. ABS has the opposite problem, it cools too quickly and tends to shrink and split. People build enclosures to try and control the ambient and eliminate drafts to help with bigger ABS prints. It's one of the oddities I noticed when I was looking atby JamesK - Printing
Re: Top layer issues - 10 years ago
Still pla or a different type? It certainly looks better.by JamesK - Printing
Re: 1 Meter bot project - 10 years ago
Oh my, that's looking very fine. I sure wish someone would sponsor me some linear rails !by JamesK - General
Re: Extrude more at start of line? - 10 years ago
Looks like Slic3r's extra length on restart setting might do what you want? It's under printer settings/extruder 1by JamesK - Printing
Re: Top layer issues - 10 years ago
Ah, the photo problems were mostly with google - when I tried to zoom in it snapped back to small size and tiled it for some reason. Now that I've downloaded it I can zoom to full size, much better. Now you need someone with more experience to weigh in, but from what I've read, the print cooling fan looks like it would be your best bet. If you don't have one, you could try a trick to allow more cby JamesK - Printing
Re: Top layer issues - 10 years ago
So the fill was fill_density = 10% fill_pattern = rectilinear and it looks like the print speed is about 40 or 45 (I can't remember how all the different speeds interact). You could try increasing the fill density to 30% or so and see if that helps support the top surface during printing. Do you have a fan that is directed onto printed material (separate from any fan that might be cooling theby JamesK - Printing
Re: Top layer issues - 10 years ago
What infill and print speed settings did you use?by JamesK - Printing
Re: Calculate torque to move printer components / microstepping - 10 years ago
QuoteThe high motor torque you have calculated is the result of specifying an unrealistic accleration (5m/s^2). Actually, exactly the opposite. His calculations suggested a rather low torque requirement when compared to what we typically use, leading to the question and discussions.by JamesK - General
Re: Calculate torque to move printer components / microstepping - 10 years ago
Interesting questions. I took the motor recommendations on faith without looking at the math. I'm guessing that the sizes used have been found to work well in practice. Connecting up the logic would suggest that the apparent over-spec correlates with several factors: reduced per-step torque due to micro-stepping, most motors are run well under spec to avoid heat problems, missed steps are reallyby JamesK - General
Re: Auto bed levelling... I think i am doing it wrong - 10 years ago
I doubt if bed flexing is your biggest problem unless you are printing really big heavy objects. More likely it is simple lack of flatness or lack of reproducibility in the Z probe. You could check flatness with a straight edge and a flashlight, the the behaviour of the Z probe by experiment.by JamesK - General
Re: Optimizing CAD designs for strength and filament consumption? - 10 years ago
It's a great idea and I'd love to see some sort of opensource tooling in this area. I'm not sure Voronoi is the ideal choice for FDM printers - the resulting shapes tend to be hard to print and don't maximise the benefits of continuous XY extrusion, but some form of stress analysis that could identify areas where material could be removed for minimum loss of strength would be neat.by JamesK - Printing
Re: minimum printer to build a printer - 10 years ago
It's an interesting question, and I don't know what the answer is. Build volume is often a major factor, it being a lot easier to build an accurate small printer than a large one. You could download the STL files for the printer of your choice and run through them to find the biggest part - that would determine the minimum build volume for your starter printer. Material would be the next questionby JamesK - General
Re: Auto bed levelling... I think i am doing it wrong - 10 years ago
Does Repetier's bed height map tool work with Cartesian printers or is it for Deltas only? It looks like an interesting way to visualize bed flatness (or lack of).by JamesK - General
Re: The BASICS for 1st Time - HELP - 10 years ago
Quoteand finally... Have a stiff drink! Hmm, I'm adding that one to my list of notes to self.by JamesK - Printing
Re: HELP!! Issues with printing with RoBo R1 (MatterControl, Repetier Host, Slic3r) - 10 years ago
There probably aren't many users of the Robo printers on this forum, and for some reason mattercontrol doesn't get mentioned much either. Better that people don't try and guess and possibly waste your time. I see you also posted on the Robo users forum - hopefully that will get you some answers. If not, I see Robo offers 24/7 support - seeing as you've paid your money you might as well take advanby JamesK - Printing
Re: Getting LCD To Work 
- 10 years ago
You need to uncomment either doglcd or the reprap_discount..., not both, they are two different LCD types.by JamesK - Printing
Re: Optimizing CAD designs for strength and filament consumption? - 10 years ago
Quoterealthor Now about the monocoque, a beam with 15-20% infill with the original simple design and with a number of shells on the vertical walls and a smaller number of shells on the horizontal front: is this what the general suggestion inclines to? The sparse infill will somehow resemble the monocoque in itself, would I need to add ribs myself within the structure? I would also like to get thby JamesK - Printing