I was wondering what the minimum recommended pulley size is for the steel core belts. I assume it's bigger than for the glass cores.by JamesK - CoreXY Machines
QuoteLykle Another way to get the part to release easily is to freeze it with Freeze spray. That's a cool idea. Sorry, couldn't help myself. I should get myself a Feeze can, embarrassed to say I haven't owned one in probably 20 years. Not doing as much electronics as I used to. Fortunately I'm not having too much trouble getting parts to release now that I've dialed in the first layer temperatby JamesK - General
That's interesting, petg is normally pretty dimensionally stable during printing. I do generally print it on the slower side though, at around 30mm/s (but I have a rather slow printer), so I guess we wait and see how your current print turns out.by JamesK - Printing
What sort of plastic are you using? If it's ABS you may find it difficult to print that shape in a single wall without a heated enclosure. PLA should be easier, or PETG if you need more temperature resistance.by JamesK - Printing
Good quality filament, or no-name budget stuff? Black is notorious for being the dumping ground for waste plastic, because you can hide all manner of evil with that black colorant.by JamesK - Printing
From the video, it looks like your model is not manifold.by JamesK - Printing
QuoteDjDemonD The signal generated by a sensor squeezed between two flat surfaces is 100 times smaller than when you bend it. That isn't necessarily an issue, provide there's still enough signal to reliably detect it against the noise. A smaller signal and more gain on the detector might be a reasonable trade-off for a simpler physical design. The original tests I did were with a piezo elementby JamesK - General
I guess polycarbonate is the highest temp of the 'common' filaments? Haven't tried it yet.by JamesK - General
QuoteLykle I was thinking of adding a torsion spring to keep the cam closed, not sure if it is needed. Simple add. Typically not needed, just make sure that the off-centre axis is placed so that the closed position is just past the maximum diameter. Then you get over-locking such that extra force has to be applied to open the cam.by JamesK - General
Ah, great, glad you got it sorted. I haven't used marlin for a while, so I was going to struggle to helpby JamesK - Printing
Drat, I think I'm going to have to search the forum for tips on bridging. I can't print that part very well at all.by JamesK - General
QuoteSupermec The brain slipped out of gear in my last post, seems to be happening a bit lately (must be getting old). I know that feeling oh so well. Quote I should have said that the Anets happily drive two Nema17 type motors with 8mm lead-screws in parallel off the same A4988 stepper driver . I have a slightly different config with two 8mm lead screws driven from a single motor via a belt fby JamesK - Printing
I like that idea of inserting a piece of belt to cross the join - very clever!by JamesK - CoreXY Machines
What's a "LR7843 stepper driver" ? I can find a mosfet with that number, good for 100+ amps at 30V, so if it's a driver which uses those as external mosfets then I can see that not having too much trouble with a couple of nema17s There are lots of printers that drive a pair of nema17s with a single pololu style driver, but it is quite possible to run into the current/heat limits in that config.by JamesK - Printing
Stinkhorns, genus phallus. How apt.by JamesK - General
Quotedoublehelix I think it would be also possible to use one free extruder port to power a second motor for the z axis, in that way I could run the two motors with 0,6V each right? Is there any disadvantage e.g. unsynchronous movement between these motors? Yes, that should also be possible, although I haven't tried it. I'm pretty sure I've seen the support in repetier-firmware and I suspect it'by JamesK - Printing
Quotedoublehelix Yes you are right, I'm using 2 motors, but just on one driver, so the 2 motors are parallel to one driver on a rumba board. So I should double the voltage as you suggested, e.g. 1.2V? Yes, but be aware that the driver will be working hard and might over-heat unless you have a fan cooling it. You may need to find a compromise settingby JamesK - Printing
Quotedoublehelix I have conucon M 1717 stepper motors and drv 8825 drivers set @ 0,6V which equals to 1,2A so 70% of the 1.7A. Hi Herb, you used plural for both motors and drivers, is that accurate? i.e. you are using two stepper drivers and two motors? I ask because the more common approach is one driver running two motors, and then the question arises as to how the motors are connected to theby JamesK - Printing
Quoteprot0typ1cal One observation, doesn't look like there's adequate wedge to cam clearance to remove the hot end. A larger cam may be required. Isn't that why there's a flat on the side of the cam? Looks great to me. I made a metal dovetail recently that I'm hoping to use for fine vertical adjustment for leveling dual extruders, but it doesn't have any quick release capability. It's also a biby JamesK - General
Quoteleadinglights Air from the aquarium pump is blown through a stainless steel tube which is heated with a propane torch and fed to the air ring. Great test! I'm surprised but happy to be shown to be wrong Quote Unfortunately this experiment was curtailed when the burning wood started coming out of the air ring ... As it is too cold in the workshop to do much more... I think you nearly founby JamesK - General
Quoteleadinglights The only way to be sure it to try it so at the first opportunity I will be blowing smoke through my ring That gave me laughby JamesK - General
6 months seems pretty reasonable. Clever idea to include a pry-notch into the design.by JamesK - General
Yes, that's the hope. Turns out to be very difficult to get a ring shape that fits in the space available and actually provides even cooling, which is why I gave up and went to the fork shape. I hear good things about the cobra design: I haven't tried it - my setup is very nonstandard so I'm pretty much forced to do my own thing. There's an interesting thread exploring some different approachby JamesK - Printing
I use ceramic fiber insulation which you can buy quite cheaply in sheets, e.g. I cut out a box shape and then hold it in place with kapton tape. It is a bit fiddly, I admit! An easier alternative is to buy smaller strips and not worry about the sides, e.g. Kapton tape on it's own is probably better than nothing, but you need something with a bit more bulk to really improve things. The downby JamesK - Printing
The print cooling fan isn't an all or nothing deal, you set as much as you need to get the job done. 50mm blower fans produce a lot of air, with a fairly open duct like you have, positioned as close as that, you will probably only need to run between 15 and 30% of max rpm. Conventional wisdom is not to use a part cooling fan with abs as it encourages delamination. However, I think there is someby JamesK - Printing
Isn't that strange. I don't think it's the bed temperature that's affecting the adhesive since when I print abs I've used set temps up to 120C which probably gives me around 100 at the surface. I'm guessing that the glue is just inherently not that strong, and I've been lucky not to get a part so badly stuck that the force needed to get it off separates the glue. If it was parting between the gluby JamesK - General
Based on recent experiments, I think the slot needs to be narrower compared to the tube diameter. I made some printed rings similar to what you have done, and all the air escaped from the side nearest the air inletsby JamesK - General
Ye gods, the idea of that thing swinging around the kitchen with a laser attached is terrifyingby JamesK - General
For any extruder temperature oddity, it's worth checking the crimp connections between the solid core wires from the cartridge and the multi-strand used for the bulk of the connection. I've had multiple heaters with intermittent connections that were easily fixed by re-crimping.by JamesK - General
After mentioning that I had trouble ordering from McMaster-Carr LoboCNC very kindly sent me a sample of their adhesive backed polyester sheet to try as a possible printing surface. The stuff is cheap (roughly $3 for 27x20 inches) which makes it attractive for the new large bed printer I'm working on - kapton gets a bit expensive as the area goes up, let alone pei or other exotic surfaces. Howeverby JamesK - General