Show all posts by user
Everybody here is a developer. Share what you are doing !
Re: 3 points levelling system - 6 years ago
More points are better if the bed is not flat to begin with, or if the bed is thin enough that it will sag without the additional support. The i3 design is pretty whacky/efficient because the Y plate and the bed are often of similar rigidity, so leveling or straightening the bed also deforms the Y plate. This means that leveling your bed will actually bind the linear bearings unless they have eby 691175002 - General
Re: CoreXY stepper spacers... - 6 years ago
In most cases the spacers are essentially loose and do not contribute any rigidity so the material is irrelevant. McMaster has spacers in a wide variety of materials and ODs, but I generally prefer the misumi series of part numbers when available: Misumi has one OD per screw size but provides unified sizes across all three materials and is cheaper. They also have matching part numbers for m/fby 691175002 - Mechanics
Re: Meanwell Power Supply - 6 years ago
From what I can tell you need to apply 5V between PV and -V from an external source, but the datasheet is fairly vague.by 691175002 - Mechanics
Re: Is there a 3d printer that has a 4th axis head? - 6 years ago
Its a software problem, not a hardware one. The slicer would have to become manual/interactive because there would be an infinite number of ways to slice any model. You are also overestimating the versatility of a 5 axis printer, because the nozzle and extruder assembly will interfere with the part (and bed) if you try to do anything clever. Something like soluble support is cheaper, easier, aby 691175002 - General
Re: E3D's tool changing CoreXY design - 6 years ago
I'm not a huge fan of toolchanging because it is such a large and complex feature, which reduces the number of options you have in terms of heating the build chamber, layer cooling, wire management, etc... Its also expensive enough that IDX or actuated hot-ends look competitive for two nozzles, which is often enough (especially if you have a bowden splitter). Direct drive extruders still ooze qby 691175002 - CoreXY Machines
Re: Linear stepper motors - 6 years ago
The holes will certainly reduce motor force, but that doesn't guarantee it will lose steps. The H2W 0602 forcer requires 18mm wide teeth to generate 10N of force. I assume that their rail is appropriately sized, so we can assume that a 15mm wide rail can generate ~8N and the 9mm sections around the holes will do ~5N. Of course a hole only affects one half of the forcer, and only reaches its fuby 691175002 - Stepper Motors, Servo Motors, DC Motors
Re: GT2 belt types - 6 years ago
Fiberglass and steel belts have very similar elastic modulus. Steel is generally preferred for shock resistance. As far as I am aware Gates does not make steel reinforced gt2 or gt3 series belts. Page 12 Its hard to make any claims about timing belts because until you spend $$$ you don't really know who made the belt/pulleys or if they are even the correct profile.by 691175002 - General
Re: Linear stepper motors - 6 years ago
The most difficult part of the project will likely be finding appropriate rail and cutting grooves in it. I think you might end up needing one of the back-mounting variations (ex: ) because hole counterbores in standard rail might cause issues. I'd probably try to quickly rebuild the existing forcer with new wire and magnets so you have something to test the grooved rail against. No need to pby 691175002 - Stepper Motors, Servo Motors, DC Motors
Re: CoreXY - 6 years ago
Quotekapperi That is rhe most expensive profile what I have seen... 50 dollars per meter, that cannot be true... Which profile are you looking at? HFS5-4040 is $15.40 per meter, and prices include cut to length at no additional cost with near flawless accuracy.by 691175002 - CoreXY Machines
Re: Linear stepper motors - 6 years ago
Quoteklcjr89All the chiwin clones I've had in MGN series are definitely steel and not stainless. Only the Hiwin's are stainless perhaps? The Hiwins are stainless, I'm not sure about the clones: Maybe do a test run with Chinese rail; but if you are going to go through the trouble of cutting grooves I feel like you might as well use high quality rail. Misumi offers their MGN equivalent in bothby 691175002 - Stepper Motors, Servo Motors, DC Motors
Re: Linear stepper motors - 6 years ago
You are primarily concerned with magnetic permeability, which is why soft iron or electrical steels are often used. In my limited experience its nearly impossible to buy the fancy stuff, so most hobbyists default to durabar or the usual steels. Modifying a linear rail is a very interesting idea. I think you might have to stay away from the MG series of rails though, as they are stainless. Tby 691175002 - Stepper Motors, Servo Motors, DC Motors
Re: Linear stepper motors - 6 years ago
If I had to make these I'd probably try to get someone to cut the teeth in 1/8 to 1/4" plate and then laminate a few together to achieve the desired width. A laminated stator will perform just as well as a solid one. The tooth size is probably slightly too small for waterjet but its possible laser could do it. If you work in a commonly used material these processes can be fairly cheap, and youby 691175002 - Stepper Motors, Servo Motors, DC Motors
Re: Better, finite-jerk acceleration? - 6 years ago
Jerk (and often further derivatives of acceleration) are often implemented in higher quality servos/motion controllers. There is quite a bit of information on jerk contro applied to CNC machining. If you have trouble conceptualizing jerk, imagine holding a 5lb weight in your hand and having someone slowly take it from you, versus having the weight disappear. In both cases the force has gone frby 691175002 - General
Re: Z axis gantry vs Z axis printbed - 6 years ago
I view moving bed vs moving gantry to be very similar, as I in practice I feel like the bed and gantry probably have similar moving mass. There are, however, a few drawbacks to a moving gantry. The first is of course that side forces now apply through all three axes instead of only two; the second is that your bowden tube must become longer to accommodate Z travel. With a moving bed you can esby 691175002 - CoreXY Machines
Re: To twist or not to twist - 6 years ago
I also find it unlikely that toothed idlers degrade motion quality as the drive pulley must always be toothed. If toothed pulleys always cause a curtain effect then all timing belt systems must be doomed. Running teeth on smooth idlers will of course introduce some degree of vibration. At some diameter this will become negligable, but I prefer to avoid the risk myself. QuoteNope, it is a 15mmby 691175002 - CoreXY Machines
Re: New printer design with new 'twist' for XY on Z - 6 years ago
Virtually any ballscrew should be fine here. I remember the Chinese rolled screws being roughly a third of the price of Misumi's C10 screws, and have found them to be acceptable, so you could give that some consideration. Appropriate screw diameter depends on how they are being supported. The weak point is likely to be the connection between the base and the screw, so unless you have a good plby 691175002 - CoreXY Machines
Re: New printer design with new 'twist' for XY on Z - 6 years ago
Quoteklcjr89If you had the choice, would you go with a single stepper and a closed loop belt? The idea to initially 'level' each corner at first is to lower the XY plate down to where each corner references the bottom Mic-6 plate (use a 123 block or similar), and then at this moment you tighten each pulley to the ballnut with a set screw, keeping synchronization. That's a hard question to answerby 691175002 - CoreXY Machines
Re: New printer design with new 'twist' for XY on Z - 6 years ago
Three screws will be easier to align than four screws but I agree that it would look a little weird. I would probably go with four screws myself. You can find standard belts in 2m+ lengths if you go up to the ~3mm pitches, but I wouldn't immediately discard the idea of using four steppers. The steppers will only be moving in Z so their weight is essentially irrelevant. Its the moving mass onby 691175002 - CoreXY Machines
Re: New printer design with new 'twist' for XY on Z - 6 years ago
The planer is a different application because its only concern is its Z height, whereas a 3d printer needs to be precise in all three axes. If you have the planer handy you can try pushing it sideways to see how it reacts. I wouldn't be surprised if the wood planer has measurable side-to-side movement, because in use you expect the force to come from only one direction. Another way to think abby 691175002 - CoreXY Machines
Re: New printer design with new 'twist' for XY on Z - 6 years ago
I edited my post with a few more details. The side-loads on a 3d printer might be small, but you are still looking at maybe 200-400g of acceleration depending on the speed and extruder being used. If you put that load on the very end of a 500mm rod that is only being held by a tiny section on one end it will still bend quite a bit. For example here is an extremely rough FEA where I modeled theby 691175002 - CoreXY Machines
Re: New printer design with new 'twist' for XY on Z - 6 years ago
You need some way to keep the shafts vertical, pressing them in wont provide enough resistance to side loads and your printer will fold like a parallelogram. The design is very space efficient, but supporting your linear shafts on only one side will cost a lot of rigidity. TBH the math doesn't look great even with 20mm shafts. Quoteklcjr89 Are you saying to add a 1/2" top plate and connect thiby 691175002 - CoreXY Machines
Re: Ball Bearings... - 6 years ago
The cheap guides are manufactured separately then assembled without adjustment, which is why they are interchangable. More expensive guides are measured and parts are chosen or adjusted to match. Your balls are almost certainly 3/32" = 2.38125mm because the Chinese should be using standard sizes to save costs. Its hard to measure balls with calipers since the jaws will rack, you really need aby 691175002 - Mechanics
Re: Ball Bearings... - 6 years ago
There isn't really any reason why you would want to replace balls with new ones of the same size. If your existing balls are damaged the rest of the bearing surfaces are almost certainly trashed as well. The interchangeable series of linear guides and ballscrews generally use nominal balls which can be replaced without issue. Hobbyists sometimes measure the play in Chinese 1605 ballscrews thenby 691175002 - Mechanics
Re: New Printer Design - 6 years ago
QuotedeckingmanSo on the one hand you say this.............. At low accelerations the printer must slow down at every corner. This slowdown is difficult to synchronize with the extruder because the melt chamber and general compliance acts as a low-pass filter. At high acceleration the printer can pass through the corners more quickly, so extruder synchronization becomes less important. At extby 691175002 - CoreXY Machines
Re: New Printer Design - 6 years ago
QuotedeckingmanThe other big factor is that there is no way on God's earth that you could accelerate the melt rate and extrusion of the filament at anything like those speeds. If you try, all you'll get is a pressure pulse but the molten filament won't accelerate out of the nozzle as fast as the print head, so you'll get under extrusion at the start of every move. At infinite acceleration the prby 691175002 - CoreXY Machines
Re: New Printer Design - 6 years ago
I wouldn't be worried about tooling plate flatness. You can't generate a meaningful temperature gradient because it will take 10+ minutes to heat and has very high thermal conductivity. I think you are underestimating the difficulty of achieving high accelerations. Acceleration is generally limited by the frame, not by the motors, because as you have noted it is quite easy to buy a larger motby 691175002 - CoreXY Machines
Re: What Do People Want In A CNC? - 6 years ago
QuoteTrakyan3d Printers really spiked in popularity after machine costs fell into the several hundreds, not several thousands, even if quality wasn't completely spectacular at the time. I'm looking to do something similar for CNC. I respect the idea here, but the low-end CNC market has been around much longer than the consumer 3d printer market, and is constrained by basic physical requirementsby 691175002 - General
Re: Cannibalize one hobby printer to build a "set and forget" machine. - 6 years ago
Quotethe_digital_dentist Does a proper bed really cost so much more than a crappy bed plus all the extra electronics and motors that enable it to be used? Does all that stuff result in a more reliable machine compared to one that has an actually flat and actually level bed? Most of the original 3d printer development was done by electrical engineers and software developers. When all you haveby 691175002 - Reprappers
Re: Gravity and Jerk, which is the greater force in 3D printing? - 6 years ago
Printing forces are more concerning than gravity, because the constant force of gravity won't produce visible artifacts whereas jerk produces ringing and other similar patterns in the print. I think the most important thing you can do is try to line up the center of gravity of the extruder assembly with the centerline of the rail. If the extruder sits too low or too high on the rail any movemenby 691175002 - Mechanics
Re: Nice and smooth - 6 years ago
They haven't done anything special to the prints in the pictures. If it looks smoother than normal, its because the pictures are low resolution and slightly out of focus.by 691175002 - General