Show all posts by user
Anything related to printer controllers not being Duet, RAMPS or Sanguinololu: microprocessors, motor and heater driver circuitry, gEDA/KiCAD issues, soldering tips, etc.
Re: P3Steel - 10 years ago
I would take a look at some of the laser cut wood designs as well as that one. I'm not suggesting doing a wood design in steel. I'd just make sure that the features are all there....by uncle_bob - General Mendel Topics
Re: Circles Quality - 10 years ago
Never ever rule out a slicing error. I'd check it with another slicer. Are you running a heated bed? If so, how hot? What kind of filament are you running? How hot are you running your hot end? How fast are you printing? Are you printing a skirt? If not, I'd try it.by uncle_bob - General Mendel Topics
Re: Best Direct Drive or Geared Extruder Mounted to Effector for Delta Printer? - 10 years ago
What kind of delta printer are you looking at? Most are designed for very low weight on the effector. Even with a direct drive, you still (probably) need some sort of filament feed tube into the extruder.by uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
Quotenicholas.seward @uncle_bob: Won't you have carriage interference if you mount bearings in the middle? Yes indeed you would have interference. That's a very real limit to how high you could put the bearings. I'd have to do some modeling to figure out how high they can be (or if it makes sense at all). My motors are pretty tall. The same issues may apply to mounting them above the build plby uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
Bearing mont: Right now my *guess* on the mount is a printed part. The bearing is captive horizontally, but free vertically. It rests on a (hopefully large) washer (or two). The washer is also captive horizontally and free vertically. The printed piece mounts to the plywood with the four bolts that also hold the motor in place after the bolts go through the spacers. Bronze nuts: The nuts areby uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
Bronze nuts for the Hi-Lead screws came in today. No screws to try them on yet. They are bronze colored and heavy, beyond that nothing really useful to report about them. Hopefully the screws will get here soon.by uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
If the arm is going to be able to drop straight down, the other two arms need to be a bit longer. More or less the arms get into the 1X rod spacing rather than 2/3 spacing vicinity. That either costs you build height or makes the machine taller. To be same / same I think you need to compare equal build heights. The same is true of the straight line vs offset arms. Loosing ~ 2" of build diameteby uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
slop: The other driver for the metal shaft on a large printer is to drop the hub diameter. If you scale everything up, the hub gets fairly large. sunken build plate: One concern would be sinking things far enough that getting the part off the machine would be harder. If you printed a "thing" that completely filled the build volume, tilting it to get it off only would help to a certain degree.by uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
Multi plate approach: I'm probably missing something very basic about mounting the motors and bearings. My approach is based on NEMA-23's and putting the bearing on the plate that's above the motors. The bearings should be small enough in O.D. to fit inside the bolt pattern on the face of the motor. Drop a few hollow spacers between the motor face and the board above it. Put bolts through the mby uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
If you are using 608's and you have 4 bearings in the stack, that would use up 28 mm of your 40 mm. A thin 8mm nut will add 2.7 mm. You are down to about 9.3 mm for spacing and what ever you are attaching to on the bottom of the stack. These guys: ? Will sell you 5 pcs that are 60 mm long for only $97.07..... These guys go to 50 mm for $15.19by uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
Speaking of discoveries: I have found a source for pretty good plywood with thickness options of ¾, 1, and 1 ½”. The stuff isn’t exactly cheap. My guess is that on a 2X larger printer, ¾ by it’s self isn’t going to do the for the horizontal plate in the middle of the stack. It *might* be thick enough for the top or bottom plate in the stack. I’d also bet that 1.5” is thick enough by it’s self foby uncle_bob - Delta Machines
Re: Offsets in configuration (again) 
- 10 years ago
Is your height goal a print height or the machine height? The bigger you make the horizontal area, the more vertical area that gets used up by the arms. I would suggest targeting a build height if it's an overall height.by uncle_bob - Delta Machines
Re: Magma Hot End w/ Marlin v1 - 10 years ago
There are some new (possibly pre-release) versions of Marlin out from MakerFarm. In the ones I have, he's moved his custom thermistor tables over to 96 and 97 rather than replacing the stock thermistor table 6 with one of his. Check on the site to see what the latest stuff looks like. ---------------- Get a 12V 30A industrial supply. It will take care of a lot of your issues. is a name braby uncle_bob - General Mendel Topics
Re: Help! Prusa i3 Hotend Snagging on Prints - 10 years ago
Depending on the filament vendor and the type of filament I run anywhere from no retraction to a 1 mm. In some cases I do a 1/4 to 1/2 layer raise on the Z. I have never seen an extruder stepper stall out. That's with the standard MakerFarm motors and drivers set to the standard Vref's or to 1/2 the standard Vref's. If you have wet filament, you need to dry it out .... there's no way to get coby uncle_bob - General Mendel Topics
Re: Confused by the electronics - 10 years ago
With the non-Ramps boards you need to be very careful about exactly what you want to (and don't want to) do. Things like auto bed leveling servos drop right into a Ramps. They don't drop into all of the other boards. You also can't do 4 extruders, two heated beds, and six independent axis with a Ramps, so there are always limits.by uncle_bob - General Mendel Topics
Re: Shorted Out Stepper Drivers - 10 years ago
There is very little on the Ramps that can fry. The diodes are about the only thing you are likely to have nuked. The stepper modules can indeed fry and they should be checked one at a time.by uncle_bob - RAMPS Electronics
Re: Rambo PID Autotune Fails - 10 years ago
Auto tune starts at a given temperature and runs up and down from there. If you start to high, it will go over the max temp you have programmed into your firmware. The code for the auto tune does not know anything about the max and min temp limits.by uncle_bob - RAMPS Electronics
Re: Very quick question about how to power Arduino WITHOUT USB connection. - 10 years ago
If you use a piece of wire instead of a 2 cent diode, you will fry the regulator on the Mega the first time you power it from USB without the +12 powered up. If you never ever plug the USB cable in with the +12 missing, all will be well.by uncle_bob - RAMPS Electronics
Re: Help with sticking stepper motor - 10 years ago
Keep in mind that the OP's comments are now 4 years old. I suspect they have worked out their issues by now ....by uncle_bob - Controllers
Re: LISA Simpson - 10 years ago
The stepper motors and the rest of the "stuff" will add to the ballast. I can always add more if I need to. I'd prefer to keep this light enough to move up and down stars if possible. That may not be practical. I've been fighting the moisture effect on plywood with my current printer. Turn on the heated bed and two days later you have a potato chip where you used to have a flat surface. The heaby uncle_bob - Delta Machines
Re: RAMPS for Due! - 10 years ago
Quotefirehopper never mind hopefully.. my package has been found in philly.. what the heck is it doing there.. now its in harrisburg.. .... speaking of these ramps-fds. anyone got a spare one in the usa? I ordered one on 12/02/13 and it made it to a town 50 miles away on 1/2/14, and then it seems the postal service lost it. and I really dont want to order another one from china. since it toby uncle_bob - Controllers
Re: Prusa i3 Electronics - 10 years ago
Start with the simple and get it working. Figure out what's going on with the base configuration. None of the electronics are all that expensive. Ramps & Mega work fine. They are easy to tweak. Micro switch end stops are easier to get going than the alternatives. If you replace them later, you are out the $4.50 you spent on the set of 3 of them. Trying to optimize this stuff to the last peby uncle_bob - General Mendel Topics
Re: Inconsistant Calibration - 10 years ago
Belts and gears are not perfect. Even if they are perfect, they don't match each other perfectly. Next you have backlash and after that stretch. Somewhere down the list you have bed level and issues with each axis being at 90 degrees to the others. Blink a few times / change the room temperature / bump the printer and things will change.by uncle_bob - General Mendel Topics
Re: Help! Prusa i3 Hotend Snagging on Prints - 10 years ago
I'm running a MakerFarm i3 with their J-Head part of the time and their Magma the rest of the time..... The only time I see anythig strange, it's because I'm extruding to much filament. As long as the extrusion is set up right, nothing bumps or bashes.by uncle_bob - General Mendel Topics
Re: Internal Holes too small in nearly all Slicers - 10 years ago
Small internal holes have been an issue with all of the slicers for a *long* time. There are a lot of threads going into the why's and the what's of the issue. Bottom line - nobody has fixed it yet on any of the programs. Until there’s a demonstrated working solution it’s hard to be sure that all of the issues are known.by uncle_bob - General Mendel Topics
Re: Spool Holder - off machine - 10 years ago
On most designs the filament feeds into the top of the extruder. You want some friction on the feed, but not a lot. To much friction and you start tipping the extruder. To little friction and you have way to much filament unwound. That leads to tangles. To me the logical location for the spool is directly over the extruder. I've tried it off to the side at table level and had lots of tangles. Iby uncle_bob - General Mendel Topics
Re: LISA Simpson - 10 years ago
The plate I'm looking at is a 18.6875" diameter 1.25 thick cast aluminum tooling plate: It's already nice and round so it will drop right in. At this point the heater is just a check mark on the list. I'm not real sure it will be part of the initial build. The main component of the horizontal structure is still ¾” plywood. I have not settled on an exact lay up yet. I’m not planning on usinby uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
This looks like a pretty good footprint. The drive shafts are blue, the supports red. Plywood is yellowish green. Print plate is green, print area is black on top of the green. This one fits through the doors. The print comes out of the inside no problem. The print area is almost the same as the plate. Supports are well out of the way. Looks like a winner.by uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
The whole process is one where you convert this or that either to the speed of light and flight time or to phase error on fringes. To do the phase error stuff you already need to know where you are within one wavelength or it's ambiguous by that amount. Simple answer - no free lunch. The tighter you want the accuracy to be, the more complex it gets. There is a TI chip that will get you sub nanby uncle_bob - Delta Machines
Re: LISA Simpson - 10 years ago
Precision laser distance measuring involves a beam splitter a modulator and a detector in addition to the laser source. You use the reflected signal as a "resonator" in an oscillator. The period of the oscillator compared to a very accurate source gives you a distance. At < 200 mm sort of distances this gets a bit complex. The delays in the electronics begin to creep into the equation. That'sby uncle_bob - Delta Machines