Good reference sheet. For anyone interested, you could also copy this sheet and just dead key the moment of inertia for different geometries.by DRobs86 - Developers
It turns out that it was all mechanical. I had two more failures tonight. All because the machine lost steps going in the negative Y direction. The last failure was a complete lock of one side of my Y axis in the negative direction. I could physically push the machine in the Y+ but couldn't even push in the Y- direction. The set screw on the motor on that side had come out and was gettingby DRobs86 - General
I am running some DRV8825s on my home made CNC machine. I have two Nema 17s on each axis rated at 1.5 Amps. I am driving them close to that rating, probably 1.4 amps. I have heat sinks on the drivers but no fan. I have probably 30 jobs through the machine with no failures until this morning. I had two failures, in both cases it lost steps in the negative Y direction. The first time it seemedby DRobs86 - General
I'm going to be building a cnc machine with a 276oz/in stepper with a 6.35mm (1/4") shaft on the X axis. The total run of that axis will be about 30 inches. I am going to have a tensioner/idler that will keep the belt fairly tight, but I want to use something wider than the 6mm GT2. I'm not married to the GT2 profile either. I'd really like to pulley and belt that was 12mm or more wide that wby DRobs86 - General
Thanks for the reply. I want to be fair to the manufacturer by pointing out a revision I made to my original post. I bought these motors used on ebay from a reseller who claimed to have pulled them off industrial equipment. He's the one with no QC. (Seriously, if you are going to sell used steppers at least spin the shaft before you claim they work!). I'll check alignment. It seemed like evby DRobs86 - General
I ordered 4 used Nema 23s for another project (see new version here: ). I could not turn the shaft on two by hand. I even clamped some locking pliers to the shafts and held the motor such that the pliers were perpendicular to the direction of gravity and the shafts wouldn't turn! This was with the motors unconnected. I connected each motor to a DRV8825 that I had (underpowered it with about 2 aby DRobs86 - General
If I remember right there is a grid key hit and a corner method. I can't remember exactly how they are referred to in marlin. Is that what you are using? Marlin is reasonably well commented in that area... open up config.h and search for auto bed levelling. Give that section a read and come back with any questions .by DRobs86 - General
Correction. ... a switch case statement. .. not select case. Had my mind on visual basicby DRobs86 - Developers
I'm really.not all that sure, as I haven't dug into the guts of the communication. My best advice is yo open existing firmware and see how it parses the incoming data. I have looked at it just a bit in the past, and I am pretty sure it's literally just ascii strings of g code being sent. If you open marlin firmware I want to say there is a long select case statement that checks to which commandby DRobs86 - Developers
I haven't looked at the code, but I am.sure that an ACK is expected. I run marlin and have no problem communicating with it from repetier host. Look into marlin .... probably into the serial portion of the code and see what it is using as an ACK.by DRobs86 - Developers
Very nice build. I commend you for the excellent work, but I must say that it seems a bit overbuilt for the task. I'm sure you knew that, but still... great work! Give me some help with the engineering perspective on a water cooled hot end please. I haven't seen this in a build before. What was the goal? I could see being able to print some exotic filaments that would just be too hot at theby DRobs86 - Reprappers
Your acceleration and feed rate is probably too highby DRobs86 - General
Thanks for all the input guys.by DRobs86 - General
Hmm. Thanks to the reply. I may brush the part with epoxy for good measure. Do we know of any lubricants that are abs safe? Wd40 is a poor choice as a long term lubricant any way. What about bearing grease, white lithium grease, etc... they don't contain any kind of solvents, do they?by DRobs86 - General
I am planning on having an ABS printed part in an application that will be constantly exposed to WD-40, grease, oils, and other lubricants. Will there be any issues? Will the part be 100% unaffected? Thanks.by DRobs86 - General
QuoteXabbax I do not know if this will work but anyway - Print a hollow prototype. Mix ABS pellets and acetone to a consistency that can be injected or poured in the hollow prototype. Dry out the acetone by sucking it out in a vacuum chamber. Maybe worth a try! Intresting thought. I'm not sure that the acetone would be removed independent of the ABS. I think the vacuum would act upon the solutby DRobs86 - Developers
Quoteggherbaz Quote From what I understand of industrial injection molding, the pellets are usually melted by frictional heat as the screw turns, not by external heaters The ones I have seen use heating elements attached to the screws housing. I was recently at an o ring manufacture and all their injection machines have them (most were old 80's or so models) , maybe new machines use friction heby DRobs86 - Developers
Quotegmh39 I assume you've seen these? Would this limited run be sold as an actual product, or just used for consumer testing? Also, it might be easier to build a CNC machine to make your own molds and a DIY injection molding machine to inject with than try to use an FDM mold. Thanks for adding to the discussion. I have seen those. While affordable and seemingly easy to operate, they havby DRobs86 - Developers
Thanks for the replies. Good advice on a hydraulic system. This is doable I'm sure. Your thought on grinding the pellets is interesting. From what I understand of industrial injection molding, the pellets are usually melted by frictional heat as the screw turns, not by external heaters. Since I don't think a reciprocating screw is "doable" for homemade machine, it may help to preprocess theby DRobs86 - Developers
I am looking for a way for us to bridge the gap between prototype and production run. Parts could be made from mixing resins and pouring into a mold, but I think there is a need for creating 50 or 100 of a given item for market testing. Molds are expensive and set up fees add up. One can spend a few thousand dollars on a mold just to bring about a saleable product, the viability of which won'tby DRobs86 - Developers
When you say ramps boards that drive your stepperw, I think you mean your stepper drivers. You should be measuring the D.C. voltage between ground and the potentiometer. .. search the wiki for stepper driver tuning. The wiki will explain how to figure up the voltage to set it at. Be careful as some of those stepper drivers have different resistor values than is standard which will through the cby DRobs86 - Prusa i3 and variants
I bet the compile errors that you are getting now are from bad definitions in your config.h file. Post those errors and see if we can help. And no problem. .. I was in the same type of position as you a month or so ago (trying to get everything working).by DRobs86 - Reprappers
You might want to see what they say on the arduino boards about the warnings. Some IDEs I've worked with before have settings for how aggressive warning notification is.... the issues you are having are almost certainly with the compiler/ ide and not the hardware. I'd download a fresh version of marlin from github and compileby DRobs86 - Reprappers
Whatever you go with, I would avoid using bed springs and a mechanical probe. Perhaps I had weak springs, but I found that the force required to press the switch caused the springs to compress on the edge which was being probed. Obviously not good.by DRobs86 - General
Tom S. on youtube said he tried metal tape with his inductive sensor and did not have luck. Of course, your mileage will vary depending on the tape and the sensitivity of the sensor. You could always glue some magnets to the other side of the bed, but I think that would perhaps leave you with a very accurate reading biased somewhere to the left or right of where it should be (by way of error/diby DRobs86 - General
What is open in the arduino ide when you try to upload the sketch? There should he over 20 different files open in the ide when marlin is uploaded. I'm not all that familiar with the ide, but from the looks of the error I'm guessing that you are missing a few header files.by DRobs86 - Reprappers
I can say that I had a problem with my mega and they got me out one very quickly. I didn't order their complete kit, but I did buy one of their packages that included some electronics, gears, etc. I contacted them through eBay with a description of the problem and a request for them to propose a remedy. Within a day or so they apologized and said they would get me a new one out. I had a new megaby DRobs86 - General
I am guessing it is a terminator issue. Also look for a short between thermistor leads.by DRobs86 - General
QuoteDan crispy Have completely reasembled board. It goes a.bit up down right left.nothing with the extruder Now im.trying to calibrate the machine. I left the printer in the office,will update tmrw whats going on. Any idea.how i can make the micro sd on board,the lcd with sd carrier work? As right now im setting the machine with lcd removed as it doesn't work and its in the way. Thank you!!by DRobs86 - General
I want to post process the g code that Slic3r generates to add some dwells for cooling. On parts with tall items that end up with a small XY area for upper layers, I get too much heat on the part. Bottom layers will look great while those upper layers that have small areas are terrible. The issue is obviously that there is too much heat for too long that sometimes results in the plastic remainby DRobs86 - General