Don't know what is more interesting on this thread...the new hot end design or the comments (More efficient resistors????). Anyway, I digress: While the proof is in the pudding, this looks like a potentially very elegant and effective design. It looks (as best I can determine from the picture) that it is a two piece design...what I will call the barrel and the heat block. All the angst in thby mars bonfire - General
Wow...15Km per print! Sounds like such an incredible number (high) but I have not tried to calculate it. I am not sure how much you need to worry about the stiction issue for this application. I think of it as the ratio of the static to dynamic coefficient of friction. If the value it 1, than roughly speaking, no stiction. Practically, if both coefficients are really low, it kind of doesn'tby mars bonfire - General
I have some work related experience with plastic bearings. They can be a good choice but like everything else, represent tradeoffs. They won't, most likely, be as low friction as ball bearing based linear bearings. They will have some level of "stiction" i.e. the tendency to stick then slip when starting motion...more, in my experience than ball bearing based bearings. They do have the abilby mars bonfire - General
Just completed the shakedown testing of the "mover" systems (X, Y, Z and extrude) on my custom (mech and electronics) 3D printer and everything is working (who, me surprised?)...now on to completing the "thermals"...extruder and heated bed. I wanted to thank the forum and particularly those who wrote and contributed to Sprinter and the Pronterface...as they say, couldn't have done it without tby mars bonfire - General
I am working my way "up" the toolchain for my custom machine and things are going surprisingly well. Sprinter firmware, Printrun interface, playing with KISSlicer...things are starting to make senses. What is not clear is what role Netfabb plays in the tool chain. I have read references that say it is good to run an .stl file "through netfabb" I assume before slicing and that it "fixes proby mars bonfire - Reprappers
For those interested, based on the clue provided by nophead, I poked around the Python stuff on the web (not reprap or Printrun specific) and there are several threads where the unextractable library.zip file is discussed. Pretty much the same deal...it relates to the converting Python into windows .exes and for whatever reason, doesn't seem to affect the operation of the .exes. No harm, no fby mars bonfire - Reprappers
Brnrd, Thanks for replying. I am working on using Pronterface (as part of Printrun package) with Sprinter firmware and things seem to be working.by mars bonfire - General
nophead, Thanks for the explanation. I have Sprinter loaded and configured and Printrun seems to be totally functional and solid. One more step closer... Steveby mars bonfire - Reprappers
\catalogs&requesting=ptcatalog&location_id=5339 Hope this url survived being posted. It is a link to the synchronous belts section/chapter of the gates catalog. I don't think it will answer the naming convention question directly but maybe it can help. Steveby mars bonfire - Reprappers
It appears that I posted my concern about the corrupt PrintRun file too quickly I did not succeed in extracting the library.zip file but decided to try to run the .exes anyway. To my surprise (and embarassment) they seem to work (!) So I'll take the success and not worry about the unextractable file (and it role in the software)...though I am still curious about it. As they say..."never minby mars bonfire - Reprappers
I having building the hardware, now for the software. I have been trying to get PrintRun unto my Windows XP (home ed) laptop. I have been downloading the precompiled Windows package (18MBytes) with a date of March, 2012. The download appears to go fine. I run an extract on the .zip package and it does not error....however, inside the top level directory in the extracted files is a libraryby mars bonfire - Reprappers
I am getting precious close to have having all the hardware completed for my custom reprap machine. I must admit, the choices and integration of the toolchain software looms as a major task. So... I would like to test out the subsystems independently before trying to exercise the *whole* system (input solid file through desk toy). Question: I would like a simple set of software to test out tby mars bonfire - General
Please let me start by saying this may well be the case where I just have not found the right web link. Also, I am fairly certain the information in out there but in pieces in literally tens (hundreds?) of places. Has one of the several experts in this forum ever put together a definitive guide on hot end architecture? The more I am involved with building my custom 3d machine, the more it isby mars bonfire - Reprappers
After posting this message, I went back and reread both data sheets and the fog is starting to lift. Basically, the question I posed in my first posting is ill formed it that the real issue is the "automatic mixed delay" vs. the "always mixed delay". Bottom line, the two chips are different in that regard with the newer a4988 implementing the "ground ROSC" to get always mixed delay. Sorry forby mars bonfire - General
This a subject related to the Nophead's great blog; specifically about low current microstepping and the allegro chips. As I believe Nophead notes, the A4988 datasheet speaks about tying the OSC pin to ground to achieve a constant 30 us delay. The A4983 datasheet does not mention this, but seems to give the same delay formula. Also, everything I can seem to find that describes the differenby mars bonfire - General
GIven you have what I called the hot side on the bed and cold side up against insulation, my guess is that the Peltier is working like a resistor i.e. the amount of heat you are getting into the bed equals the power you are putting in...virtually no efficiency gains due to "pumping" action...not unlike running an air conditioner inside a closed room (knew someone who did this and couldn't figureby mars bonfire - General
A couple of comments. My guess is that in order to enjoy the increased efficiency of heating using the peltier, you need the "cold" side to be in good thermal contact with the room ambient (a heat sink on the cold side and a fan would be good). Otherwise, the heat available to be pumped across the Peltier would be limited but what can be moved into the bare Peltier side. If you have a sourceby mars bonfire - General
I thought I was told never to take apart a stepper motor because it will lose performance (torque). Not sure why (magnetics would be my guess) and it also makes me wonder how they are built in the first place(??). Sounds like you guys have pulled it off and still had functioning stepper motors. From another forum on the web and don't if it is true: "This topic came up in another group. The stby mars bonfire - General
Regarding your question of "don't you need a slot", in my extruder head, I have a wheel that presses the filament against the drive axle. While the drive axle does not have a "slot" due to the way it is fabricated, the drive wheel has a groove (slot) about 1/2 the diameter of the filament deep around its circumference that serves the purpose of keeping the filament "centered". I made the wheelby mars bonfire - General
Must admit I am surprised at your problem with them. Another source (though more limited selection) is www.mcmaster.com ...they have cogged pulleys and belts but maybe not exactly what you need.by mars bonfire - Reprappers
This is a cut and paste from an old post I made to the developers forum. It is yet another method of cutted teeth on the axle using an end mill and a CNC rotary stage: May well have already been covered but I thought I would share a method that I experimented with this weekend to make the friction drive wheel for an extruder. Based on some reprap research, looks like people are using the hob mby mars bonfire - General
I have used them for years, both for home projects and for project material for work. Totally professional, serious vendor. I would not panic on losing your money with them, though apparently, it may take time to resolve.by mars bonfire - Reprappers
If by "bond", you mean bond or glue ABS to itself or another substrate (as opposed to a treatment on the hot bed prior to printing), then my vote is for a product called "Plaster Welder". I buy it at an auto parts store. Two components in a common dual chamber syringe....so a 1:1 mix of the two components (mixed on an external mixing surface or container). Is *not* an epoxy (as far as I know).by mars bonfire - General
The rigid fiberglass insulation sheet (ceiling tile variety) (see my posts a few up this chain), while certainly not fiber free, has far fewer loose fibers than the batt stuff used in walls. I guess if you really were worried you could smear some silicone/rtv on the edges to bind and further immobilize the fibers. I personally don't worry about the fibers, particularly in the environment and qby mars bonfire - Reprappers
Another, sometimes overlooked consideration with driving FETs is the input gate capacitance/input charge. The first thing to consider is the gate threshold level but also good to think about the capacitance. The good news is that the Arduino PWM rate is very slow for things electronic...something like 540 Hertz. The concern is that this capacitance slows down the rise and fall times of the gaby mars bonfire - Reprappers
Another material to consider is what is often referred to as rigid fiberglass insulation. As I understand it, it is basically fiberglass insulation (what is used in batt form in attics and walls) but with an added binder to make it semi-rigid. You commonly see it sold in tube form for insulating iron steam pipes. The binder is the limiting factor in its temperature range and will in essence, bby mars bonfire - Reprappers
Cat litter has got to be the cheapest! I have heard (but never confirmed) that silica gel is available in relative bulk at craft stores to be used to dry flowers for preservation. Probably cheaper than cat litter but less than Mcmaster???by mars bonfire - General
I am building a custom reprap with Nema 23s. I will be driving them with Pololu stepper drivers. The Nemas I am using are rated at 1.4 Amps. The Pololus *with proper heat sinking* will drive up to 2 Amps. The difference in performance between driving a Nema 17 that is rated for 1 Amp at 1 Amp versus a Nema 23 that is rated for say, 2 Amps at 1 amp is second order, in my opinion, and gets intoby mars bonfire - Reprappers
Some kapton tape has acyrlic adhesive and some silicone adhesive. The silicone is good to higher temps...around 500F if memory serves. Acyrlic, significantly less. Something to pay attention to when buying.by mars bonfire - General
I believe products just as stove rope cement/glue and muffler patch and many (most?) common refractory cements are silicate based, often sodium silicate. Another old name for this stuff is "water glass" (if memory serves). I have had the same experience as described in one of the posts...basically, let the stuff dry out before "baking". High temp is required to make it harden to full hardness.by mars bonfire - General