Like the_digital_dentist's, most of the time my hotends either work or they don't. However, I have seen quite a bit of variability in quality of print. As I make all of my own hotends I have tried many things to optimize the print quality and have observed the following:- That the nozzle hole should be a little over twice as deep as its diameter; for example, if it is a 0.35mm nozzle then the chby leadinglights - General
Hi VDX, I used to work on a Kratos mass spectrometer which had gold ring seals and was baked out at 350C but at 6 grams per kit were not trivial - especially since somebody would contaminate it at least once a month. Do you know where I could get aluminium O rings? Mikeby leadinglights - General
Thanks Andrew, I didn't know that copper ring seals were available: Can you tell me of any stockists of small ones in small quantities? The reason that I am getting a bit paranoid is that with 5 or more hot ends something like 5 times the opportunity exists for something to leak. Picture below of one of the hot end assemblies. Mikeby leadinglights - General
To cover a wide range of materials I need a maximum temperature as high as I can get it, or at least 300C which precludes PTFE tape. With the coefficients of expansion of brass at 18ppm and stainless steel at 17.3ppm I don't think that the joint would be reliably self sealing. Has anybody used a soft metal gasket as marked in red in the drawing below. The best material for this would be 24kt goby leadinglights - General
What is the best method of sealing a screw on brass nozzle from leaking around the threads? Further info:- I have previously made the nozzles for my 4 printers as on the section on the left in the drawing below. My next printer will have 5 or more hot ends and quick changing of the whole hot end is no longer a viable option so I have opted to use a more standard threaded nozzle as shown on theby leadinglights - General
Two that fit the bill are:- Fischer Elektronik WLPG is good for 400C but is electrically conductive so not right for thermistor - also quite expensive (data sheet at ) Deep Cool Z5 thermal grease is good for 300C and is non conductive and cheap - get from Amazon:- The Fischer compound has an exceptional thermal conductivity at 10.5 W/m-K compared with a pretty average 1.46 W/m-K for the Deep Cby leadinglights - General
QuoteSrek I wasn't able to find that Renishaw system.... QuoteSrek ...So please lets discuss this in the proper context. In precisely what way did I not discuss this in a proper context? o-lampe asked if mounting the printer on a compliant platform (ball caster rollers) would help. This is a technology which is not very expensive or unmakable - precisely the proper context. My pointing out thatby leadinglights - General
o_lampe has a point. Endlessly saying that stiff frame equals obeying Newtons laws of motion does not make it so. Take an idealized Mendel Prusa I - the one with the threaded rods. If the extruder and X carriage is accelerated along the rails it tries to deform a rectangle consisting of the X rails and triangle joining rod (horizontals) and the Z rails (vertical) which couples at the top to a secby leadinglights - General
A slight modification on your idea of immersing in liquid is to use a heavy gas*. The chamber then would not need a top, only sealing around the bottom and sides. As far as heavy gasses go, carbon dioxide has a density about 1.7 times that of air falling to about 1.25 at 100C. Early very simple trials show that it sort of works. A Sainsbury's flimsy carrier bag fed with carbon dioxide was able toby leadinglights - Reprappers
I don't use a heat spreader at all, only 3mm glass directly on my heater. Maximum temperature variation across the surface is less than 10 degrees. For PLA I use blue tape but for ABS I use Wolfbite, no Kapton or other tape. Note that the temperature. The temperature under the print will be higher than the bare surface as there will be less cooling with the print keeping air away from the surfaceby leadinglights - Reprappers
To get the most accurate temperature I use a small type K thermocouple and a block of culltlefish bone as an insulator. Cut the cuttlefish bone about 20mm to a side by 10 to 15mm thick. Lower your nozzle onto the cuttlefish so that it makes a depression maybe 4 or 5 mm deep, lift the nozzle, position the bead of the thermocouple in the center of the depression and lower the nozzle again. Allow aby leadinglights - General
For about a year I have been working on a multi-material printer. After several derailments I can begin to see the light at the end of the tunnel and the need to get my teeth into the software is becoming apparent. My general idea is to have the build stage moving in both X and Y thus making the mass of the extruders relatively unimportant. The moving XY table can be seen at The general methoby leadinglights - Developers
QuoteTraumflug QuotethetazzbotTeacup: Since it is not Arduino specific, you would have to implement an I2C or SPI stack. The SPI part was done over the last few days, as part of SD card reading. It's in the sdcard3 branch. @Traumflug. Thank you for the information. I now know that there is existing SPI code that I can build on I will be able to do the other end. thetazzbot has PMd me that he mby leadinglights - Firmware - experimental, borrowed, and future
I have been working on and off for the last year or so on an idea similar to Olaf's. In my case I use the meshing of gears directly with a solenoid doing the disengaging and the same stepper that feeds the filament driving a leadscrew to select the extruder which will be used next. The gears are pre-aligned by software so that the teeth are always ready to mesh correctly when they are selected. Iby leadinglights - Developers
QuoteTraumflug QuoteleadinglightsI have been asking for any thoughts or assistance in how to control a whole bunch of extruders and a extruder swapper. You didn't. This was your question: QuoteleadinglightsDoes Teacup have a way of sending out and receiving commands from a RAMPS board through SPI, I2C or serial interfaces? In the first quote I said "I have been asking...." which referred to qby leadinglights - Firmware - experimental, borrowed, and future
QuoteAndrewBCN Quotedc42 Quoteleadinglights Nor would I expect you to. I had hoped though that you could give some starting points such as if there is or is not already code for I2C or SPI in Teacup. It is not my intention to port to a PIC, only to use a PIC controller to do the actual tool change - that is well within my abilities. Deciding whether to use Teacup or something else is my present qby leadinglights - Firmware - experimental, borrowed, and future
Thanks dc42, I will buy Duet & Duex boards. Mikeby leadinglights - Firmware - experimental, borrowed, and future
Thanks dc42. The Duet/Duex4 looks to be an excellent starting point. Would I be correct in guessing that one of the heaters could be kludged to power a lift solenoid? In it's present incarnation the hot ends are slid on, for lack of a better term, I call the X-prime axis and unwanted ones are lifted up by the solenoid so that the nozzles are well clear of the print. Mikeby leadinglights - Firmware - experimental, borrowed, and future
Nor would I expect you to. I had hoped though that you could give some starting points such as if there is or is not already code for I2C or SPI in Teacup. It is not my intention to port to a PIC, only to use a PIC controller to do the actual tool change - that is well within my abilities. Deciding whether to use Teacup or something else is my present quest. Mikeby leadinglights - Firmware - experimental, borrowed, and future
I can just about flail about in C, and maybe do something productive in less than geological time - but only if it is straight K & R. I guess what I am asking is how much can be done by some light tickling in configuration.h or similar and how much will need to be written from scratch. Mikeby leadinglights - Firmware - experimental, borrowed, and future
Does Teacup have a way of sending out and receiving commands from a RAMPS board through SPI, I2C or serial interfaces? What I would particularly like to do forward tool change commands such as M60 or T codes to a second controller. This would control print head selection, commanding the presently selected hot end to lift while moving another hot end into position and lowering it. Extruder motor cby leadinglights - Firmware - experimental, borrowed, and future
I think that whether it is too late or not depends more on yourself than on the availibility of cheap 3D printers. If you think of a model aeroplane as coming as three parts in a plastic snap together kit then you should go for a Makerbot or UP!. If however you think of a model aeroplane as being made from balsa, tissue paper, glue and sweat then there is lots of life left in the hobby. I have aby leadinglights - General
Some people will post without searching, some after searching but failing to find, others after searching but failing to understand, but presenting an opinion as fact with nothing to back up the opinion helps neither new users nor anybody else. This is especially true when there are as many opinions as long time users.by leadinglights - General
Quotecdru Quoteleadinglights When I look on this forum now, much of what I see is bombastic and opinionated. There are some gems of wisdom in some replies, but it takes a lot of searching to find them in the general detritus. That's actually great news. Reprap finally has been accepted as mainstream and now is just like every other user group out there! Almost every forum or online group I've evby leadinglights - General
When I first started using this forum I had little knowledge of 3D printing but now I have a wealth of experience and perhaps a little true knowledge. Most of the most important things I learned were from Nophead, Richrap and many others who would take the trouble to explain things. When I look on this forum now, much of what I see is bombastic and opinionated. There are some gems of wisdom in sby leadinglights - General
Quotedc42 Quoteleadinglights Thanks dc42, I will send for one from RepRapPro to try. I suspect though that in the end I will in the end keep to resistors - one by Vishay (part number RWM041022ROJR15E1) is categorized all the way up to 450C. 450C is a good maximum temperature, and the price is good too (GBP0.43 from Farnell). Getting good thermal contact between the resistor and the heater blockby leadinglights - General
Thanks dc42, I will send for one from RepRapPro to try. I suspect though that in the end I will in the end keep to resistors - one by Vishay (part number RWM041022ROJR15E1) is categorized all the way up to 450C. o_lampe, The resistance of an aluminum hot end block made from a 1cm cube would be about 28 microOhms so to get it to dissipate 20 watts would take 2670 Amps - the wires would be too thiby leadinglights - General
They actually came from two batches, both 24V and 12V - I originally mentioned the problem on this forum about a year ago There are also two other factors to consider, I use 24V as far as possible and have not yet seen smaller cartridges in 24V. Also, an axial heater works better in my multi-extruder design. I will try the heater that dc42 mentioned but I will reserve my options and mainly invesby leadinglights - General
I tried heater cartridges when they first came out but had 4 failures out of 5 - one burned out after ca 20 hours, one case short, one open circuit and one with a resistance of 13 Ohms. I would prefer to stick to resistors until I am convinced that there is a quality product on the market.. By the way, o_lampe, don't try your current controlled PSU idea, the power dissipation depends on the resiby leadinglights - General
On all of the hotends I have made to date I used Welwyn 7W W22 resistors which are 7mm diameter by 22mm long and I have never had a failure but am looking for something physically smaller to try to fit a whole bunch of hotends close together. I see that there are several makes fitting a 5.5mm diameter by 12.7mm long format which would be great - has anybody got types (Manufacture and range/part nby leadinglights - General