Hello, I am located about 20 north of Harrisburg, PA. Regards, Brianby reifsnyderb - For Sale
Hello, I am sorry I didn't see this posting earlier. Do you have the adapted liner for the 1.75mm filament? If you don't that will be a major problem as the filament will not have proper support and may not be able to build up enough pressure to extrude properly. If the liner is red, it will be the 3mm liner and have a hollow metal set-screw for a liner retainer. The white liners are for 1by reifsnyderb - General
Hello, PLA expanding in the hot-end will cause many hot-ends to jam. The trick is to keep the filament cool as long as possible until it needs to be heated. If the PLA is not kept cool enough, it will expand and jam. The resolution is usually to have a hot-end with either a heat-sink or some sort of ventilation system that keeps the filament cool for as long as possible. At this time, the Arby reifsnyderb - Plastic Extruder Working Group
PM Sent. thekendall Wrote: ------------------------------------------------------- > Do you guys offer any sort of educational > discount?by reifsnyderb - For Sale
Hello, I make the J-Head nozzles and hot-ends. Thus far, nobody has reported any issues with the heater resistors that are used. However, unlike the chassis-mount resistors, these are inserted in a hole in the heater block. The resistors are basically used as small nichrome heater cartridges. At this point, 6 out of 8 reliable hot-ends that are regularly sold use the heater resistors. The oby reifsnyderb - Plastic Extruder Working Group
Hello, I have opened hotends.com at as a web site specializing in the sale of hot-ends made by my company, Reifsnyder Precision Works. The first hot-ends for sale are J-Head hot-ends and related parts. I have been active in the Open Source community since 1998 and started providing hot-ends for the RepRap community in 2009. In 1998, I started developing software for the FreeDOS project and cby reifsnyderb - For Sale
Hello, In the next couple of weeks, I'll be opening a web shop and have the individual parts for sale. Regards, Brianby reifsnyderb - Wanted
Hello, You can insert the nozzle holder (PEEK) into the extruder body and either drill through it where the holes are in the body or you can mark the PEEK and file grooves for the screws. Since there is a good possibility that the drill bit will wander, I suggest marking the hole locations and filing two grooves in the PEEK. Regards, Brian NelsonRap Wrote: ----------------------------------by reifsnyderb - General
Hello, One of my goals is to make the lightest hot-end available. The Mk IV is a step in this direction...if it works with PLA. I don't see where it would have any problems with ABS as the Mk I and II worked fine with ABS and they are identical internally. In addition, the Mk IV will be a lot easier for me to make. Once I find out if it prints PLA as well as the Mk III-B, I'll switch to makiby reifsnyderb - General
I added instructions, in the Assembly section of the J-Head nozzle wiki. (http://reprap.org/wiki/J_Head_Nozzle) Regards, Brianby reifsnyderb - General
Hello, With the J-Head you will need to secure the resistor and thermistor with something. While some people have just pushed the resistor in the hole, as it is a pretty close fit, you can either put a little bit of muffler cement on it or carefully wrap a little strip of tin foil around it. The main thing is that the more contact the resistor has, with the brass, the better. In this applicatby reifsnyderb - General
Hello, Another option is the J-Head nozzle and hot-end: Regards, Brianby reifsnyderb - General
Hello, That is a concern of mine, as well. The hole would need drilled after the part is anodized. Then, since the hole is really the most important section, as far as wear is concerned, the anodizing wouldn't help. It would look nice, though. I wonder how well the anodizing would hold up with the heat, as well. Regards, Brian Andrew Diehl Wrote: ----------------------------------------by reifsnyderb - Plastic Extruder Working Group
Hello, The nozzle tip is at roughly the same angle as the drill bit in order to ensure that there is very little metal that the plastic must extruder through. However, I could probably shorten the spout a little more and will keep that in mind. Thanks, Brian Lenbok Wrote: ------------------------------------------------------- > The extended nipple just means there is more > length tby reifsnyderb - Plastic Extruder Working Group
Hello, I have created a blog to record the development of the J-Head Nozzle. I plan to post any news, prototypes, etc., that doesn't need to be recorded in the Wiki here. Regards, Brianby reifsnyderb - General
While the aluminum, that I am using, is pretty hard that is a great idea as it would create a really hard surface coating! I never gave it a thought. The nozzle orifice be a problem...or not. But, we'll see how the aluminum works out first. If it does, then I'll investigate. Thanks! Brian raldrich Wrote: ------------------------------------------------------- > Brian, Have you considerby reifsnyderb - Plastic Extruder Working Group
Thanks for the posting. Maybe drilling it is the way to go? > When ABS is heated above 260C, it starts to > decompose and it becomes insoluble to acetone and > probably most organic solvents. This happened to > me a couple of times. I followed spacexula's > repraplogphase video using a propane torch to burn > off the insoluble ABS. This would require taking > the hot endby reifsnyderb - Plastic Extruder Working Group
Hello, The second test nozzle varied 2-3 degrees, according to the software. Regards, Brian camblonie Wrote: ------------------------------------------------------- > What is a normal temp range? I'm using a J-Head > and I simply pushed the resistor into the hole. > The fit was very snug and some material was > actually shaved off. Right now I'm seeing > fluctuations betweeby reifsnyderb - Plastic Extruder Working Group
Hello, I'll try to find out for you and post it here. I may be able to tighten up the fit on this as well. The reason it is a little lose on this nozzle may be due to the drill bits. I have a really cheap set of fraction, letter, and number drills that I use for making a prototype. They don't hold their edge very well and are not all that accurate. The nozzle you have was made with a more eby reifsnyderb - Plastic Extruder Working Group
Hello, I had a discussion, recently, with a J-Head nozzle user about cleaning. Since it is pretty easy to disassemble you can take it apart and clean everything. Optionally, it appears that acetone doesn't react with the PEEK, PTFE, the resistor, the thermistor, etc., so it may be possible to dip the whole thing in acetone. That idea needs some more testing, however. I don't know how fire ceby reifsnyderb - Plastic Extruder Working Group
Thanks for the heads-up. The set screw really isn't that tight against the resistor and is kept tight by another set-screw in behind it. But, you do have a really good point regarding the possibility of damage and shorting out. (I didn't think of that.) Maybe a piece of aluminum foil should be placed between the set-screw and the resistor? Either way, furnace gasket cement, aluminum foil,by reifsnyderb - Plastic Extruder Working Group
I purchased a few 6.8 ohm resistors to see if I could reduce the size of the J-Head nozzle heater block any further. I managed to reduce the heater block foot print to 13mm x 13mm (1/2" x 1/2"). While I was at it, I added some 0-80 set screws in order to secure the heater resistor and thermistor. The set screws are stacked in the holes in order to lock them in place. This prototype weighs 3.1by reifsnyderb - Plastic Extruder Working Group
Hello, The biggest reason is to keep the number of parts down. While aluminum is cheaper than PEEK, it is cheaper to have one expensive part as opposed to two cheaper ones. More parts also means more tooling, more time setting up machines (which is the most time-consuming part of making parts), and even more machines can be needed. So, if possible, it would be ideal to have just a fancy PEEKby reifsnyderb - Plastic Extruder Working Group
Thanks! The main reason I fluted it was to reduce the weight. But, at the root of the flutes the PEEK is very thin. I would have to check my calculations; but, I think it is down to a little over 1/2mm. I do agree that the thermal conductivity of PEEK is very low. But, it could be enough to keep it cool. I don't really know. If it does keep it cool, it could completely eliminate the need fby reifsnyderb - Plastic Extruder Working Group
Hello, I got the Vishay ones from Digi-Key. The part number is RWMA-6.8CT-ND. I think mouser had them too. They are rated at 6.8 ohm, 3 watts. In order to fit everything in a 13x13mm foot print, I'll have to leave the last 0.250 (or less) unsleeved and drill the remainder out to 3.5mm. I don't think that will be a problem as it will create a "heat chamber" of sorts. Besides, other designsby reifsnyderb - Plastic Extruder Working Group