I need extruder help please.

I have a wades extruder block that does seem to grip really well.
I have a big nozzle with 0.5 hole and a one piece with 0.35 holes.
I have tried ptfe, peek, and hybrid insulators.
tried resistor heating, direct nichrome, and nichrome on a removable brass piece.
relied on threads in the insulator and have since moved on to supporting the barrel with bolts that run parallel.
tried a number of heatsinks like copper pipe end, and insulators over the heating / nozzle zone.
extruding PLA. tried temps from 170->190+ when it was working for me I was at 177

I have tried every combo I could with what I have. The only time I was successful I had a leak (#1 in the pic), when I fixed the leak the pressure pushed the barrel out. I created some supports for it, and then it just jammed in new places. Not sure what else I can try... I'm cool with spending money on it if I think it will solve my issues... but I'm waiting on the v4 hot end to arrive from mendel-parts and an arcol hot end v3 to show up as well. I also have a project to work on more reliable designs so people like me don't have this issue. Any suggestions on the equipment I do have, how to make it work?

thanks.

Out of the options you have listed only hybrid works for me. PTFE always finds a way to leak or let go unless you totally encase it in something. This one has printed more than 100 Mendels: [hydraraptor.blogspot.com]

PEEK on its own isn't slippery enough. I have also been using one of Brain's hybrid ones for ABS for some time now and found it reliable since he added the circlip.

My stainless steel design is also totally reliable: [hydraraptor.blogspot.com]

This one should also be totally reliable: [www.thingiverse.com]

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[www.hydraraptor.blogspot.com]

what are you using to create gcode? might be a software/firmware issue (well ya never know, was for me)

thanks nophead... I know there are decent designs out there... the 2 im waiting on will hopefully be decent. A lot of your solutions are very custom need special tools and can't be easily bought. I'd buy a kit or extruder from you in a heartbeat, till then I'll see how close I can get.

buback... I can make extruders fail without gcode... just using the control panel and adjusting speeds and temps.

Where did you get your parts?

Rick

I think I bought them all from that guy on ebay that starts with an R ... I don;t see them there anymore. New stuff I'm waiting for is from mendel-parts and arcol.hu ... neither are speedy about it. I took a hard look at your inventory, probably 10x, if you had this...
[www.mendel-parts.com] or something that seemed just as promising I would have bought it. It may be overkill but I'm really sick of extruder issues.

Sorry about your misfortune.

Given your diagrams and reference to the larger nozzle, removable brass peice, etc., I think that some people may interpret them to mean you're having problems with MakerGear parts (even though you did not mention a source). I just want it to be clear that you are not using MakerGear parts.

It's unfortunate that time after time it is necessary to reiterate, the parts on ebay may look like ours but they are not the same. You had a bad experience and now believe there is a design problem when in reality the problem is with your specific parts.

Well over 500 botters are using our hot-ends and hot-end parts. They work and they work reliably. In the event that a botter has an issue, we support our products. Drop by the MakerGear IRC channel anytime and chat with people who are actively using our products.

Rick Pollack
MakerGear
irc://freenode/makergear

PM Sent. While I haven't been making parts lately, due to other obligations, I am still here for support.

While I don't know exactly why the parts were failing as hundreds of people have used my parts successfully, I have offered him a set of the "Geared Extruder Nozzle" parts at a reduced rate.

Regards,

Brian

thanks, I really appreciate that. you always were very responsive on ebay as well, I know a lot of this can be me... and that it's all experimental. I have a couple of freinds with similar issues that bought parts in various places... one guy I know has about 5 hot end assemblies plus various parts, and has similar issues to me with all of them. I do no people with working sets as well. I can;t figure out the factors that have them working and others not.

This is something I have been struggling with off and on as well. I have always used a PTFE insulator in the makerbot MK4 with virtually no trouble. Take the same hot end construction (including hose clamps and bolts) and put it on a reprap and it doesn't work as well. I would get one to work for 2, maybe 3 weeks then it would start jamming again and I would have to replace the PTFE.

I have not had a good opportunity to print since rebuilding from my last failure, but I'm thinking the problem has to do with the PTFE expanding in the section just above the barrel. Even if you clamp over the threads to prevent leaks and use bolts to stop it from pushing out, there is still a cm or so stuffed in the extruder block. On my wade's block, there isn't a good way to constrain that area if the fit is loose or the extruder block itself softens and expands.

While attempting to think up a new way to mount things, I took a failed insulator and threaded the top end into a 3/8 x 1/4" FIP reducing coupler ( Watts part number A-765 from home depot). I noticed that this compressed the inner diameter to its original size. I went ahead and clamped it up like normal and bolted it back in the extruder. The smaller end of the coupler happened to fit in the insulator cavity perfectly, but I need another piece to guide the filament through the 1cm gap that it leaves. For now, simply bending the curl out of the filament before feeding it in has worked well enough.

I have not printed with it yet, but I was able to extrude very easily again. I did an open air extrusion that was around 1 meter in length. Prior to adding the coupler, it would jam after just 15 cm. I think what happens is once the top expands, it allows the filament to feed into the rim of the barrel and jam instead of guiding it into the tube. If you remove the idler block and pull out the filament, you may see a sort of crook in the filament where this is happening.

makergear Wrote:
-------------------------------------------------------
> It's unfortunate that time after time it is
> necessary to reiterate, the parts on ebay may look
> like ours but they are not the same. You had a bad
> experience and now believe there is a design
> problem when in reality the problem is with your
> specific parts.

You don't have to reiterate. In fact, all of this reiteration gets annoying. I don't think that anyone assumed the parts were MakerGear parts.

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If the filament feeds for a few seconds and then jams solid it is usually due to a small gap between the end of the barrel and the inside of the PTFE. That joint must be tight but not too tight and even a small gap will make it impossible to extrude. ABS above its glass transition but below the melting point expands into the gap forming a barb that is impossible to push forwards but easy to pull back.

I put a 3mm rod in the barrel and tighten it until the PTFE starts to just grip the rod and then back off a little. I.e. when the barrel bites into the PTFE it causes it to bow inwards reducing the diameter.

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[www.hydraraptor.blogspot.com]

nophead, I'm glad you spelled that out for the thread, I found that out the hard way, it's illustration #3.

about the filament curve... that definitely seems to be a factor. A few of us tried some experiments to see if they would get us past certain issues, like having an air gap instead of an insulator... the key thing that affected those was the filament curve. The filament curve is also what requires low friction in the insulator to guide the filament into the bolt.

Maker Gear Rick. I appreciate your pride in your products and how available you are for people. I will probably also get a set from you just to compare, I'm going to have to label all of the sets and run some head to head comparisons, especially since I'll be getting so many new ones.

I appreciate the responses from everyone, I may try rebuilding again once or twice before new stuff shows up... I won't post every failure, but will try to write something up if I find some definitive fix. I think an extruder troubleshooting guide is in order... I must have hit most of the common ones, I have also tried the hose clamps and re-drilling, and assembly with 3mm rod in the whole shaft (Only recently). Also found som tricks in re-asembly, unblocking parts which need to be shared.

The great thing about using stainless steel instead of PTFE/PEEK is that it just works, hard to see how it could ever fail, and so doesn't need a trouble shooting guide. It does need a small heat sink and a tiny fan though, or a large heat sink.

PTFE can work if everything is just right, but sooner or later you will have an accident that destroys it and then you need to start again.

Hybrid seems to be OK as long as it is assembled just right.

The other advantage of SS is that the length doesn't change significantly when it warms up, neither does my copper encased plumbstruder, but I find with the hybrid I have to leave it 2 minutes after warming up otherwise the height of the first layer varies.

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[www.hydraraptor.blogspot.com]