Which hotEnd?

Im looking for a fairly cheap hotEnd that can be mounted on a wade's extruder. Im using Gen6 electronics from mendel-parts , if that matters.
Im liking the v6 hotEnd from mendel-parts , but its a little pricey @60$ + shipping to USA.

So any recommendation?

Edited 1 time(s). Last edit at 04/05/2011 12:49AM by Rooski.

How about the Makergear hotend? $75+shipping... not cheap.. but since MG is in the US, should still be a little cheaper after shipping.

I would recommend either getting the model that Mendel-Parts sells from somewhere, or the arcol.hu hot end. There is a guy in the US who makes them for a reasonable price and is very helpful and easy to deal with, I'm running his extruder now reliably.

I've been through at least 5 hot end variations... these 2 designs are the only ones that stood up reliably. Out of the 2 I'd have to say I prefer the arcol.hu design. I can get a more detailed print from it, but that may be the nozzle size.

I recommend AGAINST buying anything that relies on PEEK or PTFE threads for structural integrity.

regardless of shipping, you're likely to regret buying a design that is error prone.

@Rooski We've got well over 500 hot ends in the field. If you have questions, please stop by the MakerGear IRC channel (irc://freenode/makergearv2). I hang out there and you can discuss products with MakerGear customers.

@Anthong Redbeard "I recommend AGAINST buying anything that relies on PEEK threads for structural integrity." <- total nonsense. You do the community a disservice by posting stuff like this...

Rick

makergear Wrote:
-------------------------------------------------------
> @Rooski We've got well over 500 hot ends in the
> field. If you have questions, please stop by the
> MakerGear IRC channel
> (irc://freenode/makergearv2). I hang out there and
> you can discuss products with MakerGear
> customers.
>
> @Anthong Redbeard "I recommend AGAINST buying
> anything that relies on PEEK threads for
> structural integrity." <- total nonsense. You do
> the community a disservice by posting stuff like
> this...
>
> Rick

Please do not change peoples words when you quote them. He said "PTFE or PEEK" not simply "PEEK".

And recommending against PTFE threads for structural integrity is fairly common. In fact, using PTFE for *anything* structural is not recommended (by me anyway) while PEEK is still used by many as a structural component, I prefer all steel. No PEEK, no PTFE.

---

--
I'm building it with Baling Wire

@jgilmore use what you want...it does not change the FACT that PEEK is extremely reliable and field proven.

Sorry...just that PTFE and PEEK are very different materials and should not be used in that context.

Rick

Rick--

A RedBeard is entitled to his opinion. Also, he does have a point as all metal hot-ends are much more reliable. My Mendel uses an all-metal hot end similar to what I found in the Wiki. I wouldn't even want to try PTFE or even PEEK.

I'd keep in mind that A. RedBeard isn't selling anything and doesn't have any skin in the game, either.

I have a MakerGear hot end with a Wade's, and have run several pounds of PLA through it without a single jam. No leaks either. The arcol.hu hot end looks very nice, and looks like it would be totally reliable as well. I do like how compact my MakerGear end is though.

How does the Makergear one stay cool enough for PLA at the top end, being so short?

---

[www.hydraraptor.blogspot.com]

nophead Wrote:
-------------------------------------------------------
> How does the Makergear one stay cool enough for
> PLA at the top end, being so short?

I have a small fan blowing over the PEEK section on mine, but that's to keep my PLA Wade's from softening. I'm actually not sure how well it would do without it.

I was cringing when I wrote it, thinking specifically of you Rick.

I haven't had much luck with the thread of PTFE or PEEK under heat and pressure... both materials are fine, I just don;t want to rely on the THREADS for strength, I think support structures such as the peek block in the stepper extruder hot end for support are much better.

I have experience with a lot of extruder variants by now, please, please lets not get into where they came from right now.

my suggestions for anyone getting a new hot end is to get something that has structural support besides threads on the thermal barrel (Unless they are metal).

I would have no problem with that being your typical design with the addition of a PEEK block and some way to secure it to the extrusion block.

I can say with some confidence that between myself and several others I know pretty well... the Stepper Extruderdesign by Adrian is less error prone, has a higher success rate, for whatever reason, than the older thermal barrel + nozzle design.

Rick, Why don't you start carrying the Adrian stepper extruder hot end? I'd love to recommend you as a US vendor for it.

In terms of PEEK, my experience could not be more different than yours. We've been using PEEK for 18 months, have more than 500 hot-ends in the field and we've tested it in-house. Here is a testing rig where early variations of the current GrooveMount were tested at operating temps well above normal for weeks at a time with 10-20 lbs hanging from the nozzle throughout the testing (see the wire coming from the nozzle).

PEEK is absolutely fine for structural purposes and we have over 500 hot-ends in the field and in-house testing to support this. Perhaps your issues were related to the specific parts you were using.

Rick

FWIW I have the PTFE/PEEK hybrid developed (to my knowledge) by Brian Reifsnyder. It contains a PTFE thermal break constrained in PEEK. The barrel of the hot end is screwed into the PEEK and butts up against the PTFE.

This configuration was developed (apparantly) due to the fact that PTFE thermal breaks that the barrel screwed into was giving under pressure & heat.

I had to bore out a new PTFE thermal break to a smaller inner diameter (3.1 as opposed to 3.5) and replace the original. Having done that I seem to be fairly trouble free. So my 2p is that PEEK is fine for holding threads.

Of course, I do not have the volume of printing that many others have so things may still go wrong, but I have managed to print 6 vertices without a failure now. All other failures were not related to the PEEK / barrel interface.

I have put 150Kg of ABS through my plumbstruder: [hydraraptor.blogspot.com] which uses a PEEK thread and it hasn't let go yet.

---

[www.hydraraptor.blogspot.com]

ok, I concede PEEK should not have been in the same statement. I do still feel that an external support, like the PEEK block on the adrian setpper extruder hot end is better than not having it... even if the threads don;t fail I have pushed the entire barrel out of the filament drive block more than once.

lol - Anthong you seem to indicate you feel you have been bashed by a heavy club

To clarify though - have you had the barrel pushed out of the PEEK/PTFE section or the entire hotend+thermal break being pushed out of the extruder mount?

I have a strip of metal which backs up against the PEEK and holds the hotend+thermal break assembly to the extruder block in much the same way the external support you mention is secured. It does not touch the barrel though as I did not want to put undue pressure on the threads and also did not want to transfer more heat to the extruder mount than neccesary.

This was simply because I could not see a decent way of connecting the hotend+thermal break assembly to the extruder mount block in a fail safe but easily dismantle-able way.

with PTFE I had every failure imaginaeable, pushing apart the 2 hot end sections, shrinkage or warping not allowing filament to pass, the whole thing getting pushed out, leaks from various places etc.

PEEK there seemed to be friction issues, it seemed to transfer more heat than PTFE, and allow the filament to be hotter than PTFE, I've had this entier hot end pushed out of the b lock, I added on a metal strip like you said, and it kept it from moving but the heat and friction seemed to cause more jams... especially if the internal transition wasnt perfect between the 2 hot end parts.

The Hybrid one was similar to the PEEK but without friction issues... but i kept some of the PTFE issues, if screwed in too tightly the ptfe could warp, too loose and the gap would cause a jam.

I would be happy to do some testing video with anyones stuff, for good documentation purposes, and Im not afraid of buying the parts to do that testing with... I'm not religious on this subject, if a simple or older design works just as well or better than some of my newer ones I would be just as happy to have another working extruder.

Anthong Redbeard Wrote:
-------------------------------------------------------
> with PTFE I had every failure imaginaeable,
> pushing apart the 2 hot end sections, shrinkage or
> warping not allowing filament to pass, the whole
> thing getting pushed out, leaks from various
> places etc.

Yes PTFE only works if it is fully constrained.

>
> PEEK there seemed to be friction issues, it seemed
> to transfer more heat than PTFE, and allow the
> filament to be hotter than PTFE,

Yes that is my experience also.

>I've had this
> entier hot end pushed out of the b lock, I added
> on a metal strip like you said, and it kept it
> from moving but the heat and friction seemed to
> cause more jams... especially if the internal
> transition wasnt perfect between the 2 hot end
> parts.

Yes the join has to be pretty seamless or it will jam. With a Wades type extruder the top end of the PEEK is attached by bolts so no support is needed at the hot end.

>
> The Hybrid one was similar to the PEEK but without
> friction issues... but i kept some of the PTFE
> issues, if screwed in too tightly the ptfe could
> warp, too loose and the gap would cause a jam.

Yes my experience also with Brian's. It is critical how far the barrel is screwed in but if you get it right it works. For my plumbstruder the brass barrel also screws into the PTFE. The PEEK makes the mechanical support but the seal is in the PTFE. Normall that would bulge and leak but when fully constrained it just gets tighter as it gets hot.

>
> I would be happy to do some testing video with
> anyones stuff, for good documentation purposes,
> and Im not afraid of buying the parts to do that
> testing with... I'm not religious on this subject,
> if a simple or older design works just as well or
> better than some of my newer ones I would be just
> as happy to have another working extruder.

The only problem I have with the hybrid design is the top gets too hot for PLA.

---

[www.hydraraptor.blogspot.com]

Quote
nophead
The only problem I have with the hybrid design is the top gets too hot for PLA.

@nophead: What temperature do you print PLA at?

My hybrid PTFE/PEEK hot end from Brian suffered the problem that happens with just PTFE hot ends.
My current hot end is however a similar type of design and I print only PLA (at 210 degrees C) with no such problem.

---

Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Anthong Redbeard Wrote:
-------------------------------------------------------
The Hybrid one was similar to the PEEK but without
friction issues... but i kept some of the PTFE
issues, if screwed in too tightly the ptfe could
warp, too loose and the gap would cause a jam.

I had an issue with that, but what I now do is when I screw the barrel into the PEEK and it buts up against the PTFE I see how easy it is to push som filament into it and through the transition zone. If there is any resistance I stick my 3.2mm drill bit in and turn out the bulging area. Then I remove the barrel and once again turn my 3.2mm drill bit ensuring I remove all scraps of PTFE from the thermal break and the barrel. Screw the barrel back in and check again. I screw my barrel in quight tightly and having removed the PTFE that bulges inward I have no problem. My seal is good and as I said earlier - 6 verticies and no problem yet.

I also had a leaking problem where the barrel and the nozzel were not sealing properly, but again I tightly screwed the nozzel on and no leaks there either thus far.

Keep banging away Anthong. You will get there in the end

thanks, I'm there... just using different designs, which was my point in the beginning... same idiot, accident prone operator can still get printing with a different design... however, I DO have a lot more expereince at this point. I may be able to make the others work as well, knowing what some of the issues are.

One tool that is very valuable to me no matter what extruder I run at the time is a 3mm round file... intended for sharpening chainsaw blades... I run it through ptfe stuff whener it warps, or gets narrows, clean it up good and resume. It has helped a lot.

nophead Wrote:
-------------------------------------------------------
> Anthong Redbeard Wrote:
> --------------------------------------------------
> > PEEK there seemed to be friction issues, itseemed
> > to transfer more heat than PTFE, and allow the
> > filament to be hotter than PTFE,
>
> Yes that is my experience also.

PTFE/PEEK have about the same thermal conductivity (0.23 vs 0.25 W/m*K). Either PTFE or PEEK is "blended" or there is some other effect, like not the same thermal contact.

Some time ago i spent some time looking around for info on advanced plastics and afaik all advanced plastics in commercial sorts have aditives which radically, totally change their properties to the roof. I found that is incredibly hard to pull information from this field as almost every recepy and composition is patent protected and more or less commercial secret, but also because almost all sellers have no clue what they are actually selling. Nobody wants to say (or knows) the exact composition and etc, but some properties are available at big producers, however they dont seem to be comparable to each other (using different testing methods, technical bloat, etc). I guess what actually goes on the market and can be found by me (or to say, within the reach of random guy), is only the mere ends of production from business-to-business orders that were made for a purpose and with certain specifications and may or may not be suitable for our purpose(s).

Talking about ptfe or peek, but each exact type matters alot as these stuffs have (more or less depending on manufacturer) 20+ commercial variations each and the mechanical thermal and structural strength properties differences are to the sky between each other variation. From what i saw to be most common variations here is what i remembered.

PTFE:
Pure (only the pvdf polymer without any additives) has a melting point at 175C (!) and can work in continuous mode only to max 150C. Almost anything is additivated and thus rated at 260-280C temp. Thermal conductivities (W/Kxm) from 0.20 up to 0.77 in some cases. For example addition in ptfe of 15-40% glass or mica(!) increses strength by alot at the expense of an increase in friction (gives an ~ ivorish color). Result is 9 times better in terms of deforming under load and the dilatation coeficient is only 1/5 of that of pure aluminium. There are like countless sorts of ptfe on the market and the differences between them are huge in terms of mechanical resistance and thermal conductivity. All have super low dinamic friction coeficients. Generally ptfe commercial sorts may vary in resistance to traction from 50-300 kg/cm2 with an elongation property directly proportional to it (more or less). Some sorts are actually more brittle.

PEEK:
Peek has a melting point at 340C and vitrous state transition at 150C, around which pind all the properties starts to degrade. It can work continuous mode at 250C or short time peaks at 310C. What i have met the most are variations:
- addition of 30% fiber glass (+strength +friction, in fact gets slightly abrasive so recommendation is strongly against any sliding application); thermal conductivity ~0.43 W/Kxm; color grey-brown; this seems most common sort because ppls buying it want strength so additions to increase this property even further makes sense, peek sorts dont seem to care much for friction because i think who wants sliding applications normally use teflon not peek anyway;
- with 30% carbon fiber (+mechanical properties and lower friction, but increases up to ~3,5 times the thermal conductivity, e.g. 0.92); color darker than usual, even black color;
- with 15-30% graphite addtition: even lower friction and keeps thermal conductivity still low (not sure but i think it has somewhat less mechanical strength so it doesnt seem to be common for that reason); color still darker to black, like above;

My personal conclusions about comparing different peek and ptfe sorts:
- true in all situations, the ptfe has the lowest friction, not only to peek but to most substances (almost comparable with ice-on-ice friction coef up from approx 0.02)
- mostly true: peek is generally more rigid than ptfe, but its rigidity decreases almost 6-7 times from 100C to 230C.
- there are many teflon sorts more thermally conductive than peek
- ivorish teflon is supposed to be stronger mechanically (either that, or if its the wrong sort it may melt at 175C)
- most of the peek on the market is recommended against sliding application because of the abrasion properties of fiber glass addition, however the sort with graphite should (!) have no issue;

Also generally speaking:
- true with no exception: price is directly proportional to the qualities you want the plastic to have;
- there are sorts of plastics that will be much better than ptfe and peek, but as peek is like 2-3 times more expensive than ptfe, the same other suitable sorts will be like 8-9-10-20 or hundreads times more expensive and also out of reach, null availability or require massive orders. Going to the extremes, a certain plastic range will be monitored (!) and may have trace identifications inside.

No clue how hard or how good is this data, and this is just an overall opinion or so.

Edit: dunno how accurate this is, but some data for this discussion:
- ptfe friction coef: starting with 0.02 (but rarely found like that) depending on additives most sorts around 0.12, some up to 0.23 // thermal coef as mentioned 0.20 (white color) up to 0.77 (ivorish color)
- peek friction coef: fiberglass sort 0.30-0.45 and carbon sort 0.20-0.30; graphite sort 0.15; thermal coef as mentioned 0.43 (fiber glass sort), 0.92 (carbon fiber sort), 0.25 (graphite addition);

Edited 2 time(s). Last edit at 04/12/2011 12:19PM by NoobMan.

Adrian's latest hybrid PEEK/PTFE design that he calls PTFE Sleeve Nozzle uses a thin-walled teflon tubing which should take care of the bulging problem that AgeingHippy wrote about. The teflon sleeve also goes all the way down near the tip so there should be less friction.

I swithed to a mendelpartsv6 yesterday and it works great. lets see if it stays that way.

This is great information. This is probably the most likely reason why some people have been successful with PTFE only thermal barriers and some have not. The PTFE is not always the same.

Regards,

Brian


NoobMan Wrote:
-------------------------------------------------------
> Some time ago i spent some time looking around for
> info on advanced plastics and afaik all advanced

SNIP

> purpose and with certain specifications and may or
> may not be suitable for our purpose(s).
>
> Talking about ptfe or peek, but each exact type
> matters alot as these stuffs have (more or less
> depending on manufacturer) 20+ commercial
> variations each and the mechanical thermal and
> structural strength properties differences are to
> the sky between each other variation. From what i
> saw to be most common variations here is what i
> remembered.
>
> PTFE:
> Pure (only the pvdf polymer without any additives)
> has a melting point at 175C (!) and can work in
> continuous mode only to max 150C. Almost anything
> is additivated and thus rated at 260-280C temp.
> Thermal conductivities (W/Kxm) from 0.20 up to
> 0.77 in some cases. For example addition in ptfe
> of 15-40% glass or mica(!) increses strength by
> alot at the expense of an increase in friction
> (gives an ~ ivorish color). Result is 9 times
> better in terms of deforming under load and the
> dilatation coeficient is only 1/5 of that of pure
> aluminium. There are like countless sorts of ptfe
> on the market and the differences between them are
> huge in terms of mechanical resistance and thermal
> conductivity. All have super low dinamic friction
> coeficients. Generally ptfe commercial sorts may
> vary in resistance to traction from 50-300 kg/cm2
> with an elongation property directly proportional
> to it (more or less). Some sorts are actually more
> brittle.
>

SNIP

Has anybody been successful with PTFE only? I think it always fails in the long run and is simply not suitable because it isn't strong enough mechanically at 240C.

---

[www.hydraraptor.blogspot.com]

Although probably the ppls pre-conceptions or prejudices on the matter might be true in majority of situations, there have to be some cases where the things are the other way around - proportional to the diversity of what comes from manufacture maybe. Further on, almost all of the advanced plastics can be re-melted, re-used, even scraps might get used again, so will have same generic properties but somewhere lower values and quality, and i think items like this probably make a good share of what is available to us as reprappers. This can also impact the success rate.



reifsnyderb Wrote:
-------------------------------------------------------
> This is great information. This is probably the
> most likely reason why some people have been
> successful with PTFE only thermal barriers and
> some have not. The PTFE is not always the same.
>
> Regards,
>
> Brian

Hello,

From what I have read on both this board and in others blogs, I don't think so. (Note: I don't have a 3d printer myself. This is just from information that I collected.) The people who reported some success usually had the PTFE thermal barrier supported with a hose clamp, piece of copper tubing, a support washer, some other means of providing support, or a combination of the above.

Even after all of those extra measures, it eventually fails anyhow. While I can't remember the exact duration, I seem to remember reading that somebody achieved over 100 hours (I think the claim may have been several hundred.) with a supported PTFE thermal barrier.

While the original version of the Geared Extruder Nozzle is an improvement, the threaded joint between the brass and the PTFE is very fragile. If there is any stress on this joint it will quickly fail and leak.

Regards,

Brian


nophead Wrote:
-------------------------------------------------------
> Has anybody been successful with PTFE only? I
> think it always fails in the long run and is
> simply not suitable because it isn't strong enough
> mechanically at 240C.

Edited 1 time(s). Last edit at 04/12/2011 12:24PM by reifsnyderb.

Good point. Some PTFE is listed as being recycled.

I probably should also have been a little more clear as to what the definition of "success" is as even the "successful" PTFE thermal barriers still have a relatively short mean time between failures.

Regards,

Brian


NoobMan Wrote:
-------------------------------------------------------
> Although probably the ppls pre-conceptions or
> prejudices on the matter might be true in majority
> of situations, there have to be some cases where
> the things are the other way around - proportional
> to the diversity of what comes from manufacture
> maybe. Further on, almost all of the advanced
> plastics can be re-melted, re-used, even scraps
> might get used again, so will have same generic
> properties but somewhere lower values and quality,
> and i think items like this probably make a good
> share of what is available to us as reprappers.
> This can also impact the success rate.
>
>
>
> reifsnyderb Wrote:
> --------------------------------------------------
> -----
> > This is great information. This is probably
> the
> > most likely reason why some people have been
> > successful with PTFE only thermal barriers and
> > some have not. The PTFE is not always the
> same.
> >
> > Regards,
> >
> > Brian

Edited 1 time(s). Last edit at 04/12/2011 12:27PM by reifsnyderb.