KickStarter Campaign For Dual Extruder

Hello,

The J-Head Mk V-B weighs 21 grams. This includes the heater resistor and thermistor.

While the parts haven't been tested together, yet, a J-Head Mk V (with an aluminum nozzle) weighs under 13grams. This also includes the heater resistor and thermistor.

Also, the J-Head Mk V series is about 13mm shorter than the J-Head Mk IV series of hot-ends.

Since one hot-end, of this dual extruder, is supposed to be lighter than a J-Head this brings up a question: How much does a hot-end, of the QU-BD extruder weigh?

Regards,

Brian

Looking at what they said earlier, they were saying that a single one of their extruders is lighter and smaller not a dual. I'm not saying that yours won't be lighter but I don't think they said theirs was lighter than yours either, as they don't have one for comparison. I would assume most people would get a single extruder from them anyways.

Hello,

It looked to me as though they claimed that their hot-end (only the hot-end) was lighter than a J-head. I am hoping that they reply with the weight of their hot-end. I am also curious as I have gone to great pains to make the J-Head as light as possible without sacrificing durability.

Regards,

Brian


vulcanrd Wrote:
-------------------------------------------------------
> Looking at what they said earlier, they were
> saying that a single one of their extruders is
> lighter and smaller not a dual. I'm not saying
> that yours won't be lighter but I don't think they
> said theirs was lighter than yours either, as they
> don't have one for comparison. I would assume
> most people would get a single extruder from them
> anyways.

I'd be interested to know as well how much it weighs and if it will be available individually without the cold end.

WildBill...I noticed that you had a budaschnozzle modeled on your thingiverse. Is that the hot end that you are going to use with your cold end or are you developing a new solution?

My dual system is very different from my single, and very different from any existing solutions. It will not have a buda on it as that is a very tall hot end. I'm working to improve reprap not limit it.

You are also correct that they say they base it on the MK7/8 on their gallery page. [www.qu-bd.com]

Edited 1 time(s). Last edit at 06/25/2012 07:15AM by WildBill.

@WildBill Send me a PM when your Kickstarter is up. I will back you.

Plus, then I get to compare your wonder solution to the QU-BD effort

When I weighed them earlier I used the J-head that we had at the office, which is a MKIV-B.

The hot end which includes:
aluminum heater block
brass .35mm nozzle
stainless filament guide
two set screws
thermistor
power resistor

Altogether they weigh 17 grams per our new scale. Most of the volume of material is aluminum which explains the low weight, despite the brass nozzle and stainless filament guide.

***our scale is accurate to .1oz, the actual reading on the scale was .5oz or 14grams, I just erred on the side of caution***

-Chelsea

Edited 1 time(s). Last edit at 06/25/2012 01:34PM by Chelsea - QU-BD.

Hello,

Testing of the 13 gram J-head Mk V will commence very soon and I am planning on offering them, for sale, in limited quantities. As early J-Head Mk IV's were successfully tested, that had aluminum nozzles, and the J-Head Mk V-B works great, I don't anticipate any problems with it.

Regards,

Brian

Very cool on the aluminum J-Head!

Hi Brian,
As a matter of interest; why do you put a nipple on the end of your nozzles? I think a simple cone gives nicer prints and is easier to keep clean.

---

[www.hydraraptor.blogspot.com]

Hello nophead,

The nipple was really a left-over from earlier designs that I never removed because some people mentioned that they liked it. However, after speaking, chatting, messaging, etc., with enough people, it became clear that it needed to go. As of roughly the beginning of June, the nipple has been machined off.

Removing the nipple also allows for a shorter length of the orifice. I am aiming to keep the orifice length at about 0.5 to 0.75mm.

Regards,

Brian



nophead Wrote:
-------------------------------------------------------
> Hi Brian,
> As a matter of interest; why do you put a nipple
> on the end of your nozzles? I think a simple cone
> gives nicer prints and is easier to keep clean.

Edited 1 time(s). Last edit at 06/25/2012 05:53PM by reifsnyderb.

Interesting, I may try filing down my nipple and see what difference it makes , I was always under the impression you needed a flat end to make the filament squish out flat a little bit.

Is a nippleless nozzle less likely to catch on other parts during moves?

---

[richrap.blogspot.com]

Hello,

Yes, it won't catch as easily on parts and it reduces the orifice length. The end does have to be flat, however, having the nipple catch on parts is a problem.

Regards,

Brian


richrap Wrote:
-------------------------------------------------------
> Interesting, I may try filing down my nipple and
> see what difference it makes , I was always
> under the impression you needed a flat end to make
> the filament squish out flat a little bit.
>
> Is a nippleless nozzle less likely to catch on
> other parts during moves?

Yes there does need to be a flat section as wide as your maximum filament width, which is bigger than the nozzle aperture. Having it tapered from then on up makes it easier to plough through any plastic sticking up and you can scrape it to clean it without the knife catching on anything.

---

[www.hydraraptor.blogspot.com]

Thanks, I'll give it a go, I guess this changes the die-swell characteristic's of the J-head.

---

[richrap.blogspot.com]

Hello,

It may change it some, sure. Another issue is that I use drill bits that are slightly smaller than the rated size. Since drill bits drill holes that are larger than their size, I have done this in an attempt to ensure that the hole is of a high degree of precision and will stay within it's rated parameters for a longer period of time. For example, if the nozzle were to be cleaned, it may result in some wear to the orifice. If the hole is slightly smaller, it will stay in spec. for longer this way.

I am thinking that maybe I should just start using metric drill bits that are on-size as this strategy seems to cause more grief than expected.

Regards,

Brian


richrap Wrote:
-------------------------------------------------------
> Thanks, I'll give it a go, I guess this changes
> the die-swell characteristic's of the J-head.

The 3D models and a video of it extruding have been put in the updates section on Kickstarter.

Do you have any news on your extruder WIldBill? I thought a Kickstarter campaign was being launched imminently?

I can't remember where was a discussion about the design of dual extruder hotends (especially the makerbot ones and how it often leak plastic from the unused nozzle), maybe here (or at least not too off topic), so here is a little example to keep in mind about "how they do it"



Picture taken from the inside of a Stratasys Dimension (10-15years old machine still working nicely), the hotend is one block and contain both nozzles for material and support. To avoid draging unwanted filament during the print they use a retract and wipe routine every time they change from one to another. Probably a big rectract (completely removing the filament from the melt zone) to avoid any problems. The drawback of this method is the time it take, especially when you see it doing that at each layer. (but maybe the only way to do proper dual extrusion ?)

Hello,

Since I mentioned a 13 gram aluminum J-Head Mk V, I figured I'd follow-up in this thread and mention that testing has been successful.

Regards,

Brian



reifsnyderb Wrote:
-------------------------------------------------------
> Hello,
>
> Testing of the 13 gram J-head Mk V will commence
> very soon and I am planning on offering them, for
> sale, in limited quantities. As early J-Head Mk
> IV's were successfully tested, that had aluminum
> nozzles, and the J-Head Mk V-B works great, I
> don't anticipate any problems with it.
>
> Regards,
>
> Brian

Edited 1 time(s). Last edit at 07/08/2012 09:31PM by reifsnyderb.

vulcanrd Wrote:
-------------------------------------------------------
> Do you have any news on your extruder WIldBill? I
> thought a Kickstarter campaign was being launched
> imminently?


Sorry, it will be soon. I'm relocating from MN to Houston Tx over the next few weeks and want to wait until I can fully support it. I'll post a new thread about it, rather than muddy this one up as soon as I get moved and situated and can focus on it. I don't want to release something and not be able to give it the attention it deserves.

I apologize for the delay but the wait, I feel, is worth it.

Chelsea - QU-BD Wrote:
-------------------------------------------------------
> The 3D models and a video of it extruding have
> been put in the updates section on Kickstarter.


STL is not a true 3D model, it is a group of triangles and no solids or accurate circles. Those STLs are worthless for actual engineering evaluation. Share real 3D models or don't mention it please.

Also I have looked and still don't see a video of a dual extruder on one of the prism mendel frames you state you have on hand. A video of a single extruder pushing plastic as designed and previously tested by another manufacturer mean nothing on the reprap printing front.

Again, please show us some modal studies and a video of the dual head system on a prism frame printing at speeds near existing single extrusion speeds. I can extrude just as cleanly with my coldend setup, but I bet you cannot achieve the 250mm/s I can. Back up the claim that this is a dual head solution on an unmodified prism frame. Jigged by the book and all. Until you do this cannot be considered a dual head system for a reprap but for a makerbot only.