Mendel-parts.com - v6 hot end first impressions

I've been using the v6 hot end from mendel-parts.com for a couple of days now, and although that is not enough time to do a complete review, I would like to share a few things I've learned.

• It's working beautifully! I always thought the hardware was to blame for my sub-par print quality, but with a proper hot end and skeinforge 41, I was able to spot the hardware problems. A new belt on the x-axis and metal gears on x and y axis did the trick.
• I (and I'm not alone) needed to glue the PTFE tube/liner to the brass part to avoid it forming a blob which clogged up the whole thing. I did it by roughing up the surface of the PTFE and the inside of the heater barrel, and put on a very small amount of thermal glue. Take care not to clog the barrel! It seems to be working out nicely. Here's a picture after the first failed attempt at attaching it to a wades. The mounting bracket failed, and both the PTFE and PEEK pushed out of the barrel, resulting in all sorts of funky cleanups.

• I don't like to glue the thermistor in place. Both because it would be impossible to remove, and because the thermistor I have from ultimachine is too big to fit. I could of course use the thermistor supplied with the hot end, but then I would have to change the temperature table which is not readly available. Anyway, I went with my decision of attaching the thermistor to a ring terminal and replace the copper ring with it. It worked out fine, but the temperature was WAY off. Because I use to weak springs on Adrians extruder, I had to increase the temperature to 205 degrees to get proper extrusion. After a while it clogged up and I found this inside the barrel. (Be warned, it's not pretty).
•  I now extrude at 180-185 and it works beautifully, I think I could go lower still.
• EDIT: I have a theory the gunk was bits of PLA the extruder grinded off the filament, and not necessarily the temperature.

• I didn't damage anything apart from breaking off the filament guide off "driven-holder.stl". Here I'm printing a new "idler-holder.stl" to have a spare.

• To sum it up:
• The mendel-parts v6 hot end works great!
• Glue the PTFE tube to the barrel (carefully).
• Use strong springs on Adrians extruder.
• Test your temperatures with natural PLA to check for discolouring.
• Skeinforge 41 with volumetric 5d is incredible! (Don't waste your time slicing with the old repsnapper windows build that's available).
• When you turn off the machine, leave the plastic inside. I had no problems extruding straight away when heating it up again. If you pull it out it will most likely form a plug.

Update 01.02.2012: I've used the v6 hot end for a long time, and it's decent. Though because the melt chamber is so large it drools a lot, and the filament lingers a long time when changing colours. The Arcol v3 and J-heads (and others?) has no such melt chamber, only a straight path to the nozzle, which I find is a better solution. This is written only for completeness sake, as the v6 is no longer sold. Though the v9 looks similar, I have not seen it in person and don't know how it performs.

Well.. I'm off to figure out why skeinforge 41 sometimes decides to home during a print. It's no problem when it homes towards the endstop, then it just goes back to printing. The problem is when it anti-homes away from the endstop, trying to push the x carriage or the bed off the bars. I could attach endstops there probably, but that's just circumventing the problem.

Edit: Oh, and I made a funny Minecraft Creeper Keychain, check it out.

 -Nudel

Mendel-parts.com - New v6 hot end and positive experience.

I cringed when I read Camiels post at the mendel-parts.com blog the other day. It's easy to see the frustration, and he does have a valid point about the negative feedback getting the most attention. As I received a package from mendel-parts today, I'd like to share my positive experience with you, while I make a first-impression preview on their new v6 hot end design.

My order was in the €100+ range, which included a 5mm alu printbed and a few spares of the older simpler hotends (now discontinued?), because I know I can get that to work (at least for a day or two). I also ordered a bunch of bootlace ferrules, as I only seem to find insulated ones on ebay for some reason.

The most interesting item though, is this.

This is the newest v6 hot end design from mendel-parts.com, and it looks like it has great potensial. It's machined beautifully, and has a good deal of weight to it. The added weight might have an impact on a theoretical maximum speed, but my main goal is stability over speed anyway.

The only part I don't like is the thermistor attachment, as I don't trust kapton tape, and neither would I like to glue the thermistor permanently to the block. We'll see if I manage to build up the courage to tap a new hole and use a ring terminal with the thermistor on instead.

Another thing I'm a bit curious about is the gap inside the heater block, between the nozzle and the inlet. I have always understood the inside of the hot end needed to be a smooth as possible to decrease the pressure needed to push plastic through. This design have some pretty big threads where the plastic will pack up, and most of us have probably fought with hardened PLA. Yes, I understand they get the design to work very well, though I don't know if this gap has any down sides, especially regarding long time reliability and cleaning.

Edit: I have the peek block the wrong way around in these pictures. More info from araspitfire here.

Back to the order and lead time discussion.

I put in the order 3/26, got a manual order confirmation 3/31, and the package was shipped 4/6. According to the excellent UPS tracking system, it took less than 8 hours to ship the package the ~1000km from the Netherlands to Oslo. It then took 4 days to ship it the last ~100km from Oslo to me, let's blame the weekend for that. All in all I must say it was pretty good!

In total it took 16 days to receive my order, of which 5 days was in transit. I ordered on a Saturday, so the first working day was 28/3. Is 9 days of lead time something to make a fuzz about? I really don't see why people complain. I'd also like to add that they sent me a new printed baseplate for the v6 hotend for free, which they really weren't obliged to do. That's great service!

Some people will probably mention it, and I'd like to agree in advance; this wasn't a complete mendel kit, which may have a longer lead time. But for those of us who have a mendel in our possession, it's irrelevant, because we're mainly interested in fast dispatching of spare parts anyway. And in that regard, I approve of mendel-parts.com, and recommend them as a webshop who delivers what they promise: high quality parts, and a decent lead time.

Update 01.09.2012: Mendel-parts has been getting a lot of bad press over a long period of time, and although the grief is mostly about Orcas, I can not recommend shopping with them until they fix their issues. For high quality extruder hot ends, check out J-heads at hotends.com and Arcol versions at arcol.hu.

Now I'm looking forward to trying out the slick v6 hot end! A proper review is coming up when I have some experience with it running, and made up my mind about it.

-Nudel

A coalition of obsessions.

You like?

First blog, first post, first print!

So, how do one start out one of these blog things? How about a historical event?

I hereby present Aida - my RepRap Mendel - and the first output she produced that did something else than not stick to the platform.

 We have low stiction levels.

And it stayed put the whole time, oh joy!

RepSnapper even predicted the strings.

Hi to everyone on #reprap. Thanks a lot guys, wouldn't and couldn't have reached this RepRap milestone without you!

So, why am I starting up this blog thing anyway? I have a fever, and the only cure is MORE REPRAP. So I went to my doctor and told him, and he gave me a RepRap Prescription. How's that for a blog intro? *insert wacky smiley face*

A proper introduction to Aida is appropriate, and is in the works, meaning I have not even started writing it.

Have fun, all my fellow reprappers, and everyone else.

-Nudel