DIY tech shop defective hotends

Quote
cfy7
The fire hazard pard scares me though, what do you consider a fire hazard? The pla sitting on top of the brass block? Would that reach temperatures hot enough to ignite? Thanks for the warning.

What I don't like with this design, besides it's leaking, is the orientation of the heater cartridge.

The distal and proximal ends of a heat cartridge are cooler than the center.

With the heater cartridge orientated orthogonal to the axis of flow, the heater has to
over compensate (i.e. operate at a higher temperature) to increase the temperature at the nozzle.

If the plastic flows down and over the hottest part of the heater, or worse
is wicked, or dripping into the heat cartridge well where it's the hottest,
it's possible that a fire could start, but will one start I don't know, leaking plastic looks unsafe.

If you look at the latest designs of hot ends you will note that the majority have orientated
the heat cartridges tangential to the orifice axis, or in the case of the Pico design parallel.
These designs are more efficient as they are locating the hottest part of the heat cartridge near the work zone.
Possibly they run a little bit cooler as well, as they don't have to over compensate to push the heat a greater distance.

There are so many different scenarios to consider, be as safe as you possibly can be, you don't want a home fire.

It's best if the hot end didn't leak.
Hot ends are called hot for a reason.

Just an update .. I sent two defective hotends back to DIYTechshop Mar. 3 .. They should have recieved them a few days later, but haven't heard back from them since. Sent an email yesterday , but no response .. Not super surprising I suppose..

I hope other are getting replacements also.

dwalker dont feel bad i have never gotten anything back from them in under 30 days.

I had one of the bad ones as well from before they say they fixed them. Diytechshop sent a new one out on March18th and I got it today. It came first class mail. They gave me no hassle whatsoever about replacing it. It took a little over a week from when I first emailed them to get it.

I've put it together and the tolerances are much better then my first one. The nozzle appears to seat fully into the Peek plastic body.

In order to use it right now though I have to heat up the old one to disassemble it since it's surrounded in melted plastic from the leaking. I'm waiting on some wires from China to set it up since I used the only set I had to wire the thermistor on my E3D.

Once I get it going I'll post an update here on it's performance.

Dwalker, I've had a couple emails get lost when I've tried to contact them, although recently they've responded to everything within 24 hours. In the past When I called them after I felt like an email hadn't been responded to in a timely manner they've taken care of me and done things like shipping stuff overnight or priority mail at their expense.
Also thanks for the advice on the E3D. The thing is amazing. I can't believe how fast you can push filament through it! I kinda feel silly getting this little brass hotend up and running, but perhaps I'll throw on a second extruder. Are you waiting on a replacement or just looking to see if this problem has been solved?

I'm just waiting to see if they solved the problem , but I payed for a hotend so I expect to get one that works.. I figure I can do dual extruders with the second one.

Just wanted to come in and confirm that a J-Head will actually work on the DIY Tech Shop i3x

I had the same issue. Is the J hotend a dirrect replacement or will I have to print out another hotend holder?

Kdoskh is it a direct replacement?

In the 3rd issue of the Reprap magazine Richrap has taken a picture of an energized cartridge heater.
[reprapmagazine.com]



You can see that the distal end is cold, the center is hot, and the proximal end is cooler.
Due to manufacturing variability the center zone can shift.

Little Brass Hotend
[reprap.org]


With the cold end of the heater cartridge near the nozzle, this configuration is more likely to have larger temperature swings.

Another issue is that the heater cartridge is not fully encapsulated within the heater block.
This prevents you from taking advantage of all the heat generated, i.e. waste energy, and it reduces the life of the heater cartridge.



The advantages of the Little Brass Hotend is ease of manufacturing, which lowers the end users cost.
To improve this design, among other things, rotate the heater cartridge 90 degrees, and fully encapsulate the heater cartridge.

Edited 1 time(s). Last edit at 03/25/2014 09:33PM by A2.

So sent the defective heads I had back to DIYTechShop March 3, they confirmed they received the heads March 21 (after poking). And now here we are on April 11 , and still nothing new received from them. I still poke them regularly (weekly or so) , the most recent email was from someone who said they had no idea what the email thread was about but they would look into it.

This might be a more special situation since they told me they were sending me some new type of head they were working on , instead of the little brass head. After reading at A4's post, I can't say I really want a LBH now.

Where are the blueprints for this hot end, it has a CC BY-NC-SA licence so there should be some prints some were.
If there is some thing to work with I'll modify their design.

Little Brass Nozzle created by DIY Tech Shop
[reprap.org]

Hi all,

I noticed this thread hasn't been updated recently and am not even sure if it is still active anyway but I wanted to kinda share my experience with DIY Tech Shop and their support/hot end.

I purchased the i3x kit from DIY Tech shop about a month ago and finally got all the kinks worked out about a week ago and had been working perfect since then. Now two nights ago my extruder kept jamming, I figured it was because I had the speed too high (as this was a previous issue that turned out to be a tuning issue), I got the printer reset and sure enough about 100mm of filament in it jammed again. I disassembled the hot end to figure out what was going on and lo and behold there was a nice little bulge in the middle of the PTFE tube...I only got one section of tube with my kit so I couldn't replace it and make sure I had everything tightened down to try and see if it happened again right away. So I emailed asking for the exact dimensions of the tube so I could get replacement and they told me they were going to send out replacement tube right away and that the jamming issue could be because the speed is too high (don't think it is). They then sent another email asking if I would send the hot end in for their engineers to look at and they would send another.

The long boring story has one goal, I just wanted to add that first they have been good so far with emails (calls get an immediate reply) and they have always been helpful and friendly.
Second, I think there is one thing to keep in mind about the hot end and that is that this is their own design and a new design (less than a year). It is also meant for an open source application and open source cannot evolve without input from the community, I would certainly hope that they are more than willing to take in the folks here's input on their design and consider it to improve upon the design. From what I've seen so far that is exactly what they are willing to do as well since they are more than willing to replace the hot end you have with their latest and analyze the old one for faults.

Now I could be completely wrong and off base about all of this and their willingness to help may go away shortly (I hope not) but that's my opinion on this whole hot end/support debacle.

Update on DIYtechshop hot end.
Even though their website is not updated, they told me they will stop selling their own hot end they called "Crayon" and will sell E3D hot ends.
Not sure what they are actually doing now.
The Crayon they sent me in the Prusa i3 kit, I could not assemble because of manufacturing defect so they sent me a Chinese clone J-head, not sure how long that will last.
I have a spare E3D v6 hot end waiting for my next assembly project - what ever that is.....

RTurnock, I am in a similar situation. I spoke to them last week and was told that they may have to have a hot end crayon made???? Was told they are now offering a different hot end. In the meantime I have a paper weight that craps out uneven blobs of plastic and have to invest more in a completely different part that should be available from them, I'm kinda angry about it. On top of that, getting them to answer the phone and or respond to an email is pretty tough. They are great about most things when you can reach them, but I'm feeling a little jipped on this hot end issue at this point. Neat kit, great policy on helping or replacing parts, when you can get them, but not being able to use the product they sold to me is getting on my nerves. Not sure I would recommend them at this point due to their limited communication ability and not servicing their own product, as in the hot end. Is this normal in the 3d printer industry? Sorry for the rant, just want to be able to print and am so close but for the bed hot end.