Broken internals of a seemecnc hotend

[nathanstenzel]

Besides the teflon tubing which seems to have an identical inner and outer diameter to my bowden tube, there seems to be another piece of tubing. It is cracked. I have more teflon tubing coming in the mail soon, so I think I can replace that easily, but I have no idea where to get the larger bit of tubing. Help? My hotend is the standard SeeMeCNC hotend.

https://plus.google.com/110783321730730 ... hqohmicAR7" onclick="window.open(this.href);return false;

[Nylocke]

Its not actually cracked. It is a piece of tubing for 3mm filament (4mm ID 6mm OD) that was part of the earlier SeeMe hotends. I think it has been removed from the newer design, but its intentionally split so it fits over the 1.75mm tube (2mm ID 4mm OD). Tolerances ya know.

Judging by the picture it should be alright, after some use the tube tends to brown a bit. When you should get worried about it is when it starts to deform excessively, like your smaller tube. If its excessively difficult to get the smaller tube (the new one) into the larger tube, or you have problems feeding filament into your hotend, then that tube is probably deformed too much to function. I'm sure if you asked SeeMe would send you a new hotend if that tube is an issue. In the mean time just make sure you have a PEEK fan on your hotend at all times and you don't go above 250C.

[nathanstenzel]

Ah. Thanks for the reply. If the outer tube is good, then I should probably be ok assuming I can cut the new teflon tube to the correct length using my dremel tool.

I only use ABS, so I do not plan on using a peek fan. My understanding is that I should not need a peek fan for ABS.

[Nylocke]

You should always have a PEEK fan, regardless of what you print. The point is to keep the PEEK and teflon tubes from deforming at high temperatures, similar to what you have seen. All you need to cut the tube is a razor blade. The teflon is soft enough that you don't need to use a dremel.

[Eaglezsoar]

I agree with Nylocke, you should never turn on the hotend without a peek fan. It is the most important fan in the whole printer.
Please, Please put a peek fan on your printer!

[Mac The Knife]

I assume you could buy the latest version of the Peek section that Seemecnc sells, and eliminate the split teflon tube. I'm sure Guano, or Gene will chime in if I'm wrong.

[0110-m-p]

I agree with Nylocke, you should never turn on the hotend without a peek fan. It is the most important fan in the whole printer.
Please, Please put a peek fan on your printer!

+1

I have my hotend fan wired directly to the power switch on my printer. That way if the printer is on, the hotend fan is on...just incase something gets messed up in the config and the fan doesn't get turned on.

[geneb]

You're correct - the new PEEK barrel design eliminated the requirement for the outer PTFE sleeve.

g.

[nathanstenzel]

OK. I finally have a PEEK fan. It is hooked up directly to one of the 12V cables from the power supply. The mounting is ugly and temporary. I tried to hook it to fan1 on the RAMBO and set the pins.h for it, but it did not want to respond that way or on Fan0 either. Screw it anyways. People say to just keep it at 100% speed anyways. I will try to get a good print of a mount for it later. It seems the mount that I had printed for such a thing a long time ago has too small of a hole to fit the fan. It might be ok if I OpenSCAD it and delete a box from it or if I am lucky I can find one. This is the fan that came with the Rostock Max. Any links for a mount would be appreciated.

Now....I tell you folk I must be cursed. My heated bed's wires seem to be heating up at the mountings on the board. It seems those thick wires still have too much resistance. My heated bed was the one that was sold in July 2013. I think it was revision 1 of the Onyx heated bed. I could have swarn I had a good enough wire for hooking it up. At this point, I don't know how messed up the screw terminal is connection wise, but there is scorch on it and a bulge in the side. If the wire was heating up instead of the bed, that would explain why I had such bad heating times despite having 4 sets of 12 wires going to the power for it. I have no idea anymore how many AMPS that would be. There might be some clue in my original build thread.

[nathanstenzel]

By the way, my PEEK fan is pointing inbetween two extruders. It is not pointed at the center of a PEEK heat break. I have tested it though and I can extrude a rather large run of filament with much less in the way of bucking/skipping. This arrangement is about as good as I think I will be able to get it.

[nathanstenzel]

I have pretty much finished an OpenSCAD copy of https://github.com/seemecnc/RostockMAX/ ... shroud.STL" onclick="window.open(this.href);return false; with some adjustments to fit my dual extruder setup. I might end up posting it later. I have that link in the OpenSCAD file. If I can print it out OK, I will use it to hold my PEEK fan.

[teoman]

About the fan pointing in between the PEEK parts,

You could design a part that looked like the mcdonalds M. With the middle part fitting in between the parts. That way the air would be forced to circulate around the parts.

[nathanstenzel]

https://plus.google.com/110783321730730 ... 5FfXJCZ9HM

There is a link to my post about my new cooling fan mount. It did not want to clip on as easily as I wanted it to and the fan needs a shim on the side to keep it quiet, but I heated it up to temperature with no problems and I suspect it will work great.

[nathanstenzel]

About the fan pointing in between the PEEK parts,

You could design a part that looked like the mcdonalds M. With the middle part fitting in between the parts. That way the air would be forced to circulate around the parts.

That sounds problematic....especially since I may later on wish to use the 3rd hole in the hotend mount.

[nathanstenzel]

http://www.thingiverse.com/thing:596964" onclick="window.open(this.href);return false;

[Eaglezsoar]

Thanks for posting the fan mount!

[nathanstenzel]

Thanks for posting the fan mount!

No problem. I hope it is useful to others.

It is roughly version 2, so the ability of it to clip onto the spacers is not tested yet. I have version 1 on my printer and it was hard to clip on, so I enlarged the cylinder holes in the clips before posting.

[nathanstenzel]

http://www.bld3r.com/obj/5818080542326784" onclick="window.open(this.href);return false; There is a 3D design repository link for Bld3r.