Tried something new....I mean different

[BuckeyeVolunteer]

I was tired of replacing the resistors on my stock hot end,( I run mostly ABS at 240) I had ordered some one hung low canned heaters from amazon so I decided to try one instead of the resistors. I checked the fit and they actually fit well with some heat sink grease. I put one on each side and wired them in parallel, put it back together and ran the PID tuning and for the first time ever I actually got consistent results from the PID tune. I have a background in calibration and the results from all of my PID tunes up till now were from my perspective CRAP. It's probably my failure but it's working properly now. Before anyone starts about the thermal runaway I attached a 292 c thermofuse next to the block and wired it into a safety relay I setup for the power supply so if it pops it shuts everything down. My averags were Kp=8.16 KI=0.51 KD=32.86 set at 200c for the hot end. Re-leveled everything and turned it loose! Running Printrbot black abs 240 and 75c. I don't like the Printrbot abs it is too brittle but I wanted to use the rest of a roll and thought this would be good for this test. I'm printing 4 parts for a friend of mine that is making a Prusa I3, he didn't order a kit so I'm helping him with the printed parts. I can say that throughout the print 4.5 hours it kept the temp within 1 degree c for the whole print. Now the true kicker in this test I asked myself why I needed a PTFE tube in the hot end, basically it is for PLA which is a sucky filament in my view of the world, so I took it out before the print,SOOOO, I've been printing with 2 canned heaters and no PTFE tube and working pretty well. Now this probably won't work longterm, but maybe it will? I'll be printing all weekend with it so time will tell and I'll let everyone know the results. I don't care if I screw up my hot end I have 2 ready to take it's place so if It clogss it clogs.

[bubbasnow]

I think 240 the limit for PEEK? that hotend will bend over if something happens to the cooling fan/runaway heater. why are you at 240 for abs??

[BuckeyeVolunteer]

Peek is rated at 247, but the thermofuse is for final protection of the bot not the hot end. I've found that 240 works best for me in ABS but that was with the resistors doing the heating I may be able to lower it now with the canned heaters. It seems to stick better on the plate at 240 at least for me I think alot of that is the environment the bot is in garage, bathroom, living room, closet. Mine is in a heated garage with a clear shower curtain around it to keep the heat in.

[Eaglezsoar]

I was tired of replacing the resistors on my stock hot end,( I run mostly ABS at 240) I had ordered some one hung low canned heaters from amazon so I decided to try one instead of the resistors. I checked the fit and they actually fit well with some heat sink grease. I put one on each side and wired them in parallel, put it back together and ran the PID tuning and for the first time ever I actually got consistent results from the PID tune. I have a background in calibration and the results from all of my PID tunes up till now were from my perspective CRAP. It's probably my failure but it's working properly now. Before anyone starts about the thermal runaway I attached a 292 c thermofuse next to the block and wired it into a safety relay I setup for the power supply so if it pops it shuts everything down. My averags were Kp=8.16 KI=0.51 KD=32.86 set at 200c for the hot end. Re-leveled everything and turned it loose! Running Printrbot black abs 240 and 75c. I don't like the Printrbot abs it is too brittle but I wanted to use the rest of a roll and thought this would be good for this test. I'm printing 4 parts for a friend of mine that is making a Prusa I3, he didn't order a kit so I'm helping him with the printed parts. I can say that throughout the print 4.5 hours it kept the temp within 1 degree c for the whole print. Now the true kicker in this test I asked myself why I needed a PTFE tube in the hot end, basically it is for PLA which is a sucky filament in my view of the world, so I took it out before the print,SOOOO, I've been printing with 2 canned heaters and no PTFE tube and working pretty well. Now this probably won't work longterm, but maybe it will? I'll be printing all weekend with it so time will tell and I'll let everyone know the results. I don't care if I screw up my hot end I have 2 ready to take it's place so if It clogss it clogs.

Could you tell me the source for the 292c thermofuse?

[geneb]

Have you verified your thermistor reading against a thermocouple? I'm usually pretty suspicious when I see people /having/ to run ABS at 240C because I've seen some pretty weird thermistor readings. There's days I'm convinced they're more guessistor than thermistor.

g.

[Polygonhell]

Have you verified your thermistor reading against a thermocouple? I'm usually pretty suspicious when I see people /having/ to run ABS at 240C because I've seen some pretty weird thermistor readings. There's days I'm convinced they're more guessistor than thermistor.

g.

I've said for years, comparing print temperatures between printers is a waste of time, unless people check the thermistors for accuracy. My E3D's if setup as suggested by the factory using the thermistor table in repetier are off by over 20C (read high).
Having said that I usually run ABS at 240+, not because I have to, but because I commonly run cooling on ABS prints and the 240+ gives me a decent bond between layers.

[BuckeyeVolunteer]

I actually just had the thermofuse, I used to work on copiers and they were located on the fuser unit against overtemp, I can dig up a source but most likely the best place would be a copier parts supplier. I've printed about 16 parts for my friends Prusa I3 still working fine and prints coming out good. I haven't verified it but it's kind of relative you just need to do a temperature test with your filament to find what works best with your printer. Now I just need to fix the heat plate so it heats up faster, I believe it will need to have it's control separate from the Rambo board.

[BuckeyeVolunteer]

Well I've had the dual heater installed for over a week now on the hot end and have had nothing but success with the dual chinese heat cans instead of the resistors. The calibrations on the hot end have become consistent and quick to heat up and stay at the correct temp. I did pull the hot end to see the effects of no having the PTFE tubing in it and I saw no problems and haven't had any clogs either. But in evaluating this setup I've decided to instead insert a ceramic tube in place of the PTFE tube. The reason for this is I believe if I was really cramming filament through the hot end fast there is a possibility of clogging without the PTFE tubing present to keep it on a straight path. I've found that simplify 3d has an ooz control and if properly setup will remove the need for retraction which is really what causes the clogs in my opinion feel free Gene to beat me up about this. Now none of this is scientific and I am just an old guy making stuff so take it with a grain of salt. My biggest problem now is getting the supports to snap off cleaner in simplify 3d it's just a learning process, each filament behaves differently with support so if I find a magic number or setup for support please reply. I want it to pop out and not require pliers or knives or screwdrivers. I have been using Hatchbox filament from Amazon except for a roll of Printrbot filament that I didn't like. This isn't an endorsement just info. I have found a ceramic material called MACOR it is a machinable Glass Ceramic that I think would be perfect for someone to machine a new type of hot end tip and all as one piece instead of the current availability of aluminum hot ends. The properties of this stuff is unbelievable!

[geneb]

If I understand what you've done, you have installed a pair of heater cartridges in the stock hot end and removed the PTFE liner.

Why did you remove the PTFE liner? It's there for a REASON.

g.

[BuckeyeVolunteer]

I felt it was a weak point in the design and I wanted see what would happen with it out. No science just curiosity.

[geneb]

Ok, well removing the liner an then printing with it has basically ruined the hot end. The liner is there to provide a low-friction path from the top of the hot end to the nozzle orifice. The PTFE tubing actually fits down inside the nozzle.

It's quite likely that you've filled the cold section ( the PEEK) with molten plastic as you printed. Once that plastic cools, the hot end is done as you'll never get the plastic plug out of it unless you drill it or by some miracle can drive it out of the PEEK barrel.

g.

[BuckeyeVolunteer]

Have you tried it gene?

[geneb]

No, because I'm aware of the likely outcome. I don't have to smack myself in the forehead with a hammer to know it's probably going to hurt.

g.

[BuckeyeVolunteer]

Ok gene sorry I ruffled your feathers. Things must be tough that you have to deal with morons like myself. This will be my last post on this forum so I don't bother you anymore.

[geneb]

*sigh*

You could've pointed out that I missed this part: "I've decided to instead insert a ceramic tube in place of the PTFE tube", but instead you went straight to being butthurt over it.

Unless your ceramic liner has been sealed and has a highly-polished bore, you'll eventually get a pretty hard clog, especially if you print with PLA.

Apologies for the original reply - my brain locked up at "I removed the PTFE liner".

g.

[BuckeyeVolunteer]

KMA Gene stick your butthurt You have picked on me everytime I posted on here and you are so full of yourself. I asked to be removed completely from this forum and I guess that's too much to ask. So maybe I can get barred Kiss My ever lovin ass Gene you are an asshole. I have forgot more about electronics then you've ever known And your wonderful piece of shit manual is full of holes and bad advise. I tried to keep some civility till you started the name calling, Now please remove all my posts and my account. FUCKIN MORON!

[DeltaCon]

Well, that's a contribution to this forum we can do without...
C'mon Gene, speaking for myself, I DO appreciate your humouristic approach...

[geneb]

Well golly, that was unexpected.

I guess he was so looking forward to the hissy fit, he missed my apology. *shrugs*

g.

[VAXHeadroom]

... But in evaluating this setup I've decided to instead insert a ceramic tube in place of the PTFE tube. ... I have found a ceramic material called MACOR it is a machinable Glass Ceramic that I think would be perfect for someone to machine a new type of hot end tip and all as one piece instead of the current availability of aluminum hot ends. The properties of this stuff is unbelievable!

I realize this is a year old, but was wondering if you had actually replaced the liner with a ceramic (rather than just planning to)? I had the same thought and started looking through the forum to see if anyone else had the same thought. Macor is pretty cool stuff, but I also found: http://www.ortechceramics.com/products/ ... both-ends/ which has tubes in several other materials in stock; I've asked for a quote.
-- Emory