thanks loads guys gees, must be Brain Freeze from the cold Northern climate or something.
the 2 people calling our advice on SD2 printer issues nonsense. finally admit they never even owned an SD2.
way to go with discrediting knowledgeable users of a machine in question, then telling us to calm down and stop over reacting DUH. read b4 replying. and its NOT just a temp control thing either, its a combination of things.

the SD2 is still a great 3D printer long as you understand its limits and needed upgrades for more options in materials. when I had my 3Dhubs hub My SD2 was classified as an 'Ultra high quality finish' due to its smaller nozzle and calibration ability of user/machine with only SLA type printers able to slightly surpass it on tiny prints which is my main printing type items. but 3Dhubs didnt bring much jobs with only 4 customers in 4 years lol so as it is the largest such site I will no longer waste time trying those markets. most those clients have no clue what to expect from 3D printer owners or printers much less cost/time to print items. many would just send a single JPEG of an item with Copyright seen at a store and ask if you can make one just like it for a fraction of the cost and send it to them tomorrow ROFLMAO. starting from designing from that 1 pic. so yeah lucky I even had 4 real jobs completed.

I don't think I ever used the word "nonsense", my English is limited but I somehow feel it is rude to use it, I may be wrong about this.

Also when I reply to the post, I did not realize we are talking about SD2 specific issue, I was more interested if Carl's CTC can switch between ABS and PETG following this method.

I have not used PETG before, and I'm very much interested using it when the price goes down. If switching between ABS and PETG involves replace hotend can make things complicated, I do have whole box of E3D clone I bought 1 year ago, just need to make clip on hotend mount like Da Vinci Jr. so that it is easy to swap.

Well as with my previous post I was asking about better more modern machines. That includes better nozzles and the like. I had destroyed a nozzle trying to remove it before. Not a fan of gentle parts.

yes I know, sorry for my rude buddies.

you also stated in the 1st topic you had an SD2 and some of us were just trying to help you understand and work with what you have until you feel comfortable knowing how to do all the basics and learn what you want to upgrade to.

the Nozzle you destroyed was likely on that SD2 and that is why there are how to videos on here and youtube for this as those factory hotends were not service friendly and also topics here with links etc for upgrades.

its easier/cheaper to fix & use what you have through the learning curve so not to waste money on a much costlier unit during the process.

the SD2 is still a great 3D printer long as you understand its limits and needed upgrades for more options in materials. when I had my 3Dhubs hub My SD2 was classified as an 'Ultra high quality finish' due to its smaller nozzle and calibration ability of user/machine with only SLA type printers able to slightly surpass it on tiny prints which is my main printing type items. but 3Dhubs didnt bring much jobs with only 4 customers in 4 years lol so as it is the largest such site I will no longer waste time trying those markets. most those clients have no clue what to expect from 3D printer owners or printers much less cost/time to print items. many would just send a single JPEG of an item with Copyright seen at a store and ask if you can make one just like it for a fraction of the cost and send it to them tomorrow ROFLMAO. starting from designing from that 1 pic. so yeah lucky I even had 4 real jobs completed.

If this is the case, you can not take the temperature from the above method, instead, find out what is the minimal temperature that allow you extrude filament from the nozzle and what is the optimal temperature to get best print quality (if you turn off layer cooling fan, it will print well while not oozing too much).

When you unload PLA, preheat nozzle to PLA minimal temperature, when you load ABS, preheat nozzle to ABS optimal temperature and extrude 2 ft filament from nozzle.

When you unload ABS, preheat nozzle to ABS minimal temperature, when you load PLA, preheat nozzle to ABS optimal temperature and extrude 2 ft filament from nozzle.

Also when you unload filament, let extruder unload it instead pulling with your hand, pull out too fast with nozzle temperature higher than minimal temperature increase the risk of some plastic stuck in PTFE tube in some hotend designs, which will be harder to purge out with normal approach.

also this issue is SD2 specific it seems

Ok, so it seems we ALL need to take a step back and cool our jets a little.

I have never had an SD2, so have no knowledge of what it did, or did not come with, or what it was/was not capable of.
Yes, I can understand your frustration with what you experienced, but NO, I was NOT calling you, or anyone else a Liar. Not even close.

i apologize if you took the comment personally - it was not intended as such.. at this point I will bow out of the conversation.

and as much good info as you guys usually supply on this site most the time, I couldnt believe it when you replied with such a harsh statement against others just trying to warn newbies of such an easy to mess up issue to avoid so they dont ruin their machine and give up on 3D printing when it can be avoided & left to maybe more experienced users. especially when even Solidoodle themselves warned against swapping between the 2 types of filaments on the same model machines for this reason.

and the method you explain for purging old filament dont clear 100% of the PLA that is plenty large enough when crystallized to restrict the much smaller SD2 nozzle and cause feed jams, excess heat and permanent damage to parts of hotend. do you think those of us that have experienced this 1st hand intended to ruin our printers?? if it had happened to you would you be POd over it and even more so when others called you out over it in the way you are doing? think about that just a minute before continuing this annoying practice of rubbing salt in old wounds needlessly just for self glorification which is all that it is.

also this issue is SD2 specific it seems, just like the nearly 2 year long debate on imperfect circles was an SD3-4 issue due to using same thickness frame metal and rods for a build area 33% larger putting much more stress on them causing twist,flex and bowing of said parts which the SD2 did not experience and SD2 machines always had no issue with perfect circles. yet us SD2 users didnt rub that in your faces even though it seemed to take forever to figure out the simple design flaw on Solidoodles behalf and after lots of trys finally fix it.

so lets all be a little more understanding and less short tempered or Heart-less towards fellow members on posts for help  here please. now back to OP question as this pecking is futile.

heartless wrote:

carl_m1968 wrote:

This was assuming you don't have an E3D which many of us still don't. That hotend does make big difference in all aspects and operations of printing including changing material.

If I could design a dual carriage for two E3D that would not cost me any of my 150 Z height I would use them as well. But there is little support for my CT'c Dual in the after market parts area.

Again - nonsense.. I did swap between PLA and ABS regularly using the stock Solidoodle hotend and we all know how crap-tastic those were.. it is all in HOW you make the swap. setting the correct temps for the initial purging is key!

Well instead of bashing us for being wrong why not share those magic numbers for others who might want them rather than acting like your some magic printing guru?

Just because YOU have had luck making filament switches does mean it works for everyone nor does it mean that those that have mentioned having issues are spouting nonsense. Maybe consider for a moment you have just been lucky? I mean after all a simple Google search yields millions that have had clogging issues after trying to switch filaments. So obviously you have some magic numbers no one else has used or you where just lucky and you don't need to be calling the comments of others BS or nonsense when they are not the only ones who have experienced an issue that seem only you have not.

Don't get me wrong, I respect your opinions and knowledge most of the time but I think in this example you may be just a little out of line.

Maybe next time instead of calling another post Nonsense you could simply say that YOU have never had that issue and then suggest something to try.

And now you know what it feels like on the other end of a blanket statement.

I know you and I have butted heads in the past, Carl, but I still respect you and your opinions as well.
I guess the lesson here is we both need to learn to not make "blanket statements" like these.

See my post above for the "magic numbers" thing.

yeah tried that, it didnt work... with the SD2 factory extruder with plastic peak and .25 nozzle and factory heater with limit set. there are several things you will have issue with burning PLA already in extruder when trying to push it out with ABS IF you can get to 230C without tripping limit or frying heater or board connections you will melt peak at least enough to cause jams feeding and ware motor out skipping. plus the PLA your trying to push out will crystallize and turn black at least partially clogging that .25 nozzle plus cling to the inside of feed tube where it necks down into hot end/nozzle. I know this not only from dozens of youtube videos about how PLA cooks when over heated but also because I bought a pack of very costly Phosphor bronze rods in .08 dia to push melted plastic back up out of hot end when heated to remove any PLA/ABS/burnt clogs out and at same time wasted most that rod as it could not be re-used. but by the time I completely cleared it damage was already done to hot end, feed drive motor, peak etc so havnt been able to use my SD2 for 2 years due to no funds to upgrade/replace all these parts including board and PSU needed to power upgrades. so I say you all that claim its NO BIGGY easy to do HOG WASH! and from this ol Missouri boy "SHOW ME", that west coast smug attitude wont cut it on this issue as its the main reason besides Atlas scanner aggravation that my dreams of 3D printing have ground to a halt. I got near a full white roll of that dam PLA that you can have and never want to see PLA again. who cares if it smells like Maple syrup, it degrades fast in wet,Sun areas dont paint as easy as ABS which BTW is what plastic model kits been made of since the 60s. PLA 3D printing is for children to play with for as I'm concerned. so just stow it. make a Youtube of you printing an item using a factory original SD2 in ABS, then use same printer and do same print in PLA, then switch back to ABS and try printing a 5 hour object with that same smug zero issues. until then DONT TELL OTHERS that lie while calling those of us that KNOW better We are liers. hell next thing you'll be trying to tell us is you run you car on Karo syrup when low on gas and it dont lock up engines like 100 years of mechanics have proven it does. ROFLMAO

Your attitude here is just a little unfounded, n2ri.

At no time did I call anyone a liar.
I simply stated that one does not have to change their hotend to be able to do this.
Just because you, and apparently plenty of others, have had problems does not mean "everyone" has problems.
And it does not mean I, or others like me - the "lucky ones" as carl calls us - are liars either.
Learning the correct way of doing it, however, IS important. If it is done wrong, then yes, there will be problems.

I have done it, and still do it, all the time, with no issues.
you want video of it? I can provide that for you if you really, really want it.
I do not own an SD2, however. The best I can offer is an SD4.
I think I might still have a stock SD4 hotend around... would have to do a bit of digging to make sure.

And can you please learn how to use the "enter" key? That one, big, massive pile of print is difficult to read.

Those of us that have/had Solidoodles KNOW that the stock hotend temp settings are not "typical" of most.
For mine, the stock hotend temp for PLA was in the 165c range, ABS was in the 195C range.. those were the settings that worked for me, on my machine, without issues.

So, taking the "actual" temp settings with a grain of salt... no, on the stock hotend, one did not use 245C.

I cannot believe I am saying this, but Yizhou.he is (gulp) correct - you use the higher temp setting to start with.

When switching from PLA to ABS... set the temp to YOUR machine's required temp for ABS, turn it on.. as SOON as the temp is high enough for the PLA, start extuding it to purge the hotend. This way it does not get burned and cause a clog. continue extruding until all the PLA has been purged and you get clean ABS coming out.

When switching from ABS to PLA - again, set the temp for the ABS, when hot enough start extruding until you get PLA coming out, then immediately turn the temp down to the correct setting for YOUR machine. Extrude more so that any possibly overheated material is expelled.

Done.

Do NOT leave the machine unattended and hot when doing the changeover. You need to be paying attention to it and what is coming out of the hotend at what temperature.

For those that STILL have issues doing this, there is a "cleaning" material you can use in between materials to completely purge one before starting another. I, personally, have only used it a couple of times and only because a friend sent me a sample of it to try, but it is out there and it does work.

you do NOT have to change your hotend to be able to do this. A little common sense will go a long way.

I know it can cause clog if not doing it right, this is my magic method:
Squeeze out 2 feet filament from the nozzle at 230C regardless you switch to ABS or PLA.

I think this should work when you switch between ABS and PETG, but not sure.
Squeeze out 2 feet filament from the nozzle at 245C regardless you switch to ABS or PETG.

yeah tried that, it didnt work... with the SD2 factory extruder with plastic peak and .25 nozzle and factory heater with limit set. there are several things you will have issue with burning PLA already in extruder when trying to push it out with ABS IF you can get to 230C without tripping limit or frying heater or board connections you will melt peak at least enough to cause jams feeding and ware motor out skipping. plus the PLA your trying to push out will crystallize and turn black at least partially clogging that .25 nozzle plus cling to the inside of feed tube where it necks down into hot end/nozzle. I know this not only from dozens of youtube videos about how PLA cooks when over heated but also because I bought a pack of very costly Phosphor bronze rods in .08 dia to push melted plastic back up out of hot end when heated to remove any PLA/ABS/burnt clogs out and at same time wasted most that rod as it could not be re-used. but by the time I completely cleared it damage was already done to hot end, feed drive motor, peak etc so havnt been able to use my SD2 for 2 years due to no funds to upgrade/replace all these parts including board and PSU needed to power upgrades. so I say you all that claim its NO BIGGY easy to do HOG WASH! and from this ol Missouri boy "SHOW ME", that west coast smug attitude wont cut it on this issue as its the main reason besides Atlas scanner aggravation that my dreams of 3D printing have ground to a halt. I got near a full white roll of that dam PLA that you can have and never want to see PLA again. who cares if it smells like Maple syrup, it degrades fast in wet,Sun areas dont paint as easy as ABS which BTW is what plastic model kits been made of since the 60s. PLA 3D printing is for children to play with for as I'm concerned. so just stow it. make a Youtube of you printing an item using a factory original SD2 in ABS, then use same printer and do same print in PLA, then switch back to ABS and try printing a 5 hour object with that same smug zero issues. until then DONT TELL OTHERS that lie while calling those of us that KNOW better We are liers. hell next thing you'll be trying to tell us is you run you car on Karo syrup when low on gas and it dont lock up engines like 100 years of mechanics have proven it does. ROFLMAO

I think this should work when you switch between ABS and PETG, but not sure.
Squeeze out 2 feet filament from the nozzle at 245C regardless you switch to ABS or PETG.

I hate to say this, but I agree with heartless on this issue. I have more than 20 3D printers, they came with different hotend and have no issue switch between ABS and PLA. I did squeeze out 2 feet filament from the nozzle at 230C regardless ABS or PLA. I imagine Carl's issue may because he use PETG and ABS, and I suggest try purge at 245C. Always purge at the higher temperature of the two filament you are switching.

I think for CTC Dual, if you want to switch to E3D without loss max z height, you will have to switch to bowden setup. This can be a problem if you plan to print flexible material. Direct drive setup also get clog partially easy when filament run out or break inside. keep filament dry and use filament sensor can be very helpful.

So you must be another lucky one. Again I point out there are countless post on google of the exact issue we are talking about. So two who have never had the issue versus many who have simply mean the two have been very lucky and maybe they should play the Lotto more as well.

I am not saying either of you are wrong. I am not saying a million with the issue are right. All I am saying is that there is an issue with changing filament materials and getting clogs. So if you have some magic method that works for you maybe share it with the community rather then just boasting and making it sound as if you have L33T skillz..

All I know is that have one hotend right now I can't use because I went from PLA to ABS and now I cannot get all the ABS out no matter how hot I go and trust me I have went to 350 in desperation which probably just cooked the clog even more. I am getting ready to change out my mainboard to an Azteeg X5 so I can take advantage of the Bigfoot drivers. I am  also replacing the X carriage completely with an entire new assembly motors and all. So I would like to not get another clog if possible.

I think for CTC Dual, if you want to switch to E3D without loss max z height, you will have to switch to bowden setup. This can be a problem if you plan to print flexible material. Direct drive setup also get clog partially easy when filament run out or break inside. keep filament dry and use filament sensor can be very helpful.