Feedback for the manual (thermal head, I cracked something)
Hello,
something for the building manual (i3 MK2). When building the thermal head I cracked the plastic. It is the place where you have 2 square nuts in place close to each other. I was convinced that the screw was intended to pass through both of them. But one of the nuts was not correctly in place. It was also not clear that the screw must not be to long. So I tried to screw the screw through both nuts but the force against the furthers nut cracked the plastic.
Only later in the manual I discovered that one screw must go through one nut and later a second screw would go through the other nut for the back side when you mount it to the machine.
The manual should state caution and only use the correct screw at this stage.
The crack is minimal, if needed I can repair it with glue I think.
Re: Feedback for the manual (thermal head, I cracked something)
I really don't want this to sound like I'm being condescending but every screw size is marked clearly in the instructions as to where it should go.
Re: Feedback for the manual (thermal head, I cracked something)
But this is the only screw that can damage the kit.
If you wonder why I took the wrong screw, my eye sight is not that good as it used to be and the difference between crack and no crack is 1 or 2 mm different size of screw. You barely notice it.
Re: Feedback for the manual (thermal head, I cracked something)
Thanks obaeyens
I am sure Prusa will look to add something when updating the manual. All feedback is helpful. And the more warnings the less chance of it happening to anyone else. 🙂
We do still however have people not reading and putting the bed frame on upside down and asking why the screws do not meet up. so it is then a case of if the assembler decides to read the warnings 😆
Re: Feedback for the manual (thermal head, I cracked something)
I am dyslectic so written text does not work for me.
But when you are building it you feel excitement, you enjoy the process of discovering. You are more focused on the built than the manual.
It is actually interesting that Prusa not only have to build a good working printer, but on top of that design it in such a way that people that maybe never put something together can do it too.
It is the first real machine that I ever completely assembled. I am not a trained mechanics engineer, neither do I have lots of mechanics experiences. I definitely are in love with this printer and the fact that I can now pick up together and improve its design.
Re: Feedback for the manual (thermal head, I cracked something)
You should put this in as feedback on the specific step that you are talking about in the online manual.
http://manual.prusa3d.com/Guide/5.+Extruder+Assembly/114
(just click the little speech bubbles next to the step in particular to add a comment)
That way folks reading the online manual can see your feedback and take notes, Josef also views the feedback there as well and sometimes updates the online manual with helpful hints such as yours. 🙂
(you can understand due to cost of printing they dont update the written manuals as often. )
Re: Feedback for the manual (thermal head, I cracked something)
I'm really glad you took what I said in the manner it was intended. Sometimes it's hard to word things properly without upsetting someone.
I was wondering if there isn't a way to color the threads without gumming them up? Then they could shown in the manual as to which color goes where. Wouldn't want to color the caps as that would take away from the aesthetics.
Re: Feedback for the manual (thermal head, I cracked something)
@richard.l its ok we still love you 😆 The written word in a forum can upset people, I know. We should all follow the 12 steps. Or the 10 steps!!!! or what steps? Or just comment freely as we find things 😉
Nigel
Life is keeping interested and excited by knowledge and new things.
Re: Feedback for the manual (thermal head, I cracked something)
I checked the manual, actually it is correct what it says. It does talk about 2 different screws.
It is hard to think how to improve, the point is that you should take the shorter screw for the part where you find 2 square nuts and it should only go through the first nut. The furthest nut will be used by a screw from the back when we montage it to the big frame.
My reasoning of thought (I am not a mechanical guy) is that the 2 square nuts was trying to distribute the force evenly so I thought that I had to screw it harder to keep the extruder in position. But the second nut was not deeply enough so I cracked between the screw and the first nut.
Is there a way to print that part again?
Alternatively I was thinking about gluing it, but I am not sure yet if glue affects the plastic. I assume that it is BSA? (It is orange)
But first I want to see the printer print and maybe it is OK without having to touch it.
Re: Feedback for the manual (thermal head, I cracked something)
In the early days of the Mk2 this was an issue and the part could easily crack with the correct screw without too much tension (it happened to me).
The part was subsequently strengthened to prevent the problem, but over-tightening will still cause the cracking.
The part is ABS and can easily be glued with superglue or ABS juice. I used the former and have not had any issues with the repair.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Feedback for the manual (thermal head, I cracked something)
Thanks.
The extruder is working on my printer, just issues with sticking the ABS to the bed.