Very Strange here.. temp holds great for first layer.. then drops like a rock  

Re: Very Strange here.. temp holds great for first layer.. then drops like a rock

PJR: reworked extruder looks great 💡

Re: Very Strange here.. temp holds great for first layer.. then drops like a rock

Hi Roman.

Thanks. Basically it is an i3 extruder with Chinese clone mods. It came about when I realised I could bet an additional 30mm print height with these changes, plus modified Z top and bottom pieces. Now all I need is another 50mm in both X and Y...

Peter

Re: Very Strange here.. temp holds great for first layer.. then drops like a rock

Peter

Yes I thought of that expansion too. But never actualy got around doing it.And never wanted anything that big. And I totaly understand you, and It is true that it is wasting energy when it can be printed in smaller temperature. You are right. What I was saying that at that time solution was to swap cartrige and everything worked better then before. Thats it. Your designed looks like new Titan extruder.

Re: Very Strange here.. temp holds great for first layer.. then drops like a rock

Hi Jozef

My design actually looks more like my chinese clone than the titan. I had a project to re-use the clone parts to build a reworked original.

The additional size is quite important for me as I tend to print larger objects.

Here is my current project:

It has one working clock (so far) and it will be fitted with at least 10W of LEDs and chimes. At the moment it is about 1.2 metres tall, but I would have liked to to have been bigger all round to be more stable.

Peter

Re: Very Strange here.. temp holds great for first layer.. then drops like a rock

Peter

:-O I was just looking at it for a solid minute before responding. Ii is quite astonishing . In this case , yes more height is better. I have not seen your printer, but are you utilizing all of the smooth rod ? there is quite a lot hiding under the Z axis switch holders (just waste space). If it will be remade higher and using shorter switch holder or even put switch in Z motor holder then you would have that much space more. I guess you are selling it ? I mean its 3D printers work but Im pretty sure you have to make it look this good by yourself. Do you have a youtube channel I can watch ? 😀

Re: Very Strange here.. temp holds great for first layer.. then drops like a rock

Hi Jozef

Big Ben was printed with the standard "original". I haven't finished my taller printer mods yet (I just don't have the time), but here's a photo of the right Z axis - the end-stop holders are the next change I have to make, and they will be the height of the end-stop:

You will notice that the motor is raised 3 cm with the modified holder, as is the smooth rod.

I do have a You Tube channel: https://www.youtube.com/channel/UC_bv6U4vfeVJ6rwBy4ncs3w

Be aware that there are very few 3D prints there though; mainly my (and my wife's) other hobbies: the farm, various exhibitions and model railways.

When I first bought a 3D printer I had intended to use it for printing models for the railways. Then the prints started to deviate from this aim when I realised what it could do...

Peter

Re: Very Strange here.. temp holds great for first layer.. then drops like a rock

Nice , thanks for picture. I imagined this. Do you think that this rod is better then standard M5 rod ? You cant get that resolution right ? BUt if you dont use it I guess its more stiffer , making prints look smoother in Z direction ?

Im goignt to take a look on your Youtube chanel. 😉

Re: Very Strange here.. temp holds great for first layer.. then drops like a rock

Jozef

Regarding resolution. Standard M5 has a pitch of 0.8mm, whereas the lead screw has a pitch of 8mm, therefore one tenth of the resolution.

But, these stepper motors have 200 steps per revolution and 1/16th microstepping, so 200 * 16 = 3200 microsteps per revolution.

8mm / 3200 = 0.0025mm per microstep (or 2.5 microns), which still gives a much better resolution than the 50 microns specified by PR for the 0.8mm pitch threaded rods.

Regular threaded rods are manufactures cheaply and have significant play. Lead screws have 4 threads and are manufactured to a higher specification and therefore are more accurate with less play.

Working on the principle that the Z axis really should only be moved in full step increments**, the most accurate prints would be produced with multiples of 16 * 2.5 micron (40 micron) layer heights, so in use, the lead screws can generate a higher resolution print (40 micron vs. 50 micron layer height).

Peter

** this used to be the case when the Z motors were turned off whilst a layer was being printed. The firmware is now changed so that the Z axis motors are not turned off and are able to hold microsteps.