Things you wish you knew before building the kit...
I'm eagerly awaiting the arrival of my Core One kit. I haven't looked through the assembly instructions yet, as I don't want to spoil the fun!
Just wondering if there are any things you wished you had known before you started assembling your kit?
Any special tools I should be sure to have available?
Are there any gotchas that people commonly run into, or bits where the instructions aren't totally clear?
(I'm not a complete novice, I previously built a MK3S+ with no particular difficulties).
RE: Things you wish you knew before building the kit...
one recurring issue, make sure that you have the toothed pulleys the right way round, like the Mk3 and mk4, one pulley is apparently upside down ( design intent)
And belt tension has been revised, used to be 85hz for both belts, now I believe it's 92hz and 98hz...
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility.Location Halifax UK
RE: Things you wish you knew before building the kit...
Make sure you clear a LOT of desk top or (better) floor space quite close to where you'll be building your printer, so that you can keep all of the parts boxes open. There's no 'step 1 = box 1'. Prusa may like to think that the parts are 'organised into' a number of themed boxes, but I prefer to think or them as being 'randomly scattered' among those boxes. 🤣
Honestly, you'll have a great time building the CORE One, as long you can get over the frustration of having to memorise multiple similar box names when you go to collect the parts needed for each step.
On a more serious note - the mounts at either end of the z-rods can need a firm push to make sure that the XY frame sits at the right height and lines up with the frame screw holes, and make sure you look into the recommended way to correct any skew in the x-axis gantry before tensioning the belts. Also, a drop of oil, grease or anti-seize compound on the tension screws, before you insert them, will help you avoid the dreaded 'spinning tension nut' issue.
RE: Things you wish you knew before building the kit...
A few steps where I wished the assembly instructions were more clear (unless they have been changed in the meantime; I built my kit in early April):
- The trapezoidal nuts on the Z leadscrews get installed before the smooth vertical guide rods are in place. This leads to a disagreement between the smooth rods and the leadscrews regarding the lateral position of the heatbed. I installed the smooth rods first; then the trapezoidal nuts will automatically end up in the correct positions. Alternatively, after completing the build, move the heatbed all the way down, loosen all mounting screws for the trapezoidal nuts, and retighten them.
- There was no step in the build instructions to ensure that the two Y guide rods are precisely parallel. After attaching the X gantry, you should loosen the screws which hold the mounting blocks for one of the Y rods. Then push the X gantry all the way back and forth, so it can push the Y rod into the correct position. Gradually tighten the screws and repeat.
- In the side filament sensor, the little magnet in the moving lever is a millimeter too wide. Make sure it sticks out about equally on the top and bottom side of the lever. If it sticks out too far on top, it will block the lever movement after you install the lid of the sensor housing.
- When attaching the right side panel with the filament sensor, make sure the sensor cable slides back through its zip-ties and is routed straight. If it gets stuck somewhere and bulges inwards a bit, it may get in the way of the CoreXY's right-hand Y bearing -- causing calibration errors of the Y axis later.
- When sticking on the door handle, be sure to position it right -- both height-wise, and pushing the clear panel all the way into the V shape of the handle. The double-sided adhesive tape is very sticky: If you try to detach it again to correct the position, it will rather rip apart its foamy substrate than release the adhesive joint.
RE: Things you wish you knew before building the kit...
Square the gantry up as best as you possibly can when installing. It'll make the final tuning nd configuration easier later 😉
RE: Things you wish you knew before building the kit...
- When attaching belts to the Nextruder carriage make sure that the equal number of teeth are sticking out
- Make sure to use the correct screw for the pulley (M3X18, step 5.24, Assembling the belt tensioner left II)
- As suggested by @JingleMePringles I postponed the step 3.30. Attaching the fans until 5. Core XY Assembly, Step 76. I think that was a great tip
- Take your time to tune the belts, make sure there's no play between the left and the right during the process (move the head to the middle, check for play, move back to the right and continue). Tune both belts bit by bit. Not first one then the other, as think can misalign the gantry.
- Reserve enough table space and enough time. Do not rush it. Make breaks.
- If you have a hex key with a handle use it instead of the small keys provide with the kit.
RE: Things you wish you knew before building the kit...
- Read the step fully and then proceed. Do not just look at the pictures.
- Prepare that there might be issues when you think you're done. You might have to go back after you think you finished everything.
- When you get tired you start making mistakes. Better to make breaks.
RE: Things you wish you knew before building the kit...
- When attaching belts to the Nextruder carriage make sure that the equal number of teeth are sticking out
With due recognition that this should be a positive, helpful thread, I hope you don't mind me taking issue with this point. Each tooth is worth 2mm of belt length, which, when wrapped around the tension idler means that 1mm of tension screw adjustment can fully absorb a 1 tooth difference. Given that the range of tension adjustment is over 10 times that, I really can't see how this can be critical. As long as enough belt teeth are pulled through for the end to lock against the main belt when the carriage is screwed down, and for the amount of slack not to exceed the adjustment range of the tensioner, any residual difference can be accommodated by the independent tensioners.
RE: Things you wish you knew before building the kit...
- I recommend to click through the whole step first, before doing anything, and reading all the comments: some optimize work, some save huge searches by pointing where the parts are. Once done, go back and take it slowly.
- As shared by others make sure you have a lot of space to have the boxes all open and accessible.
- The metal parts box has multiple "floors" and especially the last one looks like if the box were empty. It took me a while to find the angular vertical parts 😀
RE: Things you wish you knew before building the kit...
With due recognition that this should be a positive, helpful thread, I hope you don't mind me taking issue with this point.
I'm not claiming that it's the solution. My issue was resolved after fixing two things: reattaching the belts to the carriage symmetrically and the left tensioner pulley screw. Could be only one of them or both.
That said: there are many comments claiming that could be the problem. It's very easy to set this symmetrically upon assembly. Because if then OP discovers homing issues it will be quite difficult to reattach (and that's what OP will find as a recommendation in this case).
RE: Things you wish you knew before building the kit...
That said: there are many comments claiming that could be the problem. It's very easy to set this symmetrically upon assembly. Because if then OP discovers homing issues it will be quite difficult to reattach (and that's what OP will find as a recommendation in this case).
I agree that it's a lot easier to get this right during the build than it is to correct it afterwards, and in that respect it's good advice for the OP. One less thing to worry about afterwards.
But I'd also say that it wouldn't be the first time that 'many comments' are, er, wrong 😈, and until someone can explain ‘why’ to me I'll remain to be convinced that this can be critical.
RE: Things you wish you knew before building the kit...
Back on topic....
The supplied rubber feet don't stick well the to the base of the printer - it's a tricky thing because the double-sided adhesive sticks better to the metal printer than it does to the rubber feet - nothing sticks well to silicone. So take care when moving the printer into it's new home, since the feet will likely shift if you're not very careful.
Consider printing some squash ball feet as a long term fix.
RE: Things you wish you knew before building the kit...
... and apparently they leave black marks on the surface they rest upon. So if you care about that, you may want to put something below them.
Back on topic....
The supplied rubber feet don't stick well the to the base of the printer - it's a tricky thing because the double-sided adhesive sticks better to the metal printer than it does to the rubber feet - nothing sticks well to silicone. So take care when moving the printer into it's new home, since the feet will likely shift if you're not very careful.
Consider printing some squash ball feet as a long term fix.
RE: Things you wish you knew before building the kit...
Thanks for all the replies, keep the suggestions coming!
I found this Noizie Works video pretty helpful... (warning, it's quite long)!
It is good to know that I should take a bit of extra care with the motor mount and pulley bolts to avoid stripping the plastic threads.
RE: Things you wish you knew before building the kit...
Label "Left" and "Right". For me, flipping the frame over repeatedly while installing parts got me mixed up with which was right or left a couple of times. Nothing major, just annoying as I had to remove/reinstall bits screwed onto the frame. This was also cases where I wasn't really looking at the photos in detail.
The BEST thing I did was to print a screw organizer beforehand. https://www.printables.com/model/1324003-prusa-core-one-screw-organizer
Made it so much easier to grab the right fasteners.
RE: Things you wish you knew before building the kit...
Made it so much easier to grab the right fasteners.
That seems like a good idea. I worked from the little bags, with a small slit in the corner so that they didn't all fall out. As a consequence, the second biggest chunk of build time (after finding the parts in the boxes) was spent squeezing individual fasteners out of the bags. And of course all the other bags emptied themselves anyway! Some kind of fastener organisation will be a big help.
RE: Things you wish you knew before building the kit...
I upgraded my MK4S to the CORE ONE so I already had a printer handy. First thing I did before disassembling my printer was to print
1. PRUSA CORE One screw organizer - this was a massive time saver
2. Prusa Core One Belt Tension Gauge - was able to get might belts in the right ballpark so it would register on the belt tuner app
RE: Things you wish you knew before building the kit...
Feel free to give my video guide a watch through before you start [link in sig] - just gives you an idea of what to expect. Then when you follow the standard official guide you have an idea of what to do already......
RE: Things you wish you knew before building the kit...
@iftibashir, great job on those video guides. Really helpful. I'll probably go through those in parallel with the official instructions when J do the build.
RE: Things you wish you knew before building the kit...
FWIW, I asked similarly of things I should print before disassembly of a MK4. If you've access to another printer there's somethings in my list that may be of use to pre-print...
https://forum.prusa3d.com/forum/postid/760002/
Good luck, HTH
David