Reduce Y-Axis Weight with MDF?
Hey Everyone,
First and foremost I'm absolutely :heart: my Prusa MK3. The quality of prints is amazing! One thing I want to experiment with is reducing the weight of my Y-Axis. This is so I can cut down on ghosting etc.. It's not bad right now but I want to start dialing up the speed to see what I can achieve for 80mm/s and faster.
One idea I have is replacing the Y-carriage with something lighter like MDF. I've had great success with 6mm ~ 1/4 inch MDF on other printers. I think the MDF will be lighter. I have a 220mm x 220mm square that weights 285g and I think I can drop about 50g by selectively removing material. Does anyone know what the stock Y-carriage weights? Or if someone has one unattached could they pop in on their kitchen scale for me?
Thanks for your help! James.
Re: Reduce Y-Axis Weight with MDF?
TBH I'd be wary of doing so... MDF isn't dimensionally stable with humidity and temperature. Auto Bed Levelling will help some, but there's a limit to what it's capable of and it's far from perfect at times.
Re: Reduce Y-Axis Weight with MDF?
Existing y-carriage should weigh around 220 gm, give or take a bit, assuming 2.7gm/cm3 for density of aluminium.
Re: Reduce Y-Axis Weight with MDF?
Hey @vintagepc, my old printer uses a sheet of MDF and with an inductive probe I don't have any issues. Maybe in extreme climates this is an issue but with my printer indoors with fairly constant temp/humidity it doesn't appear to be anything the inductive probe can't handle. Before inductive probes I remember needing to bed level fairly often.
I decided to bite the bullet and weighed my Y-Carriage and it's 322g. @martin.a22 how did you calculate the surface area for the Y-Carriage? Could it be the paint on the carriage that's adding the additional weight?
Thanks for your help!!
Re: Reduce Y-Axis Weight with MDF?
I grabbed the volume from the cad model.
Re: Reduce Y-Axis Weight with MDF?
IGNORE: Move along, nothing to see here, Keep moving please .... ➡
MDF density is 460 to 800 grams per cubic meter (per Wiki).
MDF density by weight of real panels is closer to 0.96 grams per cc.
PETG density is 1.27 grams per cubic centimeter.
The stock extruder weighs around 387 grams. Most of the weight is motor and metal in the hotend. A typical stepper weighs in around 250 grams, leaving only 137 grams for hotend and plastic. If we subtract 25cc of aluminum and a bit of brass and steel, we are left with about 50 grams of plastic.
This means the best case is a reduction of weight of a whopping 12 grams ...
Buy this instead, it will save over a hundred grams:
https://www.bondtech.se/en/product/prusa-i3-mk2-5-mk3-extruder-upgrade/
Re: Reduce Y-Axis Weight with MDF?
Might want to check your axes there tim.
Re: Reduce Y-Axis Weight with MDF?
So the MDF that weighed 285g is 230mm x 230mm x 6.35mm (1/4" stock from big box store) and that's a square piece. The ALU carriage weighs 322g. So right there I'm saving 37g. I'm guessing I could cut out 30% of the MDF and still be structurally sound. That would weigh in at ~200g. Saving 122g seems like it's worth me trying 😉
Re: Reduce Y-Axis Weight with MDF?
@martin: lmao - yep, I misread the OP intentions. Thanks for the subtle tap.
Re: Reduce Y-Axis Weight with MDF?
@martin, you mentioned getting the "volume" from the cad model. Is it possible you could find the "area"? I'm going to cut up that MDF sheet "Tom's Dolly style" but it would be great if I could estimate the weight savings beforehand. I know that my 23cm x 23 cm x 1/4in MDF has an area of 529cm^2 uncut My CAD experience/skill is ... lacking.
Re: Reduce Y-Axis Weight with MDF?
19040 mm^2.
I suspect you'll need a bit more than that, as the long spindly arms may need to be beefed up a bit for MDF.
RE: Reduce Y-Axis Weight with MDF?
Following up on this topic, I have the chance to laser cut a y carriage almost for free, but not in 6mm aluminum. My options are aluminum 3mm, or steel (I can choose the width, be it 2, 3, 5 mm etc).
Any recommendation?