[Closed] Which upgrades would you recommend for a new mk3 build?  

Re: Which upgrades would you recommend for a new mk3 build?

Here are a few:

Would be best to have one of these first two printed and ready to assemble with if you are getting the MK3 kit.
https://www.thingiverse.com/thing:2727523

There is also a two piece split version.
https://www.thingiverse.com/thing:2731484

Belt tensioner:
https://www.thingiverse.com/thing:2740715

There are a few part cooling fan housings that allow better access to a view of the nozzle.

Re: Which upgrades would you recommend for a new mk3 build?

Thanks. Unfortunately this is my first printer so I can't print anything until it's built.
There seems to be a fairly common view that the standard bearings are poor but there is still some debate over the rod quality as that's meant to be improved for the mk3 so I'll have a look around but might hold out and try the std versions first.
I can print the upgrades required once everything is up and running and will see how the rods look before I commit to a rebuild.

Its a good sign that the majority of the kit is considered spot on I guess 🙂

Wingers

Re: Which upgrades would you recommend for a new mk3 build?

Thanks. Unfortunately this is my first printer so I can't print anything until it's built.
There seems to be a fairly common view that the standard bearings are poor but there is still some debate over the rod quality as that's meant to be improved for the mk3 so I'll have a look around but might hold out and try the std versions first.
I can print the upgrades required once everything is up and running and will see how the rods look before I commit to a rebuild.

Its a good sign that the majority of the kit is considered spot on I guess 🙂

Wingers

I personally wouldn't go much beyond the back cover listed above and bearings and maybe rods. The back cover looks important enough that I'm having mine printed at Shapeways. My thinking is being that I'm new to printing if there's a problem I want to know it's with the printer and not one of the "upgrades". If I upgrade it will be after I'm comfortable with the printer.

Re: Which upgrades would you recommend for a new mk3 build?

i think the X belt tensioner is another good option, I have printed one but not fitted it yet, I am waiting for some toothed rollers with dual bearings to arrive to replace the belt idlers which have single bearings,and see if that reduces the belt twisting .. the X axis bearing in the idler roller collapsed on my Mk1 prusa

and I made a tab that attaches to the back of the X motor and takes the weight off the cabling to the einsey case. I used braided covering for these wires ad attached the motor end to the tab, to give strain relief. I expect you could do the same with wire wrap.

regards Joan

Re: Which upgrades would you recommend for a new mk3 build?

My money is on shafts and bearings, for one you can't scratch a genuinely hardened shaft that easily and the reports I've read are disturbing, if such a shaft is scored then the balls are harder than the shaft and aren't rotating as they should but sliding - this can be cause by too much of the wrong lubrication on the shaft itself which causes sliding but I reckon that the bearings are garbage. This is based on hearsay of course but more and more users are complaining about this.

I don't have my MK3 yet but I already have LBBR8-2LS/HV6 (SKF's) and hardened 'H6' stainless rods. My experience with 3D printers tells me that solid and repeatable bed movement is fundamental unless you want to be chasing issues caused by movement 'irregularities' - and bad bearings can cause all manner of bad things to manifest themselves.

My next 'mod' is switching the alloy hot end for a nickel plated copper and PT100 sensor, already have those too, but I'll run some test prints off with the standard setup.

I also agree on the back cover and the belt alignment issues that others are posting about but I want to assess the fit / build and why the belt isn't tracking properly before making that decision.

Comments about the belt tension slipping and requiring packing are a concern too, not sure how to handle this one so I'll assess during the build, if this is nothing more than pure QA / design then support will get a call. I can understand why the printer doesn't ship with high end rods and bearings since most would choke on the cost - but parts and components that are designed and printed in house is a QA issue that won't fly for what's been paid.

Joan - where did you source the toothed rollers ?

Re: Which upgrades would you recommend for a new mk3 build?

toothed rollers off Ebay

https://www.ebay.co.uk/itm/GT2-Idler-Pulley-16-teeth-3mm-Bore-for-6mm-wide-belt/322771668916?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

37 available! 🙂

I am still using the same smooth rods and bearings that came on my prusa mk1, which I upgraded to Mk2 and then MMU...
they don't seem to have suffered

I didn't go for MK2S, modified the cable management on the old setup instead, and left the bearings and shafts alone... I have drylins but not needed to fit them yet!

I broke the Mk2 Y motor mount and have a replacement printed ready to go on there... but the glue is still holding, and the original fracture was more to do with dropping a 1kg roll of filament on the motor, than wear and tear... so I haven't got round to fitting that, or the Y axis belt tensioner that I printed for the Mk2... thinking of that, I might print an X axis belt tensioner for the Mk2 as well, it's a simple upgrade...
regards Joan

Re: Which upgrades would you recommend for a new mk3 build?

Thanks Joan, there will soon be only 34 available.

My mods are a combination of wanting the absolute 'best' there is and laziness - once I've built this thing I don't want to spend more time maintaining than using for its intended purpose - fit and forget.

Historically every printer I've had has resulted in numerous mods / tweaks / fixes and £$£$£$£$ being spent to 'try' things - I've got boxes full of failed experiments ... my goal is to print stuff for my modelling habit - not develop a printer habit (although I've failed to do that so far)

Re: Which upgrades would you recommend for a new mk3 build?

Neil,

That's my approach as well. Looking to do some mods during assembly. Have my fingers crossed and hope my mid February delivery will have the bugs worked out. I won't be happy if this unit is a "Let's try this" version.

Re: Which upgrades would you recommend for a new mk3 build?

Toothed rollers here work out cheaper and you have spares or to use on other printers.

https://www.amazon.co.uk/gp/product/B06VSS4VQF/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Fitted them on mine and they run quite well. I reworked the X-axis idler mount to have two standoffs printed on it to stop the idler running on the side of the mount and getting the the squealing noise some are having.

I also fitted the split backplate from the second post. Haven't needed to adjust the belt but happier that it's simple to if I need to.

Added the cable chain setup to the X and Y axis but that was more of just wanting to try rather than a 'must have'

Re: Which upgrades would you recommend for a new mk3 build?

The amazon order seems good, but below the free delivery cost, unless you have Amazon Prime....
Might be worthwhile ordering some filament or similar as well, to get free delivery...

regards joan

Re: Which upgrades would you recommend for a new mk3 build?

Good point. I've got prime so never saw delivery cost.

Re: Which upgrades would you recommend for a new mk3 build?

Can anyone offer update on any of these mod or add more?

Thanks

Re: Which upgrades would you recommend for a new mk3 build?

So what's the advantage of the toothed idlers vs the smooth ones shipped with the unit? Mines due in next week and now I'm wondering if I should throw "better" idlers on. Though all of the ones on Amazon and Ebay may be of questionable enough quality to make me consider sticking with the Prusa ones.

Re: Which upgrades would you recommend for a new mk3 build?

As USB connections have been a pain, one of the Wifi SD cards described in this thread: https://shop.prusa3d.com/forum/original-prusa-i3-mk3-f30/flashair-wifi-sd-card-setup-and-drive-mapping-t13693.html

An e3d sock is always good, it helps stop filament getting stuck to your heater block if nothing else: https://e3d-online.com/v6-socks-pro-pack-of-3

The printer itself is pretty solid IMO besides teething issues.

Re: Which upgrades would you recommend for a new mk3 build?

So what's the advantage of the toothed idlers vs the smooth ones shipped with the unit? Mines due in next week and now I'm wondering if I should throw "better" idlers on. Though all of the ones on Amazon and Ebay may be of questionable enough quality to make me consider sticking with the Prusa ones.

Or just print your own. I added a toothed pulley (see link in sig). Works great.

Re: Which upgrades would you recommend for a new mk3 build?

The primary differences are,

Prusa pulley is smooth and has one central (We hope) bearing
there are concerns that the belt tension will squash the ridges on the belt...
My mk2 has had the smooth pulley that was supplied with my original mk1 build the single bearing did collapse after many spools of filament, but a new bearing, returned it to working condition. It still works and the belt doesn't seem to have come to any harm.

the replacement toothed pulley has the same mean diameter as the prusa pulley, but it has teeth and two bearings, one at each side of the pulley, this should reduce the individual bearing loading and also prevent the pulley tilting to one side, especially if the bearing has moved from the exact centre of the assembly.
this may address the belt twisting that some report, and the squeaking that others report.
and may make the bearings last longer, additionally the teeth on the pulley should prevent the ridges on the belt from squashing and perhaps reducing belt tension.

whether it provides any benefit is to be seen... Mi replacements are still on the window cill

regards Joan

Re: Which upgrades would you recommend for a new mk3 build?

With the bearings on the toothed idler being flush with the outer face of the idler it's also easier to add a shim or reprint the housing with a boss around the screw so that it rides against the bearing rather than the face of the idler which is where the squeaking is coming from. For optimum use you shouldn't run a toothed belt against a smooth surface as others have said but realistically in our sort of usage with this it's not going to be that detrimental. Using the toothed idler will support the belt as intended though.

I've had no belt twisting or squeaking on mine. I built it from the start with the toothed idler though so can't say whether it would have done if i'd used the stock parts. I saw both on my Mk2 but lack of squeaking is more down to it being spaced off the side. The bearings I had from Amazon seem decent enough quality. Had 7 days worth of printing time through mine now, nothing collapsed so far 😀

I also put the E3D sock on this one but that was just to hopefully stop any big messes one day.

Re: Which upgrades would you recommend for a new mk3 build?

Thanks all. I have to say the argument for a toothed pulley makes sense to me. I really like the way you think JLTX but unfortunately, I don't have a 3d Printer and if I do choose to swap the pulleys I'm doing so during the initial build so I don't have much of a choice other than purchasing one... Now I'm kind of conflicted though as the opinions of two respectable posters are in slight disagreement. Joan.t is pointing toward a 16T pulley and JLTX is currently using a 22T Pulley. The issue I see with the 16T is it doesn't seem to be possible to get one with the larger, presumably better, GT2 bearing but the diameter of the 16T matches that of the smooth idler...

Re: Which upgrades would you recommend for a new mk3 build?

With the bearings on the toothed idler being flush with the outer face of the idler it's also easier to add a shim or reprint the housing with a boss around the screw so that it rides against the bearing rather than the face of the idler which is where the squeaking is coming from. For optimum use you shouldn't run a toothed belt against a smooth surface as others have said but realistically in our sort of usage with this it's not going to be that detrimental. Using the toothed idler will support the belt as intended though.

Exactly. I hadn't noticed initially, but was surprised to see the single bearing on the stock idler when I was investigating the squeaking. I came to the same conclusion and designed the dual bearing version with washers to shim it. They press precisely on the bearing axle.

I also put the E3D sock on this one but that was just to hopefully stop any big messes one day.

I highly recommend the sock. It helps prevent globbing and messes and keeps the hot end temp more stable while print cooling is varying. But they don't last forever and can cause problems when they age and sag. I added the garter screw to my extruder cover and it works beautifully to solve that latter problem.