Dolly Build

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GDS
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Joined: Thu Dec 28, 2017 12:41 am

Dolly Build

Post by GDS » Fri Jul 20, 2018 5:51 pm

Hi all,

Still relativly new to the world of 3D printing, I was on the verge of buying a Anet A8 when I stumbled accross Tom's Dolly build. As I intend to use the 3D printer to build things with it seemed like a worthwile move in building my own 3D printer to help better understand it.

I do have a few questions before I jump head first into the build:

- Is it worthwile upgrading the power supply from 12v to 24v and if so will this result in me needing to upgrade any other parts?

- I would like to go with the mk42 heated bed straight away, are there any other changes I need/should make to the install for this upgrade.

Any other worthwhile upgrades suggestions are always welcome :)

Regards
Mark

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Moorviper
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Location: Hessen/Rhön - Germany
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Re: Dolly Build

Post by Moorviper » Sat Jul 21, 2018 12:09 am

https://discourse.octoprint.org/t/two-d ... lack/899/6

these are mine
the mk3 style version is a 12v version

the dolly style is a full 24v system (hotend, fan, heated, board(mks sbase with marlin 2.0 ) ... everything)
with a base you need to use tl smoothers or replace the stepper drivers with external ones.
I had luck and got a mk42 and a pinda. for free from 3dvs_ch here in the forum which i plan to put in the 24v system.
Then i will use a 20A 24V > 12V stepdown for the heatbed.

But after some month i think the MK2/MK3 frame design is crap / good some parts of my mk3 are from wood.
But this
Image
-> help-requests-purchasing-assistance-f4/ ... t1106.html
will be definitely better :D

What i learned when i build the dollies -> when you go cheap its crap ;-)

My next plan is to get the display working on the mks sbase with marlin.
And later port the prusa firmware to 32 bit or the features to marlin 2.0. / depends on which is easier to do.
But actually it looks like the 32 bit fork is easier.

So to your questions:
- Is it worthwile upgrading the power supply from 12v to 24v and if so will this result in me needing to upgrade any other parts?

first i had a mixed setup 2 power supplies one 12v and one 24v because i bought the 12v first and then 24v because the mk3 heatbed draws to much energy and the 12v supply shuts down.
I used the 12v for the electronic and the 24v for the heatbed. The ramps has normally 2 independent rails -> the closed source ramps 1.6 has only one btw.
with a mk42/52 it is not necessary to switch to 24v. BUT when you buy new don't use a mk42 ->
Buy a mk52: https://orballoprinting.com/en/home/186 ... atbed.html + a pinda2 https://orballoprinting.com/en/home/202 ... ensor.html.

Then you have a removable build plate and you can later use the prusa firmware when a ramps port is done.

And when you have the money then you can buy a eins board and take advantage of using most of the prusa mk3 firmware.
(you have to disable the filament sensor / maybe power outage needs an addition pice of hw ?!?)

- I would like to go with the mk42 heated bed straight away, are there any other changes I need/should make to the install for this upgrade.

As I said use the mk52. Ok xyz calibration would not work but the normal mesh bed leveling works with stock marlin because the whole area is usable with the sensor.
it cost a few €$ what ever more but then you have a removable build plate.
Changing a PEI-sheet on a mk42 takes around 12 Minutes and is not so hard but / only change the build plate is faster an cheaper than the hassle with the m3 adhesive ;-).

My printer design will be open source and documented on GitHub when it is finished by the way.

Stefan
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Joined: Thu Jun 15, 2017 12:46 am

Re: Dolly Build

Post by Stefan » Sat Jul 21, 2018 5:31 am

IMG_0139.jpg
IMG_0139.jpg (589.83 KiB) Viewed 400 times
Here's an older pic of my Dolly (actually a Rosie, as it was made by a Dolly and came out slightly modified).
  • It is all 12V. Biggest downside of that is a slower heating bed. But, if you get a good bed to begin with, this is not an issue (it heats up to 80C in a couple of minutes.)
  • Avoid threaded rods. I've long since replaced them with proper trapezoidal rods and never looked back. Cheap will cost you here. If these rods aren't perfectly straight, you will get z-wobble in your prints.
  • Buy extra bearings. They are cheap for a reason. Some will be throwaways because they either stick or are missing balls. Just do it.
  • I don't have a MK42 bed, but I am very happy. Mine is a 3mm aluminum; I use an inductive sensor to detect the surface. No complaints whatsoever about bed leveling.
  • If you are a little adventurous, get a pair of TMC2130's for your x & y drivers. A little more work to install and tune, but they ARE quieter and smoother. Plan to use a fan for those drivers.
  • If you DO use TMC2130's, replace the hotend fan with a Noctua fan. It is otherwise the loudest element in the machine.
  • My frame is Stainless rods and hardware and 3/4" birch plywood. Solid. The bed frame is 1/2" birch. Both painted to avoid moisture. I've had no warping issues at all.
One other thing; use good quality ABS for any printed parts. Having a piece crack due to delamination or some other symptom of bad plastic can really ruin your day.

@MV: Damn!

-Stefan

GDS
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Re: Dolly Build

Post by GDS » Mon Aug 06, 2018 11:52 am

Thanks for the help and advice guys, your builds look great!

I think I will try and stretch my budget to the MK52 heated bed, upgrade the threaded rods to trapezoidal rods and leave the frame as wooden for my first build. I can always upgrade the frame later :)

I will try and do a build log also :) won't be until next month now as the gf wants a holiday :roll:

GDS
Posts: 3
Joined: Thu Dec 28, 2017 12:41 am

Re: Dolly Build

Post by GDS » Mon Aug 06, 2018 4:36 pm

Thinking about it, if I did go for the MK52 heated bed this is a 24v part, I assume putting 24v through the RAMPS 1.4 will be too much? So I'd need to upgrade the RAMPS and Arduino Mega to something suitable for 24v or is it easier to have a 12v supply for these and 24v supply for the heated bed?

Apologies in advanced as there is probably going to be a lot more stupid questions during my build :lol:

Edit: Just seen that you suggested the mks sbase and marlin 2.0 :oops:

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Moorviper
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Re: Dolly Build

Post by Moorviper » Mon Aug 06, 2018 7:48 pm

I used a stepdown on the 24v printer first.

Then you can use 24v for the heatbed / and 12v for the rest of the electronic

unixb0y
Posts: 30
Joined: Wed Apr 18, 2018 4:45 pm

Re: Dolly Build

Post by unixb0y » Thu Aug 16, 2018 2:35 pm

Hi guys,
I have difficulties finding MK42 heatbed carriages that don’t ship from China.
Any help is appreciated!
~ Dave ~

Stefan
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Joined: Thu Jun 15, 2017 12:46 am

Re: Dolly Build

Post by Stefan » Thu Aug 16, 2018 9:18 pm

Hi Dave,

The heatbed, itself or the carriage underneath?

Making a carriage is pretty straight-forward if you have access to a jig saw. I've also seen .stl files for the carriage, too.

-Stefan

unixb0y
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Joined: Wed Apr 18, 2018 4:45 pm

Re: Dolly Build

Post by unixb0y » Thu Aug 16, 2018 9:52 pm

Hi Stefan,
I mean the carriage. I know that you can cut it from wood, but something slim and sturdy + matching the color of my (black) printer would just fit in so much better ;)
What do you think about this? http://zaribo.org/hardware/45-heated-bed-carriage.html (25€ plus 5€ shipping)
Pretty hard to find in aluminium somehow and even from AliExpress they aren't a lot cheaper! :-/
Maybe someone here can CNC it for less than 25€?
Thank you in advance!
~ Dave ~

Stefan
Posts: 223
Joined: Thu Jun 15, 2017 12:46 am

Re: Dolly Build

Post by Stefan » Thu Aug 16, 2018 10:47 pm

Hi Dave,

That aluminum one looks pretty good. Bonus if it is powder coated as it will reduce clean-ups. I DID cut mine from 12mm birch ply and painted it black. Sand, paint, sand, paint, etc. It is very rigid. I also mounted my heatbed with standoffs (no springs). Since I use bilinear leveling there was no reason to make them adjustable.

-Stefan

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