Wednesday, February 03, 2010
Just before he left to Starve in the New Zealand Wilderness Ed did a new RepRap design because he "had to get it out of his head". It was a mini version of Mendel. You can see it on the left in the picture above - a still from
Josef Davies-Coates' short documentary on the Bath RepRap Lab. The machine uses M6 threaded rods and M3 nuts and bolts (as opposed to the M8/M4 used on Mendel) and NEMA 14 steppers. The reprapped parts are about 30% of the volume of those for Mendel, which is to say it could reproduce three times faster.
This is a completely unsupported design for the moment (we haven't got the time...) but we have put the STEP file for it in the RepRap repository at
because it's so neat, and some of you might like to play with it...
Here's a close up rendered by M.BrittCrane:
On reflection, I think that putting the material spool underneath is not a good idea: it tends to jam. Better to have it on a separate reel above (which would make the machine even smaller).
Labels: mendel mini desktop 3D printer
Mini Mendel would be great for people who don't mind a smaller build size, (~110x140x?). It really would be easier to reproduce than the full sized Mendel. Not only is the total RepRapped parts volume 1/3 that of Mendel, the larger more difficult parts are much smaller and thus easier to print, particularly with ABS. However, I suspect the cost would only be marginally smaller.
MakerBot Cupcake CNC (RepStrap capable of producing a full set of Mendel parts)
Build volume: 100x100x150mm
Mendel build volume: 200x200x140mm
The base holds the the material spool and the electronics. Have to find a new place to put the electronics. Would also have to add some simple feet.
Here is a quick-n-dirty solution:
Should be able to re arrange some things to make it more compact and improve rigidity.
would the k'nex plastic building toy be able to support the weight/force of the machine?
also does anybody know if those pieces would be able to handle the high temps based on the distance from the extrusion head?
sorry left that part out
I'm wondering, would it be less or more stable at when the X-axis makes rapid moves at a high Z-level? Since the Darwin has diagonal ties in all directions, and the Mendel only has triangle frames to make the frame itself stiff. There is no movement that requires the stiffness because the platform moves in this direction, not the printhead, so this is just for robustness of the machine, it seems?
Of course this can easily be tested experimentally: If you print a really tall rod in the machine (e.g. a 10cm piece of makerbeam), it be wider at the base and smaller at the top.
If people get a MiniMendel and want/need a bigger one, they can print their own parts for a full-size Mendel and even give the mini-frame to the next needy soul! "Village Bike" Reprapping!
Someone wants me to make them Mendel parts. I'm gonna offer Mini-Mendel instead if it gets proper build documentation somewhere and the files get STL'd soon. I'll print one for myself too, and it'll still have only taken 2/3 of the time I'd have had to devote to a full Mendel, and there'll be two new printers in the world.
Here is a simplified design of mini Mendel:
The most notable changes are:
- Eliminated complex bottom base with filament spool
- Moved pinch wheel to top of machine & modified pinch wheel block
- Modified vertex brackets to incorporate feet & mounting points for simplified base plate
I figured 1/2 size was enough to do 100x100x70 builds tho.
I guess I must of calculated it wrong
A Stud-frame-end-top 220
B Stud-frame-side 185
C Stud-frame-end 147
D1 Stud-z-base-beam-short 177.5
D2 Stud-z-base-beam-long 209
E Stud-z-lead screw 165
X x-bar 247.5
Y y-bar 203
Z z-bar 165
So it's still to print its first part. I don't think this is going to happen in Bath anytime soon, so the race is on amongst the community so to speak. Oh and thanks to RustySpoon at thingiverse for the STL conversions.
mini-mendel is a cool idea to have more parts quickly as a starter kit.
it would be interesting to know if a mini-mendel could print the part for a mendel twice the normal size. probably not...
on the other hand would a 2x larger mendel use more 2x more plastic, or plus? (without a redesign I mean)
has anybody got an idea of the curve the material use would be compared to print area?
If you are making improvements or anything to do with the Mini-Mendel it would be greatly appreciated if you posted or linked-to your work from that page so that it's easily accessible in the future (it's a wiki; you can edit it!).
Also, big credit to PADDY for getting his head round the X axis and redesigning it specially for the mini. Couldn't have done it without his german genius.
Love to you all from up south - eD
The NEMA14 motors are also listed there. If you find more suppliers, please add them to the wiki. I'll include them in the spreadsheet.
Skeinforge ended up with <10h of print-time using just 110g of ABS.
I guess this is the fastest way to print a 3d-printer at the moment. :)
I am a newbie to RepRap, and am very excited about the whole concept.
I want to start by building a Mendle, but all the parts I have come across are .stl which I cant open. Is there any way for me to get .igs or .step or preferably Inventor, because that is the program I work in?
I am a newbie to RepRap and am very excited to get going . I want to build a Huxley, and have got very frustrated trying to download any plans that can be opened. Could anybody point me in the right dirrection please? I do all of my work in Inventor so any file types such as .igs or .step would work. I dont know why it seems so complicated!