Aluminum Mendel

by dkennell, published

Aluminum Mendel by dkennell Jan 16, 2012


This MendelMax inspired printer is compact, lightweight, and totally self contained. Nothing protrudes beyond the frame. Z axis motors are mounted low, and thrust bearings carry the weight. Note that the z axis uses the aluminum extrusion for a guide, saving space and expense. The linear bearings and belt and pulley upgrades give high quality prints. All dimensions are chosen so that you can use 4 smooth rods and 2 threaded rods, plus all other parts from you mendel.
All parts are easy to print without support. The 60 W onboard power supply runs the motors and extruder heater. The heated bed used a 120 vac and a solid state relay. The extruder is very accessible. The heatsinks on the extruder are optional, but help keep thing cool when printing ABS.

See BOM and exploded veiw of X axis below

I added a pdf of an exploded frame drawing 1/19/12

Wire clips and T-slot cover for Misumi extrusions are at thingiverse.com/thing:16344

Below is a zipped archive of all the Inventor source files.

Full BOM added per several requests.

.stp files added.

See video of this printer at youtu.be/JysNv3Hi67k

Recent Comments

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Great job on your printer. I use Slic3r, and have good results with it so I haven't tried anything else. I am glad that you are happy with the design, these printers have proved to be dependable workhorses.

I use Marlin firmware and Cura. works great for me with this printer. What software do you use.
Thanks for sharing your design. Mine is number 9.

Here is a link to the new printer.

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Note: MakerGear has changed the Stepper Plastruder and it will no longer fit on the x carriage. Use the low mass gearExtruder thingiverse.com/thing:61818 instead. This will give better performance.

PLA can be drilled and tappped if you go slowly. This design requires the use of a 6-32 and 8-32 tap. These can be obtained from any hardware store. PLA also holds sheet metal screws very well if you drill the appropriate size hole. I use a 1/8" drill bit for a #8 screw. This is much easier and stronger than trying to use captive nuts. I will work on a exploded drawing to aid assembly if there is interest. The parts were designed with Autodesk Inventor, and I will provide files if requested. The BOM has the parts and sources for converting a prusa mendel to this model.

There are a couple of omissions on the Full BOM. You actually need 4 stepper motors, not 3 as listed. You also need two 608ZZ bearings, available at Ultimachine.com. Let me know if there are other omissions.

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fvvhgl on Apr 9, 2014 said:

I use Marlin firmware and Cura. works great for me with this printer. What software do you use.
Thanks for sharing your design. Mine is number 9.

dkennell on Apr 13, 2014 said:

Great job on your printer. I use Slic3r, and have good results with it so I haven't tried anything else. I am glad that you are happy with the design, these printers have proved to be dependable workhorses.

dkennell on Feb 17, 2014 said:

Here is a link to the new printer.

PrintAlot on Jan 27, 2014 said:

what's the print size of the bed ?

dkennell on Jan 27, 2014 said:

I believe it is about 195 mm x 195 mm. I don't know exactly because I dismantled mine some time ago to make an improved version. The beta testing is done on the new model, with 5 printers now running. I will post the new version soon, I need to finish the documentation. The new version has 225 mm x 225 mm printable area with a smaller overall size.

Winder_3B on Oct 19, 2013 said:

Hi there, I am almost complete with this printer and I am wondering what firmware you used? Also would it be possible to post your configuration.h file?

Thanks, and great design.

dkennell on Oct 20, 2013 said:

I use Marlin. I posted the config.h file.

torus on Oct 12, 2013 said:


I'm looking at the BOM and the CAD models, and I'm confused about the number and type of screws necessary here.

- On the exploded X motor end diagram, there are two socket head cap screws (ANSI B18.3 - 6-40 UNF - 0.5) that hold on the nut cap. What do these thread into? You seem to use sheet metal screws for attaching the X inner slide, but not for the nut caps.

- what are all these imperial socket head cap screws used for? The 8-32 x 3/8, the 8-32 x 1/2, and the 6-32 x 1/2?

Thanks so much in advance, and for your great design.

dkennell on Oct 15, 2013 said:

I sometimes thread socket head capscrews directly into PLA. These will self tap into a slightly undersized hole. The ANSI screws work a little better for this than metric screws because the threads are coarser. I know that the screw counts are off. My philosophy was that since it is often cheaper to buy box quantities (at least in my hardware stores), I just buy them in quantity and have them on hand. This design is nearly two years old, and I never had any idea that so many people would make this printer. I am working on refinements to the low mass extruder, and never seem to have the time to correct the quantities. My apologies, you will end up with a bunch of extra screws. I will try to use all metric sizes and document the parts more thoroughly in future designs.

FlexxyArne on Oct 4, 2013 said:

Some of the parts are missing in the step file folder, ie "y motor bracket."

dkennell on Oct 20, 2013 said:

OK, I have updated the stp zipped file with complete part files.

dkennell on Oct 15, 2013 said:

Sorry for the delay, I have this on my to-do list.

Gemini64 on Aug 3, 2013 said:

Hello David,

Nice design. Would you be willing to export your assembly file to STEP? It's a universal exchange format that most CAD packages can open. Of course it won't be parametric but at least those of us who don't have access to Inventor could open it with other CAD software.

Creating STEP for each file would be a hassle, with just a STEP assembly we could extract those parts.


dkennell on Aug 7, 2013 said:

There is a zipped file of the parts in .stp format at the end of the downloads. Let me know if this does not work for you.

BV3D on Jul 25, 2013 said:

hello really sorry if I have overlooked this detail but what size extrusion are these parts built for. I currently have 8020 10 series will your parts work with this extrusion?

dkennell on Jul 25, 2013 said:

The parts are designed for 30 mm extrusions.

benbjw on Jul 21, 2013 said:

Thanks for designing one of the worst 3d printer out there! If you are thinking building this printer then think again! This design is a fine example of somebody using CAD to design something without understanding the materials and more to the point the mechanics behind this vertical sliding mechanism. Works fine inside inventor but real life not a chance!

legion on Feb 13, 2014 said:

lets see your awesome printer then?

dkennell on Jul 23, 2013 said:

Actually it works quite well, and other people have had good results with this design. My printer and others who have made this design use our printers heavily, and this has held up well over time.

arejay on May 8, 2013 said:

Well I just tried the project using the files in Mendel_Al_Inv.zip but still the following files can't be found.
I'm new with Inventor so I just might not be doing things right.
ANSI B18.6.4-1_4-20 UNC-1.25(13)CI.ipt
ANSI B18.3.1M-M5x0.8x10(1).ipt
8-18 and 6-40 ipt files
Stepper Motor.ipt
Z Rod.ipt
Z Threaded Rod.ipt
Thrust Bearing.ipt
Linear Bearing.ipt
X Rod 420.ipt
Y Carriage Mounts Single.ipt
Thanks for your patience, RJ

arejay on May 3, 2013 said:

Thanks for that design, I going to make one or more with slight mods. But you're assembly file in the download misses the libraries, are they available? I would like to see the complete assembly not only the printed parts.

dkennell on May 4, 2013 said:

Try the file Mendel_Al_Inv.zip. It is the entire inventor project zipped and should have everything you need

IcanCwhatUsay on Feb 2, 2013 said:

What motor couplers did you use for the Z-Axis?

dkennell on Feb 3, 2013 said:

I have been using Misumi MCJSN18-8-5 resin couplers. They are about $5. Any coupling with set screws should work. The clamp type couplers that are commonly available wobble because the threaded rods are a little smaller than 8 mm and tightening distorts them.

karandex on Aug 12, 2012 said:

Got any better alternative the in-slide z axis ? i think it will be fragile and unreliable

Rawpork on Jul 4, 2013 said:

Try a piece of clear tubing that is smaller inner diameter than the two rods, works much better than any plastic coupling. I have been using on my Bukobot since I got it and have had no problems. Thanks to the boys down at Deezmaker(:

dkennell on Aug 12, 2012 said:

It is actually very strong. Print in PLA, make sure the layers are well bonded. I have printed over 30 lbs of PLA with no problems.

mkeveney on Jul 25, 2012 said:

gt; ...Let me know if there are other omissions.

Minor note; Both BOMs list this item twice:

8-32 x 3/8 socket head capscrew, count 50.

Do we need 50 or 100?

dkennell on Jul 26, 2012 said:

Sorry for the duplication, 50 should do it.

mkeveney on Jul 25, 2012 said:

Thanks for sharing this impressive design. I've decided to build one and am acquiring parts. I'm building from scratch and have no existing printer to inherit parts from. I have a handful of questions so far:

* The BOM lists two aluminum plates, apparently for the bed and bed-carrier, correct?

* Your second photo shows a carrier built from two plates which do not appear to be the BOM dimensions of 9.25" x 10". I'm guessing that, perhaps the version in the photo was made from materials you had on hand
, and that a more conventional structure would use a single plate for the carrier, with the bed mounted via standoffs or spring-loaded screws, is this correct? If not, please clarify.

* Your bed is not square. Which way is it oriented?

* Is this drilling template appropriate?


* I'm planning to use PLA and will forego the heated bed initially. I'm thinking I'll make the bed and possibly the carrier of acrylic or polycarbonate instead. Do you anticipate any problem here?

* I'm still figuring out an e
xtruder to use. My favorite so far is the x-carriage from the VertX. Can you see any obvious problem with this choice?


dkennell on Jul 26, 2012 said:

I cut one plate to make the carrier so it would not hit the power supply. One piece is 10'' x 2', the other is 7" x 2 1/2". I screwed them together into a "T". They could be made from acrylic, see the derivative by duncan. The bed is 10" in the X direction, so the print area is relatively square with the screws on the outside. The drill template is too small. You can position your Y smooth rods to fit around your power supply, and adjust the dimensions for your plate accordingly. I think you could make most extruders work with this design.

b6rian on Jul 24, 2012 said:

Anyone interested in helping me by printing me these pieces for me? I have cash!

[email protected]

Also do i just use the standard mendal profile in replicatorg? Or do i need to make a custom one?

dkennell on Jul 24, 2012 said:

The standard mendel profile should work since we are only changing the frame. I use marlin firmware with pronterface control. Slic3er works fine out of the box, and your can easily fine tune its settings. Your machine is capable of printing out all of the parts for this new frame.

b6rian on Jul 24, 2012 said:

I have a compete makergear prusa mendal, i am wanting to build this frame and more over the electronics and extruder, etc. Will that work?

xnaron on Mar 28, 2012 said:

Nice machine!

Sorry if I missed this but what is the build area for this machine? Also how does the Z ride on the extrusion? Do you have any build pictures anywhere?


xnaron on Mar 28, 2012 said:

It looks like the z is guided by a plastic piece that attaches to the x-end with two screws and runs inside the extrusion track. I'l really curious to see how layer alignment looks on your prints. I'm especially interested to see it in taller prints over 100mm.

Anonymous on Mar 12, 2012 said:

when trying to open iam with inventor he is mssing a few parts like the hfs6-30-30 and others, can you upload the rest of the file?

dkennell on Mar 16, 2012 said:

I zipped the entire project, including the assembly file. There are a lot of other parts, such as the stepper motors, which I modeled for the assembly. Since this duplicates many of the previously uploaded parts, you might want to keep this as a separate project. It is named Inventor Complete.zip.

hlyman on Mar 11, 2012 said:

I have finished my Aluminum 3D Printer. I posted a photo in "I Made One:. It is running at this moment printing two parts each 190mm long at a speed of 200mm/sec, wow!!

Love it. Thanks for sharing.

I made my own hobbed sleeve out of a piece of brass and I got a geared motor direct from Kysan. I had to order two to get it, so I have an extra one if someone wants one.

atntias on Mar 25, 2012 said:

id be happy to buy it from you. please pm if relevent

hlyman on Feb 24, 2012 said:

I have this great printer almost done. The last thing I need is a geared step motor for the extruder, as my old mendel used the standard motor etc. Where can I get one quickly and what are the specs for it?

dkennell on Feb 24, 2012 said:

I got mine from MakerGear. I have another one on order, but they take a little while to get. They have a link to the specs at http://www.makergear.com/produ.... I have not checked elsewhere to see if they are currently available.

tolemo on Feb 20, 2012 said:

This design really caught my attention! I was so enthused I built the frame already from your posted drawing. I am doing this from scratch but I work in a shop where I can salvage enough material to work on building one. We have an industrial 3d printer so I may be able to con an engineer into helping me print some parts.( unless I can machine some) The problem is I just started and don't have a clue yet about what I need besides the files you have on this page. Any advice for a noob who never built one before? Like a list of the parts needed from the original Mendel?

Phoenixblack on Feb 21, 2012 said:

look into ramps, im starting out too and am finding it pretty good.

tolemo on Feb 20, 2012 said:

Just found the Full BOM. Thanks!

Phoenixblack on Feb 18, 2012 said:

I'm currently building a copy of this that is slightly changed and will have a roughly 1m^2 build area lol. what tips can you give me with the build?, any changes that you would make in hind site?



dkennell on Feb 19, 2012 said:

I think you should be able to extend the axes to your dimensions without other modifications. The post by Pointedstick below indicates that 280 mm with 8 mm rods is fine. I am happy with the present design, I look forward to input from others. Any change to the x or z axes will start a cascade of other changes, as the design fits the components together pretty tightly. I look forward to seeing your design.

kiltannen on Feb 17, 2012 said:

Could you post a BOM to make this from scratch?

I think I would like to build this - but it would be my 1st RepRap and so a full BOM would really help figure out exactly what I'm doing...

Also what do you think about using extrusion for the X-axis instead of smooth rods?
amp; maybe 10mm smooth rods for the Y-axis? Would this help with the flex you mentioned earlier?

I am quite keen to make one with a large build volume, like around 500mm cube... I realise that just makes it phenominally harder BUT I think your design is likely to give the best shot at it. Even better than the MendelMax if you ask me.

kiltannen on Feb 20, 2012 said:

thank you for the full BOM.

That REALLY helps.

It will be a month or maybe 2 before I start my build - but this helps me to start locating all the parts and costing the whole project out.

I'll post details of how things go when I do my build...

mojomoney on Feb 13, 2012 said:

I don't see the 8mm rods listed in the BOM. Am I blind or were those omitted? Pretty nice design regardless.

dkennell on Feb 14, 2012 said:

I listed only the parts needed to convert a prusa mendel to this model. Sorry that I wasn't more explicit, I had no idea so many people would be interested. This design uses 4 of the smooth rods and 2 threaded rods (cut to length), motors, RAMPS, etc from an existing mendel.

royco on Feb 11, 2012 said:


Any chance you have the Inventor iam file?

I will try to build your design.



dkennell on Feb 11, 2012 said:

I added the printer assembly iam file below. I has all the axes and most of the important components.

hlyman on Feb 10, 2012 said:

Thanks from this dummy, I just figured it out and it works great.

hlyman on Feb 10, 2012 said:

I am building your design. Right now I am stuck on wiring the relay. Do you have a wiring diagram for the relay? I have an Arduino board and a Ultimachine ramp and a GHDIDZ power supply from Lutz. Thanks.

dkennell on Feb 10, 2012 said:

See the relay wiring pdf below. This is for the 120 VAC heat pad and solid state relay.

lincomatic on Feb 7, 2012 said:

Are the inner slides on the nylon, or just printed? Also, is the vertical brace printed or metal?

dkennell on Feb 7, 2012 said:

The inner slides are printed PLA, as well as the vertical brace. The vertical braces could easily be made from aluminum plate if desired. I originally planned to make them from aluminum, but the printed braces along with the blind screws proved to make the z axis very rigid.

lvdahlgren on Feb 6, 2012 said:

Can this all be printed on a TOM?

dkennell on Feb 7, 2012 said:

The vertical braces and x carriage are too large for a TOM, but the other parts would print ok.

Phoenixblack on Feb 3, 2012 said:

i found a website about play-free fastening of aluminium extrusions, and thought you might get some good ideas from it to fasten your 3d printer together without needing to drill, making it tighter and more accurate.

Here's the link:


dkennell on Feb 3, 2012 said:

Thanks for the tip. It would be nice to have a design that could be made and assembled with only simple tools.

TheCase on Jan 29, 2012 said:

Do you think there is space on the x carriage for a Greg's Wade's extruder body?

dkennell on Jan 29, 2012 said:

I think you could make it work by adjusting the width of the aluminum extruder mounting plate. Mine is a 65 mm square. Keep in mind that any width you add will subtract from the x travel. Also all the weight will hang from the front of the axis. You may be able to adapt the vertical x axis design found at http://www.thingiverse.com/thi...

Miro87043 on Jan 28, 2012 said:

Could you describe and/or post a picture of your z coupling setup. I'm not sure where the thrust bearings fit in. Do they sit between the motor case and the coupling?

dkennell on Jan 28, 2012 said:

I posted 2 new files, a pdf of a more complete printer exploded drawing and an animated assembly. The animation is low res, but if you look at the exploded drawing first, it may be helpful. The thrust bearings are at the top on the z threaded rod brackets.

Miro87043 on Jan 26, 2012 said:

This is very cool!

I would like to modify it to accommodate a 12"x12" build platform. Are the Z extrusions solid? Any loss of resolution at tall print heights?

I really like the heat pad you're using. How fast dose it heat?

Do you think 8 mm smooth rods would be sufficient for the increased build area?

dkennell on Jan 26, 2012 said:

The z axis is rock solid. The x and y have a lot of flex, but I think others have made extended mendels with 8 mm rods. The heat pad is great, thanks to Kludgineer for that tip. Time to heat from 22 to 75 C is 63 seconds.

brianblanton on Jan 24, 2012 said:

Nice Design. I landed on some of the same decisions you did in my build. I started with the MendelMax BOM, but decided 90 degree angles made more sense. I'm building my Z axis now, so I'm going to spend some time reviewing your solution. Again, nice job.


mattdm on Jan 20, 2012 said:

This is really cool. To what precision can you make things? (Can you make, for example, Lego-compatible bricks?)

dkennell on Jan 21, 2012 said:

I downloaded a Lego design (http://www.thingiverse.com/thi... and it worked very well on the first print. It did fit a real Lego brick, although little more loosely than a standard brick. I am sure that with a little fiddling I can get a good fit.

robinarvidsson on Jan 19, 2012 said:

Awesome, Well done! im about to build myself an aluminium one as well. I got a hold over some really cheap aluminum profiles. Thanks for sharing your design.

dkennell on Jan 18, 2012 said:

I added an exploded view of the x axis motor end as a pdf at the bottom of the downloads. Hope this helps.

tbone_atl on Jan 18, 2012 said:

Would love to see it in action...looks great though.

Anonymous on Jan 18, 2012 said:

Apologies for the triple post :(

bmsweb on Jan 18, 2012 said:

Great build and design with this. I just purchase T-Slot and I'm not having to re-think my design. I love the simplicity of your design. Looks really clean. Have you had it printing yet and if so how do the results compare to your prusa?

Anonymous on Jan 18, 2012 said:

Yes, I have printed quite a bit with it. It works great. My last version of the prusa had the linear bearings and the same belts and pulleys, so it was doing a great job. In fact, my last prusa printed all the parts for this before I disassembled it to make this version. So the print quality is about the same as the fine tuned prusa. The big advantage to this is the compact size, light weight, and portability. It looks good, I always thought the threaded rods were a little crude. Also the extruder is very accessible. The quick release extruder body for the Makergear extruder is a big improvement, I will try to post that design tonight.

Anonymous on Jan 18, 2012 said:

This is a really interesting design. Could you please post more drawings/pictures/videos? I've searched misumi-ec.com for tolerance data on the extrusions but haven't found any. Is there a link to such data?

Anonymous on Jan 18, 2012 said:

I was basing my statement of the tolerences on my experience on using it for a slide, so I don't have any hard data. I also did not find any readily accessible data on the tolerance. I will try to do some exploded views asap. Thanks for your interest.

Anonymous on Jan 18, 2012 said:

This is a really interesting design. Could you please post more drawings/pictures/videos? I've searched misumi-ec.com for tolerance data on the extrusions but haven't found any. Is there a link to such data?

Anonymous on Jan 18, 2012 said:

This is a really interesting design. Could you please post more drawings/pictures/videos? I've searched misumi-ec.com for tolerance data on the extrusions but haven't found any. Is there a link to such data?

watsdesign on Jan 17, 2012 said:

After seeing the Rook it's interesting to see another t-slot mendel, and other choices.


Maybe there are some ideas I can keep in my folding huxley ^^

dkennell on Jan 17, 2012 said:

I had not seen that, but if you start thinking about what support is needed, the design by rook and this design is the obvious choice with seven extrusions. Getting rid of the diagonal braces gives great access to the extruder and good visibility of the print job. I use blind screws as well as the printed braces and feet for a very rigid frame without using corner brackets.

danielpublic on Jan 17, 2012 said:

Nice! Hopefully anyone who decides to convert their mendelmax give half of their extrusions to a friend/random neighbor. Sharing is caring!

bmsweb on Jan 17, 2012 said:

So instead of using a smooth rod for the Z Axis, it's utilizing the T-Frame? is that correct?

dkennell on Jan 17, 2012 said:

That is correct. It saves a lot of space, plus the expense of 4 linear bearings. You can see the detail on the second photo. The design utilizes inner slides, much like a T-nut, attached to the x axis ends with screws from the inside. The tolerances are very tight on these extrusions, so you can get very good sliding action. In another design, I would not be afraid to try it for the y axis.

sgraber on Jan 17, 2012 said:

Please post video of this printing. I'd really like to see it! :-D

Anonymous on Jan 17, 2012 said:

Please post video of this printing. I'd really like to see it! :-D

MakerCubed on Jan 17, 2012 said:

Love the extruder layout. Excellent!

Whizbang on Jan 17, 2012 said:

Very interesting competitor to the MendelMax. What is the build envelope of this machine?

dkennell on Jan 17, 2012 said:

The build envelope is a190mm cube.