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Custom Machined Metal Mendel

Posted by swighton 
Custom Machined Metal Mendel
November 09, 2009 06:27PM
Hello,

I have been following the development of the RepRap for some time, and now with the release of the Mendel I knew it was time to jump in on the fun. I don't have access to a RP machine but I do have access to a great machine shop, so I have been modifying most of the mendel parts to be easier to machine and to utilize as much English hardware as possible (due to its cheapness compared to metric in the US) I will be uploading 3d models and cad drawings of all the parts as soon as I get them made, in the meantime here is a snapshot of the progress so far.



I can't figure out how to insert a thumbnail with a link to the larger images so here is a link to a gallery of it on my blog so that I don't clog everything up with a bunch of huge images.

Pictures Of Metal Mendel
Re: Custom Machined Metal Mendel
November 09, 2009 08:41PM
awesome work!
Re: Custom Machined Metal Mendel
November 09, 2009 10:06PM
Yeah, that is beautiful! That is going to be one solid machine! smiling smiley

Wade
Re: Custom Machined Metal Mendel
November 10, 2009 04:33AM
Yeah that looks fantastic!
Re: Custom Machined Metal Mendel
November 10, 2009 06:01PM
Thanks! I'm very excited to see how it turns out - hopefully with the increased precision of machined parts higher print quality can be achieved.

Today I machined the carriage for the extruder and most of the components of the extruder assembly (sans thermal barrier, nozzle, and the barrel). I think it's pretty self explanatory, the bottom plate (with the two angled bearings) is located to the upper plates with two pins, and the compressed springs around the screws on the bottom apply a preload on the bearings so everything runs nice and tight. Hopefully I will be finished with the construction by next week!






Custom Machined Mendel and Other Interesting Projects on My Blog
mechanicallyinclined.net/blog
Re: Custom Machined Metal Mendel
November 12, 2009 12:29AM
I believe this is a huge step in the paradigm. I haven't reviewed the current state of machined metal repStaps but they are the obvious first step to building a machine that can replace itself. The close tolerances of quality machining should aid in the rigidity of the axial reference points one to another. The eventual plastic replacement parts need to address this issue as well so we need to achieve the the finest possible initial resolution. Add to this the fact that the American Landscape is littered with idle machine tools we start to see a path to true Open Source Stereo-Lithography - Desktop object printers for the masses!

Edited 2 time(s). Last edit at 11/12/2009 01:24AM by Symplox.

first-order predicate calculus
_ another of the things one can't casually say
Re: Custom Machined Metal Mendel
November 15, 2009 06:04PM


Mechanically the RepRap is done! Unfortunately I have to do some homework so I can’t wire it up and take it for a spin. I still have to figure out how to run the stepper motor on the extruder from the extruder controller board (via the two H-Bridges), and put the nichrome wire and thermistor on the barrel. I’m lovin it so far though!
Re: Custom Machined Metal Mendel
November 16, 2009 05:30AM
Re: Custom Machined Metal Mendel
November 16, 2009 02:45PM
Super!
How much time did you spend for this??
Re: Custom Machined Metal Mendel
November 17, 2009 05:10AM
thanks!

I'd say total time machining was around 55 hours. I have no idea how much time I spent designing all the parts and making drawings probably 10-20 hours. Its amazing how long parts take to make! That's why I'm building a RepRap - when I need a simple part I don't have to spend my time in the machine shop smiling smiley
Re: Custom Machined Metal Mendel
November 23, 2009 07:55PM
I have mashed together a zip file of PDF's of all the part drawings for the machined bits of my aluminum mendel. I have to disclaimer that I made these drawings for myself so I may have left things out, or made things not as clear as I normally would since I made the parts and knew the exact design intent. I also apologize for the lack of tolerances - once again since I designed them the tolerances were in my head. Just use common sense. I will clean them up eventually when I find some time. If there are any questions just ask me and I would be glad to answer/make a clearer drawing. In the mean time you can download a zip file of them from the link to my site below.

Download Drawings Here

Enjoy!
Re: Custom Machined Metal Mendel
November 24, 2009 03:51AM
Thanks so much for making this set of dimensioned drawings.
I haven't studied them in detail yet, but the few I opened showed exactly the sort of dimensional detail I was seeking!

Thanks again!
Gogo
Re: Custom Machined Metal Mendel
November 24, 2009 06:00AM
Have you drawings with metric dimensions too?
Re: Custom Machined Metal Mendel
November 24, 2009 06:01AM
swighton, is it ok if we co-host your drawings on the mediawwiki? I think it would help a lot of folk.

I'd put it under
[objects.reprap.org]
or so.
Re: Custom Machined Metal Mendel
November 24, 2009 06:37AM
Larry_Pfeffer Wrote:
-------------------------------------------------------
> Thanks so much for making this set of dimensioned
> drawings.
> I haven't studied them in detail yet, but the few
> I opened showed exactly the sort of dimensional
> detail I was seeking!
>
> Thanks again!

You're very welcome! I'm glad you're finding them useful!

Gogo Wrote:
-------------------------------------------------------
> Have you drawings with metric dimensions too?

I will make some dual dimensioned metric/english drawings. Keep in mind that I used 3/8 inch (9.525mm) studding and BZP rod so the dimensions on the triple bearings and holes for studding are bigger than they would be for 8mm rod. If I can find some time I will modify the parts to fit 8mm rod and make new drawings accordingly.

SebastienBailard Wrote:
-------------------------------------------------------
> swighton, is it ok if we co-host your drawings on
> the mediawwiki? I think it would help a lot of
> folk.
>
> I'd put it under
> [objects.reprap.org]
> or so.

Sure you can host them! I will be making a set of dual dimensioned drawings with metric and english, with metric screw equivalents etc. Will there be a way for me to update your hosted drawings once I make those and any other changes?
Re: Custom Machined Metal Mendel
November 25, 2009 03:59PM
There is an error in the extruder pulley drawing - it says to deeply knurl the larger diameter of the part - that is backwards - tap and drill the hole through the larger part and knurl the smaller part.

I recommend not building that extruder - I couldn't get a direct drive pinch wheel extruder to work and had to build a reduction gear drive out of erector set. I will be machining a proper one this week sometime and will post the drawings as soon as I get it designed.
Re: Custom Machined Metal Mendel
December 01, 2009 05:10PM
Re: Custom Machined Metal Mendel
January 05, 2010 10:07AM
This is very pretty and good work on machined components. Certainly can be replicated pretty good.
Thanks again and update as all details go for the finals.


JAGS
DESIGN FOR A CHANGE!
Re: Custom Machined Metal Mendel
January 05, 2010 06:51PM
I hope you don't mind. I extracted the images from the pdf files and saved them as png picture files. That way I can browse through them easier.
Attachments:
open | download - REPRAP_PNGS-1.zip (541 KB)
open | download - REPRAP_PNGS-2.zip (494.3 KB)
open | download - REPRAP_PNGS-3.zip (509.5 KB)
Re: Custom Machined Metal Mendel
January 05, 2010 07:21PM
Mind? That is wonderful. That will be immediately useful. Want to put them up on the wiki, at
[objects.reprap.org]
or according to :
[objects.reprap.org]

and then my fellow library gnomes and I will have a go at tidying?

Edited 1 time(s). Last edit at 01/06/2010 05:51AM by SebastienBailard.
Re: Custom Machined Metal Mendel
January 12, 2010 07:11AM
Why make the parts out of aluminum? Why not make them out of some sort of plastic (like that from thick plastic cutting boards)?

I know that the aluminum parts would be stronger than plastic parts, but wouldn't the plastic parts be strong enough (and cheaper)?
Re: Custom Machined Metal Mendel
January 14, 2010 10:23PM
Aluminum is often easier to grip and cut in a machine, and you can put threads in it directly smiling smiley
Re: Custom Machined Metal Mendel
January 15, 2010 01:31AM
Such a stunning machine.

I think we need a good writeup of it on the wiki for folk, with the good photographs and so on. That task is logged here for anyone interested:

[dev.forums.reprap.org]
[objects.reprap.org]
Re: Custom Machined Metal Mendel
January 21, 2010 12:55PM
Added a stub for this to the wiki, I'm sure Swighton and his accomplices can provide more details smiling smiley

Metal Mendel Wiki Stub: http://objects.reprap.org/wiki/Development:Metal_Mendel

Edit: erm actually Sebastien added that page but I figured i'd post a link anyways

Edited 1 time(s). Last edit at 01/21/2010 12:58PM by theOtherRob.
Re: Custom Machined Metal Mendel
January 27, 2010 10:31AM
Swighton, what belts and pulleys did you use on this? It appears that the ContiTech belts are hard to come by in the USA, and I'm looking for an equivalent.

Thanks . . .
Re: Custom Machined Metal Mendel
January 27, 2010 04:13PM
www.sdp-si.com has sells metric timing belts. It is a little confusing navigating their site, until you notice the metric/inch options at the top left. I have spec'd out the part numbers needed - but I don't have the list right now. I will post it tomorrow morning.

I have also thought about buying english belts and gears. sdp-si sells .2" pitch pulleys with a metric bore. I probably will go this route if I can't find someone to print my parts before I get too impatient. I am thinking of going the wooden-mendel route - not sure if I would/could make gears out of wood.

I priced out several options with them - I'll post all my results.

They also have worm gears... saw someone talking about them the other day. Who was it that made their own worm gear?
Re: Custom Machined Metal Mendel
January 29, 2010 11:33AM
For belts within the USA:

[sdp-si.com]

Axis Part # Price
X/Y A 6T35M276100 17.02
Z A 6T35M198060 8.67

Sub-total: 25.69

When I priced english belts and timing pulleys, the total was $50+. Also, some amount of resolution is lost in this solution as well, as the smallest timing pulleys they have are 10 teeth. (5mm * 8 teeth = 1.57"/rev. vs. .2" * 10 teeth = 2"/rev.) So I still think the best solution is to use the printed gears and metric belts.

If you can find someone to print you english gears (8 teeth * .2") then the english belts would be a cheaper solution. The two english belts needed comes out to $17.66 at sdp-si.
Re: Custom Machined Metal Mendel
February 09, 2010 03:24AM
Hi,

Can You make plans to DXF?
Then I could import them on our CAM and mill the parts with CNC.
And even try to convert them metric.
Re: Custom Machined Metal Mendel
March 07, 2010 05:28AM
Hello all,
this is my first post. I've been aware of the reprep project for a while and have had an interest in building one. I now find myself in a career transition and am a student in a machine tool and mechanical design program. I'm taking a solid works course and would like to build a virtual Mendel in solid works. And since I'm also a machine tool student, I would like to also fabricate the aluminum build. Along the way if I can contribute to the community in any way that would be fantastic.
So my first question is: the 28 or so PDF files found on the wiki under the "Metal Mendal", is that a complete, final revision (to a working model) set of parts?
Is there a completed and extruding Metal Mendel?
I look forward to this project and contributing my results.
Thanks,
Peter
Re: Custom Machined Metal Mendel
March 10, 2010 01:10AM
@PeterBrazier

Yes, it does seem that swighton has a working metal mendel; whether he has overcome his extruder woes is yet to be seen, though. Everything else in the plans sans extruder looks like it's fine and machinable, though (based on the pictures), and we're working on replicating his work.

So, if the PDFs are from swighton, then I'm guessing that they're alright, and it's complete.

HTH
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