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Wooden Mendel

Posted by trystanlea 
Wooden Mendel
October 19, 2009 03:10PM
Hey all

Im starting on a build smiling smiley I thought id just introduce myself and say a little about were Ive got to so far. My name is Trystan and Im from north wales, uk. Been following the reprap project for sometime, well done guys for all the hard work and spectacular results! It feels really good to get started on building, Im going for a mendel and have started using wood for the rp parts and have so far built 6 frame vertex's, 1 z leadscrew bracket and 4 bar clamps. All with a bit of modification to make them easier to make out of wood. I reckon however that its going to be a real challenge to make some of the other parts out of wood that Ive yet to make but I came across Adam's blog here who is also building a wooden mendel and he's worked out some good simplification for the print tray so maybe we will get there smiling smiley Is there anyone else building a wooden reprap?It would be great to collect all of our ideas together.

Here's a picture of my mendel so far:

reprap01.JPG
From reprap build


a closeup on a frame vertex:

reprap02.JPG
From reprap build


and the z leadscrew bracket

reprap03.JPG
From reprap build


The black bars are tent poles... which unfortunately are a little bent from being used in an old tent otherwise they could be a good material to use very slidy although they may not be stiff enough. I ran out of studding and so thought I would use them until I order some more steel.

I also found a good tutorial on converting the STL files into 2D drawings that print out to scale using blender here:

http://www.opendimension.org/blender_en/line_drawings.php

and you can find the drawings that I have converted so far here:

http://picasaweb.google.co.uk/trystan.lea/ReprapBuild#

If anyone would like any specific STL converted let me know It only takes a minute and I dont mind doing that if I have a minute.

Looking forward to print! but I imagine that will be a while yet...

also im in Cardiff for the next month and will be doing a bit of building on it with a friend here, if your in the area and would like to come round and have a chat and a build let me know

Trystan
Re: Wooden Mendel
October 20, 2009 04:57AM
Looks verrrry interisting! Keep up the good work!

Have you been drawing the parts in a cad program?

Which one and are they available?
Re: Wooden Mendel
October 20, 2009 06:08AM
Thanks Arvin!

I have been downloading the STL files from the repository here:

[reprap.svn.sourceforge.net]

and then importing them in to the modeling program Blender which is free and an amazing piece of software you can get it here: [www.blender.org]

I then followed the tutorial I linked above to convert the STL files in blender to 2d drawings smiling smiley
Re: Wooden Mendel
October 20, 2009 11:08AM
Hey another wooden one smiling smiley

I'll have some cad files to post soon. Trystanlea if you are interested in working together let me know, I think there will be a fair amount of engineering involved. The bearing design I posted last week has a new revision that makes it MUCH easier to work with, and I have a CAD file of it which I am trying to figure out how to get posted.

Other then that, your build looks great, I can't wait to see more.
Re: Wooden Mendel
October 20, 2009 01:19PM
Hey Adam, certainly would be interested in working together like you say there's quite a bit of engineering involved and so it would be great to get all of our ideas and modifications together smiling smiley

Look forward to seeing the bearing design revision! could it be uploaded to the wiki? Maybe we could start a wooden mendel page under builders/cartesian bot variations? [objects.reprap.org]

could anyone advise on whether this would be ok?
Re: Wooden Mendel
October 20, 2009 02:06PM
yeah that would work. You'll love the new design, so simple it hurts smiling smiley
Re: Wooden Mendel
October 20, 2009 04:27PM
sounds great! look forward to seeing it!
Re: Wooden Mendel
October 21, 2009 09:40AM
I made a wooden Darwin and blogged about it. I'm not sure my notes will help you much though.

[www.codeerrors.com]

Good luck!
Re: Wooden Mendel
October 21, 2009 11:03AM
It looks like you are using "regular" wood, rather than a composite like MDF or even plywood. Have you thought about the effects of humidity changes on the parts? You will get expansion and shrinkage at different rates along different axes, and may even experience warping with some parts.

You might think about making anything with important dimensional tolerances, or that need to stay flat, out of MDF (or perhaps plywood, though there are issues there also), rather than wood with a grain. There are issues with MDF as well, but at least it changes pretty evenly in all directions when humidity varies.
Re: Wooden Mendel
October 21, 2009 11:46AM
mccoyn: your darwin looks great! I will have a good look at your blog, thanks foe letting me know

quadshop: I had not thought about the effects of humidity, good point! How large an effect would it have would you say? thanks for the tips about using plywood and mdf.
Re: Wooden Mendel
October 21, 2009 01:01PM
Greetings all,

I agree that MDF, plywood (or LVL scrap) would be better than plain wood, due to grain effects. However, humidity-related distortion should be somewhat less of an issue for Mendel (vs. Darwin), since the bearing kinematics is forgiving of slight bowing/misalignment of the guide rods. The one place that it isn't very forgiving is the spacing of trios of bearings evenly about one guide rod of each pair -- if there's a change in those bearings' spacing, that could easily lead to binding or slop.


Larry Pfeffer,

My blog about building repstrap Cerberus:
[repstrap-cerberus.blogspot.com]
Re: Wooden Mendel
October 21, 2009 02:53PM
Ours is made out of Ply wood smiling smiley
Re: Wooden Mendel
October 24, 2009 10:37AM
Hello, sorry about taking a while to reply, been exhibiting a wind turbine and energy monitoring stuff at a micro maker fair here in Cardiff smiling smiley

Larry Pfeffer: thanks for the info, I will bear it in mind when Im working on those parts. I guess I could also use some acrylic sheet for some of these more critical parts.

Adam, you are thinking ahead! smiling smiley

I'm looking forward to being able to print plastic!
Re: Wooden Mendel
October 25, 2009 10:40AM
I got the Y-Axis mounted and it seems to work well, I'll make a more detailed blog tomorrow with photos and a screen shot of the cad drawing. Does anyone know how/where i can host the CAD files to be downloaded?
Re: Wooden Mendel
October 25, 2009 09:31PM
I'm in the process of getting parts for a wooden mendel, would *love* to see some 2D projections of the parts online, especially if they've been altered to be easy to make from wood!

Perhaps inquire about getting a section in the svn repository to upload yours?
Re: Wooden Mendel
October 26, 2009 04:43AM
Hmmm thats a good idea. I have drawing files for the bearing mounts (If someone wants them just email me for now). From what I saw it looks like trystanlea has most of the Z Axis figured out.
Re: Wooden Mendel
October 26, 2009 04:53AM
Greetings all,

Since I'm still sub-expert with the various CAD tools (gotta work on that), I would be very interested in such 2-D projections, especially if they had critical dimensions added. Until I get some form of CNC "making" machine built, I'll be manually machining parts.

Thanks,


Larry Pfeffer,

My blog about building repstrap Cerberus:
[repstrap-cerberus.blogspot.com]
Re: Wooden Mendel
October 26, 2009 10:26PM
I don't think you'll have problems with humidity-related expansion in things like the corner connector blocks. You really only have to worry about things where flatness is important, or the dimensions have to stay constant after adjustment. One of the awesome things about mendel is it was specifically engineered to work well with imperfect parts. However, plastic is very dimensionally stable relative to wood, so it is unlikely that mendel was deisnged to be tolerant of expansion/shrinkage/warping.

Based on a cursory look at the mendel drawings, I would be worried about anything to which bearings are mounted (since you have to adjust those to prevent binding, and you'll end up adjusting them every time the weather changes). I would also be a bit concerned about the large flat-ish pieces that the support rods and threaded rods for the Z stage go through (on the "sides", one pair attached to the base, one pair anchoring the Y stage).

How much it warps really depends on the type of wood you use, and how the grain is laid out (how the wood was cut from the original tree bole). Also, if the mendel is going to "live" in an air conditioned, relatively constant-temperature place, you will have lots less problems than if it is in a non-temperature-controlled garage where the humidity approximates the outdoors.

My advice would be to get some MDF and use it for at least the pieces holding the bearings against the support rods. MDF is pretty darn cheap, and a 2'x4' piece of 3/4" MDF should be all you need (a few dollars at my local Home Depot).
Re: Wooden Mendel
October 27, 2009 03:57AM
Here are my 2d projections so far:

[picasaweb.google.co.uk]

framevertex.jpg
From reprap build
ybarclamp.jpg
From reprap build
all.jpg
From reprap build


I will update it as I go. svn sounds good, who would I/we ask about that?

Thanks for the advice quadshop, really helpful!

Edited 1 time(s). Last edit at 10/27/2009 03:58AM by trystanlea.
Re: Wooden Mendel
November 09, 2009 06:36PM
Wow it's bizarre how your frame vertex is EXACTLY the same as the one that I made out of aluminum.

I am building a reprap out of machined aluminum, and redesigning many/all of the parts to be easier to machine. If something is easier to machine it most likely is also easier to make out of wood, I will be uploading dimensioned drawings of all the parts as soon as I get them done. I don't know if any of my modifications will help you but you can check the out here
Re: Wooden Mendel
November 10, 2009 12:35AM
@trystanlea

Sorry guys off subject question...Date: October 24, 2009 05:37PM

Have you any links to your (wind turbine and energy monitoring stuff at a micro maker fair here in Cardiff)

I have a keen interest energy generation stuff like Hugh Piggott's

I didn't relize there were micro maker fairs in the UK/Wales either!

[bodgeitquickpassivesolarproject.blogspot.com]


Bodge It [reprap.org]
=======================================

BIQ Sanguinololu SD LCD board BIQ Stepcon BIQ Opto Endstop
BIQ Heater Block PCB BIQ Extruder Peek clamp replacement BIQ Huxley Seedling
BIQ Sanguinololu mounting BIQ standalone Sanguinololu or Ramps mounting Print It Stick It Cut it


My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]
Re: Wooden Mendel
November 10, 2009 04:18AM
BodgeIt Wrote:
-------------------------------------------------------
> @trystanlea
>
> Sorry guys off subject question...Date: October
> 24, 2009 05:37PM
>
> Have you any links to your (wind turbine and
> energy monitoring stuff at a micro maker fair here
> in Cardiff)
>
> I have a keen interest energy generation stuff
> like Hugh Piggott's
>
> I didn't relize there were micro maker fairs in
> the UK/Wales either!
>
> [bodgeitquickpassivesolarproject.blogspot.co]
> m/

Have a look at instructables.com, they have plans for a wind turbine made out of plastic pipe and a car alternator.
Re: Wooden Mendel
November 10, 2009 03:43PM
swighton, your mendel looks fantastic! The drawings will be useful thanks smiling smiley


Bodge It, Here are the links for the open energy monitor project and the cardiff wind turbine project, thanks for asking.

openenergymonitor.org

cardiffwind.blogspot.com

Im in the midst of building another hugh piggott turbine at the moment for a college, just spent all day carving the blades smiling smiley

Had a look at your blog, really nice pv setup!

Here's a link to the maker fair wales website:
http://www.mayyouliveininterestingtimes.org.uk/makersfaire.html
Re: Wooden Mendel
November 16, 2009 05:29AM
trystanlea

the open energy monitor looks very usfull for my solar project I bought some low cost ATmega boards for this porpose Im sure I can turn them into Arduino compatibles they have a built in LCD interface as well as USB.

This realy will save reinventing the wheel thank you!

I had to get my CNC working before I could attempt the hugh piggott turbine just need time to start work on it. I bought all the matterials required some time ago.
As you need planning permision for any kind of fixed turbine I will not be making a propeller based system that needs a fixed tower. I keen to try out VAWT that can be deemed as portable not fixed, my location also dictates that a VAWT would be a better solution.

On your [cardiffwind.blogspot.com] Blog could you add the ability to follow this blog?


Thank you for the links..


Bodge It [reprap.org]
=======================================

BIQ Sanguinololu SD LCD board BIQ Stepcon BIQ Opto Endstop
BIQ Heater Block PCB BIQ Extruder Peek clamp replacement BIQ Huxley Seedling
BIQ Sanguinololu mounting BIQ standalone Sanguinololu or Ramps mounting Print It Stick It Cut it


My rep strap: [repstrapbertha.blogspot.com]

Buy the bits from B&Q pipestrap [diyrepstrap.blogspot.com]
How to Build a Darwin without any Rep Rap Parts [repstrapdarwin.blogspot.com]
Web Site [www.takeaway3dtech.com]
Re: Wooden Mendel
November 16, 2009 08:02AM
hi guys,

finally managed to get a print-out of one face of the frame vertex with added lines through the centers of the horizontal M8 holes, following the guide from rab3d.com's precision modelling pdf, pages 73-88. Macs are infuriatingly difficult to use :/

will glue and cut-out next chance I get, maybe wednesday
Re: Wooden Mendel
November 21, 2009 10:56PM
my wooden mendel frame is up!




got blender working too - had to force software rendering. difference in render speed is unnoticeable with the few polygons and effects in reprap parts while doing CAD work winking smiley
Re: Wooden Mendel
November 22, 2009 02:26AM
my wooden mendel frame is up!




got blender working too - had to force software rendering. difference in render speed is unnoticeable with the few polygons and effects in reprap parts while doing CAD work winking smiley
Re: Wooden Mendel
November 22, 2009 08:47AM
Hey Triffid_Hunter

Nice work! I had to force the software rendering too... damm graphics card! smiling smiley
Re: Wooden Mendel
November 28, 2009 02:54AM
600DPI, A4, print-ready images for those who are interested.

make sure you turn off page margins, and set scale to 100% or dpi to 600.0 or it won't be to scale. Use the rulers on the page edges to check - marks are every 5mm, with larger marks every 1cm.

I'll post more as I need them for my own wooden mendel.

Pictures of Z motor brackets up soon!

[wooden-mendel.blogspot.com]
Attachments:
open | download - frame-vertex-g-print.png (356.3 KB)
open | download - y-motor-bracket-g-print.png (568.8 KB)
open | download - z-leadscrew-base-g-print.png (360.4 KB)
open | download - z-motor-bracket-g-print.png (468.2 KB)
Re: Wooden Mendel
November 30, 2009 02:20AM
Thanks for all the drawings triffid-hunter, Im working on my second z-leadscrew base at the moment. How did you cut yours out, they look like their made from one piece?

BodgeIt: Sorry I didn't see your last post, good to hear the energy monitor project will be of use to you. Id definitely like to try to make parts for the turbine with a cnc and hopefully with the reprap at some point, should be fun!
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