Welcome! Log In Create A New Profile


Micro Mendel

Posted by spacexula 
Micro Mendel
January 09, 2010 08:58PM
I have been messing around with sketch up trying to build a small scale (100x100x100cm build area) Mendel.

The design is in 3 different programs and in my sketch book, but basically it's Mendels outer frame and Z axis, Makerbots XY axis & electroncis

The reason I am doing this is I want to expedite RepRap reproduction, and given all parts for Mendel can be printed by Maker bot, why not just build the Mendels to that scale? This design will have some benefits.

-Less print time (Aiming at a 50% reduction in print time)
-Equal cost for Electroncis, Motor, and bearings
-Less cost for rod belt and screws (but nothing drastic)

The extruder I am using is actually a hybrid between the Paxtruder and the Pinsturder. It will use the Polyoxymethylene plastic like the Paxtruder as the tensioner, but is printable like the pintruder. It will have 1 wall that is clear acrylic so you can see into it, but it will be non load supporting, so you can table saw it.

Had a few questions I needed answered before I got too far into this, because I have never built anything quite like this monster.

-Given the over all smaller size, would there be a benefit to going to M6, or should I leave it at M8 Rod?

-The extruder uses the Makerbot Gear motor, is that an issue internationally?

Bottom line, for me the smaller print area is a welcome price to pay so I can get quicker reproduction, and lower cost. Would anyone else build this thing besides myself if I keep working on it?

Re: Micro Mendel
January 09, 2010 09:55PM
I'm using M6 in my full size wooden mendel.

frame has a fair amount of flex, but I don't think fatter rod would make much difference with that since it's mostly due to not-very-square faces on my frame vertices, nuts only being finger tight, and no circuit board holder. will have to wait until it's finished to see if it's strong enough.

I had to make a collar to fit the M6 rod snugly into a 608 bearing, consider using a 606 if the outer diameter is close enough, or you can adapt the z-leadscrew bases.

Re: Micro Mendel
January 10, 2010 05:08AM
Sounds cool!

While you're developing, be sure to keep dump as much notes as is convenient here:
Along with your project blog and this thread.

Would anyone else build this thing besides myself if I keep working on it?
I think you'll see some enthusiasm. If a user/builder's got a full size mendel, (s)he'll be happier to run off a set of Mendel/Micro parts as a favor due to the decreased print time.

My gut says to stay at M8 just so folk who build Micro Mendels can use their left over fasteners and rod when they build Mendels, and vice versa. To say nothing of greater stiffness.

It's a pity that RepRap's wiki-based CMS doesn't really encourage user innovation like those extruders yet. sad smiley Ah well, we're working on it.
Re: Micro Mendel
January 10, 2010 05:35AM
What a neat Idea Micro Mendel!!

I have used 8mm studding & Bar on Mendel, I think considering the size reduction using 6mm studding & bar would be just fine. Its also easier to cut and cheaper to buy.

I use 8mm Aluminium tube from B&Q cut in 7mm lengths to insert into the 8mm bearings with the help of a small rubber hammer.

There are proper 8mm to 6mm bearing inserts they are used in Roller blades. So if you have an old set of roller blades hanging around, or some EBay skate bearing sellers include these inserts with the new bearing sets.

It will be almost a small handbag shape and size easy to take to a show or demonstrate 3D printing, It Might even fit as hand luggage to take on a plane.

A realy good machine for promoting the use of RepRap printers.

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: Micro Mendel
January 10, 2010 05:55PM
For a collar, I used some copper pipe that was a bit bigger than the right size. just cut a lengthwise slot and you can adjust to whatever you need - once this is done, the wall thickness is more important than any of the other dimensions.
Re: Micro Mendel
January 10, 2010 07:22PM
Some of the mechanics are coming together today while I am sitting here at work.

Ystage trolly: Top is a small peice of acrylic, with two RP brackets to hold acrylic spacers (could not get bearings to fit) , one has two Mendel belt clips. Build plate is removable like maker bot, but uses throw y magnets instead of the pretty gold ones.

Xstage trolley: Base is cut Acrylic sheet, with motor and Mendel style trolley attached to the bottom, Ystage rods and drive set attached to RP components on top. Changed setup slightly so that the Ystage tension pulley is easier to calibrate.

Both could function as RP drop in replacements for the laser cut Makerbot sets.

The Xstage is actually driven by the Ystage drive system from Mendel, so mechanically it's turned 90 degree from Makerbots design, but that will be irrelevant.

Zstage: Because the Z stage is now static, it only consists of a RP acrylic "deck", that is again a knock off of Makerbots Z stage, but is driven off 2 smooth and 2 screw rods (Mendel). The Extruder is set up identically to Makerbot. I am even going to use the same Dino legs (RP).

All boards are now on top of the printer. The Motherboard and extruder on the front, Stepper motor drivers on the back. It will use the Makerbot ATX power system. I have not figured out how I will attached the power supply to the printer (Wife said I should go look for A REALLY old power supply, and place the whole printer on top of it).

These are my 1st mechanical drawings, and blender is killing me. Can someone suggest an "easy" open source mechanical drawing program. I need a shallow learning curve.

Funny thing is, A "Micro Mendel" is going to be mechanically almost identical to daddy Mendel in the Z and Y drive. Also it looks like you might be able to build it using the Makerbot laserless kit and software, which would be the most awesome thing possible. smiling smiley

Edited 2 time(s). Last edit at 01/10/2010 07:30PM by spacexula.

Re: Micro Mendel
January 10, 2010 09:09PM
I've touched up the Mendel/Micro page with some better structures for photos, notes, and documentation, once folk get to that stage.

Micro is a neat idea; I'm curious to see how it turns out.

These are my 1st mechanical drawings, and blender is killing me. Can someone suggest an "easy" open source mechanical drawing program. I need a shallow learning curve.
Nope. That's why we're not a few light years beyond Mendel, really. There's some people working on "BlenderCAD" but I don't know how deeply they're thinking about fabrication issues like 1) generating drawings for old school "twirl the handwheels" machining, 3) general fabrication issues or 3) Deeeeeep Geometry Issues That You Run Into Coding CAD Programs.

Heck, even having live calipers would help. I'll go track down the lead BlenderCAD devs' emails and see if they want to parachute in and introduce their project. Then maybe I'll put down the pompoms for a bit and pick up the soldering iron.

Blender is really efficient and "intuitive" once you've spent a while mastering it. (So I've heard, anyway.) But the main devs are highly resistant to user interface fixes and restructurings because they don't need them.

In an ideal world, Google would GPLify and linuxize Sketchup. It's not going to happen, because Sketchup is all about luring content into 3D Warehouse and whatever post-3D Warehouse ad-supported walled garden they've got up their sleeves. Pity, because it could do a lot for the <$USD2/day wages crowd that makes up a big part of the world.
Re: Micro Mendel
January 10, 2010 10:32PM
spacexula Wrote:

> These are my 1st mechanical drawings, and blender
> is killing me. Can someone suggest an "easy" open
> source mechanical drawing program. I need a
> shallow learning curve.

Blender I have found makes the job so much easier, unless anyone can find an easy to use CAM package, I have found even the pro CAM packages SolidWorks and AutoCAD to be not very user friendly.

There is a good tutorial around call Blender: Noob to pro.

I followed this tutorial and have a really good grasp of mesh modelling, though I stopped following it as it went onto armature animations.
Re: Micro Mendel
January 10, 2010 11:07PM
Blender 3D: Noob to Pro Link:
Re: Micro Mendel
January 11, 2010 06:50AM
Re: Micro Mendel
February 04, 2010 03:16PM
Have you seen this yet
Seems like just what you are after.
Re: Micro Mendel
February 04, 2010 11:19PM
If you want help in converting parts to 3d files in any cad file data i can help out and create the parts and upload for easy conversion between CAD data if it can be helped.Mainly may use SW for the work and provide the easy to use STL file.
I work in almost all CAD packages and can convert to any format that will be usable for folks here creating the micro mendel which is quite a cool idea. Provide the sketches and will make the 3d file ready for easy use..Post the links for the sketches and revisions and i will update

Re: Micro Mendel
February 05, 2010 04:03PM
That's the problem, I don't have anything besides blender, and now the Micro mendel has showed up and I want to use it's parts instead of the FrankenMendel I have been working on....

Honestly I am so tempted to just work on finished up the Micro Mendel as it stands.

Sorry, only registered users may post in this forum.

Click here to login