Bootstrapping Mendel with McWire.

I would like to bootstrap Mendel and have some questions about using McWire to do it.

First the big question, is it possible? Does McWire have a large enough build volume? I have seen solutions to warping parts where they built an apron around the part, would that work with McWire? I guess the real question is how can I find the build volume of McWire?

Is it feasible? How long would it take to print all of Mendel's part with McWire? My math says it would take between 1100 and 1400 hours of printing, but I don't trust my math. I think a hybrid method would be best, where I have the "easy to machine" parts machined and print the rest. Borrowing from the wood and aluminum mendels.

Metal Mendel
Wooden Mendel

Because McWire moves so slowly could there be problems with the plastic completely cooling between layer? Could that cause the layers to de-laminate?

Can the current Gen3 electronics and motors work with McWire? I am assuming the answer to this is yes because nema14 templates are included in the McWire drawings. It would be nice to be sure though.

Finally the extruder, because really it's the first thing you should address. I have seen many laser-cut and RP extruder designs but is having parts laser cut absolutely necessary to build a repstrap? Are there any any extruders that can be built with a moderate set of tools? IE) table saw and drill press. A workable version of the current Mendel extruder might be built from a block of wood with a drill press and some careful measuring. It only needs to make one part after all.

Extruder

If anyone already has 2d drawing of this part with dimensions can I have a copy? Otherwise I will try to convert the .stl file to .dxf, as I am sure I have seen a post on how to do that.


Thanks for the great project.

I have been doing a lot of research on bootstrapping mendel with a mcwire. I don't have all your answers but this is the direction I am taking...

* Best I can tell mendel CAN be made on mcwire, it was very fuzzy if anyone has actually completed this though
* If you use ABS you may have some warping problems but you can probably address those with some hackish hot-bed solutions, specifically it seems to be an issue only on 4 or 5 larger parts. google site:blogspot.com abs warping . I think it was hydraraptors blog that had a lot of information.
* I think your print speed math is off, I had it as 300-400 hours though everyone I talk to seems to have a completely different
* Extruder wise everything I found indicated you will need laser cut parts, either ponoko, polulu or a local plastic supply with a laser cutter can probably make both the mcwire parts and the extruder parts for under $200 US. I chose the plastruder design from makerbot, they had the best assembly instructions. See my recent other thread on the extruder.
* For electronics the GEN 3 from makerbot seems the best option because they offer it pre-assembled (for me that was completely worth the time-money tradeoff) and had really clear instructions if you want to assemble yourself. There are some simple modifications you can do for appearance reasons (removing the rj45 header and wiring makerbot uses) but they don't seem to alter performance. You do need to use the different firmware.

* As soon as I can get my hands on some mendel parts either by making or borrowing I will start molding and pouring them, I should be able to produce quite a few quite cheaply though I may focus on just the hard or time-consuming to print parts. I intend to do this specifically to help people with bootstrapping as I have already been at this for 2 months and it has been hell to get clear directions on anything.

If you are US based I will post my cheatsheet instructions for what and who to order from.

I am currently building a Mendel using my McWire repstrap. If you really rachet up the speed to push the steppers as fast as they will go reliably you can build parts without delamination.

The extruder is made out of MDF, probably not the best solution as it tends to jam between models, but it has worked so far and is capable of printing a replacement for itself. The plus to using this wooden extruder is I built it in 20 minutes and the only tool being a hand drill with various bits for the different holes. A drill press would perform better but is not required. Here are some pictures of it, sorry no build diagram yet but I could probably make you one if you need it.

[www.binaryconstruct.com]


Also, The Gen 3 electronics from the makerbot do work with the McWire.


I used abs for some of the smaller parts, pla for the larger parts complex parts and planned on making the corner brackets out of wood/metal at least until I have a faster machine. I don't feel like waiting 8 hours for one corner bracket.

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[www.binaryconstruct.com]

Nice photo on the extruder. Could you create a wiki page on the steps you took with instructions and measurements? This is definitely near enough to the bootstrapping extruder I was looking for. Where did you get the motor that drives it, and what are the stats on it? What other parts did you need to actually make it extrude? Where/how did you make the barrel?

(I'm not sure the process for creating a wiki page on the reprap wiki.. Sebastian did this for my RepolaRap page.)

Thanks, if you do put it up, and bummer if you don't! ;-)

I'm not sure the process for creating a wiki page on the reprap wiki.. Sebastian did this for my RepolaRap page.

Just log in, go to a random wiki page, change the name in the URL, and then click "edit". Use the wiki page 'Generic' as a source text. (Again, click 'edit' to get the source text aka Mediawiki markup language text.)
[objects.reprap.org]

It's really very very easy after you've done the first one.

The extruder is made out of MDF, probably not the best solution as it tends to jam between models, but it has worked so far and is capable of printing a replacement for itself.

Yeah, thats pretty much exactly the picture I had in my head. If possible, I would be very interested in more information on how you made it. I think BeagleFury's idea of a wiki page is excellent. In my opinion, a repstrap extruder that doesn't require laser cutting is a needed addition to the project.

Are you using a splined shaft or gear or anything for traction on the drive shaft of the extruder?

For Mcwire, are you using nema14, 17 or 23 motors? What thread pitch are you using for the lead screws? And/or how many millimeters per revolution do your axis move?

I don't feel like waiting 8 hours for one corner bracket.

I realize this number may not be accurate but I would be interested to know how long it took you to print a particular part. A real world example of cc/hour for mcwire would be great.

If you really rachet up the speed to push the steppers as fast as they will go reliably you can build parts without delamination.

This kind of makes me nervous. I was hoping cold plastic wasn't a big deal. Have you printed any large parts where it takes a long time to finish one layer? Do you know if abs or pla is more likely to have trouble with delamination?

Is running the steppers "as fast they will go reliably" hard on them? Do they get hot? I wonder if anyone has tried to gear up the lead screws on mcwire.

Thanks.

It takes me ~2 hours to print a Mendel vertex bracket at 16mm/s. I have heard people only get 4mm/s out of a McWire so 8 hours sounds about right. I expect it could go about twice as fast with firmware that could do acceleration and perhaps a higher supply voltage.

As long as you extrude ABS at 240C it will stick to ABS at room temp. Similarly 190C for PLA, assuming your room is ~20C.

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[www.hydraraptor.blogspot.com]

I am only able to get about 4 mm/s out of my McWire. I'm not quite printing yet though. I plan on converting it to a belt driven X and Y axis, which shouldn't be very difficult. I'll post back if/when I get it done.

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Help improve the RepRap wiki! Just click "Edit" in the top-right corner of the page and start typing. Anyone can edit the wiki!

Yes after I finish my Mendel build

I will also be trying to add X & Y belt drives to my McWire build pictured here. It was abandond for Repraping as it was too slow.

Its still sitting as in this picture here it will to be replaced by Mendel.

As Mendel will fit on this desk as Rep Strap Darwin wouldnt fit!.

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Bodge It [reprap.org]
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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]

Hello, im new here. When you say bootstraping what do you mean?
I have been looking into making a mendel, but would like to base it off of a belt driven mcwire design... is this what your talking about?

In this case Bootstrapping means a way of making a self replicating printer without having a self-replicating printer to start with. In this case turning a McWire CNC machine into a 3D printing machine to create the parts of a self replicating printer.

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Bodge It [reprap.org]
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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]

sounds good to me. Is the final goal to build a reprap out of parts printed by the mcwire or to make parts to upgrade the mcwire to reprap status?

Sorry if i appear to be hijacking the thread at all, but if you turn a mcwire into a 3D printer, what would be the point of making another one (besides to give it to someone, or just for the point of having another printer)?
I think what i am asking is what advantage does a mendel have over a hacked mcwire (belts instead of threaded rod etc...)?

Im guessing the mcwire design would need many more modifications to make it compatable with all of the software of mendel? too much troubleshooting?

mendel can replace many of its own parts, mcwire can't

Sorry if i appear to be hijacking the thread at all, but if you turn a mcwire into a 3D printer, what would be the point of making another one (besides to give it to someone, or just for the point of having another printer)?

A lot of people want a 3D printer, and with Mendel and McWire and machines made using other equipment, they have two+ different ways to make them.

And then sell them for lots of money, or use them to make other machines.

McWire is a bootstrap machine for people who don't have a mom-Mendel; if Mendels were omnipresent, we wouldn't need McWires to prime the pump.

Say you know you want to make camera-microscope adapters out of black abs. You run the numbers, you can't afford a lasercut RepStrap or your laser cutter is out of CO2 or something, so you decide to build a mcwire, then a mendel, then two more mendels ... you've got 127 mendels and 1 mcwire, and now you've got your factory and can start pumping out adapters for your store.

I'm going the McWire->mendel route (or trying to) myself. The reasons that I have for making a mendel even after I get the McWire working enough to print out all the parts for a mendel include but are not limited to the following:

1. Speed. The McWire uses threaded rod, and is slow. Unless I upgrade it to belt drive, which I'm seriously considering trying to do before my extruder is even working...
2. Head changing. I want to do a pick-and-place head, and a solding wires to SMT parts head. And probably a syringe head for support material, glue for the pick-n-place, silicone calk for soft flexible parts, etc. Trying to have multiple heads on the McWire is silly, partly because of design, partly because of reason #3.
3. Compatibility. Other people are working on improving the design of the Mendel. From head changing to heated beds to improved software that makes assumptions about mechanics, these improvements are all based of the mendel design. While it would no doubt be possible to adapt most (if not all) of them to the McWire, it wastes less effort to just use the mendel already.

Although I plan on keeping the McWire around, that is mostly because I figure that development is easier if I have two working 3D printers. One to be in pieces while I "improve" it, and the first to print parts to improve the second. Also, some vital part breaking doesn't mean somehow jury-rigging a temporary replacement so I can print a permanent replacement.

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I'm building it with Baling Wire

I do hope that we will be able to start making things to improve machines like the Mcwire CNC machine using Mendel.

For example:-

Anti backlash drive nuts for Mcwire
Drive couplers.
Opto end stop flags.
Dremel mounts
Right angle Stepper mounts to convert Mcwire to a belt drive
Drive Belt pulleys
Or
Forrests new rack and pinion drive system adapted for McWire.

With a working 3D printer I am expecting a whole new world of possibilities to open up.

Edited 1 time(s). Last edit at 01/17/2010 10:12AM by BodgeIt.

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

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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]

The trouble is I just have too many ideas and not enough time to do them.

My priority's are Self sufficiency first as my mortgage protection insurance ends in July ~ then playing with all these exciting possibilities.

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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]