WHY THE HELL...

...IS IT SO DAMN HARD TO GET PLASTIC MENDEL REPRAP PARTS?!? AND WHY ARE THEY SO EXPENSIVE?

...IS IT SO DAMN HARD TO GET PLASTIC MENDEL REPRAP PARTS?!?
Because it takes ~36 hours to print a set.

AND WHY ARE THEY SO EXPENSIVE?
Because people are willing to pay too much money for them.

I would suggest you address the situation by building a WolfStrap,
Eiffel, or XCbot. And then make a set of Mendel parts.

And then donate that set to our super-secret Loaner Program.

Or sell it on ebay to the highest bidder. That's your decision. We're not really control freaks here. If you choose to help your fellow developers by donating one or more sets to the loaner program, please email me and I'll announce it on the blog once you have the set ready.

Please note that if you buy a set of mendel parts from ebay for $400, build a mendel, and then sell 1 set back to ebay,
THE PLASTIC PARTS OF YOUR REPRAP ARE ACTUALLY FREE!!!!!!

good luck.

Edited 1 time(s). Last edit at 07/24/2010 09:18PM by SebastienBailard.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

Great responce as usual Sebastian!

Htimstyler, trust me the community is going 15 different directions trying to fix this situation. We have 3 different versions of laser cut Mendel not ready for prime time. A lasercut Darwin that is hard to build, 2-3 people making cast parts and selling them. 10-50 people, including myself selling parts at a labor rate less than minimum wage (I set my price at $3/hr when I am selling parts, I sell Mendel for RP parts for $150-$200. Not because I want to get rich, but because I have to replace the parts that break on my Repstrap when I print.

The price has dropped significantly in the last few months, and once one of the lasercut sets are ready for prime time, or we get an easier/well documented alternate electronics set it will improve more.

Remember 2 years ago there where only a few dozen people in the world that had a printer capable of reliable printing, now we are up to likely near 1000 printers in the world at any given time printing RepRap parts. If we keep this rate of improvement up your wish for cheap ($100 to a non friend), will likely be around very soon.

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repraplogphase.blogspot.com

Quote

once one of the lasercut sets are ready for prime time, or we get an easier/well documented alternate electronics set it will improve more.

Don't understand this part. Why would one build from lasercut parts if the "real thing" is available in form of casted parts? Pololu electronics exists in two versions already, is (almost) as simple as one can imagine, but both are hidden on some special Wiki page. Why?

I'm pretty sure giving people alternatives would improve the situation even more. Mendel ist nicely modular, after all. You can mix built parts with casted or milled parts, mix Gen3 electronics with Gen2 electronics, mix a wide range of stepper motors and so on ...


BTW., here's an Auction which obviously falls through ebay's search engine somehow.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

I am the one that set up that Ebay search... dang... I wonder why that one didn't come though, need to go look at the settings.

Cast is far from the real thing. Resin cast is MUCH more fragile than lasercut or RP. Cast also very much limits spread of production. If a viable lasercut design is available, almost every college student on here can print one at the university, and the "rest of us" can order the parts from BigBlueSaw or Ponoko. But RP is always going to be the final answer.

Part of the issue is the Mendel was designed around the strengths of RP, like the fact that 2-3 mm worth of plastic around bolt can hold a significant amount of weight, and tolerate vibration, that's true for RP, but not resin and lasercut, both of which would fall apart if heavy loads are applid with only 3mm of material wrap around. Most cast and lasercut parts to date have just ported the Mendel design over to another medium, without rethinking the design much. That' part of why people have such issues.

Foton is in the process of designing a Cast Mendel variation,

The Rapman and Makerbot where designed around Lasercut.



Traumflug Wrote:
> Don't understand this part. Why would one build
> from lasercut parts if the "real thing" is
> available in form of casted parts? Pololu
> electronics exists in two versions already, is
> (almost) as simple as one can imagine, but both
> are hidden on some special Wiki page. Why?
>
> I'm pretty sure giving people alternatives would
> improve the situation even more. Mendel ist nicely
> modular, after all. You can mix built parts with
> casted or milled parts, mix Gen3 electronics with
> Gen2 electronics, mix a wide range of stepper
> motors and so on ...
>
>
> BTW., here's an Auction which obviously falls
> through ebay's search engine somehow.

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repraplogphase.blogspot.com

You may also want to consider an Isaac here:
[forums.reprap.org].

It's a milled derivative of the Mendel, and to me at least it looks like a really good alternative. The parts are made out of a sort of plastic-wood that seems to be really strong. It's still a work in progress, but hey, everything here is.

Hi Guys,

Thanks for all the responses.

I Realize it takes 36 hours to print parts, but what is the setup time? After it is setup it, is it not kind of a hands free operation?

I was forced to settle for the woods from Techzone, and have been pretty disappointed due to major discrepancies in hardware, lack of documentation, missing parts from my kit, plus missed holes in the laser cutting and post processing, and overall quality. Does anybody know of anyone that has got a Techzone Mendel working?

My plan is to get Techzone's Mendel working with Makerbot's electronics and build a second Mendel out of plastic and do it right.

Jeremydeath... that milled derivative looks pretty sweet.

Sibastians 36 hours assumes a very fast machine, 25mm/s is the average most people get so 50+ hours is quite common. For Makerbots Mendel is 24 plates, each taking around 1-2 hours (some take 2.5). Rapman does mendel in 6 plates, both assuming you are running HBP, if not then you likely have to print over 30-40 times.

For each plate there is at least 2-4 minutes worth of set up time, (if it's your 1st plate 5-10 minutes to heat up). Plus all "sheets" need to be processed though skeinforge, which takes for Mendel about 5-6 hours of just processing time. Compiling to print for a Makerbot is total around 1-2 hours.

All this time you are likely to break SOMETHING, a heater barrel, and idler wheel, something, so you have to count in down time, repair costs. Then of course you have a loud machine that you need to baby sit. No RepRap can tell when something goes wrong that doesn't kick it out of it's build area, so if you z gets jammed you just going to keep extruding .

What parts are sub par on the techzone build, I can start printing them.

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repraplogphase.blogspot.com

Hey Spacexula,

I'm going to pick up more hardware tomorrow and hopefully finish my mechanical this week. A few things that worry me about Techzone parts are that the springs seems very brittle, some of the wood is very soft, and a few of the gears are too lose for a press fit on the motor shafts. I am going to do my best to make them work.

If I could order an extruder from you that would be awesome.

Springs? When did Mendel get springs?

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repraplogphase.blogspot.com

Quote

Plus all "sheets" need to be processed though skeinforge, which takes for Mendel about 5-6 hours of just processing time. Compiling to print for a Makerbot is total around 1-2 hours.

EACH time?? Can't you store the compiled g-code and re-run it without recompiling?

Are these not springs shown in this picture?

[reprap.org]

That's just what I've seen them called in the assembly instructions, and they definitely resemble a spring.

looks like screwed rod to me, some call it studding.

edit, sorry, do you mean the double S shaped things under the bed

Edited 1 time(s). Last edit at 07/26/2010 05:36PM by johnrpm.

Yes I do mean the s-shaped things, they are springs, if you've read the assembly instructions. I'm qouting the bom:

"bed-spring_4off.par"
"z-axis-opto-spring_1off.aoi"

Edited 1 time(s). Last edit at 07/26/2010 07:04PM by htimstyler.

Yes they can be reused IF you don't monkey with your bot and change your skeinforge attributes in the mean time, and IF you are printing from SD, and IF you print a second Mendel.

Most people get sorta sick of printing Mendels after 2-3. Remember even if you sell them for 3-400 you still dont' make minimum wage.

peer Wrote:
-------------------------------------------------------
> Plus all "sheets" need to be processed though
> skeinforge, which takes for Mendel about 5-6 hours
> of just processing time. Compiling to print for a
> Makerbot is total around 1-2 hours.
>
> EACH time?? Can't you store the compiled g-code
> and re-run it without recompiling?

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repraplogphase.blogspot.com

Sorry your right, I have a stack of them here. I thought you meant metal round springs, sorry.

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repraplogphase.blogspot.com

Yeah Spacexula... thought I'd be confusing people. Do you think I can substitute with metal springs anyway?

Also, can I buy and extruder from you? And if so, does it use a dc or stepper motor? My buddy got one from Techzone, but the post processing isn't done on it, and there is zero documentation on it. We would need to by clamps and glue it together, so it would probably be cheaper if we just bought a new one.

Let me know if I can snag one from you.

Which would you prefer? Prinstruder is easier to hook up, but you really need to get a Makerbot Worm gear if you use that. Wades you have to make your own worm gear for, and I can really only print the [www.thingiverse.com] version because I have a Cupcake.

You name it and I will print 2-3 up and put them on ebay tomorrow.

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repraplogphase.blogspot.com

I have Makerbot Electronics, so I think that means I have to use an extruder which uses a DC motor. I'm not sure though, because Reprap home page shows a picture of a reprap running Makerbot electronics with a extruder with a stepper motor.

Does anybody know anything about this?

The MakerBot Electronics is the same as the Gen 3 RepRep Electronics.
What you need is the RepRap FW loaded into the boards to make it a RepRap and it is setup to use a stepper for the extruder.
As I understand it the next version of the MakerBot FW will again provide stepper support but I have no idea when it will be available.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Which generation of Makerbot electronics, as the Mendel can use the Makerbot electronics but the firmware in the extruder drives a stepper motor connected to the PWM chip (i.e. it is not a true stepper motor driver chip). The cutting edge designs that some people are working on use 4 stepper drivers to provide the functionality as required. But as I said, this is the cutting edge of the design, but just if you read the mendel design information on the wiki, then it does explain all the details about using the Makerbot electronics on the mendel and the test approach to use for them to work. (It applies to the lasercut versions of the mendel as well as the plastic versions).

Dave

You simply attach the wires from D9 & D10 to the step & direction lines of your Pololu stepper driver (or whatever other stepper driver board you are using).

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

I'm building a Mendel with cast parts. It's definitely a lot work finishing the parts with all the drilling etc. But hopefully once it's built it will be able to print replacement parts for itself. I think this is where there is a flaw with the lasercut version.

Follow my progress by viewing the link below.

http://jsrreprap.blogspot.com/


JSR

Hi Dave and Bob,

Thanks again for all the quick responses. I do have generation 3 electronics. They have dual h-bridges, so that must give the capability of running a a stepper motor.

Bob, why do you mention a seperate stepper driver, is this something you would be adding to maker bot electronics? I have a driver board similar to that, leftover from sparkfun, called easy-driver, it has the same chip with a step and direction input.

Hey JSR, where did you get your cast parts from?

Quote
htimstyler
Bob, why do you mention a separate stepper driver, is this something you would be adding to maker bot electronics?

Some people don't like the double bridge.
I myself bought some Pololu driver chips and was going to use one for the extruder but I bought another stepper motor instead. The 14V MakerBot stepper motors work fine for X, Y and Z axis but is lousy for the extruder. So now I have a 2.85 V stepper motor for the extruder, it gets a little warm but has plenty of torque using the two bridges on the extruder controller.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Bob,

I see, Is you build posted anywhere? Seems familiar seeing a separate stepper driver mounted somewhere on a Mendel. Thanks for the advice.

I have seen the picture but it's not my machine.
My pictures can be seen on my Picasaweb Mendel album.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Hey Spacexula,

I'm still trying to decide which extruder to use. Definitely going with a stepper motor. I'm thinking about going with wades geared extruder.

Any suggestions?

If you put them on ebay are you going to have a buy now option? I hate bidding, don't really have time for that, let me know the price.

Wades is the only way to go with a stepper. My nichrome just fryed while printing off a wades. Should have it back up tonight (cross fingers)

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repraplogphase.blogspot.com

Sounds good. Go ahead and prints some wades if you can.