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Larger reprap mondo - anyone got one?

Posted by madprof 
Larger reprap mondo - anyone got one?
June 14, 2011 01:26PM
HI all

Has anyone got the new larger mendel?

It is here

reprap mondo


Which of all these company kits would you recommend.. I am after some accuracy and not a pile of goo bits! :0)
(I;ve seen all sorts of variations) one seems to be more cog driven like this one)


Which extruder head would you recommend for accuracy?
Which mendel variation has the best results you have found so far? (with some printed part examples).

Any help here would be welcomed!
The Glider looks to be a good price for a pre-built machine, but while researching them I read about a lot of people have had QC issues and long delays.

I, too am interested in the large build envelope of the Mondo and would be very interested in any input people that own or have used one may have to offer.
Re: Larger reprap mondo - anyone got one?
June 23, 2011 07:22PM
There's very little information on the web on the Reprap Mondo. I would want to see it running and I would want to see some sample prints before investing any money. I don't think that build volume would be of much use unless you operate it inside a heated chamber. For that, the wood parts instead of plastic would be an advantage. On the other hand, is that frame rigid enough?

There are a lot better choices for less money than the Glider. Please read this forum carefully before making a decision.
Re: Larger reprap mondo - anyone got one?
June 24, 2011 03:41AM
"There are a lot better choices for less money than the Glider"

The rapman 3.1 looks like a decent machine what do you think of that unit. It is very neat and the results look's good.
Re: Larger reprap mondo - anyone got one?
June 24, 2011 06:02AM
I'd suggest going for a regular mendel prusa as your first machine, and then think about building a larger machine later. 20x20cm is quite a big build area for 0.5mm nozzle size.

Blog with RepRap Comic
Re: Larger reprap mondo - anyone got one?
June 24, 2011 01:35PM
I'm not happy with the print results of these make shift prusa's and I havent the time to go blue peter on them. I'm after one premade or at least quality manufactured for under 2k. So far the UP vs rapman or bfb 3000... the mondo is gonna have to be really stable to work... its been nearly a month of its release date and still no videos or prints it has to prove it's worth.. and not create blobs of mess. I see many of these DIY units and the results are mixed.. way to much faffing about just to print something..

One test I was thinking if people could do it is to create

m4 m5 m6 m7 m8 m9 m10 m12 m16 bolts and nuts to see the actual detail level for each unit. If the threads work then its good enough for most jobs.

Anyone up for the challenge to see who has the best bolt and nut prints :0)
Re: Larger reprap mondo - anyone got one?
June 24, 2011 04:30PM
madprof Wrote:
> I'm not happy with the print results of these make
> shift prusa's

I am quite literally baffled by that statement, and will suggest you take a better look around, like here: [www.flickr.com]

I hate to break it to you, but RepRap is a DIY project, and so are any "low" cost 3d-printer you buy in a kit. If you don't want any DIY, maybe [www.shapeways.com] is a better option.

Blog with RepRap Comic
Re: Larger reprap mondo - anyone got one?
June 25, 2011 05:38AM
What I mean is a company that has the kits with good print results... putting a kit together is not the issue.. just the end results are.. its all in the extruder/motors/software... but not one of these companies are really showing off their prints in 18 million pixel images+... the best results I've seen are from nophead but not a complete kit as yet (I hope he does sell everything that is needed) ... now that's quality with decent photos to back up how good the prints really are. From a designers point of view decent accuracy is a necessity.

The bolt and nut idea will show the threshold of the smallest details and accuracy from each company made kit. The smallest bolt to the largest that way its a benchmark system for ALL users and companies who have gone through the headache of all the right parts... some heads may only handle m6 or m8 and up that will really help users decide to buy a professional premade kit.. I don't care if a printer looks like the inner guts of an R2D2 just the end prints are all that matter.

To many of these companies show really low pixel images of prints :0) which shows they are trying to hide the crude nature of the prints.. even a low end sharp 10 million pixel image would be something.

The BFB 3000 has great results but again not enough high resolution images to prove its worth... and the videos lol... and some of the ahem... issues are of a concern... maybe a bad extruder here and there and not the unit itself as such..

There seems to be a lack of focus and to many variations which lead to bad print results!

It's a case of telling someone everything and showing someone nothing....

By any chance has anyone come up with a prototype / inkjet head / powder system as that seems to be the best type of printer over all the other types... accuracy, colour, speed, no support needed and little waste...

That is my rant over with :0) I'm gonna try and offer my photographic services to these "mendel on roids" companies to show the product for what is can do and not what is looks like ;0)

rant over!
Re: Larger reprap mondo - anyone got one?
June 29, 2011 07:29PM

What I mean is a company that has the kits with good print results... putting a kit together is not the issue.. just the end results are.. its all in the extruder/motors/software...

The end results are all about how good you are at putting the kit together. I guarantee that if I were to buy a second TechZone Mendel and assemble it, I'd be getting better prints out of the gate on the second build than I did on the first.
Found someone that has a Mondo here: [uavs.us] (part 1) and [uavs.us] (part 2)
Re: Larger reprap mondo - anyone got one?
July 11, 2011 06:20AM
Thanks 7777773
Re: Larger reprap mondo - anyone got one?
August 06, 2011 10:38PM
Sorry to bring up an old thread, but I have one currently in shakedown if you want any further information.
Re: Larger reprap mondo - anyone got one?
August 07, 2011 09:11PM
I'd be really interested in more info on the Mondo please.
Re: Larger reprap mondo - anyone got one?
August 08, 2011 08:03AM
I'm still trying to dial it in, but here's what I've noticed so far:

The assembly is rigid when assembled. Nice and solid. I have a warped Z-Axis rod, so it flexes a bit during use, but that's a rod issue, and it'll be replaced through my local sources after the rest of the device gets squared away.

The laser cut parts are . . . iffy. My extruder had holes off by half a diameter. I don't know if they changed designs mid production or what, but some parts are kinda out of spec. Nothing you couldn't fix with a drill, file, or even a tap set if you were stretched for parts. Similarly the cuts are not perpendicular, so some holes taper pretty strongly. This also manifests in friction fit gears on steppers that absolutely require adhesive or set screws. Nothing a person looking into rapid prototyping / Reprap shouldn't be able to handle with a little effort.

Laser cut extruder gears aren't the best choice, but they're functional until you can upgrade.

There are documents about the electronics package, and once I wrapped my head around some stuff it all worked very well. Needed to swap the Y and Z in the firmware, which marked my first microcontroller flash that wasn't an arcade game. Seems solid, as does their nozzle assembly.

Conversely there is ZERO documentation on the mechanics. You're stuck with looking at similar designs and the photos on their website. And apparently that other site mentioned above.

At least for me, the build envelope was a little generous on their page. It's partly because of the endstops (more on that in a sec) but those measurements are from the build plate. I have a smaller envelope, but still a sizable 275x400x190 or so. I haven't pushed the limits. The biggest problem is at X=0 and Z=max you'd run the stepper motor into the frame. Still, a large envelope, and with a different extruder and endstop setup, I have no doubt you could pull the listed 305x460x280.

So, the opto endstops. The endstops don't have pre-wired cables, and the ends provided have the wrong pin spacing. They work, but they tend to walk off. I've heard suggestions of simply soldering it together. I was also provided with a length of cable only sufficient for two endstops. Again, not an issue, I had plenty of wire lying around. They don't really have any mounting locations, so it took a bit of work, and the results are the build envelope is smaller than the build platform, but it's fully functional.

In the interest of full disclosure, it took quite some e-mails and a month and a half from initial order to them getting me some parts shorted from the first shipment, but the quality of their printed parts and design is pretty high, so if you're willing to wait, it's not a bad unit.

To sum up:
Pros: Solid unit, large build platform, solid electronic documentation, and enough bearings to make the device smooth even unlubricated. Not that I recommend that.

Cons: Non-standard electronics, non-standard form factor, little mechanical documentation, an obvious limited production young design.

Recommendation: Not for newbies (that was my error), and frankly it's like the old days of Linux, if you have the time, effort, and temperament to do the required work on it, it'll do things beyond what other models can do, but I'm starting to see the appeal of paying more for a smaller, but more idiot-proof, machine.

If you've made one already, it should all be old ground for you, though. I'm curious why someone with a printer would repstrap, though.
Re: Larger reprap mondo - anyone got one?
August 09, 2011 11:09PM
Many thanks @Michael F, that is very helpful.

I'd be very interested to hear how you go calibrating, and printing decent sized parts. When do you think you will get to that stage? Are you using a heated bed? ...PLA? ....ABS?

I'm a reprap newbie (technically competent in a home workshop) so I'm concerned hearing your recommendation that the Mondo is not for newbies. I need the large build envelope of the Mondo and there don't seem to be other large machines out there - did you find any?

I'd also be interested in Techzone's comments on your post (hopefully they are monitoring this forum). Maybe they have addressed issues that you raise.
Re: Larger reprap mondo - anyone got one?
August 10, 2011 07:21AM
SydneyDesigner Wrote:
> I need the large build envelope of the Mondo and
> there don't seem to be other large machines out
> there - did you find any?

every size you like!

Re: Larger reprap mondo - anyone got one?
December 01, 2011 08:19PM
Hi again @Michael F

Just wondering how you have been going with your Mondo. Have you calibrated it OK and printed any decent sized parts?

Are you using a heated bed? ...PLA? ....ABS?
I am a reprap newbie. I am bit experienced with electronics but definitely a beginner to ground-up projects. However, I took a dive off of the deep end and purchased a mondo kit. I've been putting it together in my spare time and it has turned into a very long project. However, most of the trouble is that there are no formally published instructions. Everything that I have used to put the kit together come from photographs and tips others have posted on their blogs (Such as [www.uavs.us]) and instructions for similar machines on the RepRap Wiki. I have managed to completely assemble the entire machine, configure the motors and electronics, and talk with the repsnapper printing software. I am now working on the bed of the machine (I'll explain in a moment).

There are some issues that you should expect to run into with reprap kits in general, and the mondo in particular. You will need to buy a lot of extra tools if you don't have them already (Drills, wratchets, screwdrivers and bits, etc). Some of the pieces in the mondo kit were supposed to have screw holes, but didn't. I wound up having to add a few where they were supposed to be already. Next, many of the people that have ordered a mondo kit have received a badly warped printing surface. If the bed is not flat, the extruder tip can rub against it mid print. Also, your models will have a slant. Also of note, the mondo's bed is not heated, making it more difficult for the plastic to stick to it and can also cause the base of larger models to warp during printing. Since printing large models is the whole point of the mondo, it's kind of silly that it does not ship with a heated build platform. I am going to try to follow instructions for building heated beds for other models to make my mondo's bed heated as well.

So, if you are a newbie interested in building a reprap, I can confirm that it is not easy. However, it can be done with A LOT of determination and perseverance.
Re: Larger reprap mondo - anyone got one?
January 26, 2012 03:09PM
Hey all

I bought my 3d printer at thefutureis3d.com. Jeff is making really big printers. I'm new at 3d printing, but have lots of experience in hardware and software. The machine is well built, quiet and I'm very pleased with the results. Their customer service is very good. Jeff is a good guy. I'm not involved with him in any way, I'm just telling it like it is. smiling smiley

Re: Larger reprap mondo - anyone got one?
February 10, 2012 02:47PM
Saw this thread and had to contribute.

I bought a mondo last may. It has been a real pain in the arse. If I had to do it over again, I would have bought an ultimaker which has a slightly smaller print area but is faster and better supported.

That said, It took a LONG time to get it working and I would like to share some of my experiences with those of you who have mondos that might benefit from my learning curve.

1) The techzone driver board is crap. Get RAMPS from ultimachine.com or elsewhere. I do not think that the techzone driver board has the current to handle the nema 23 motor that they put on the Y axis.

2) The stainless steel hot end they sell with the kit is also crap. Mine would not get above 60 degrees C. Get any one of the other hot ends that are available. I use a maker gear groove mount hot end and it is great.

3) Wood construction is really problematic in a few places. The first thing you should print is a new extruder because the wooden one is not going to last too long. The design from techzone is bad with the wooden extruder since the bolts that tension the idler bearing go into the wood in between plys and use the wood as the nut. The wood will eventually delaminate (split) and you can no longer tension those bolts.

Also, the way the extruder is assembled, if you want to work on the hot end, you need to disassemble the entire extruder and part of the x-carriage. Pretty tragic from a usability standpoint. I ended up printing a greg's accessable wade's extruder and an open-x carriage as some of my first things once I figured out what was happening to my printer.

4) With a 12 x 18 print area, getting the bed flat is almost impossible. My aluminum plate came to me with a nice bend to it. I straightened it out manually and then machined the surface flat with my cnc mill. Since most people probably do NOT have access to a milling machine, that is going to be a little harder. I think the mondo is a candidate for a replacement Y carriage supporting a plate glass bed. That is the only way you will be able to maintain level surface over the entire print area.

5) Speaking of the y carriage... It is really hard to level the bed with the wooden Y carriage. It wants to bend, which gives really funky results. I have already replaced mine with a welded aluminum carriage that I welded together with 1/8" thick aluminum angle. Again, most people will not have access to a tig welder, but that is how I fixed it.

6) Under the Y carriage, you have very long linear rails. They want to bend so that makes getting a level bed even harder. I designed my new Y carriage to just sit on top of these so that when I get around to it, I can support them from below and reduce that.

All of that said. I HAVE gotten my mondo to work, and I am printing some very nice things with it. But it has taken a LOT of work, had me cursing for a very long time, and it is not an experience I would wish on any other reprap newbie. The folks at Techzone are not bad people, I think they are pretty nice actually - they are just incompetent.

If you are looking for a larger printer, get something else. There are more options out there now then there were when I got my mondo.

If you have a mondo and are having a hard time with it, I feel your pain, and I'm happy to help with advice to get you through it. Just contact me.

Re: Larger reprap mondo - anyone got one?
February 10, 2012 02:50PM
oh and also... It is VERY easy to have backlash issues on the Y axis because the carriage is so big and heavy.

Make sure you use firmware that supports accelleration and decelleration otherwise you will lose steps on rapid Y moves. I use Marlin and it works just great.
Re: Larger reprap mondo - anyone got one?
February 10, 2012 07:51PM
this company also makes giant mendels [thefutureis3d.com]
they look like normal mendels only bigger.

on y axis lash:
is it better to have a shorter belt? cause i think if you mount the y motor and idler
inboard of the frame (there should be enough room for this on a mondo) then
that would make it a little shorter.
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