Seeking advice on an alternative to MOD-t

[Jackson He]

To me the MOD-t's promises were two: inexpensive (it was an impulse buy for me), and ease of use. The first was delivered, clearly. The second, not yet. And according to ajfoul's judgement, the MOD-t has some designed-in inefficiencies that make it incapable to be very good. I'd like to ask for advice to potentially get/make a different printer.

My parameters are: 

• I only have casual use for it. And therefore hopefully it'll be low maintenance.
  
• I don't care much if it's slow. I won't be making a lot of parts.
• While it would be nice to be able to make larger parts, I don't have a particular size in mind. Something with a volume similar to MOD-t is acceptable.

So my questions are:

• What kind of printer should I get? A delta, something similar to Mini Kossel? I learned from ajfoul that deltas are much better at producing good quality parts. But then people seem to say it takes more to maintain, such as more time to calibrate.
  
• How should I get it? I mean, buy a complete unit, buy a kit, or start from scratch?

Thank you very much for your time.

[ajf]

So, I’m pretty firmly in the linear deltabot camp in terms of printers.  The cartesian format like with the MOD-t or MakerBots, is way more common though.  There are a couple of other configurations, like scara and core XY, but they are quite rare and more experimental.

Though I don’t have all that much experience with the cartesian format, I have heard very good things about the PrintrBot Simple Metal which is available pre-assembled from Adafruit for ~$600.

There are more than a few delta kits and pre-assembled versions available too:

http://deltaprintr.com/product-category/3d-printers/

http://www.ultibots.com/printer-kits/ (they have some cartesian kits too)

http://www.seemecnc.com/collections/3d-printers

Of those, I’d probably suggests DeltaPrintr. It was started as a school project and the kid who runs it is pretty passionate about what he’s doing.  They’ve got a new model coming out soon which looks pretty cool.  Other than MOD-t, the only assembled printer I've bought was the SeeMeCNC Orion. I just got that because at the time it was the only assembled delta that I could get in time to show in my booth at a hackathon alongside my Kossels and a loner from MakerBot. It was okay, though over priced I think, but in the end I had to return it due to a glitch with my particular unit that their support just couldn't resolve.

All that being said, I’d recommend building your own from scratch. It’s not all that difficult, will likely be cheaper (excluding the build time, which I feel evens out in the long term w/ regard to performance and maintenance), and you get to customize to your needs. As, noted I like deltas personally, but there are others who swear by cartesian. A well built machine of either type will deliver high quality prints.

Some things I like about the linear delta:

• It's elegantly simple mechanically. Each tower is identical whereas on a cartesian you generally have 2-3 completely different motion setups to do XYZ movement.
  
• The bed is stationary (mostly), which I think helps deliver higher quality parts.
  
• Very scalable. 
  
• Watching it print is mesmerizing.
  

The Kossel mini is a great design and quite stable now.  And there are people who will give you the printed parts on a pay-it-forward basis, that is, you just need to promise to complete the printer and make a set of parts for someone else... Just ask at the deltabot group. (That's also a great place to ask about kits and assembled printers, lots of very knowledgable people there.)

The first key to building a reliable, accurate printer (any style) is getting the structural and mechanical parts right. For a delta, that means having the towers spaced at exactly 120º and perpendicular to the bed. Next is having good linear motion components.  I like to use high quality linear rails and carriages, but they are kind of expensive. Lot's of people use delrin wheels on V-slot extrusions or other alternatives.

The other important choices are the controller and firmware. Though you can get by with running Marlin/Repetier/etc on RAMPS 1.4/Arduino  I'd recommend going with a more powerful 32-bit board.  I have moved completely to Smoothieware and Smoothieboard/AzteegX5mini. Also use Smoothie on my converted K40 laser. 

Not sure where you're hearing that calibration and maintenance on a delta is more difficult than a cartesian, again, in either case, if the machine is built well, calibration and maintenance shouldn't be an issue.  In fact, with Smoothie, I just run the calibration routine with a simple microswitch as the probe (or on some machines FSRs under the bed which are triggered when the hotend touches the bed) when I make mechanical changes.  There are some one-off calibrations to the motors (especially the extruder) when you first build the machine, but that's the same for either delta or cartesian.

I’ve been working with Johann Rocholl (the father of the linear delta printer) and a few other people around the world (Latvia & Singapore, what! ) to bring some simple components to market which facilitate building a more robust, inexpensive, and versatile delta printer.  The first part we’re releasing is a simple aluminum bracket which, when combined with off-the-shelf aluminum extrusions and the appropriate electronics/hardware, will make for a world class printer. 

Hope that was at least somewhat helpful... Feel free to ask any questions.

regards,

aj

[Jackson He]

aj:

Thank you very much for your detailed reply. I've started to look into acquiring the parts for a mini Kossel.

Best regards,

jH

[ajf]

You're quite welcome. I'm sure I left out a bunch of stuff and got some things wrong (-ish).  

You can't go wrong with the standard mini Kossel.  However, if you're not in too much of a rush, the Kossel 25000 with the aluminum vertices is going to be really excellent.  The printed vertices of the current mini Kossel are fine for the standard size extrusions (15x15mm; w/ 600mm verticals and 240mm horizontals), if you go much bigger though, the 15x extrusions and printed parts aren't really rigid enough. There are some versions of the plastic parts that accept 20x20mm extrusions, I printed a set for a guy in Canada and he was pretty happy with them (though, he's also requested a set of the metal parts.) 

The aluminum vertices (Kossel Metal Bracket) will accommodate 15x15mm, 20x20mm and 20x60mm extrusions and both NEMA 17 & 24 stepper motors.  I'll be distributing those via Amazon (Prime eligible) in the US and Canada, while orders from other countries will be fulfilled by my partner via a distribution center in China.  And, just to be clear, on this initial release at least we're pretty much just hoping not to lose too much money.  It's not really a for-profit venture at this point, we just want to get the parts out to the folks on the deltabot forum and other enthusiasts. The initial cost for a complete set of 12 brackets will be something under US$45, I think.

There is a great source of delta printer parts based out of Washington state in the US.  Really great people and very knowledgeable, lots of great info on their site too. They provide assembled carbon fiber rods in various lengths at reasonable prices.  I build my own, but that can be a bit tricky if you aren't used to working with carbon fiber and have the tools needed.  It's especially important that the rods (arms) on a delta all be the same length (within 0.1mm tolerance.)

regards,

aj

[Jackson He]

aj:

Yes, I've gotten to the tridprinting site from your previous posting, somehow. I didn't order anything because some items for their mini Kossel was out of stock, such as the nuts and bolts set, and the ebay listings for the same are not exactly the same.

When are the brackets coming out? And how about the Kossel 25000 design? (I mean, I can find mentions of it on the internet, but no actual design yet.)

Another thing I'm curious about is support for the diamond hot-end. Just the ability to switch between three colors is fascinating to me already. But I also read (http://www.thingiverse.com/thing:968485) that they are working towards true 3 color mixing. While that is still not the same thing as full color printing (for that you'll need to have 5 color support, with black and white in addition to RGB), it's very very exciting. To work with the diamond hotend one needs a board that supports 6 motors, such as this one: http://www.panucatt.com/Azteeg_X3_Pro_p/ax3pro.htm. 

Again, thank you very much for your help!

Best regards,

jHe

[ajf]

Not exactly sure when the brackets will be shipping, I'm still waiting on my samples... But, it should be just a few weeks. (I'm only doing US/Canada distribution, someone else is doing the manufacturing side and international distribution.)

There isn't a BOM or build instructions yet as far as I know.  Some of us have an earlier prototype part, but the dimensions are different, it supports a smaller range of extrusions (it's the blue and frosted acrylic brackets on Johann's Flickr stream.)

Would recommend that you hold back for a bit and let things sort out.  

I buy all of my hardware (nuts and bolts, etc...) from Mcmaster-Carr in bulk. You can email Tridprinting and ask when they'll have their parts in stock, sometimes it's just that the store software is funky and doesn't keep good track of stock...

I'd recommend leaving multi-hotend and color mixing for later. It's still all quite experimental, and without a good background in 3D printing with a single hotend will likely be very frustrating.

The Azteeg X3 Pro is a nice board, I have one though I have yet to use it, but is based on the ATmega 2560, so it's basically just a RAMPS board with more motor drivers. Though the 8-bit boards will work with a delta, they do struggle a bit with doing the calculations. The Smoothieboard and it's variants are 32-bit  and run at 100-120MHz (as opposed to 16MHz of the 2560) and are thus much more capable. It looks like many of the Smoothieboards variants are currently out of stock, that may be because version2 is coming out soon, but I'm not sure.  I really like the Azteeg X5 mini because of it's small size and excellent quality, but it does lack some of the features of the Smoothieboard 5X (the naming is a bit problematic), like ethernet (not really all the useful.) The Smoothieboards proper can be expanded to accept more stepper drivers and MOSFETs to run more hotends/extruders, don't think the Azteeg X5 can though.

[Jackson He]

That's fine with me. I'll wait until the new BOM and instructions come out.

I didn't realize that the different Azteeg boards have different processors, and that the Smoothieboards are extensible while their clones are not. Good thing I asked.

Again, thank you very much!

JH

[Jacob Zdvorak]

Hi ajf,
It sounds like you have deltaprintr is that correct?  I like the build volume and price point of this printer but am having trouble finding reviews.  There are a few negative reviews from people who got the printer right after the kick starter was fulfilled.  What was your experience building and using the deltaprintr?

On Sunday, December 13, 2015 at 9:20:45 AM UTC-8, Jackson He wrote:

[ajf]

No, I don't have a deltaprintr. I do think it's a pretty good kit for the price, but there are things I don't like about it...:

• It could be more rigid.
  
• Acrylic arms.
  
• I don't like wood structure.
  
• RMAPS electronics
  

All of those issues are addressed with their upcoming Delta Go machine

I like to build my own machines from scratch, but that's not for everyone.  As noted earlier, I'm working with some other people to bring the Kossel 25K brackets to market and am also considering offering a partial kit. Basically, all the structural/mechanical components. Still working out the details with regard to size, but it looks like it will have a 300mmø bed and a Z height somewhere around 300mm+.

I got my samples of the brackets a couple weeks ago and have been working on building a machine.  Due to the parts I had on hand and the fact that I'm a bit crazy, it's kind of monster.  Stands 1.5m tall and weighs in at nearly 90 lbs. But, even so, assembling the frame was a breeze...:

BTW: I've also, finally, decided to develop a fully assembled delta printer. Been kicking the idea around for a while, but was hoping someone else would offer one that was super high quality so I wouldn't have to... And, honestly, what pushed me over the edge was the deficiencies of the MOD-t and NM's failure to address them in a timely manner, in my opinion. Hope to have it out by the summer.

[Jacob Zdvorak]

I was looking at the Delta Go.  It's too bad the print area is so small.  It would be nice to have the build volume of the Deltaprintr with all the upgrades of the Delta Go.  The Mod-T was my first printer and I quickly realized I wanted a larger print area.

There are so many things I want to print now that I got a taste of 3D printing.  I realize most printers take time to set up, get printing and maintain but I'm looking for a printer that wont be too much trouble even if its not exactly what I want.  That way I can be printing while I read and learn before building my own from scratch.  There is so much information out there to take in.  Anyways, I don't want to get off topic.  Thanks for all the help!

[AlanZ]

 

I don't know if anyone else is interested, but while I wait for a new hot end for my MOD-t,  I am in the middle of building a Rostock MAX v2 delta style printer.

It's a very interesting project, I've got about 20 hours into the build process so far. 

I have been documenting the build with time lapse and detailed videos that I will publish soon. 

I put my workspace/unboxing video on YouTube   https://www.youtube.com/watch?v=e_ZKE3VN_pc

[ajf]

Alan, you are annoyingly organized! 

Would suggest you take special care in assembling the E3D v6 hotend.  If it's not done just so, it will be prone to jamming.

As I noted earlier, I had issues with the SeeMeCNC Orion, but those were weird and unique to my particular machine.  The SeeMeCNC folks are great and stand behind their products.  I get my heat beds from them the samy Onyx 300mmø that you got in your kit.

[AlanZ]

Here is a photo of the "kids" sharing a bedroom...

[ajf]

Nice!

I suspect the MOD-t isn't going to get a whole lot of use now...

If you want to print with ABS, I'd highly recommend AtomicFilament.  It's very good and practically odorless when printing.

[AlanZ]

Thanks. I received 4 rolls of Atomic PLA a few weeks ago, just before my hot end failed. I should get the replacement hot end in a few days, and I am looking forward to testing this brand. I bought a roll of Verbatim ABS for my first print on the new machine (printing an ABS PEEK fan shroud is part of the build)

[Crispy Cat]

@ajf

was thinking about building my own 3d printer as with many finding the modt to be a bit of a waste of time thats left me hungry for better machine so wondering what are your views on sla printers? there seems to be a growing number of home made ones using altered projectors or lcd panels to emmit/block uv light going to the resin tray..

they seem alot faster and better resolution than the extrusion based printers but haven't seen one with a decent print size  

[ajf]

I don't have an SLA, may build one at some point in the future, but I've got other machines I want to do first.  My interest is more in building/tinkering with the machine than with producing parts on it and the SLA machines just aren't mechanically interesting. 

SLA is actually not that fast, FDM beats it there, I think. And FDM is catching up on resolution.  

Build volume on the DLP/LCD machines is limited by the ability to focus I suspect.  Machines like the Form avoid that limit since they use a laser, but there's also a limit imposed by the resin tank and managing the resin at the exposure layer. Then there's CLIP which is super interesting, but not really hobbyist/consumer level at this point.

SLA is very expensive in terms of consumables (resin, tanks.)

All in all, I'd say go for a good FDM machine before jumping into SLA.

[Crispy Cat]

thanks for the input ajf!

 i agree the fdm do look more fun to build!

ive been reading all day and am starting to agree that sla just isnt where i thought it was in terms of the speed and technology

i also think i was confusing sla and clip as they are seemingly similar and hadent realised the sla would have to lift and return every single layer!

so taking your advice and previous posts  i will start researching deltas.. have a few questions you might be able to answer 

1) what limits the speed of a delta printer? is it the motors or the hot end?  i have 4 large  "Nema23, 3.1Nm High torque Stepper Motor 1.8 Deg" from an old cnc that im guessing might be overkill?

2) you previously recommended the smoothie board controller in another post would that still be the best choice?

cheers

[ajf]

Yeah, those motors are bit overkill unless you're building a very large machine with heavy linear guides and that would just be crazy ;-)  Pretty much everyone uses Nema 17 like these Kysans (I personally like the 1124141 because it's not hardwired, but it's the same spec.)

There are a lot of factors that can limit print speed. How efficiently you can melt and deposit plastic is certainly one, and the hotend/extruder come in to play there.  The rigidity of the frame, the mass of the effector and other moving parts play a huge role too.  It's basically a matter of how fast and accurately you can move the nozzle until you reach the point where you can't melt and push plastic through to keep up.

Over on the Deltabot group we are working on getting to printer with no structural or mechanical printed parts, mostly metal with some carbon fiber thrown in... And, as I mentioned up thread, I'm putting together a kit (my username is profeti there) to put on Amazon.

The Smoothieboards proper are great, seem to all be out of stock now as v2 is close to being released.  Panucatt just released Azteeg X5 mini v2 (Smoothieware compatible) and will start shipping next week, it's freaking awesome. There are several other 32-bit boards and firmware, I don't have experience with any of those. David Crocker has some great info about Duet on his blog. He's also the developer of the PanelDue, which is nice touchscreen for the Duet (something not yet available for Smoothie.)

[AlanZ]

I calibrated my new delta, and made its first print (an ABS fan shroud).
Beautiful print. This could be habit forming!

That said, I would like to see how the MOD-t behaves when the new hot end arrives. I have gotten some nice prints out of the little machine, but so far, the Rostock is quite a stellar machine.

[Crispy Cat]

@ajf thanks! you always give the most informative posts! 

Crazy sounds fun! and while i dont have the space to do THIS..  i could go for 60cm long base sides with 1m to 1m20 height and still keep it next to my main computer :)   

How you have described the speed limitations makes alot of sense.. its not how fast it can move but how fast it can accurately extrude and place the filament at speed.. certainly given me some ideas to look into!

your kit looks perfect but being uk based and having a disorganised room full of machining tools (lathe, manual mill and the trusty 130w lasercutter) ,  i should really try making the connectors,rods etc myself!

im guessing this will be a fairly long project for me so holding out for the smoothie 2 is probably going to be my best bet also being close to the computer i hopefully wont need an lcd   

will start looking around the delta bot group :)

thanks again  

[ajf]

Okay, I'm envious of the 130W laser, mine is a cheap-o 40W.  Building a new machine with 1m x 1m bed (with passthrough) that should accommodate 1500mm tube internally and larger with extension. Making space for it in the shop is the hardest part! It will also use Smoothie.  I also manage the Opensource Laser group, come on over!

I'm doing the brackets and kit on Amazon in the US/Canada, but my partner will be providing the brackets for other countries from a fulfillment center in China.  The brackets are opensource and the files are available here. Make it super simple to get a very rigid frame built quickly.

[ajf]

Picture or it didn't happen...

How was the oder from the Verbatim ABS? Every brand I've tried other than Atomic has been pretty bad in that regard.

[AlanZ]

I barely smell any odor from the Verbatim ABS filament.  My wife can smell it, but does not find it objectionable.

I will post photos/videos of the prints soon.  I am working on the time lapse video of the build process first... it's rendering right now. 

[AlanZ]

I tried posting a link to a youtube video of the build process (twice) and they were removed.

I don't know if the system removed the link, or if the moderator did.

[ajf]

Not sure what happened.  I saw the two posts in the moderation queue, even though moderation is turned off for the group. When I okayed them, they just disappeared. Sometimes/often Google's software is crap.

Here the video link.