Like I was saying in my previous post, my MarkOne failed during a print and the fiber was jammed up in the feed mechanism. I had a support call in to Markforg3d, but I decided to be daring and take apart this mechanism to see how it worked.
Thankfully, it was a very simple process. The feeder is basically two thin metal tubes fixed on either side of a pair of opposing-spinning rubber(ish) wheels. The fiber is simply forced through by the wheels, just like a baseball pitching machine or battery-powered Nerf gun.
Just after the exit tube is a small gap before the next tube. This gap is where the razor blade passes to cut the fiber. They use a standard RC servo to do the cutting, which is a great way to do it. Closed loop, high torque, small package. The problem is the noise. I suspected they were using a servo for the cutter because of the characteristic chirping, and disassembly confirmed this.
So the problem my machine was having was that the fiber got jammed up inside the wheels. All I had to do was to provide light tension on the fiber by pulling it, while I manually rotated one of the wheels. I ended up pulling a huge strand out of there!
After the repair, I was able to print two versions of the quadcopter, one with concentric fibers, and the other with isotopic fibers.
Concentric fibers just make outline passes around the perimeter of your object, as well as around any adjacent holes.
Isotopic fibers will do passes like it would for filled layers, but it doesn't do an entire layer of fiber. Instead, the layer is partially printed with fiber, while the rest is completely filled with nylon. The next layer is oriented at a different angle, as are all subsequent layers. You get to control the layup angles through Eiger, if you like.
And the results? Well, the parts are a little stiffer. Not a lot, but I think I need to play with infill. Concentric @ 25% was slightly stiffer than without fiber @ 25%. Isotopic was a little stiffer than concentric, but that could be because it is basically going to print at 100% fill.
Unfortunately, my long follow up build (to complete all of the quadcopter parts) overnight failed, but this shows off another really nice feature of their system -- I just submitted a problem ticket, and they told me they will go into my machine's logs remotely and try to determine what went wrong! So my MarkOne is out of commission for a few days, but hopefully this will help them fix a bug or two in the process.
On Monday, I finally got my registration issues with Eiger resolved. I wasn't going to use specific product names and screenshots in this blog post, but I just noticed that Markforg3d updated their website and are now showing off their software. So I assume that I can now pretty much talk about whatever I want! Eiger is their cloud-based 3D printing software. I'm concerned about this platform for the obvious reasons, like how they can shut a printer down with a remote command if they really wanted to, and how customers are stuck with a paperweight if they go out of business. I hope they eventually release desktop software for the MarkOne, I really do. More about the software later.
So, how was the setup experience? Overall, it was simple and there weren't any surprises. The only problem I ran into was that the dry box that comes with the MarkOne is a rather large OTS Pelican case, and it doesn't fit on the bookshelf with my MarkOne. All of the photos online show just the printer, but I think they should also post accurate images where they've got a large black plastic box adjacent to the printer. Or they could avoid this altogether by shipping with longer flexible tubing so customers have the freedom to place the dry box wherever they like. Since I was forced to place the box to the left of the MarkOne, I just left it sitting precariously between my desk and bookshelf.
The spool holder is really nicely designed. They printed it out of nylon and embedded magnets for attaching the end cap. All you have to do is put the spool on the holder, snap on the magnetic end cap, and then drop the assembly into the dry box. Next, feed the filament to the MarkOne, power it up, and then run the load filament utility from the touchscreen. Simple!
Power up video! Ok, it's not that exciting and it's also upside-down.
And here is the model that I decided to use, along with some of the images of the file getting processed.
The next step involved figuring out Eiger without first looking for a manual. Thankfully, the software is so easy that you don't even need one. It's a bit light on the options -- I like the fact that they don't expose a lot of features, but I'd also like to see customizable slicer profiles that allow me to mess with bridge settings, at the very least. Of course, this assumes that their software even supports bridging. I have no idea if it's an in-house software, or if they are using someone elses under the hood. I'm sure that the fiber-related code is all theirs, though. One other small nitpick is that they use sliders for entering some of the information. I would much rather enter the parameters via textboxes because I generally don't like
having to drag an object on the screen around just to decrease my number
of base layers from 4 to 2. I just want to hit 2. If it's a slider where the exact number doesn't matter so much (like in my GUIs where 1 unit doesn't make a whole lot of difference), then it's generally okay in my book.
Overall,
the workflow is intuitive and quick. After logging in, you start in your library, where you can simply drag and drop STL files. From there you can choose which object you'd like to
print. It takes a little while to process each step because the data
is uploaded to their server, processed, and then
the resulting data is downloaded to the browser. Oh, did I forget to mention
Eiger only supports Chrome? Not a big deal for me, but I just wanted to
let you know.
The 3D rendered parts are gorgeous. I haven't
seen a single 3D printer software package that renders models this
nicely. I also love how rotation is extremely quick compared to something like MakerWare, which I use with my Replicator 2.
Once the part is sliced and viewable, you can check out the
individual layers by clicking Internal View and cycling through the layers. Finally, click Save and then Print. Select your
printer from the droplist of available printers (I guess companies can
afford multiple of these expensive machines), click Print again and the
data will get transmitted over the network to your MarkOne. That's it!
Having a cloud-based printer software is extremely nice. Let's say you're at work and you come across a part that you really like. Just submit the job remotely through Eiger, and you might be lucky enough to have a completed part right when you get home!
I submitted the print job and waited for it to complete. Unfortunately, it was a failure because the part came out warped (but at least it completed!). I guess I was expecting too much
by assuming that a machine that claims 10 micron repeatibility can stay
level even after shipping. :)
I ran the bed leveling
program, which was extremely simple to follow. The only thing that
bothered me was that no matter how many times I leveled the bed, I
couldn't get the piece of paper to slip under the extruder nozzle at the
center point. I also noticed that the knobs are extremely sensitive.
If you literally tap them, you can go from feeling slight resistance to
feeling none at all. Despite all of this, my reprinted part came out very flat. Here are the two prints side-by-side.
After
this model printed, I moved on to an iPhone 6+ stand since my wife has
been bugging me to design one and I keep forgetting. I ended up just
printing the awesome Octopus Stand by notcolinforreal on Thingiverse.
I then moved on to printing a stretch bracelet from anoved and a couple of GT2 and GT3 belts by LionAlex. Nylon is a pretty awesome material. I've wanted to print this material for a very long time, but didn't have a printer capable of handling the higher extruder temperature. I love how it's very stretchy and tough. The belts seem to work pretty well (I'd rather have an OTS belt, of course), but these can work for some prototyping. The bend radius isn't very good, but I think that if you're willing to sacrifice durability, you can print with 0% fill, 0 base layers, and 1 shell. The print will delaminate but the teeth are still intact!
After all of this printing, I decided to move to Kevlar printing last night. Setting it up was also simple, but you need to read the directions. It's very important to use the provided tape to keep the kevlar fiber under tension. Just feed the fiber through the tube until it reaches the feeder/cutter mechanism and then run the load utility. It will feed the fiber all of the way through the extruder, and when you tell it to cut, it will cut off that length of fiber, which you can then pull out through the extruder.
I decided to print the Mini Flame Wheel Styler Quadcopter by tosjduenfs, because quadcopters need to be tough, but rigid. This would be a perfect test to see how stiff the parts come out, and how heavy they are compared to tosjduenfs' numbers.
Unfortunately, the first print failed because the nylon jammed up before the first layer was even partially complete. You know it's jammed because the extruder makes a loud clicking noise, which is pretty much like all other FDM printers out there. The layer was extremely thin, and almost looked thinner than 0.1mm. I tried again and got the same results. The funny thing is that fiber prints start each layer by printing a "timeline" cylinder in the rear left corner of the build plate, and the first layer of the cylinder printed perfectly. I cleaned off the build platform and tried again -- exact same result.
As a sanity check, I printed the quadcopter piece without fiber, just to verify that it was a software issue and not a bed-leveling issue. The part printed perfectly, so it had to be software.
In the main settings page under "Material Settings", you can enable the "Use Fiber" option. However, when you do this, the "Layer Height" setting disappears. If you disable Use Fiber and change the layer height to 0.2mm, it resets to 0.1mm if you disable/re-enable Use Fiber. I figured the printing problem could be related to this, so I disabled fiber. The trick is that you can still selectively enable fiber after you slice the part!
With the new approach to using fiber, the first layer of nylon went down! And the second! And the first layer of Kevlar! But then the fiber feeder jammed. :( I aborted the print and started looking into it by checking the online help pages. It could definitely be an extruder jamming problem, so I followed the disassembly instructions. The fiber was still in the tube -- it hadnt even reached the end of the extruder. I then disconnected the feed tube from the output of the feeder/cutter and extracted the fiber. What I found interesting was that there was still a piece of fiber in the tube after I removed the other piece! I only ran the load procedure once, so this fiber had to have been left in the tube prior to shipment. So I think what happened is that the fiber that got jammed had actually gotten caught up on the other piece, which then gunked up the inside of the feeder/cutter mechanism.
I imagine that the cutter is slightly complicated, so I submitted an online help request through Eiger. I really like how you can post comments on any canceled print, and that this feedback goes back to Markforg3d for review. That's a nice touch.
Well, we'll see if I can get this problem resolved with an engineer today! I'm waiting for the call.
After a week with the MarkOne, I have to say that it's a nice looking, pretty nicely engineered product. It almost works perfectly out of the box and the software has worked well so far, with the exception of a couple of problems. My only real complaint with the design is that it is loud. Stepper motors bolted to a metal frame just make too much noise. Operation is noisy, and the final procedure of lowering the build platform is even noiser -- so much that when it completed a print last night, my wife yelled "WHAT WAS THAT???". Hopefully, this is something they can address by softening the mounts, or changing the step resolution. It's definitely possible to get quieter stepper operation. My PP3DP Up! printer is really, really quiet in comparison to all of my other 3D printers.
Friday, January 2, 2015
MarkOne Unboxing!
I was quite surprised when my
MarkOne 3D printer arrived earlier this week. I honestly wasn't
expecting to see it until early 2015. Well, it is here, and it looks
awesome! Too bad I can't print with it yet, but more on that later.
Here's the box, and what it looks like in the box.
I
carefully removed the MarkOne and placed it on my floor. It is quite
heavy. I wish they had put in straps or some kind of carrying handle to
make it a bit easier. Getting my short arms around the machine and
lifting up from the bottom was tough. :)
Inside of the
box was also a smaller box filled with accessories. These included the
build plate, some removal tools, a wireless antenna, a spool of Kevlar,
and the power supply. Shipped separately was a Pelican box that is
used as a "dry box" for the nylon. Since nylon absorbs water, you need
to keep it dry for the best results. The case was internally modified
to accept a spool of nylon with a shaft to spin on.
The
build plate is of exceptional quality. I love the fact that it's a
machined flat aluminum plate, with fly cutter marks and all. Three
bolts are inserted in the bottom, which I assume makes up the kinematic
coupling. I don't know what material they've used on the top surface.
It's kind of tacky. And since I can't think of anything else, my guess
is PEI? I don't know.
But you probably could care less about the accessories, let's look at the hardware. In a word, this printer is beautiful.
The best looking thing I've ever seen. I once oohed and aahed over the
Form1, but this is ever nicer. I only have a couple of minor gripes.
The edges, while not technically sharp, are still...well... sharp. Not
enough to cut, but enough to not feel good. It reminds me of my iMac
from 2011ish, which I did cut myself on! And the surface feels like it
came straight out of the sandblaster. I wish the frame surfaces were
smooth like iMacs. But hey, you can't have everything.
The front door is enormous and spans the entire machine. It's very easy to lift to give you access to the entire build area.
Another really nice touch is the lid, which rotates upward and is assisted by a gas cylinder, seen below.
Opening the lid gives you access to all of the mechanical bits of the MarkOne. Here are some photos.
This looks like the FFF drive mechanism. Bowden-like design?
Here's the CFF / FFF extruder.
This
looks like an interesting spin on a belt tensioner design. I've never
seen it done this way on any of the automation I've worked on before.
Nice energy chain. I don't see IGUS anywhere, so perhaps it's a different brand.
A closer look at the FFF drive mechanism.
Here's what the extruder looks like from below.
Another
nice upgrade I wasn't expecting was an LCD touchscreen. It's a little
mushy because it's a resistive panel, but it's still very responsive and
easy to use. I set up my wireless network and didn't have any trouble
entering my huge WPA2 key.
So,
at this point you're probably wondering, "How does it print?" And
there lies the biggest flaw with the Mark One, in my opinion -- the
registration / activation process. The printer software is entirely
Chrome-based. The app runs in the Chrome browser and sends the part
data to the printer via WiFi. It sounds powerful, but I haven't had a
chance to try it yet. Registration involves going to a special website
and entering your email and a very long device key. The problem is that
my hosting provider's system somehow deleted *all* of my email aliases,
so when I registered, the notification email bounced. I have yet to
get Markforged to reset my device activation so I can try to re-register
my MarkOne.
I'm really excited about getting the new
printer, but unfortunately for the past several days I have had to be
content with staring at a very beautiful paperweight.
*** late post -- I had meant to publish this right after CES, but forgot. ***
I flew to Las Vegas early Friday morning to check out CES. Yeah, I knew that one day wouldn't be enough, but armed with my CES mobile app, I was hoping to make it through most of the stuff.
My main goal was to check out 3D printers. Actually, my only reason for going was to check out the new Robox, a 3D printer that I had backed on Kickstarter as a beta user. I ended up seeing a handful of cool things while I was there. I'll cover 3D printers first.
Cel's Robox surprised me -- it was a lot smaller than I had imagined. While the Replicator 2 takes up practically the entire depth of my desk, the Robox would sit very comfortably off to the side of my monitor, and that's probably where it will live once delivered. The frame looks very nicely designed. I should have asked how it was manufactured, but it appears to be a cast aluminum piece with very nice, clean curves. The lid rotates upward nicely to reveal a smallish heated build platform. They are using a custom-made PEI build plate, which is supposed to be the Holy Grail of all build surfaces. The ground rods for the linear axes seem a bit small, but then again the extruder is a light and small package. I forgot to ask them how torquey it is, but it might not be a problem since there is a filament feeder module inside of the Robox. There's also a second space for the extra filament feeder. They have not yet decided how the second spool of material is going to attach (if at all) to the Robox. The spools carry 40% less material than your typical FDM spool (600g vs 1kg), but at least the filament feeder has an encoder that can detect when the filament has run out. You will be able to replace the spool mid-print, though I don't know the details of how they have implemented that feature.
Print quality was very good. I held a tiny print of Yoda's head that was printed without support material. Given those settings, I think it did a pretty good job with the facial features. The buddha figurine showed impressive detail on the back with the "embroidery".
The team was very nice and Ian was especially chatty when I told him I was a beta backer on Kickstarter. It sounds like it will be very fun to work with these guys as we iron out the details of printing a variety of materials. My focus with the Robox is 100% on nylon printing.
Moving on, I saw other garden-variety printers, like the Solidoodle. Their latest gen printer, coming in at just under $1000, is pretty well built, though it's basically just a steel box with a door. There aren't any bells and whistles with this unit. The prints they had on display were very impressive, however. It seems to be able to print large ABS and PLA models without a problem. I believe the build area is 8" cubed.
On the ultra-cheap side is the DaVinci from XYZ. The $499 model is impressive, given that it has dual extruders and a reasonable display. However, I think the dual-color prints were pretty awful. They have some work to do on their software because there are very noticeable gaps between colors. The DaVinci 2.0 has a much nicer display, and while I didn't pay attention to the differences between the two products, the 2.0 also suffered from the same print defects.
MakerBot had a great booth and showed off a wide range of prints from their products. They had the new Mini, Replicator, and Z18 on display, but weren't running any of them. I found MakerBot to be the least-engaging of the 3D printer companies. No one came up to me and asked me if I had any questions. I just took a few pictures and then moved on.
mcor technologies had the most awesome 3D printer I have ever seen. At first glance, when I saw all of the motion and mechanics, I thought, "what is this monstrosity???". Then I took a closer look, and saw what it was -- a copy paper laminator that glued and cut the paper layers! And then a rep walked up to me and asked me if I had any questions (yes!), and that's when I realized how awesome this printer was.
First, I have to say that this is not a printer for home users. I am not going to be buying one of these things any time soon. At $45k (I think that's what he said), it's really aimed at those companies that own the SLS-type machines. But in my opinion, I think this product can blow the competition away.
Here's my understanding of how it works. The printer supports full color prints by using standard copy paper and a special inkjet printer than ensures that the paper is properly saturated with ink. The paper has registration marks printed on it as well, which facilitates consistent paper location as the pages are laminated together.
Lamination is done via a mechanism that drops little glue dots on the page. After the glue is applied, the next sheet is placed on top and the entire stack of pages are pressed against a heated platen at the top of the machine. Following the lamination process, a swiveling knife blade of sorts traces the outline of a single layer of the part. This process is repeated over and over again until the part is fully "assembled". The excess paper is very easily removed by hand. The rep allowed me to take one of their parts and peel away the layers. It was a much more enjoyabled process than removing support material from FDM printers.
I'd love to have a printer like this, but obviously I could never justify it.
I couldn't help it. This machine looks too awesome to pass up. Let me introduce to you... Robox.
Why did I back this Kickstarter project? After all, I already have a Mosaic M1, 2 PP3DP UP! Pluses, and a Replicator 2. The main reasons were better layer resolution (0.02mm vs 0.1 for the R2) and material support. I recently saw nylon prints and found them amazing -- I bet a lot of people would love to print their own soft, custom iPhone cases! In addition, the extruder head has two nozzles -- one large diameter one for fast infill, and another small diameter one for fine details. On top of that, they will be supporting dual extruder heads soon, which means I'll be able to print support material out of dissolvable PVA and HIPS. They have put a lot of thought into the design of this machine -- only time will tell if they can deliver. I'm a beta tester, which means I'll get my unit in January 2014. I cannot wait. This machine should be truly awesome... and if it delivers, it looks like I'll have a few printers to sell soon.
For SLAS 2014, my company is going to build a custom booth. You know, because we just roll like that. It turns out that the custom tabletops that would normally be really expensive fit on the ShopBot (just barely), so I was tasked with running the job.
Yesterday, I went to the TechShop to generate and verify the toolpath. I haven't used the software in a while, but got through it with a little bit of help. In this post, I just want to record the little tidbits of info I re-learned so that two years from now, I will be able to recall the necessary info.
First, I got the DXF in AutoCad R12 format to be on the safe side. Then I created a new project in VCarve Pro 7.0. Since the DXF was in mm, I set the project to be in mm as well.
The important thing to remember with the software is setting up the origins and XY definition properly. The origin should be in the lower-left corner.
I then used Import Vectors and specified the DXF. It might not appear on-screen, but hitting F9 will auto-center the part. Awesomely useful!
I'll jump ahead a little and talk about a problem that I had. After generating the toolpath, I noticed that the endmill was doing something weird. While the bit was supposed to cut on the outside of the part, in a few places it was actually flipping to the inside! In the end, it turned out that some points on the path were not joined. So after breaking the path up into discret curves and using the Join function in VCarve Pro, this problem went away.
Another part that gave me problems was the exporting of the ShopBot toolpath file. Most normal software packages put something like that under File -> Export, or File -> Save as, but in this case, there's a "Save Toolpath" button that appears when you close the preview window. Ok. Hopefully I won't make that mistake next time.
After loading the .sbp in the ShopBot software and previewing the cuts, I was happy and it was time to call it a day.
This morning, Eric (coworker) and I stopped by MacBeath to pick up the wood for the tabletops. Instead of mahogany plywood, Eric decided to try bamboo because it would preclude the need for veneer or any other finishing strips to cover the edge of the plywood. This is where a minivan really shines -- you can fit a stack of 4' x 8' pieces of plywood in a Honda Odyssey without any problems! Sweet!
Then we made it over to TechShop, got Eric his $25 guess pass, and unloaded the material. I love how TechShop has everything you need -- we found one of those Home Depot-like carts and used it to get the raw materials over to the machine.
Getting the material aligned properly wasn't too bad. After homing the X&Y axes to their proximity switches, I moved to the far end of Y (48") and then commanded a 96" X move. We watched the bit as it traveled over the end of the bamboo, and believe it or not, our first try was pretty much dead-on! After drilling four brass screws through the wood and sacrifial layer and into the leveling bed, we were finally ready to start! This is where the wheels came off.
I really need to post screenshots, but the short story is that ShopBot came in last night to perform a software upgrade. That's great and all, but they never bothered to tell any TechShop staff how to iuse it! Man, I'm getting really sleepy so I have to make this quick. After selecting the file and clicking start, a dialog pops up. It has a yellow square next to the part filename, with what looked like a "!" inside. So that means we have a problem, right? Well, normally I wouldn't have looked at the yellow box if the dialog had a Start button in it. Instead, it had a cancel button. So we thought it might have something to do with my .sbp being in mm instead of inches, yada yada yada. Apparently, TechShop SF had the same problem last night and couldn't run the machines. In the end, the yellow exclamation point was really an I with a _ underneath it. Seriously??? It turned out that you juse have to click the Start button again and then things magically worked.
Here are some photos of the machine in motion.
Bamboo sure cuts nicely! I think I will use it for my next projects.
Here's how it looks after routing and on the Item frame the guys designed:
Today my PCBs from oshpark came in. Check 'em out!
My Replicator 2 has been really busy running makexyz jobs, and work has been a little crazy, so it haven't been able to tinker much. I am currently learning more about the TI MSP430, because I think it's the perfect micro to power my laser tag project. More to come later...
