Thursday, July 19, 2012

PRINTXEL Progress Update

I wanted to keep us all up to date with the progress of some of the Kickstarter and Indeogogo 3D printer projects.


Billy Zelsnack has posted a video showing the components of his new 3D printer, the Printxel, that we discussed in an earlier post. 

Without ever having seen one in action, I'm going to step out on a limb and say that it appears to me to be a sleeper among the new offerings that is destined to get more than a little attention.

PRINTXEL Assembly Videos

One of the things that impresses me is that Billy is taking the time to create instructional videos to help buyers build their systems.  The videos not only tell us a lot about the PRINTXEL parts and assembly, they also provide a window into Billy Zelsnack's commitment to the buyers of his printer.  I cannot imagine a buyer that will not appreciate the effort that he's put into this series.  It's not super slick.  It's down and dirty video.  But, each one clearly accomplishes the main goal... which is to be helpful to those trying to put a PRINTXEL kit together.

I'll only include a few sample videos.  The first is a short video on attaching the hot end to the chassis.

And, here is the video showing how to attach the hot end wiring to the circuit board.

I really like the fact the terminals that Billy has chosen to use in his board.  It makes not only makes the initial build wiring much easier.   It also makes repairing, upgrading or modification a lot easier should that be required in the future.  There are at least 8 videos related to the build experience  Nice job!

Saturday, May 12, 2012

Autodesk 123D Catch - Fire Truck Model

Ultimately, software will determine the success or failure of 3D printing to catch on with the larger public.  Attempts at easier to use 3D software are going on all over the globe.

One of the most promising technologies is being explored by Autodesk.  In the next few posts we will explore the implications for those of us with 3D printers.

What we will see is that while it is not yet a mature technology, it does show promise.  When I began playing with the beta it was called PhotoFly and the Photofly team believed that you could not use a turntable to capture items.  That is because their engine relies on background information to determine angles and stitching points.  It turns out that it IS possible to use a turntable; but, you have to creaet a false background.

Here is an image of a small fire truck model on a turntable with colored posts acting as false backgrounds.

Using a series of pictures at 10 degrees rotation for each image, the following 3D object was created in 123D Catch.

As you can see, it is definintely NOT perfect.  In large part that is because the surface is smooth and shiny.  123D Catch does not like smooth and shiny.  But, it's passable.

Here is a video that probably priveds the best way to view the quality of the resulting 3D object.

Turning this object into something that can be printed involves exporting the object as an OBJ file and importing it into a program like the free NetFabb to be cleaned and converted to an STL file.

Here is the resulting print using a RapMan 3.2.

 It certainly isn't a rousing success; but, it definitely is a modest success.  We started with normal 2D images and ended up being able to print a recognizable 3D object.

Subsequent posts will explore objects that show even more promise.

Friday, May 11, 2012

New 3D Printer Start-ups

This is the year for 3D printers.  In fact, this is the year for a plethora of new designs for 3D printers.  It isn't hard to find a number of them in funding sites like KickStarter.  Here are some recent KickStarter projects that met or exceeded their funding goals.


One of the more successful KickStarter 3D printer projects is Printrbot, by Brook Dunn.  Printrbot managed to find more than 1,800 backers for a total of $830,827 in pledges!  Not bad.  Especially when the goal was a modest $25,000.

Some printers have already shipped.  So, we should be hearing from new owners shortly.

But, it appears to me that success can be as difficult as not meeting your funding goal.  It may be that actually receiving the funds requires delivery and when you go from 0 to 1800 machines to deliver it can be more than a little challenging.

This video by Brook Dunn is very instructive.


With 11 days to go in their funding window, BukoBot, has raised $43,582 from  127 backers.  Again, this is more than their goal. 

The design of the Bukobot is a bit different than previous kit 3D Printers in that it makes use of extruded metal frames rather than rods.  This might make it a bit more stiff.  But, since, as far as I know, none have been delivered, we'll have to wait to see how it performs.  The important thing that the BukoBot teaches us is that we have not finished exploring all the possible designs for a 3D printer.

Here is a Flickr Photo Stream with a number of images of various models and their design studio..


This little 3D printer, from Adjunct Engineering, LLC, is one that I DEFINITELY want to follow.  At $300 it is destined to be one of the least expensive kits available.  Billy Zelsnack is the mind behind this project and he has a lot of experience.  However, as with any start up. he is going to have his hands full getting the first units out the door.

The good news is that he set a modest goal for his first set of deliverables and this will give us an opportunity to get some feedback about the performance of the printer in the not too distant future.  A goal of $7,500 was set and $7,874 was raised from 52 backers.

Here is the video of his KickStarter pitch.


All of the other 3D printers in this post use extruded plastic to build 3D objects.  The B9Creator is different in this respect.  It uses a liquid resin based system yielding 100 micron layers making it the resolution leader.

C9Creator had set a KickStarter goal of $50,000.  83 backers helped them exceed that goal with total pledges of $84,668!  What is really remarkable is that they reached that goal in ONE DAY!

There is a video of the machine in action; but, the music SO LOUD that I'll simply post the link.
It is innovation like these that will move 3D printer forward at a rapid pace.  Nice job everyone!

Thursday, May 10, 2012

A Horizontal Filament Spool System

Some of the objects I print take a LONG time and I don't want to have to babysit my RapMan printer for the entire print time.  Early in my quest for a spool holder, I realized that a spool holder with a bearing was my best choice.

The vertical spool holder I created for the RapMan spools worked very well.  But, it was a pain to go from one color to another.  Plus, I'd begun to experiment with various sources of filament and each of them seems to have a different spool type and size.

I needed a different solution.  And, it seemed to me that a horizontal spool holder was my best bet for easy interchangeability.  Here is what I came up with.

First the base unit.

The base unit is built so that it can be clamped to a table.  There are recessed to take 3 bearings upon which the spools can rest.  However, they are optional since a nut on the bolt or threaded rod can be used to support the bottom bearing of each spool.

It is designed to be a quick change system, allowing different spool hubs to be easily interchanged.

Here is the base and three different spool holders.

In this photo the base is at the left and is surrounded by 3 different spool hubs.  Each hub has bearings pressed into the top and bottom.  The bearings make for very smooth filament feed.  And the small hook to the left, that attached to the bottom of the RapMan helps to feed the filament extremely smoothly.

Here is a close up of the filament guide.  It's very simple.  But, hugely effective.

 I'm using commonly available 8mm x 22mm x 5mm skateboard bearings that cost about $10.00 per set of eight.  Here is the drawing for the most unusual hub that fits an offset hub.

And, the largest hub for the system.  The Spool for Bits and Bytes materials.

The system really works well and I will be putting up the STL files into free download sites.

Z-Axis Wobble Fix Update

It's been some time since I created some fixtures for my RapMan intended to reduce or eliminate Z-Axis Wobble.  Before posting I wanted to make sure that the fix stood up to day-to-day printing.

Here is the fix as I now have it installed on the printer.

The fix involves isolating the print bed from the source of the Z-Axis wobble, the Z-Axis threaded rods.

It involves using two separate new pieces to guide and  hold the bed.

The bed is detached from the Z-Axis holding plates and the bottom printed block is attached in its stead.  There are four of these.  One for each corner.  These blocks are held rigid at all four corners by connecting rods. 

The bed is attached to the new top printed block.  This block attaches the bed to the outside rods of the RapMan using 3 small bearings.  This piece is completely isolated from the Z-Axis threads once the Plexiglas supports on two corners that connect both the outside rods and the threaded rods are cut.

A short piece of spring steel is inserted into the blocks.  These pieces of spring steel will be used to hold the bed up.  The fact that the spring bends is what provides the isolation from any wobble for the bed.  It is strong enough to support the table; but, still flexible enough to not pass the wobble to the top bed holders.

Here are the drawings for the bottom fixture that is fixed to the original bed mount. 

Bottom Z-Axis Wobble Fix Fixture

Note the post in which the flexible wire is attached. 

The top unit is a bit more complex. 

Top Z-Axis Wobble Fix Fixture.
The top fixture is designed to accommodate 3 bearings that attach the fixture to the smooth corner rods of the RapMan.  "Piano Wire" commonly available in hobby stores is used to link the bottom and top fixtures and provides the isolation between the printing bed and the Z-Axis threaded rods.

The wire is strong enough to raise and lower the bed without being strong enough to break the hold that the bearings have on the smooth rod.

I have one or two more extended tests to perform before declaring that this system is a complete success.  If it passes those tests the items and a more full explanation will be uploaded to free download sites.

Tuesday, March 27, 2012

A Z-Axis Wobble Limiter Proposal

Once we have identified that we might have a Z-Axis wobble issue with .125 resolution prints, we need to decide is it's bad enough to worry about or not.

Z-Axis Wobble under a 40x Microscope

The reason I chose an extruded triangle for creating my test tower is that I knew it would form and sharp edge that would provide the best look at the wobble under a microscope.  I wasn't disappointed.  Now, remember, each layer is just .125mm high.  So, with this better image, I estimate the wobble is probably just between .25mm and .50mm.  That is not very much.

Pulled back a bit, we can see how shallow the wobble is in the case of my RapMan.  This image also shows that the wobble mirrors one turn of the threads of the threaded robs.  The pattern will always be the same length.  Only the depth of the pattern will change depending on how badly the threaded rods are bent.  This is so shallow that it probably represents a single rod, not all four.

Wider View of the Z-Axis Wobble Evidence

In my case, I really don't think it's a show-stopper.  However, this is a blog about 3D printing and that raises the bar on the level we need to expect for ourselves.  And, that is nothing less than the best prints that might be possible from a 3D printer.  Period.

That means addressing the problem if for no better reason than the general issue among all users needs to be addressed.

Z-Axis wobble is a well known issue for most 3D printers.  So, there are some very good solutions floating around in various 3D and RepRap forums.  There are even fixes that you can download to replace the default Z-Axis system that came with your RapMan.

There is one problem with each of these solutions.  They require taking your RapMan apart to replace the Z-Axis lifts on all four corners of the RapMan.

My goal, in pondering a solution was to find a way to minimize or eliminate wobble WITHOUT taking the RapMan apart.  I wanted to be able to continue the original RapMan system for raising and lowering the bed.  I have no clue if the solution I am proposing will work.  At the moment I have run out of filament and can't build and test the idea immediately.  But, I can describe the proposal.

Here is a rough image that, hopefully, explains what I am planning to try.  There is a LOT of design work yet to be done beyond this rough concept drawing.

Proposed System - Rough Outline
First, the blue section represents the original parts that hold the nuts that raise and lower the bed on the threaded rod.  You'll have to imagine the nuts and springs that comprise the lift mechanism.  The hole in the blue part represents the hole for the threaded rod.

Normally this plate would be directly connected to the bed frame.  But, in this case I'm proposing to put some parts between the lift plate and the bed frame.

The first of these is the bottom red part.  It bolts to the lift plate in place of the bed.  It has a fixture into which we will insert some spring steel (Grey in the above image) that can be obtained in any hobby store.  The optimal gauge and length we will need has yet to be determined.  It is this wire that will provide rigid support for vertical movement while dampening lateral movement.

The wire fits into a similar fixture in the underside of the top red piece.  It is locked into place with a set screw and/or appropriate glue.

It is the top fixture that isolates the wobble in the blue section.  Notice that the hole through which the threaded rod runs is larger in this fixture.  We do not want it to make contact with the threaded rod.  As I said, this is a rough approximation of the plan.  In the actual part, it will have to be made so that we do not have to remove anything.  So, the right side of this section will probably have to be in two parts.  And, the hole on the far right, which represents the hole for the smooth outside support rods will actually be two bearings.  Again, this is simply a rough concept.

The bed support will be bolted to the top red part.  This part will be isolated from the source of the Z-Axis wobble by the spring separating the top and bottom units.  And, the bed will be steadied by the top component's connection to the outside vertical support rods.

Hopefully, then, the spring will make a tight vertical connection while allowing the lower section to wobble without that wobble being transferred to the top section and bed support.

Until the replacement filament arrives, we won't know if this technique will work.  But, we do know that if it doesn't we have not altered the basic Z-Axis operation and can return to it fairly easily.

I'd love to hear ideas pro and con about this proposal.  Perhaps you have already tried something similar.  If so, please let me know.

What is RepRap & RapMan Z-Axis Wobble?

I'm fairly confident that any issues with the Y-Axis alignment and the Bed Leveling alignment on my RapMan has been successfully solved using the new tools that I designed to make the process more precise.

But, when printing at .125mm, it is apparent that one more issue may need to be tackled.  And, that is probably some issue with some relatively minor Z-Axis wobble.

This video isn't all that great.  The lighting is poor and the image is 640x480 because it was shot at 240fps so we could analyze the image in slow motion.  I'll try to get better images of all four threaded rods this evening.
However, it is still useful enough to use right now.

What this video shows is that if there is any wobble at all, it is very. very minor.  Yet, because we are working with such tiny tolerances, it is still noticeable in the printed output.  As the following samples show.

Here is the test object.  It's a tower having 3 equal sides.  This shape was chosen because it results in 3 sharp edges.  It was printed at .125mm resolution.  And, as you can see, there are some visible ridges that probably indicate Z-Axis wobble.

Test Tower
Looking at a crop of the image, we can see the ridges a bit more distinctly.

Test Tower - Crop showing ridges more clearly
By laying the tower on its side and angling the light to create shadows, the ridges become more identifiable.

Lighting to accentuate the ridges
While we can see an interesting pattern in the above picture, it's not so clear as to how many layers there are in the repeats of that pattern.  For that we need a microscope.  Again, the following picture was created using the worst microscope I have in my collection and the camera was hand held to the eyepiece.  So, it's not the best we can do.  Even so, it is helpful to see for this article.

Ridge pattern through a 20x microscope
The most important thing about this image, and something with which I want to follow up, is that the ridge pattern looks to be about 12 rows.  If 12 (or so) rows equates to a full turn of the Z-Axis threaded rods, we have evidence of Z-Axis wobble.  Yes, it's on a small scale.  The wobble appears to be less than .5mm.  But, it is there.  And, theoretically, we should be able to get that down to virtually zero.

In subsequent posts, we'll explore some of the solutions that other 3D printer users have come up with to deal with this issue.  But, before we leave this subject, it might be interesting to see what we are up against in dealing with the threads of the threaded rods.

Threaded Rob Up Close and Personal
If you click on the above image, you will see that threaded rods aren't always as cleanly threaded as we would like.  In fact, I don't believe I have ever seen a perfectly clean threaded rob.  This one is as good as any I've seen.  Yet, it clearly has some defects and/or debris that might affect the print.

While looking at the screw, it dawned on me that I should be able to place the test tower next to the threaded rob and take some macro images to see if the threads match the pattern of ridges.  I'm guessing they do.  :)

Sunday, March 25, 2012

Fine tuning RapMan 3.2 - Hot End clearance

The RapMan gives us several tools to raise and lower the hot end relative to the bed.

The first, and most basic, way to set the distance between the hot end and the bed is a long screw that hangs down from the extruder assembly.  Each time we select the bed height option on the console, the printer homes the machine so that this bolt can activate a switch and then the printer uses that position to move to the center of the bed and lower the hot end to the position called for the bolt's length.

The manual calls for adjusting the hot end so that it barely touches the bed.  "Barely" is the operative term.  I'd like something a little more measurable.  To get the most precise setting, I decided to use a mechanic's tappet gauge.  So, I started with the 0.102mm leaf on the mechanic's gauge to get the hot end as close as I am able to measure. But, through trial and error, I found that my particular printer responded best (laying down an undistorted raft) at 0.254 for PLA.

Here are the steps I use.
  1. Press the Z-Height Selection
  2. Make sure the Z-Height Offset is 0
  3. Try the 0.254 leaf of the gauge under the hot end.
  4. If there is a lot of clearance, tighten the adjustment bolt.
  5. If there is no clearance, loosen the adjustment bolt.
  6. Exit Z-Height adjustment

Repeat the above steps until the gauge just slips under the hot end.  Do NOT make changes to the Z-Height offset.  You are setting the base point and will use the offset to further fine tune for different situations or special cases.

I understand the critical nature of getting the hot end (Z-Axis) height right for the raft.  But, it's still unclear to me that it makes much of a difference in subsequent layers as the Z-Axis increments should take care of itself in spite of the starting height as long as the height was sufficient to create a starting raft.

And, the optimal height for any given printer with any given material might be a bit different.  That is because the setting you end up using is the setting that is able to lay down a nice raft without tearing it or distorting it.

The point is that we can get more precise in by using tools, like a mechanic's tappet gauge, we are better able to control our printing environment on a repeatable basis.

Fine Tuning RapMan 3.2 - Precise Bed Leveling

Making sure that the RapMan 3.2 bed is level is probably among the most important things we can do to ensure better results.

The build manual and the display panel gives up some tools to level the bed using three bolts.

But, my eyes were having a hard time seeing the hot end height.  So, I decided to make some tools to help me do this more precisely.  First, I bought a set of mechanic's valve tappet gauges.  Using a gauge under the tool that I am going to describe is the most precise way to ensure that all points are even.

First the tools...

Bed Level Tools

 Basically, these two tools are hung over the X-Carrier rails and hang down.  The four points are an even length.  Here is how they are used.

Tools hung over at each end of the X-Carrier rails.

Notice that that a tappet gauge is being slipped under one of the pointed rods.  Adjust the height of the bed using the console until the gauge can be just slipped under the point.  It should NOT lift the tool.  Now, by simply using the bed leveling bolts, ensure that the gauge just slips under each of the other points.

Do this front and back.

Gauge being used at the back of the bed
These tools are a LOT easier to see than the tip of the hot end because you can place them so close to the edges of the adjustable bed assembly.  You can get up close and personal.

Finally, I had created an earlier set of alignment tools designed to do the same thing.  However, these sat on the bed, itself and had clips similar to those of the X/Y Carrier alignment tools.  I now use these just to verify that the bed is level.

Verifying that the bed is level

The latter step  is not really required.  I simply have the posts already and it's a good tactile way to verify that the bed is level.  Raise or lower the bed until one of the tools clips easily on the carrier rod and the other tool should also clip easily.

Once bed leveling is complete, we need to adjust the hot end height.  And, for that I also use the mechanic's tappet gauge.

Fine Tuning the RapMan 3.2 - X Carrier Alignment

So far, I have not found a single defect in the design of the RapMan 3.2 that I could pinpoint for you.

However, the printer is only going to print as well as we have built our RapMan printer.  And, I am determined that I am not going to be content until I have assured myself that the printer I have built is as good as any other RapMan out there.  And, that means finding ways to fine tune as many of the variables as I can.  And, at least for me, this means a By-The-Numbers approach to alignment.

Fortunately, the RapMan can help us out here, by allowing us to build alignment tools that we can use to ensure that we are as close to the most precise tolerances as we can get.  I want to talk about some that I've created for myself.

The first is a tool that allows me to align the Y-Axis travel.  The RapMan uses two belts for the Y axis.  And, it's possible that these two belts are pulling at an angle.  The best way to ensure that both belts are adjusted so that the X-Carrier is in perfect alignment is to measure the distance on both the left and the right sides to make sure they are equal.

Here is the alignment tool that I built for this job.  We use two.

Y-Axis Alignment tool
Notice that these alignment tools have a small half circle and a large half circle.  The small half circle fits over the top front rail and the large half circle fits over the front carrier bar for the X-Y carriage.  Clip the tool on the front rod and move the X-Y carriage carefully until it's possible to easily clip the tool onto the first rail of the carriage.  Do NOT force it.  Here is what it looks like.

Left Side Y-Axis Tool Attached
Then clip the other alignment tool to the front rod and ease it down to the carrier rail.  Again, do NOT force it.

2nd Alignment tool attached to front rail

Alignment tool being lowered to carrier rail

If the 2nd alignment tool will not easily clip onto the carrier rail, then the carrier is out of alignment.  Loosen the Y-Axis pulley at the back right of the printer and pull or push the right end of the carrier until the tool can easily be clipped to the carrier.

Carrier aligned
Then tighten the pulley.  The carrier should now be aligned.  But, you may want to remove the alignment clips and try the steps again to ensure that the X-Carrier is, indeed, permanently in alignment.

Tuesday, March 20, 2012

RapMan 3.2 Unattended Print:125mm - Part 1

Good news!

I arrived home this evening to see the print job still going strong.  An hour or so later, the job was done.  The RapMan successfully printed without intervention and unattended for more than 13 hours!

Once again, for now, I am using a point and shoot.  So, the focus isn't going to be as clear as it could be.  I am leaving the support material on until I can take some better images tomorrow.

Peyton Duncan - Chow: View #1 at .125mm
While the detail is a bit greater in the above image, there are what appear to be printing errors at the rear of the dog.  They might be related to the support material for the tail since they can be seen on both sides as View #3 shows.

Peyton Duncan - Chow: View #2 at .125mm

Peyton Duncan - Chow: View #3 at .125mm

Peyton Duncan - Chow: View #4 at .125mm
 In the above picture, it's clear that there is a bit more detail that comes through at the mouth and eyes.  But, as I hold the two different prints in front of me to compare them visually, those details isn't nearly as different as I'd expected.

Peyton Duncan - Chow: View #5 at .125mm
The top view shows a VERY different outcome between the two different prints.  There appears to be tiny holes near the ears and a prominent hole in the tail.  Again, a better camera and lighting will show this more clearly.

BOTTOM LINE:  For me, the additional printing hours did not yield the kind of difference I had hoped to see.  But, the real proof will be side by side comparisons once the support material is removed.  However, it's important to remember that I am new to both the software and the printer.  An error or oversight in either would yield unexpected results.  I wonder if the result will be the same if  I tried this experiment a year from now.

However.  It cannot be overemphasized that the RapMan, with a roller bearing hub, is a workhorse!

I plan to seek ideas as to what is taking place on the .125mm print in the RapMan forums.  I'll post an update if I find out anything significant.

RapMan 3.2 Unattended Print at .250mm

UPDATE:  I did manage to figure out why the .125mm test was not, initially. printing well.  It didn't dawn on me that because the layers were 1/2 the thickness, I needed to raise the bed to compensate.  Once that was done, it was running fine when I left it this morning.  Hopefully, it completed the job.  I'll find out in an hour or so.  I HATE DC area traffic!  LOL!

Before leaving for home... and hopefully finding a higher resolution print of Peyton Duncan's Chow waiting for me... I managed to capture some better images of the printed model from my RapMan 3.2 printer.

Nobody is trying to fool anybody.  An extrusion printer doesn't cost $400,000.  Neither does it perform like one.  But, it still does a very credible job at rendering what one creates.  And, frankly, I'm quite pleased with the result at .250 vertical resolution.  So, here are some images.

NOTE:  Any lint, etc. comes from the fact that this poor guy spent all day in my pocket.  :)

Click on any image to see larger versions... 

Peyton Duncan - Chow View #1:  .250mm

Peyton Duncan - Chow View #2:  .250mm

Peyton Duncan - Chow View #3:  .250mm

Peyton Duncan - Chow View #4:  .250mm

Peyton Duncan - Chow View #5:  .250mm

For these next two images, which only appear to be identical, I raised the F-Stop for each to try to get a bit more depth of field.  I think it helped.

Peyton Duncan - Chow View #6:  .250mm f16.0

Peyton Duncan - Chow View #7:  .250mm f18.0
As you can see, the RapMan, once properly set up, begins to crank out some very nice 3D prints!  And, that is even at the Mid-resolution.

Note for Peyton...  I KNOW that is a DIME in the image and not a quarter as you asked.  How in the world did you think I might have a quarter to my name left while I'm spending all my money having fun buying tools and materials for my RapMan???   LOL!

Note for everyone else...  Peyton is my nephew.  And, I have a LOT of respect for his work and for him personally.  Both Peyton and my artist daughter Cheryl continue to amaze me with their talent. Here is just a sample of Cheryl's beautiful sculpture that got me interested into digital photography and  3D printing in the first place.

Fleurette by Cheryl Meeks

I'm surrounded by geniuses and loving it!

Now... I gotta get out of here to see what awaits me at home... a mess or a Chow!!  :)

Monday, March 19, 2012

First Unattended Print!

I apologize for the images.  All I had was a point & shoot that does not seem to like to focus on white plastic objects.  :)

I'll take better images tomorrow.

The important thing about this post is not the quality of the photography; but, the fact that the roller bearing hubs WORKED!   This morning before leaving for work, I started printing Peyton Duncan's Chow figurine and when I came back this evening it had successfully printed.

This may not seem much to you.  But, it's a HUGE milestone for me.  It means I can print complex or larger objects and still get some sleep.

First, let's discuss the object being printed.  It's a beautiful image of a Chow dog.  It's by artist and photographer Peyton Duncan, and the STL file is uploaded on the Cubify site.  More of Peyton's art and photos are on RedBubble.  If you want a real treat visit his sites.  But, beware.  He's got quite a unique sense of humor!

I made the decision to print the Chow at the middle resolution for my RapMan, .250mm.  That made the run 5+ hours.  It's not that I didn't trust the new spool hubs to work.  It's just that... well... I couldn't be absolutely sure that they would work flawlessly for 5 hours.

Not to worry.  They worked like a charm... as did the RapMan's print engine.  When I came home this evening this is what greeted me.

Chow with Support

The Chow was finished and ready to be cleaned of the support material.  Interesting, Axon seemed to use a different strategy for the support materials that made it very easy to remove.  Here is the cleaned version.

The layers are clearly visible at this compromise resolution,  It will be interesting to compare this version with the one being printed at .125 resolution.

All-in-all, however, I am very pleased with both the process and the result.


I'm afraid that I will NOT be testing the finer resolution tonight.  For some reason, which I will have to test with something smaller, the RapMan is not printing correctly at the highest resolution.  It's probably an extruder pressure issue.  And, I don't have time to mess with it tonight.  We'll all have to wait for an update!   ARRRRRGGGGHHHH!  LOL!

Sunday, March 18, 2012

RapMan Reel Holder Using MOI 3D

Moment of Inspiration, or MOI 3D, is an absolutely wonderful application.  I installed it two days ago and was immediately able to design some things that will be not only useful to me; but, other RapMan and RepRap users as well.

One of the things that became immediately apparent when my RapMan was completed was that unless I baby sat the printer, the filament would not feed well.  As soon as enough filament had been used that more should be unreeled, the drag simply was too much for my extruder.  That may or may not be the fault of my extruder roller pressure.   But, if so, with my lack of experience, I couldn't trust I would set it right.

So, I determined that roller bearings would probably solve the problem.  And, it did!  I cab now leave the printer unattended for hours on end without a failure to feed.  That was a MAJOR breakthrough!

So, I want to show you how MOI 3D enabled me to go from having absolutely NO experience with the program to creating hubs permitting me to use bearings to support my RapMan filament reel,  My first hub probably took an hour to an hour and a half.  All the subsequent designs took well under an hour and most less than a half hour.  This is remarkable since (1) I am NOT an artist; (2) I am NOT an engineer or draftsperson and (3) I'd not even seen this program before installing it.

I not only created one roller bearing hub.  I refined the design a number of times with different goals in mind,  MOI 3D allowed me the freedom to do this in very easy fashion.  Here is my first design.

First MOI 3D project.  A filament reel hub with roller bearing
As you can see, this is a relatively simple design.  But, it has some features that might not be apparent.  One feature is that it accommodates two different 8mm Inside Diameter bearing sizes, 16mm and 22mm.  This nested design was easy using MOI's Boolean operations that make it easy to remove material.  The lofted shape was accomplished using MOI's scaling.

I then felt I wanted a lighter weight hub.

Attempt at lighter hub using MOI 3D

This design definitely created a lighter version of the hub.  And, it retained the design allowing for a choice be two different sized bearings.  But, it did not allow me to use the 8mm bolt that came with the RapMan reel holder kit.  The bolt wasn't long enough.  So, I used a 5/16" threaded rod to see how it worked.

It worked BEAUTIFULLY.  What a difference!  The bearing allows the filament to be played out with no intervention by me at all.

But, if a hub was to be useful to a wider audience, it should probably be designed to be used with the bolt the user already has.  So, back to the drawing board.

Hub designed to work with the original reel holder bolt

 This design accomplished several goals.  First, it was light.  Secondly, it was designed so that the 8mm x 7mm x 22mm bearing I found at a hobby store would mount flush to the top of the hub.  This meant dropping the ability to also use a 8mm x 5mm x 16mm bearing.  But, the flush mounting was critical to being able to be used with the 8mm x 120mm bolt used with the RapMan Reel Holder.

Here is the above design being used to print the final design.  Note, too, that MOI 3D allowed me to design a base for the filament reel holder that keeps it locked into place.

Test Hub in use with original bolt

While the above design worked beautifully, I still felt that I could lighten the hub even further.  So, I came up with one more design.

Final RapMan Filament Reel hub Design

As you can see, this final design is very, very light.  Yet, it has turned out to be as effective as all the other designs.  Here is an image of the final product.

Final RapMan Filament Hub Printed

While I am very grateful that I was able to come up with something that allows my RapMan to run for hour on end with attention, I am even MORE grateful to have found MOI 3D.

Here is the final version of the reel hub being used with the RapMan filament reel holder, including the original bolt.

Final RapMan Filament Reel hub Design in the Reel holder

I will be putting up all these designs onto various sites.  The last design will be uploaded to 3D Systems' Cubify site that is now in beta.

I'm loving this software and printer combination.  And, I look forward to the new Cube when it arrives.