Rehorst, Mark – Milwaukee Makerspace https://milwaukeemakerspace.org Conceive, Collaborate, Create Mon, 25 Feb 2019 04:04:43 +0000 en-US hourly 1 https://wordpress.org/?v=6.4.4 Updated Filament Spool Holder for SoM https://milwaukeemakerspace.org/2019/02/updated-filament-spool-holder-for-som/ https://milwaukeemakerspace.org/2019/02/updated-filament-spool-holder-for-som/#respond Mon, 25 Feb 2019 04:04:43 +0000 http://milwaukeemakerspace.org/?p=10112 Big thanks to Tom Klein for a great modification of SoM’s filament spool holder!

The original design used to have a printed ABS top roller and I just pushed the roller against the flanges and finger-tightened the nut.  The problem was people kept taking it apart, so I added rubber bands to pull the roller down, and a nylock nut to prevent tool-free disassembly.  Then the rubber bands kept disappearing, and Tom came up with the idea of making a heavy top roller so the rubber bands wouldn’t be needed.  He cut a new, steel top roller on the lathe and it works great!  The bolt is just loose enough to let the roller slide up and down in the slot in the frame.  The roller is heavy enough that it just falls into position on the spool flanges.

Tangle-free filament spool holder

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We have a new Prusa i3 Mk3 3D printer! https://milwaukeemakerspace.org/2018/04/we-have-a-new-prusa-i3-mk3-3d-printer/ https://milwaukeemakerspace.org/2018/04/we-have-a-new-prusa-i3-mk3-3d-printer/#respond Thu, 19 Apr 2018 21:00:13 +0000 http://milwaukeemakerspace.org/?p=9868 This is the printer that we won in the Hack-a-Day contest about 2 months ago.  It arrived at my house last night, so I decided to open it up and inspect the contents.  That’s when I saw it…

Broken upper left Z axis guide rail bracket.

Broken upper left Z axis guide rail bracket!

I lifted it out of the box and discovered that the left Z axis motor mount was also broken:

Broken upper left guide rail clamp and left Z motor mount.

Broken upper left guide rail bracket and left Z motor mount.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A quick trip to the Prusa web site found STL files ready for printing…

 

New motor mount and upper left guide rail clamp printing on UMMD.

New motor mount and upper left guide rail clamp printing on UMMD.

Finally, printed parts installed…

Broken parts replaced.

Broken parts replaced.

 

Alas, it appears that the lead screw is bent- you can see it wobbling when it rotates.  I’ll be contacting Mr. Prusa for a replacement…

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Fun in the Booth at the Milwaukee Maker Faire https://milwaukeemakerspace.org/2017/09/fun-in-the-booth-at-the-milwaukee-maker-faire/ https://milwaukeemakerspace.org/2017/09/fun-in-the-booth-at-the-milwaukee-maker-faire/#respond Fri, 29 Sep 2017 14:44:29 +0000 http://milwaukeemakerspace.org/?p=9595 Last minute decisions work out once in a while.  For example, I was going to be at the Makerspace booth at the Milwaukee Maker Faire for the weekend and wanted some examples of the sorts of things you can use a 3D printer to make, so I grabbed the usual collection of sample prints, and then I thought, “sure, why not?”, and loaded the Van de Graaff generator into the car.  It sat on the floor in the booth for about 1/2 of Saturday and I was getting a little bored, so I moved it closer to the foot traffic and plugged it in.  Wow!  Kids and adults with stunted emotional development went nutz!  They were zapping themselves and each other as if it were more fun than painful.

Sparks!

Sparks!  The VDG produces about 400 kV.

Then I found a plastic bucket and the fun really started.  We had kids and many adults who were definitely much too heavy, standing on the bucket and making their hair stand up with moms, dads, boyfriends, girlfriends, husbands, wives, partners all taking pictures.   I had to move one gentleman who was breathing oxygen from a tank away from the machine.  Fortunately, no one fell off the bucket or caught on fire, and next year we’ll do it right and take a block of styrofoam for people to fall off of  to stand on.

Kylee was ready to join the Makerspace just for this… and with that shirt, she’d fit right in!

 

Blondes really do have more fun!

Blondes really do have more fun!

Even Gordon couldn't resist!

Even Gordon couldn’t resist!

 

Last year Son of MegaMax (a 3D printer built at the Milwaukee Makerspace) went to the Faire.  This year he had two companions to keep him company- an extra-beefy printer being built by Erich Zeimantz: MiniMax XY.  MMXY isn’t complete yet, but promises to be a super high quality, high speed printer.  He’ll be operational at next year’s Maker Faire.  SoM also brought his big brother, Ultra MegaMax Dominator, named that because he is ultra, mega, maximum, and he dominates.

MiniMax XY at Milwaukee Maker Faire

MiniMax XY at Milwaukee Maker Faire

 

Ultra MegaMax Dominator and Son of MegaMax at the Milwaukee Maker Faire

Ultra MegaMax Dominator and Son of MegaMax at the Milwaukee Maker Faire

UMMD and SoM rotated between the booth and the dark room where the both printers’ UV lighting and fluorescent filament was a big hit.

UMMD in the Dark Room at Milwaukee Maker Faire 2017

UMMD in the Dark Room at Milwaukee Maker Faire 2017

We had a few things besides 3D printers at the booth.  Tony brought in some Bismuth crystals to give away, and surprisingly, they didn’t all disappear in the first hour.  Tony thinks people left them because the Makerspace logo on the info board on which the crystals were sitting looked a lot like the skull and crossbones that usually indicates poison.  The crystals do have an other-worldly toxic look about them.  Oh well…

Bismuth Crystal

Bismuth Crystal

Marcin’s LED signs on the table at the booth and hanging above the entrance to the Dark Room were also very popular and hard to miss, though I managed not to take any pictures of either.  The one above the Dark Room was so bright that if you saw it, you’ve probably still got its image burned into your retinas.

Everyone involved had a great time and we’ll be there again next year with even more cool stuff!

 

 

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Replacing the Glass Print Bed on the Taz 3 Printer https://milwaukeemakerspace.org/2016/04/replacing-the-glass-print-bed-on-the-taz-3-printer/ https://milwaukeemakerspace.org/2016/04/replacing-the-glass-print-bed-on-the-taz-3-printer/#respond Mon, 25 Apr 2016 04:44:14 +0000 http://milwaukeemakerspace.org/?p=8988 The glass bed on the Makerspace’s Taz 3 printer recently did what glass does- it broke.  Time for a repair and upgrade!

I started by cutting the under carriage down and modifying it for a three point leveling system instead of the stock four point undercarriage/bed plate bending scheme.

Modified undercarriage mounted on the printer

Modified undercarriage mounted on the printer

 

 

 

 

 

 

 

 

 

 

 

 

 

The original heater was separated from the shards of glass and glued to the 12″ x 12″ x 1/4″ cast aluminum tooling plate using high temperature silicone.  3x #10 countersunk screws and springs support the plate on heat resistant teflon blocks.  The whole assembly stands about 1 cm taller than the original bed plate so I printed a small extension for the Z=0 set screw so it would trip the switch from the higher position.  I tested the heating time and found that the bed gets up to 110C in about 16 minutes- a little slow, but we probably won’t be printing much ABS with this open frame machine anyway.  Next- run PID autotune for the bed heater and adjust acceleration (greater moving mass means lower acceleration and print speeds).

New bed plate and undercarriage mounted on the printer

New bed plate and undercarriage mounted on the printer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Some of you might ask why I would replace the glass bed with a piece of cast aluminum tooling plate.  Thermal performance is one good reason.  Here’s an IR photo of the original glass bed:

 

 

Taz_glass_thermal

IR image of the Taz 3 printer with original glass bed.

 

 

 

 

 

 

 

 

 

 

 

 

Notice the hot and cool spots- 30C temperature variation across the bed.

Here’s what the new aluminum bed plate looks like:

 

Taz_aluminum_Thermal

 

 

Temperature variation is just a few degrees over the entire surface (the bright almost horizontal lines are not hot spots- they are reflections of the X axis guide rails).

 

I have run the PID tuning on the new bed and modified the firmware with the new constants.  It heats from 25C to 100C in about 9 minutes.

I officially declare the Taz printer ready for action.

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Chocolate Printer Cooling System Test https://milwaukeemakerspace.org/2015/11/chocolate-printer-cooling-system-test/ https://milwaukeemakerspace.org/2015/11/chocolate-printer-cooling-system-test/#respond Sun, 22 Nov 2015 21:57:01 +0000 http://milwaukeemakerspace.org/?p=8717 This week I attempted the first test of the chocolate printer cooling system.  The cooling system is intended to solidify the chocolate just after it leaves the extruder nozzle so that by the time the next layer is started it will have a solid layer to sit on.  The cooling system consists of a centrifugal blower with a brushless DC motor blowing room air into a styrofoam cooler containing a block of dry ice.  The air passes over the dry ice and gets chilled as the dry ice sublimates directly into very cold CO2 gas.  The chilled air and CO2 mixture exit the box through a port with a hose that will ultimately blow the cold air on the chocolate.  At least, that’s how it is supposed to work.  It blows air at -12C as measured via a thermocouple, but unfortunately, the air exit port ices up in about 2 minutes and blocks the air flow.

There are many possible solutions.  I can add a heater to the exit port to prevent formation of ice, or dry the air going into the box using a dessicant cannister or maybe just use water ice instead of dry ice if the higher temperature will still cool the chocolate adequately.   Maybe using an old miniature freezer with an air hose coiled inside would do the job.  It would be really interesting if I could use the waste heat from a freezer to keep the chocolate liquified and flowing.  Back to the drawing board!

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Chocolate Cooling System Almost Ready For Testing https://milwaukeemakerspace.org/2015/08/chocolate-cooling-system-almost-ready-for-testing/ https://milwaukeemakerspace.org/2015/08/chocolate-cooling-system-almost-ready-for-testing/#respond Sat, 01 Aug 2015 18:56:29 +0000 http://milwaukeemakerspace.org/?p=8563 Chocolate printer progress continues.  This week was devoted to the print cooling system.  The chocolate will come out the extruder nozzle in a semi-molten state.  It needs to solidify by the time the next layer of chocolate gets deposited on it, and I’d prefer it doesn’t drip or sag, so it needs to be chilled right after extrusion.  The current plan is to blow chilled air over the chocolate just after it leaves the extruder.   The chilled air will come from a foam insulated box containing a block of dry ice.  There will be a blower pushing air into the box and a hose delivering the chilled air/CO2 to the print.

A couple weeks ago I got a blower from American Science and Surplus and this week I got it running by using a model airplane ESC and servo tester to drive its brushless DC motor.  It appears to be capable of blowing much more air than I’ll need.  There are many unknowns yet to test.  How much chilled air/CO2 will it take to solidify the chocolate after it leaves the extruder?  How long will a block of dry ice last when used this way?  Will ice build-up inside the chiller box adversely affect its performance?

I designed and printed three parts for this system- a mount to attach the blower to a foam box up to 1.5″ thick, a hose coupler to allow delivery of the chilled air/CO2 to the print, and a hole saw to cut holes to fit the other two parts.   The printed parts fit as if they were designed for the job!

3D printed hole saw

3D printed hole saw

Hose connected to hose coupler

Hose connected to hose coupler

Hose coupler parts

Hose coupler parts

Blower mount for air chiller box

Blower mount for air chiller box

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First Ever Test of the 3.5 Liter Syringe Extruder https://milwaukeemakerspace.org/2015/07/first-ever-test-of-the-3-5-liter-syringe-extruder/ https://milwaukeemakerspace.org/2015/07/first-ever-test-of-the-3-5-liter-syringe-extruder/#respond Sat, 04 Jul 2015 22:58:37 +0000 http://milwaukeemakerspace.org/?p=8538 My last post showed how I made a plunger for a 3.5 liter syringe.  Today’s post is the results of the first ever test of that syringe assembly including the plunger.  The goal of the test was to determine if the syringe pusher would be able to push very thick, viscous paste (sort of like melted chocolate) out of the 1/4″ syringe nozzle.  It was also a test of the ability of the previously made silicone plunger to maintain a seal even against whatever pressure develops inside the syringe as it is pushing.

I mixed about 1 liter of extra thick pancake batter to a consistency that I thought would be much thicker than molten chocolate (pancake batter is much cheaper than chocolate) and shoveled it into the syringe, then bolted on the pusher and hooked it up to a power supply:

Looking back, I probably should have loaded the syringe from the other end.

Syringe loaded with super thick pancake batter.

Syringe loaded with super thick pancake batter.

 

 

 

 

 

 

 

 

 

 

 

Here’s the actual test.  It gets especially interesting about 1 minute in:

The syringe continued drooling after power was removed due to air that was trapped inside the syringe.  As the plunger pushed, the air was compressed.  When the motor stopped the compressed air continued to push out the batter.  I will have to be careful to eliminate air bubbles in the material when it comes time to use this in a printer.

It only took a couple minutes to clean out the syringe after the test was done.

The pusher did its job much better than expected, and the plunger held up just fine, too.  I feel confident that this device will be able to extrude chocolate.   Now the real work begins…

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Making a Plunger for a Chocolate Syringe https://milwaukeemakerspace.org/2015/07/making-a-plunger-for-a-chocolate-syringe/ https://milwaukeemakerspace.org/2015/07/making-a-plunger-for-a-chocolate-syringe/#respond Fri, 03 Jul 2015 04:13:43 +0000 http://milwaukeemakerspace.org/?p=8523 My latest project is a 3D printer that will produce chocolate objects.  Like many other chocolate printers, it will include a syringe to dispense the chocolate.  Unlike those other printers, the syringe in my printer will have 3.5 liter capacity to enable printing large objects.

The syringe is made from PVC pipe using mostly standard fittings.  One piece that wasn’t standard was the plunger that fits inside the syringe tube and pushes on the chocolate contained therein.  I had to design and fabricate the plunger.  PVC pipe isn’t perfectly smooth or perfectly round inside, so I needed something compliant enough to ride out the pipe’s bumps and constrictions while maintaining a seal.  The seal needed to be tough, yet safe for use with food because it will be in contact with the chocolate inside the syringe.  I found some food-grade silicone casting material and ordered it.

While waiting for the silicone to arrive, I designed a 3D printable core for the plunger and a mold and jig.  The core fits on the end of a linear actuator that will provide the push.  The jig centered the core a few mm above the bottom of the mold.  The mold was tapered and the widest part -the bottom- was a few mm larger diameter than the pipe, and several mm larger diameter than the core.  The silicone envelops the core and is locked in place by holes that connect top and bottom side of the core.  The plunger squeeze-fits into the pipe to maintain the seal against the uneven inner surface of the pipe.

Mold, jig, and core for syringe plunger

Mold, jig, and core for syringe plunger

Mold, jig, and core for syringe showing core inserted into jig.

Mold, jig, and core for syringe showing core inserted into jig.

 

 

 

 

 

 

 

 

 

Mold, jig, and core assembled for silicone over-molding.

Mold, jig, and core assembled for silicone over-molding.

I measured and mixed the silicone, coated the core with it and then set the core and jig in/on the mold and let it cure for 24 hours.  Then I removed the jig and broke the now silicone covered core out of the mold.  Result: a perfect, tight fit inside the syringe tube.

Core in mold with silicone.

Core in mold with silicone.

 

 

 

 

 

 

 

 

 

 

Finished plunger removed from the mold.

Finished plunger removed from the mold.  The mold had to be broken off by design.

 

 

 

 

 

 

 

 

 

 

 

Plunger mounted on linear actuator.

Plunger mounted on linear actuator.

 

 

 

 

 

 

 

 

 

 

 

 

The assembled syringe.

The assembled syringe.

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Experiments in optics and image processing https://milwaukeemakerspace.org/2015/06/experiments-in-optics-and-image-processing/ https://milwaukeemakerspace.org/2015/06/experiments-in-optics-and-image-processing/#respond Fri, 12 Jun 2015 19:55:44 +0000 http://milwaukeemakerspace.org/?p=8493 After successfully mating a web cam with my microscopes (http://www.thingiverse.com/thing:216821) and telescope (https://www.youmagine.com/designs/web-cam-adapter-for-meade-telescope-eyepiece), I decided to design and print adapters to mount my Droid Turbo phone on the same scopes (https://www.youmagine.com/designs/microscope-adapter-for-droid-turbo-phone and https://www.youmagine.com/designs/droid-turbo-phone-to-telescope-adapter) so I could shoot higher resolution stills (21 Mp) and 1080p (and even 4k) video.   The telescope adapter fits over a Meade 32mm focal length Super Plössl eyepiece and provides about 47X magnification with the telescope.  I printed a similar adapter for my surgical microscope.

IMG_0995_crop

 

 

 

 

 

 

 

 

 

 

 

 

The telescope adapter firmly grips the phone and the eyepiece.

 

IMG_0993_crop

 

 

 

 

 

 

 

 

 

 

 

 

Initial tests were a little disappointing.  The combination of the phone’s camera and the telescope’s optics has significant pincushion distortion.  The image has only been mirrored L-R and scaled down (original is 21 Mp).  Note the lack of contrast (looking through 1/2 mile of humid air) and the curves in the power line and pole, and even the grass line:

pinch test original

 

 

 

 

 

 

 

 

 

A quick search found that the Gimp has built in transform tools to correct (or create) lens distortion.

 

gimp

 

 

 

 

 

 

 

 

It only took a couple minutes of messing around to get acceptable results.  Here’s the same image with the pincushion distortion corrected (whole image), contrast stretched and white balance corrected (rectangular area).  The pole, power line, and even the grass line now look straight.

pinch test corrected

 

 

 

 

 

 

 

 

 

And here’s the final image with all corrections and cropping applied:

final

 

 

 

 

 

 

 

 

 

 

Next step: photograph known square grids through the microscope and telescope and then create and save some preset corrections to apply with Gimp.

I wonder if something like this exists for video.  Hmmmmm…

 

 

 

 

 

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Son of MegaMax Enters Instructables 3D Printing Contest https://milwaukeemakerspace.org/2015/05/son-of-megamax-enters-instructables-3d-printing-contest/ https://milwaukeemakerspace.org/2015/05/son-of-megamax-enters-instructables-3d-printing-contest/#respond Fri, 29 May 2015 16:38:32 +0000 http://milwaukeemakerspace.org/?p=8486 Many 3D printers being given away as prizes!  If I win one I’ll be donating it to my son’s school or other school or library that would like a machine and doesn’t already have one.  To do that I need your votes!

Son of MegaMax

Son of MegaMax

Please see my Instructable here:  http://www.instructables.com/id/An-Almost-Reliable-High-Precision-3D-Printer-Son-o/and vote for me by clicking the little red “vote” ribbon in the upper right corner of the start page.

Thanks!

http://www.instructables.com/id/An-Almost-Reliable-High-Precision-3D-Printer-Son-o/

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