Power Wheels Racing

Race HeadLast month the Milwaukee Makerspace power wheels team packed up the cars and road tripped to2 images vertical Maker Faire Detroit.  After long nights working at the space until 4am for the week before the drive Ed, Kathy, Pete, Andy, Vishal, and too many others to mention got 3 cars race ready.  The Bluth Stair Car, Super Tux Kart, and Hippie Rose made the journey to Detroit without damage are and were a blast to drive.

 

Our 3 cars raced with 34 others in the biggest Power Racing Series event to date on the biggest track ever made.  It was great to see all the hard work paying off as the builders of the cars became the happy drivers of the cars. Both days of races were streamed live by our friends at Make Magazine to Twitch.tv where they can still be watched. Be sure to check out the race at Maker Faire Milwaukee September 24th-25th.

 

Check out the race from day one at the link below:

https://player.twitch.tv/?volume=1&video=v80805800&time=04h50m54s

Time To Get Nerdy!

Nerdy Head

Make sure not to miss this weekend’s Nerdy Derby at American Science and Surplus. Adrian and the rest of the nerdy team will be helping kids and kids at heart turn blocks of wood into rolling masterpieces of speed. If you have not been to a Nerdy Derby event this will be one not to miss.  3D printed wheels have been coming in from printers all over the city and from our Makerspace 80 at a time.

2 images nerdy

Building a car is easy and there will be a nice long track to race down once you’ve finished your creation.  You start by picking a block of wood and some wheels. After a bit of nailing its off to nerdy up your car from piles of amazing decorations. Makers are encouraged to decorate, test, and re-decorate. Everything that you glue onto a car affects the way it moves down the track. See you there!

MFMKE2015_8211small

August 20th 11am-3pm
American Science & Surplus Milwaukee
6901 W Oklahoma Ave
Milwaukee, Wisconsin 53219

Replacing the Glass Print Bed on the Taz 3 Printer

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.

Chocolate Printer Cooling System Test

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!