Niles – the Ball Bearing Glockenspiel

I have been working on a ball bearing glockenspiel. The contraption will be comprised of 3 systems – ball bearing launcher, ball bearing collection and return mechanism, and the instrument itself.

I started with the the launcher. There will be 25-30 notes and a fast and accurate launcher will be needed for each one. My design parameters were to launch 4 bearings a second within a 1/2 inch diameter over a 2 ft. drop. Here’s my first attempt.

2014-12-20 17.50.55

2014-12-20 17.51.03

A pipe feeds ball bearings to a rotating platform with a hole just large enough for one bearing. When it’s ready to drop, the servo rotates the platform by about 30 degrees and the bearing falls out the bottom. The platform then rotates back  to the home position and loads the next ball. The mechanism could definitely deliver the balls quickly but the accuracy just wasn’t there. The balls would hit the side of the hole as they were exiting. On to the next iteration…

3.0

3.0.1

I forgot to take a picture of this one so I am posting the drawings instead. The concept is the same as the previous version, except the slider is linear instead of rotary. I added a longer channel after the initial drop to guide the ball bearings as they fall. But I had the similar accuracy issues.

So, I kept iterating the design to minimize potential disturbances after the ball is launched. And of course, decided to use magnets. The bearing are made out of steel and magnets suspend the ball till a servo controlled “plunger” launches them. This design worked beautifully! I have attached two slow motion videos below. As you can see in the second video, it’s so accurate the balls are literally hitting each other like Robin Hood “splitting an arrow”!

Next, I will work on making this design more compact and also, several ball return mechanisms.

 

 

Our woodshop has a Router table!

The woodshop now has a Rockler router table! Thanks to Bill M for donating the table and James for adapting the plate to an existing Craftsman router we can now use this fantastic router table. The table has a convenient switch(visible in the picture with a large safety STOP button), an adjustable fence, anti-kickback finger, slots for jigs, and is conveniently placed on wheels so the whole unit can be wheeled to where ever it is needed. If your wondering “what the heck is a router table, or a router for that matter” then check out the links below to get started.

Some great information on using a router table from Rockler is available here:

A great video for absolute router beginners, Steve Ramsey also has a bunch of other great woodworking videos:

How to make a picture frame using a router table, another Steve Ramsey YouTube video:

An overall pic of the router table.

An overall pic of the router table.

A tight picture of the top of the router table showing slots for clamping  jigs, fence, and anti-kickback devices.

A tight picture of the top of the router table showing slots for clamping jigs, fence, and anti-kickback devices.

 

A close up shot of a craftsman router mounter under the router table

A close up shot of a craftsman router mounter under the router table.

Weekly Maker Spotlight #3 – Tami Weiss

IMAG3166

How did you first find Milwaukee Makerspace?

I don’t know. Which is a terrible answer, I know. But I had heard something about shared work spaces, and through some means or another had directly heard about Makerspace, because I know I eventually searched for the name Milwaukee Makerspace. It was like it was floating in the ether but I’m not exactly sure what source it came from.  I know I dallied about for a year before finally acting on it.

Why did you decide to join?

The tools! Yes, that sounds mercenary. It is. A frustration I often had is just that I can’t afford every tool I need to make the things I want to make. And Makerspace has all the tools I might want, and so many more! I never knew I wanted to use a laser cutter or 3D printer, but gosh darn it, that’s an option now.

What do you do at Milwaukee Makerspace?

When I first joined, Brant and I had a lovely conversation where he referred to a condition afflicting some members where they have “an allergy to finishing projects.” I groaned, because that’s me. I am so embarrassed to say that is me and I haven’t finished one thing yet. I’ve started some lovely things, though. I can say that.

Most of what I do there revolves around my primary hobby, which is breeding seahorses. And while I haven’t really finished a project at the space yet (though I’ve started many), I have used the space to do little things that add to projects I’m working on at home; painting something in the winter, working on a wood stand with my husband to put fishtanks on, sending him to make something I need, etc.

The biggest problem I have is that I walk into Makerspace and it’s such an endless world of possibilities, that my project idea list has tripled since joining.

The other thing I like to do though is just go there as a place to hang out. I went there for a while regularly while working on a freelance project when I needed to get out of the house. I’ve gone there just to hang out on the couch and think. It’s that kind of place.

What would you like to tell others about Milwaukee Makerspace?

I probably sound like someone with a gym membership who never goes, but I love Makerspace and couldn’t imagine not being a member. It has some of the nicest, most helpful people there doing insanely creative things. I haven’t run into any egos or crazy politics that many groups succumb to. Everyone is excited to be there. And there is so much potential at the space. My biggest hurdle is the distance to Makerspace – we live just far enough away that it can be a hassle to go there without a lot of planning. But I’m looking to move to Bay View or a nearby neighborhood specifically because I want to be nearer to the space. That’s the kind of place Makerspace is.

What do you plan to work on in the next few weeks?

Really boring stuff. I wish I had a really cool project to talk about. I need to clean up some mistakes I made on painting some aquariums for my fish room expansion. I painted the wrong end, so I need to clean and repaint the other end. I’m using glitter spray if that makes it sound more interesting! It’s part of a larger project since I’m expanding my fish room to make more space for more species, and to semi-automate some of the processes for raising the babies.  I’ll be using peristaltic pumps and an Arduino controller. That’s like a 6 months to a year timeline though because I have a lot to build before I can get that far.

 
 

Further Adventures in 3D Printer Upgrades (upgrades?)

As previously promised, MegaMax’s Y-axis has been converted to screw drive along with the addition of a larger motor, DSP based driver, and 32V power supply.  The SmoothieBoard arrived and was quickly swapped in to replace the ATMega2560/RAMPS combo.  After studying and configuring the Smoothieboard I attempted a few test prints.  That’s when the problems started.

32V Power supply for Y axis motor.  No regulation necessary!

32V Power supply for Y axis motor. No regulation necessary!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Smoothieboard is supposed to read the config.txt file from its uSD card (conveniently accessible via USB) every time it boots.  That makes changing configuration very easy and fast – all you do is edit the config.txt file, save it , and reboot the board.  Firmware is updated the same way.  With the ATMega2560 you have to find the configuration variables by searching through multiple configuration files, make the necessary changes, recompile the firmware, then flash the controller.  I said the SmoothieBoard is supposed to read the file every time it boots, but it wasn’t doing it.  I’d make changes and they would not appear in the behavior of the printer.  Hmmmm.

Layers kept shifting in the X-axis- I expected Y-axis problems, but not X!

Layers kept shifting in the X-axis- I expected Y-axis problems, but not X!

 

 

 

 

 

 

 

 

 

 

 

I attempted some prints and managed to get two decent ones in about a week of screwing around with it.  I tried dozens of combinations of speed, acceleration, junction deviation (smoothie-speak for jerk) and even tried different slicers.  The machine went completely nuts on two occasions and ignored the Z-axis limit switch and slammed the extruder into the print bed, gouging through the Kapton tape and into the aluminum!  I decided I needed some professional help so I got on the #smoothieware IRC channel and discovered that the developers of the board/firmware hang out there quite a lot.  After a lot of back and forth Q and A and testing someone suggested it might be the uSD card causing the problem.  I picked up a new card at Walmart, put the firmware and config files on it , booted the machine, and attempted a print.  PERFECT!

The new uSD card worked!  The small round post is 4mm diameter.

The new uSD card worked! The small round post is 4mm diameter.

 

 

 

 

 

 

 

 

 

 

I have made several prints since last night and they have all come out fine.  I still have a little tweaking to do and to test the limits of the machine’s performance, but I think the problems are behind me.

Next up:  X-axis redesign/build.  I’m replacing the two guide rails with a single linear guide.  I have also ordered and received a BullDog XL extruder to replace the hacked up QUBD unit I’ve been using.  I’ll be adding a DSP driver and 32V power supply for the X-axis motor, too.

After that, I have some ideas for a filament respooling machine and ways to fix the retraction problem in the SnakeBite extruder.

It never ends!

 

Bay View Printing Co.

The Milwaukee Makerspace is about to get an exciting new neighbor!  Ashley Town, a former professor at the Milwaukee Institute of Art & Design (MIAD) has recently purchased the > 100 year old Bay View Printing Company @ 2702 S. Howell Ave, less than a half-mile from our space!

Ashley is taking over a print shop with a rich heritage as well as several beautiful presses, a Linotype machine and dozens of wood and metal typefaces.  She plans on doing custom work as well as running classes and building up a community around the lovely art of printmaking.

Bay View Printing Company is in the final days of its fundraising drive on IndieGogo to raise money to pay for some renovations to the space to make it more amenable to Ashely’s goal of making this a community-driven space.  The IndieGogo campaign has some great rewards like private lessons on the Vandercook press.  I’m so thrilled this is coming to Bay View that I have challenged Makerspace members to donate and will match up to $500 in donations!

Bay View is extremely lucky to have a new creative space!  If you want to support them, hurry up, though!  The IndieGogo campaign ends at the stroke of midnight on New Year’s Eve, 2014.  As of this writing, they have raised $7,635 out of the desired $11,000.  Let’s help them out and welcome our exciting new neighbor!

Read a bit more about the space at these local outlets:

Weekly Maker Spotlight #2 – David Heino

davidh

How did you first find Milwaukee Makerspace?

I forget how I first heard of it. I made several trips to the space when it was in the complex off Oklahoma Avenue.

Why did you decide to join?

A big factor was I could afford the dues after the big change. I think of myself as a life-long maker, although I tended to use the older term, craftsman. I joined because I wanted to explore.

 What do you do at Milwaukee Makerspace?

Just now, I’ve been using the space to prepare for an upcoming exhibit. I make paintings and things you might call sculpture.

What would you like to tell others about Milwaukee Makerspace?

In my opinion, it is a very good and interesting make. It’s most valuable asset is the variety and depth of knowledge and skill to be found amongst the members.

What do you plan to work on in the next few weeks?

Once I’m done with the exhibit, I want to:
1. take advantage of the opportunities the space offers to expand the tools and technologies I can use in my work.
2. I wish to work on objects that make interesting sounds that can be “played” by the user’s movement.
3. I want to work on a projector capable of producing large scale lighting effects.

 
 

Weekly Maker Spotlight #1 – Mike B.

 

We’re adding a new feature to our blog!  We’ve started sending brief surveys out to our members at random.  Each week, we will select one and publish it on our blog.  Our first participant is Mike B.!
 

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How did you first find Milwaukee Makerspace?

I believe I met Tom G and Ben who were speaking about their home made electric vehicles at a Barcamp.

Why did you decide to join?

I joined up because I had a couple projects where I needed a little advice/training to get me over the hump.

 

 

What do you do at Milwaukee Makerspace?

So far, woodworking and metalworking.Testing p1

What would you like to tell others about Milwaukee Makerspace?

You’re guaranteed to find someone with some experience in any skill or technique you’re looking for.

What do you plan to work on in the next few weeks?

I need to do a little basic electrical work to build an EXIT sign lamp. I’m also looking at a welding project to build a bench with a coat rack for my apartment.


See Mike’s blog posts here:
Building Patio Furniture For Fun and Profit
How to Build a Kitchen Table in an Assortment of Easy Steps

Square(ish) Pegs

Laser-Cut Pegs

Often laser cut parts gt attached at 90 degree angles, using finger joints, or screws and t-slots, but there may be times when you want to stack pieces of wood and have them aligned…

Pegs might be the answer!

Here’s a few photos of the pegs I’ve been experimenting with. For these pieces I don’t have a lot of room to have multiple pegs at opposing angles, but I can see where that might be useful. For these pieces the peg is really just for assembly alignment when gluing it all together.

Laser-Cut Pegs

Update on the Never-Ending Printer Project

I installed the Y-axis screw drive in MegaMax using the old NEMA-23 stepper motor.  A couple really good things came from this:

1) I can now adjust the bed leveling screws from the underside of the bed using thumbwheels instead of a screw driver.  I know, I know, everyone else in the world has been able to do this from day 1…

Thumb screw for leveling print bed.   Screw is threaded into teflon block.

Thumb screw for leveling print bed. Screw is threaded into teflon block.

 

 

 

 

 

 

 

 

 

2) Unlike everyone else in the world, with fully supported linear guide rails, the print bed does not move in any direction but along the Y axis.  In the old scheme, with the end-supported round guide rails, the rails would flex and the bed would move up and down when applying pressure to it (sometimes even the screw driver pressure to adjust the bed leveling screws).  Now, if the bed moves at all in the vertical direction it’s because the bed plate (1/4″ aluminum) itself is flexing!

A couple bad things were also discovered:

1) The vibration and noise problem I was hoping to solve has not been solved.  It has been made worse, though the character of the noise is improved to musical tones instead of just harsh buzzing and rattling.

2) Several failed test prints at ever decreasing jerk, acceleration, and speed settings have demonstrated that the old motor simply doesn’t have enough torque to drive the screw reliably at reasonable printing speeds.

Shift occurred in Y-axis due to insufficient motor torque.

Shift occurred in Y-axis due to insufficient motor torque.

 

 

 

 

 

 

 

 

 

 

 

 

Further research into the first problem indicates that the vibration and noise are inherent in using steppers, and worse in MegaMax than in machines that use NEMA-17 motors because of the higher detent torque in the NEMA-23 size motors.  Detent torque is the little bump-bump you feel when you turn the motor shaft by hand.  The solution to the problem is to use a good driver for the motor and a higher voltage power supply.  The little A4988 chips in the Pololu drivers on the RAMPS board are very unintelligent- all they do is provide microstepping.  They work OK for NEMA-17 size motors because of the speeds and low detent torques in those motors.  When used with NEMA-23 motors the driver limitations become apparent – as they have in MegaMax- lots of noise and vibration.

Good stepper drivers are DSP based and automatically sense resonance and damp it electronically.  They use phase controlled sine wave currents to drive the motors smoothly.  Fortunately, DSP stepper drivers for NEMA-23 size motors are pretty cheap.   Here’s video of the DM542a driver pushing a NEMA-23 motor around.  I have ordered a DM542a driver.

The best power supply for stepper drivers is not a switcher, and running steppers from a switching supply will often result in a dead power supply.  I will be building a simple, unregulated transformer, rectifier, and filter cap supply to go with the new driver.

Next came the question of how to determine how much torque is needed to properly drive the Y-axis.  A bit of research took me here: Motor size calculator.  You just select the scheme for which you want to size the motor, enter the appropriate data, and it magically tells you how much torque you need to do the job.  When I ran the numbers on MegaMax, it told me that I need about 350 oz-in of torque (about double the torque of the motor I have).  I did a quick search and found a Chinese made (of course) 425 oz-in motor for $50.  Also on order…

The motor mount I am using is designed for a NEMA-34 size motor with which I use an adapter plate to allow the NEMA-23 motor to fit.  Since I’m buying a new motor anyway, why not just get a NEMA-34 motor?  It turns out that the best stepper for the job is generally the smallest motor that can provide the necessary torque.  A NEMA-34 motor could provide much more torque but the detent torque and rotor inertia would work against smooth and fast operation, and require a bigger power supply.

Back side of MegaMax showing motor mount, adapter plate, flexible coupler, and drive screw  in Y-axis.

Back side of MegaMax showing motor mount, adapter plate, flexible coupler, and drive screw in Y-axis.

 

 

 

 

 

 

 

 

 

 

 

The ATmega2560 and RAMPS boards will be replaced by a SmoothieBoard.  It has a much faster processor, much better connections for motors/external drivers, etc.  It currently lacks an easy way to add an LCD controller, so I may have to connect to a computer to start prints up (it has ethernet and a built in web server so it can be accessed from any computer on the network).  When a clean way to add an LCD controller becomes available, I’ll add it.  SmoothieBoard review