Hubba Hubba – a Power Wheels Fairy tale

A long time ago (last summer) in a place far far away (Detroit, New York or something) there was a power wheels race car called Red Lotus, crying alone in the pits.

Red Lotus

All of the sudden, out of nowhere with a screech of tires and a puff of tire smoke appeared the Fairy Godfather (after all, Fairy Godmother wants “nothing to do with that dangerous racing stuff.”)

The Fairy Godfather asked Red Lotus “What’s the matter little race car?”

Blown tires

“Well Fairy Godfather, every time I try to catch up with the other cars my tires just pop!”

“Well little car, what you need are magic tires! and please call me FGF – all my drinking buddies laugh when someone calls me ‘Fairy’ ”

And with a wave if his enchanted tire iron POOF! a magical tire appeared!

New tire

“Really?” said Red Lotus “That rim won’t hold up for 20 seconds on a power wheels track.”

“Hey!” exclaimed FGF “You get a magical tire, you can figure out the rim yourself!”

Old hub

And so Red Lotus did figure out the rim herself. Thus was born the Quad Bolt, Flange Welded, Wood Spaced, super rim!

And all the rest of the season Red Lotus didn’t pop a single tire – at least not a rear tire…

Then one day when all the races for the season were over, once again Red Lotus was sitting alone in the pits crying.

With a squeal of tires and more blue smoke FGF appeared!

“What are you bawling about now? Didn’t I give you magic tires? Didn’t they last the entire season with out popping?”

“yes, they are wonderful” sobbed Red Lotus “but” (there’s always a ‘but’) “my front tires keep popping and the hubs I made suck.”

FGF thought for a minute and said “so why don’t you buy some real tires and make your own hubs to hold them?” “Here, I’ll show you how:”

Foam and tube

With a wave of his magic Tire Iron POOF pieces started to appear!

“Yum!” squealed Red Lotus “Pink frosted doughnuts!”

Bit foam

—- CRUNCH —-

“These are awful doughnuts, they taste like Styrofoam!”

—- SMACK —-

FGF knocks the doughnut out of Red Lotus’s mouth. “Those aren’t doughnuts, they’re hub patterns!”

Assembled pattern crop

“Put them on the tube like this”
“Pack it in sand”
“And pour molten aluminum all over it”


“And you get something like this”

Raw Casting

“Ewww” said Red Lotus “That’s gross!”
“Well its not done yet, you need a little time turning it on a lathe to turn it into something beautiful”

Turned casting

“Now you have your solid aluminum, hand cast, personally machined unbreakable super hub!”

And with a hearty belch FGF vanished leaving Red Lotus to do a whole bunch of work.

Tune in next time for the story of the PPPBBB – Pronounced:

Jake and the motor stack – the story of the largest motor in PPPRS racing

A long time ago (about 3 years) in a land far far away (my garage) some would be members of a Makerspace decided to build a few Power Wheels cars for the PPPRS race in Detroit.

One of the cars they selected was a plucky dump truck called Big Jake.

Big Jake ready for its 1st race

Big Jake ready for its 1st race

Well the first thing we did was pull out the stock motors (1 and 2) so we could install a surplus motor we had laying around (motor 3).

Jake's Original Motors

Jake’s Original Motors

(Sorry, we didn’t save any pictures of Motor 3)

Too bad this motor burned up – it was an odd motor anywaty, the commutator was a disk not a cylinder and the brushes were triangular – we found this out when we took the burned motor apart, doesn’t everyone take the thinks they break apart?

So we put in motor #4, a starter motor from a small gas engine, and it burned up – noticing a pattern here?

Jakes Motor #4

Jakes Motor #4

I think Fisher Price did as well – a recall about burning motors:

Then we installed a 1000W scooter motor and controller bought on-line and it was… ok.

Jakes 1000W scooter motor

Jakes 1000W scooter motor

We drilled holes in the motor and added a fan so it didn’t burn up.

But it wasn’t power full enough.

Then the big crash between Big Jake and the Yellow Escalade happened. And when the pieces were put back together – Jake N’ Stein was born.

(insert dramatic music here)

And of course such a majestic car need an equally majestic motor – so in went with a 4.5hp winch motor (#5)

4.5HP Winch Motor

4.5HP Winch Motor

Then it melted. So we took the motor from Little Pink Trike and put in on (motor #6) until we could rebuild motor #5 and put it back on (does that make it motor #7?)

Little Pink Trike's Motor

Little Pink Trike’s Motor

And it burned up.

Well we decided this wasn’t working so we did the only reasonable thing: bought a bigger winch motor! (#6/8) and it was good until it burned up.

6HP Winch Motor

6HP Winch Motor

So we re-installed the rebuilt 4.5hp motor (#5 or 9 depending on how you are counting) and added some gear reduction and it was fast until it burned up.

So back went the larger winch motor (#6/10) and added a water cooling system with some vent holes and it worked great, until we forgot to inject the water and siezed the bearings and melted the comutator – and almost got black flagged for being on fire, it was only steam!

So it came to pass, we looked around for the biggest motor we could find (too bad it was in a home brew electric car – 15″ diameter and about 200lbs) and decided to put a slightly smaller one in.

15 inch motor

15 inch motor

So motor 7/11 (lucky numbers right?) is

Jake's new MotorJake’s new Motor

Just how big is Jake N’ Stein’s new motor?

Well is 11″ long, 7.5″ in diameter and weighs around 80 pounds.

But how powerful is it?

Well, it used to haul around 6000 pounds of stuff in a warehouse all day long.

But how may horse power is it?

I don’t know, but Jake runs really nice :-)

5 of Jake's Motors

5 of Jake’s Motors

Power Wheels 1 Weekend Build

So the plan is to build a power wheels racer in 1 weekend. We started Friday night July 13th with the best of plans.

Here’s what happened:

So I got started Friday at 6pm…..

Ok, so it was dinner time so we broke to eat…..

7pm: Time so Start….

Hmm, there’s not room to do the build, I guess we should clean up and organize a bit.

9pm: Plenty of room, lets begin….

Now where did we put all those parts when we were cleaning up…..

Saturday 10am – slept in, aren’t Saturdays great?

Saturday 11:30am – found the rest of the parts, got them set up along with the camera and some “before shots”

Saturday 12:00pm – Lunch time!

Saturday 1pm, what were we going to do again?

Oh, yea – time to start building! 2 helpers!

Saturday 3pm – other commitments mean everyone quit – 6 man hours invested, front steering is rebuilt with heaver axels for the new tires, the body is off the donor car, rear axle is out of the car and marked for modifications.

Saturday 9pm – lathe time! 2 hours on the lathe modifying the rear axle and sprocket to fit.

Sunday 10am – Damn, its good to sleep in on weekends :-)

Sunday 11:30am – ready to start, Whats that? You’re hungry, ok lets get some lunch….

Sunday 1pm – 5 more man hours.

Installed rear axle, cut key ways in the sprocket, wheel hub, and axle. Tucked in batteries, wired batteries, controller, safety disconnect, fuse and cut throttle cable. Zip tied everything in place – took it for its first test drive at 6:10pm Sunday.

So far we have 11 man hours invested and a driving chassis.

Sunday 6:30 PM – Time for a test drive

Still needed:

Tune steering

Shift motor and seat further back to make some leg room

Raise steering column

Attach body

June 22 Update:

One weekend build! (Ok so, 2 weekends and a few evenings)

I put in another 9 hours during the week and on Saturday and 8 more on Sunday and we have a finished (almost) car!

I want to tweak the steering for tighter turns and add a reverse switch.

Some cosmetics and it’s ready for Detroit!

MMS Eclipse watching party

Although poorly attended (only one full and one future member) everyone had a great time observing the 98% solar Eclipse.

Using the official MMS pinhole card:





Too bad the eclipse image is so poor, what a minute – whats that on the building next door?


Openings between the leaves of trees are acting as pin hole cameras and giving hundreds of images of the eclipse, we felt a little silly looking at the tiny ones the card was making for the first half hour :-)

You can also see some on the leaf in the foreground (I’m writing this on an old netbook so I can’t tell how the pictures are coming out, so I didn’t clip or tweak them)

And just so you don’t think its some other effect, here’s a shot at the max we witnessed, notice the arc is at the top instead of the side:

I’m still not sure why we had such a poor turnout, after all its only a 36 hour drive to San Francisco!



My neverending quest for quick turnaround prototype PCBs

For years I have dreamed of a fast way to prototype PCB for projects I am designing.

20 years ago I was using rub on drafting tape and stencils – slow and spotty results.

I tried to modify a plotter to plot resist directly to a PCB – no luck.

Magic markers – I’m no artist.

5 years ago I hacked a laminate router by tapping into the stepper controllers and adding a better Z axis – It can rout boards ok, but takes some tweaking.  It only does fairly wide traces.  But its great at drilling holes!

2 years ago I tried the inkjet printing systems – lots of smeared wet ink and poor registration, not very effective.

I opened up a laser printer and tried to get a board to go through it – almost worked, but the fuser was to narrow to take the board.

Although I haven’t found a fast system yet, I get by with the PNP Blue material and a good laminator.  Although I am regularly disappointed when dust, not quite clean boards, minor wrinkles and other issues leave gaps in traces that need touching up.

Which brings us to the latest attempt:

Now that the maker space has a small laser cutter I am trying to find something I can coat a board with and either burn away or melt onto the board to act as an etch resist.

Early attempts with paint had moderate results – our laser cutters on only 25W so it didn’t burn it cleanly.  I have heard that using flat black paint and a more powerful laser works.

Paste wax and markup fluid weren’t dark enough for the laser to vaporize (thinking of trying black crayons)

The latest attempt uses laser printer toner (just like the PNP only skipping the printing and iron on steps.)

The problem is how to get an even coat on a board without it blowing around.  Static electricity has potential (just like what they do inside a laser printer) but I don’t like the idea of a 5KV power supply exposed and handling powered toner is an automatic mess.

So for the first attempt I mixed the toner with rubbing alcohol (30% water).

Messy stuff!

I painted it on with the tongue depressor but it seemed to coat evenly and took only a few minutes to dry:

It mixes well and paints on fairly easily, here are some sample prints I did at various power and speed settings.  I cleaned the board fairly aggressively with paper towel and rubbing alcohol.

None are quite clean enough to become PCBs but they are getting close.

Although the toner paint looked dry, it may still have had some water in it.  I plan on trying a batch with denatured alcohol (100% – no water) and see if it works better.



Updated progress

I have been trying a number of materials and methods to make my fast turn circuit boards.

I’ve decided that last toner is too messy and there are too many variables to create a repeatable process.  So now I’m trying various other masking materials:


Black and white spray paint – it works ok, but the ash left behind by the laser resists the etchant and leaves you with a poor etch.

I also tried tape:  Painters tape, electrical tape, clear and brown box tape.  The masking tape worked ok until the etch was slow and the tape started to dissolve.

I held a few of the boards up to the light so you can see how it etched:







One of the other members of the space found someone who had made the black paint work.  The process is to do 2 passes with the laser – the first burns off the paint, the second burns off the ash!  Then you wipe the board down with rubbing alcohol to clean off any residue.   Here is a set of 3 projects I lasered and etched at once:

This board turned out rather well, I had some trouble with the etchant taking for ever so lost some of the detail on the lettering, but the boards came out nicely.  I should get even better results on the next project.

In an attempt to speed the entire process up I tried to drill holes with the laser cutter from the back of the board:

   Not very good results!  After about 6 passes it still didn’t cut through thin PCB material and stunk and smoked the whole time!







So instead, I used the laser to cut wholes in a small piece of acrylic to use as drill guide:




This gives you a pattern to follow using a Dremel and the holes wind up in the right places and nicely lined up.  I drilled 2 holes in opposite corners of the board and used the leads from resistor to line up the template and board and hold them together while drilling.




This image shows the template attached to the board and about half the holes drilled.  This worked very nicely!  The only problems was small disks of acrylic getting stuck to the drill bit (you can see little craters on the left side of the board where these came from)  I had to clean the drill bit twice to drill the whole thing.  Either bigger holes or a different plastic might fix this.


This is first of the 3 boards I put together and it works just fine.  It is a level translator for the encoder you see in the holder.  The encoder will be attached to the drive motor in my electric car and feed back motor position to the controller.  The encoder is 5V and the controller wants a 15V signal.  The test bed uses a 15V power supply and LEDs on the 4 quaderature outputs.

Encoder test video