Where to get Triangle Head Tool

Using Arduino General Electronics
#1

Got this at Goodwill for $2 - Crayola Digital Light Designer. Doesn't spin up right now and no stylus, but this begs to be hacked or parted out, well worth $2 - it has 64 RGB leds attached to two strips on it plus the motor as far as parts go. But the thing has unusual triangle head security screws. Why would they use these?

I have no idea what size these may be. I see this tool kit: http://www.ebay.com/itm/Silverhill-Tools-ATKTR4-Triangle-Head-Screwdriver-Set-brio-roomba-happy-meal-/161559792833 Do you think this might do the trick?

Looks like there are already people out there hacking this display:

http://hackaday.com/2014/11/24/hacking-the-crayola-digital-light-designer/

CrayolaDigitalLightDesigner.jpg|1000x980

TriangleHeadFastener.jpg|1323x1478

#2

Not seen those before , wait a bit. And they will appear in one of those kits that appear from time to time. Custom security screws appear from time to time that i have regularly defeated using stell loaded epoxy provided that torque was not too high. Failing that i use a drilll. Occasionally come across a lh thread though which can be very destructive

#3

Why would they use those ?

Just to be difficult. Often makes it obvious they have been opened , voids warranty returns Just for the hell of it i beat that once using spark erosion, but got caugh when teck notice i replaced with non standard screw

I mean replaced with standard screw

Need a sonic screwdriver , cant find the right frequency though :)

#4

Why would they use these?

Keep young children from opening it.

#5

[quote author=Coding Badly date=1421634806 link=msg=2049415] Keep young children from opening it. [/quote] Are you serious? It would take a very special young child to try to remove even normal screws like that, they are small and deep and probably would not yield to a typically sized household Philips screwdriver anyway. I think the manufacturer is just being difficult in order to be difficult.

I think I will order those tools I linked. I've now got the smallest reason to order them and that is more than the usual amount of reason that I need to order a new toy... I mean tool...

#6

That's the description on Wikipedia.

The recommended floor for that toy is six years. All the children six (and older) I have met are capable of working a screwdriver.

#7

Looks like there are already people out there hacking this display:

Good thing 6 year olds don't have credit cards....

It looks like a POV device (Persistence Of Vision)

#8

JoeN: Are you serious? It would take a very special young child

Think he meant old child.

there is soh nere

#9

[quote author=Coding Badly link=msg=2049440 date=1421636429] That's the description on Wikipedia.

The recommended floor for that toy is six years. All the children six (and older) I have met are capable of working a screwdriver.

[/quote] As a four year old mum bought dad a crystal radio kit for christmas, came home and id built it. Dont remember it but both swear i did it. Remember however it was white plastic case with 180 deg plastic tuning wheel that only just got 2 stations

#10

raschemmel: It looks like a POV device (Persistence Of Vision)

It is. As soon as I saw the thing I recognized that was what it was even though I had no idea they made these. Not exactly sure how the pen works and since I didn't get one with it I guess I won't know, but the display mechanism itself should be worth much more than the $2 I paid for it.

#11

Maybe you can repair it.

#12

I would think it works like old crt pens did. The pen senses the positinn fromknowing the time from the start of the scan. In old days hardware did the rest. These days software

#13

Boardburner2: I would think it works like old crt pens did. The pen senses the positinn fromknowing the time from the start of the scan. In old days hardware did the rest. These days software

That is in interesting thought for sure. I guess the software would have immediate access to what the "latitude" of the position because it knows where the motor is. The longitude is unresolved at that point though. For a CRT, the electron beam is in one place only. For this device, it is in 32 places (32 LEDs). So I guess the software then has to strobe down the LEDs to figure out which one is nearest to the pen. Thankfully, LEDs really do respond that quickly. The physics of the things is amazing. That must be what is happening.

Maybe you can repair it.

That had occurred to me. Got to get it open first, though!

#14

I also found one for $2 at Goodwill, working, but no pen. I did a quick sketch with a pot to blink an IR LED at 50% duty cycle between 10 and 50 Hz to find what frequency it was sensitive to. To my surprise, it seemed to work happily all the way thru that range. Just a simple point of reference for anybody who needs to make a replacement pen.

#15

The screwdriver bits are available in special "security" bit sets. These sets however, only contain very short bits, so you do need a specific screwdriver of the particular size with a suitable narrow shaft. A piece of coat hanger wire and a file will sort it out for you. (A vice to hold the piece while you file it will be particularly useful.)

They arguably use the security screws to prevent people pulling it apart and fiddling with it, then complaining and expecting warranty when it fails.

For mains appliances, it is similar but with an added safety concern. There is also an element with more expensive devices, of restricting service to firms who pay (through the nose) for service documentation.

Not sure what they use to synchronise the display, but it may be the same light sensors used to detect the pen, measuring the ambient illumination over a full rotation.

#16

Why do they do that?

Well it is a safety requirement, if a tool is needed to access the dangerous bits then it relaxes the various regulatory things that need to be done to obtain certification.

#17

For mains stuff, yes.

At 6 V, less than one amp, this particular device is hardly a safety concern. :grinning:

#18

There is more to safety than simply mains voltage.

#19

I have had one apart.

The rotating bit could be considered a safety concern for a youngster.

#20

Boardburner2: Need a sonic screwdriver , cant find the right frequency though :)

Funny you should say that... I bought some Sonic Screwdrivers in order to mod them, and they use that triangle head screw.

I was just going to grind down some steel rod to fit.