Sabertooth

Here is a little about the Sabertooth 25A system I am getting. A bit of overkill, but I have read in a few places that under stress that wiper motors can produce 30A peak current! So I don't want to take any risks.

The Sabertooth 2X25 is one of the most versatile, efficient and easy to use dual motor drivers on the market. It is suitable for high powered robots - up to 100lbs in combat or 300lbs for general purpose robotics.

Out of the box, the Sabertooth can supply two DC brushed motors with up to 25A each. Peak currents of 50A per channel are achievable for a few seconds.

Overcurrent and thermal protection means you'll never have to worry about killing the driver with accidental stalls or by hooking up too big a motor.

Sabertooth allows you to control two motors with: analog voltage, radio control, serial and packetized serial. You can build many different robots of increasing complexity for years to come with a Sabertooth. Sabertooth has independent and speed + direction operating modes, making it the ideal driver for differential drive (tank style) robots and more.

The operating mode is set with the onboard DIP switches so there are no jumpers to lose. Sabertooth features screw terminal connectors - making it possible for you to build a robot without even soldering.

Sabertooth is the first synchronous regenerative motor driver in its class. The regenerative topology means that your batteries get recharged whenever you command your robot to slow down or reverse. Sabertooth also allows you to make very fast stops and reverses - giving your robot a quick and nimble edge.

Sabertooth has a built in 5V BEC that can provide power to a microcontroller or R/C receiver. The lithium cutoff mode allows Sabertooth to operate safely with lithium ion and lithium polymer battery packs - the highest energy density batteries available.

Sabertooth's transistors are switched at ultrasonic speeds (32kHz) for silent operation.

Sabertooth 2X25 uses 1.3 milliohm MOSFETs in its bridge. Going by other's ridiculous rating schemes this would make it a dual 190A motor driver!

Model: Sabertooth 2X25 Specifications: 25A continuous, 50A peak per channel. Synchronous regenerative drive Ultra-sonic switching frequency Thermal and overcurrent protection Lithium protection mode Input modes: Analog, R/C, simplified serial, packetized serial Size: 2.6” x 3.2” x .8” 65 x 80 x 20 mm Weight: 96g / 3.5oz Applications: Combat robots up to 100lb Normal and hobby robots up to 300lb Differential drive robots Electric vehicles, ride-on toys, scooters Easy speed/direction control for pumps, conveyors, automation and any application that uses two brushed DC motors

For more even more about the Sabertooth, you can go here and here

I have uploaded some information about the Sabertooth, including the manuals, so it doesn't vanish like so many things on the web do...

Sabertooth 2x25 QuickStart.doc
Sabertooth 2x25 QuickStart.pdf
Sabertooth 2x25 Manual.doc
Sabertooth 2x25 Manual.pdf
Motor Drive Efficiency Comparison Test.pdf

Knight Rider

I have received a message that the "Knight Rider" LED kits are ready for me to pick up. I am going to that today at lunch from Active Electronics in town.

This morning I ordered my motor controller. There will probably be a customs delay of a weeks or two, but shouldn't be too much longer than that. I am getting a Sabertooth dual 25A motor driver from Robot Parts, an Australian online store for robot parts funnily enough.

Wiper motors

I finally found a place that sells wiper motors in Hobart that have a long shaft! Yeah! :-) Sadly though I couldn't find a left and right motor and will have to flip one over and reverse the polarity to make one run.
I found the motors at a wreckers - Moonah Auto Salvage, and they are a pair of KF Ford Laser wiper motors, all rather greasy and muddy. If you had to pay for plastic bags, you would with these motors!! I need to clean them up at least a little before even testing them. In the photo I have already wiped them down a bit. Still, they were only $44 for the pair, so I shan't complain!

Push buttons

I looked near and far, but I seemed to have run out of luck with finding the push buttons. Either they were really expensive (about $20 each) or that they had run out of the lens colours that I needed. So I have decided to go for cutting the "buttons" out myself out of acrylic sheet using a laser cutter that I have access to.
As I have translucent red for the eyes, I did not need that, I just needed a translucent yellow, blue, and green. I also wanted a translucent white, which in the plastics industry they cal "Pearl" and is commonly used in shower screens. Yesterday I went to Eagle Plastics and gave a lovely gentleman my order, and today I have four sheets of acrylic of various colours 15x15 cm for only $5!

Yesterday I also went to the neighbouring store, which is a specialise electronics store called Active Electronics. They are a dealer for Altronics based in Perth. I bought 6m of rainbow 16 strand cable for $8.10 for the 6m and also ordered two "Knight Rider" LED kits to illuminate the buttons on the back of K-9's panel and also a false panel I am planning on making.This is what they say about it:

(SC May ’02) This little LED chaser kit is super easy to build and provides a bright addition to any shop display or vehicle. It features 32 bright LED’s which glow red. Built into it’s PIC micro controller are 12 patterns which can be selected at the press of a button. Speed is adjustable via an on board trimpot.

Requires 12VDC supply

Features

• 12 switch selectable light patterns • Adjustable pattern speed • Adjustable LED brightness • 2 pattern medleys

The K-9 Poll

By popular demand, the K-9 poll is back! :-) So for all those people who wanted to vote, now you can.

Oh, and by the way, the John Leeson photo has arrived in all it's glory! The gold pen of the signature looks great, I have to get it framed now! The postage was shocking, but I am very happy to have it :-)

A little bit nerdy!

I came across a signed photo by John Leeson of K-9 on eBay and very late last night I won it! With a little help from a friend, Niall, it will be sent from the UK, and I can't wait.
It is very nerdy, I know, but John Leeson was my favourite voice actor of K-9. He sort of was K-9.The photo is 6 by 8" and has a COA. I have included the image from eBay.

The Comparison

These RS handles pictured here are now the closest match to the K-9 prop available now, or so I have found in my research. The original handles use to be sold as "Industrial Unit" handles by RS. The current ones available are very similar, but not quite the same. Sadly the RS websites no longer carry an image of the handles or additional data on them, which makes me wonder if they are reducing their stock. However, there is an image in their paper catalogue.

RS Australia

RS Stock No.: 221-320
Manufacturer's part number: MG.01.99.01
Page : 1 - 1632

Attributes

Attribute Type	Attribute Value
Type	Handle
External Length	98mm
External Width	12mm
External Height	28mm
Material	Aluminium

This is an image of the handle from the the TV prop of the rusty version of K-9. I am still hunting for a good image of an early version of the prop to post, but when I do I will add it too so you can see it. The front seems to be a bit flatter and squarer than the current RS handle, as if the face has been ground off slightly. Not sure what it is like in real life, if the angles are as sharp. It is one of the reasons why I went for the handle I did, it is angular like this one, but without the expense of the current RS handles ($AU28.20 plus shipping!). I know mine are a little more rounded internally but I don't think it will matter that much once painted. I hope!

Handles

As the RS handles are very expensive and hard to get hold of if you don't own a credit card, I am going to be using the following handles on my K-9. I have noticed that several other people have used very similar ones too. These ones were from Mitre 10. They look very close to the RS ones. I will post an image and specs of the RS shortly.

The clear plastic bag that the handles come in have a white sticker on the outside with a barcode and description: "Handle brush nickel 96 mm 9995483R" and they are by Hettich International.

Bad Back

Unfortunately, at the start of March, I slipped a disk in my back, which was rather painful. Not only physically, but mentally as it stopped my doing so many things I loved, like building my K-9. I was forced to down my tools and take up lighter activities for a while, like knitting and reading. Sadly my knitting isn't good enough to knit a K-9, but I did think about it!! I knitted little egg beanies instead and the start of a scarf. Hmm... I could knit K-9 a scarf...? No that might be a bit silly.

Feeling quite a bit better now, I am going to start tinkering again in my spare time, which I have been itching to do so. So you might see some action on this blog again soon (finally!) ;-)

Multimeter

As I have been slowly gathering parts and also tools (as I few tools to start off with), I have come to the stage that I have had to get a multimeter. I asked my sister who works for Disk Smith Electronics what would be best to get, and she actually recommended that it would be better to go to Jaycar Electronics, the rival electronics company! That made me laugh.

I should have known thought that as soon as I mentioned my K-9 build to her my sister would relay it to my mum and then my mum would relay it to my dad. I was worried that they would think it was a waste of time and money. Perhaps they do, but they didn't mention it, instead my dad said that he had a professional multimeter that I could have! It will cover all my needs, and even if I would want to test my house electrical supply -- not that I do (and all you kids out there, don't you go trying it either! Electrocution isn't fun!).

It will be arriving in the post this Friday, together with a poppy seed cake :-) Yummy!

K-9's 30th Anniversary DWM Special

"Happy 30th Birthday K9!" says the front page in the current issue 388 of Doctor Who Magazine. The magazine is focused on K-9's 30th Anniversary with several pages on K-9. There is also an article on the Sarah Jane Adventures which I am always sad that he isn't present in. There are a few reference shots of K-9 in the magazine, but sadly not many. There are larger and better photos of Catherine Tate... Grr..

The DWM Website

This is what their web-page said about the issue...

Issue no: Issue #388
Release Date: Thursday 18th October 2007
Pricing: UK £3.99 , US $7.99, AU$13.50

Doctor Who Magazine - Issue #388 DWM Press Release

Elisabeth Sladen, star of ‘The Sarah Jane Adventures’, talks exclusively to Doctor Who Magazine about her brand new series...

“When Russell first suggested ‘Sarah Jane Adventures’, I wondered where they could take her, but she’s opened up and I’ve absolutely relished that. I loved that period of finding things in Sarah Jane, and it’s all come back. I’m so pleased.”

Lis also reveals more about forthcoming stories, including the series’ dramatic conclusion, ‘The Lost Boy’…

“All hell breaks loose! Sarah Jane tries to do the right thing, but then someone shows her something… and it’s not the right thing. There’s someone else who knows about the shenanigans in the attic. And Sarah Jane gets the shock of her life, too!”

Also in the issue, there’s exclusive access to the set of Series Four’s Roman episode with director Colin Teague; new companion Catherine Tate chats about Donna, Daleks and difficult crowds; K9’s birthday is celebrated as the magazine looks back fondly over 30 years of the Doctor’s metal pooch; actor Noel Clarke reveals what happened when he met the Daleks; the Doctor and Martha are deep in trouble in Part 3 of their latest comic strip adventure ‘The First’; acclaimed writer Steven Moffat talks candidly about who he fancies, childhood hobbies and what makes him cross as he plucks questions from Out of the TARDIS tin; and executive producer Russell T Davies writes about the Things You Don’t Write in Production Notes.

All this, plus the latest exclusive news on the new series, plus reviews, DVD previews and competitions.

http://www.drwho-online.co.uk/DWM/DWM.htm

K-9 Units

Today in my lunch hour I was surfing the net, checking to see if there were any new cool images of K-9 out there. I stumbled across a couple sites in the US for Police K-9 Units, where they use dogs to help them fight crime. I just loved the t-shirts they had, they made me laugh. I looked to see if I could get one, but sadly they are only available in the US. The same goes for the badge. Perhaps I might have to screen my own when I have time. First I better get me K-9 done! :-D

Doctor Who Night At the ABC Store

Tonight is an exciting night. Not only am I going to an art gallery opening that has two of my pieces in it, but there is a Doctor Who night at one of the local ABC stores here in Hobart! The ABC store are running quizzes, and contests including a drawing competition… Of course I couldn’t help but enter… Oh, it is like living in UK in the 70’s with all that is going on in Doctor Who here now, or at least like from what I have read and always dreamed I could have lived through.

Tonight the shop is also showing off the new radio controlled K-9’s for sale. I am guessing from the price that they are the ¼ scale ones, but it will be good to see them. I am tempted to get one myself, but I have to save up for more bits for my full-sized mutt!

Here is a close up of what I entered…

Logo

After seeing the R2-D2 websites with their cool logo of the droid it inspired me to make a K-9 logo. Here is the base sketch before I put it into Illustrator. I hope to get it done this weekend. He will have a red paint-brush style stripe through his eyes, similar to what R2 has but in blue.