Diary of the Mad Monster Robot

Emailed Mackay Engineering, a well-established independent family firm that I have a lot of respect for, in a town that I have lived in and enjoyed and loved. I thought, "great!", I'll email them because they have an engineering workshop, perhaps they can help, I'll be able to go visit them, drop by, rather than be just one more of these irritating whining beggars that firms are getting more and more of, these days.

Well, did I get a shock. "Sorry, but we are unable to assist. I wish you well with your project". I was really quite pissed off. In other words, the number of begging requests that they are getting far exceeds the tolerance and time wasted threshold for use of email as a means to do business. Let me translate that for you: the amount of Robot Wars SPAM businesses are getting is beginning to piss them off.

So, my reply was rather more sarcastic than I would have liked, "well, which _bit_ can you not assist with: engineering, sponsorship or design?". I got no reply. Plan B: actually go round and speak to someone. Don't mention Robot Wars...

Telephoned Mackay Engineering, found out where they were, went round to speak to someone. Was genuinely hoping it wouldn't be the person that responded to my email.

Apparently, steel is really cheap. It'll be about 15 quid for a 1.5metre, 36mm diam rod. It's the CNC machining that's so damn expensive, although, outside the workshop, Andy mentioned that it'd likely be about 250 quid to do each shaft pair and leg, which is a lot less than I was dreading.

Hopefully he won't ever meet the guy who emailed me.

I mentioned this all to my brother, who happens to know Donald Mackay [Cambridge is a small place]. He said that he'd have a word, see what is going on, see if we can sort this all out. I really hope that it can be.

Found out a couple of interesting things. 20 years ago, the materials used to be more expensive than working them. Now of course, it's more that the price of skilled labour has gone up proportionately, but that certain things like mass-produced goods such as extruding steel, cutting wood etc. results, in this world-wide global economy involving in some instances Chinese prison labour or exploitation of children in third world countries to make shoes, have become much much cheaper.

Secondly, that the further north you go in the UK, the cheaper machining becomes... :)

Gave up on bloody Linux 2.5.1 Sony Vaio bloody hardware damn USB built-in Memory Stick SCSI interface not damn working getting in the way of being able to use the Fuji FinePix Digital Camera, and decided to use my Sony Digital Video Camera, with its FireWire interface instead.

I did a "stills" video on the VidCam, captured a 25 second portion with 4 "photos" on it, and then used kino, which didn't actually work the last time i tried it (Linux 2.4) HURRAH! So I can do a video, record it onto my Hard Disk, then view it in Kino and do a Frame Capture to jpeg files.

Great!

Also, I used Win95 at my uncle's place to transfer the photos I had taken earlier, I shrank them to more reasonable size on CorelPhoto, emailed them to myself.

So that's why there are some smaller photos of very clear picture quality, and some larger photos of slightly dubious origin with lots of background material and no cat....

Remember Plan B...

Spoke to HPC Gears direct, having discovered that their email server was down, whoops. Nice man called Paul was v. helpful, did some calculations for me, even called me back, read out some numbers that i found slightly difficult to make sense of.

Like in the building trade, if my dad says, "The beams are twobefour 14in centres", it means "the beams are two inch by four inch, they are running parallel to each other, the four inch side is vertical / upright, and the centre of each beam is 14 inch spaced apart", the conversation was a little fraught with engineering terms that I could work out, but could not, for the life of me, tell you what they were :)

One of them - the one involving centres - I could recognise because it's evident to me that if you want to work out the sizes of gears, and you know the ratio, you can divide the distance up by the ratio and you know the size of the gears. I think there's a squared term involved...

So. Naively, I worked out these centres myself, and came up with a monster gear size. So, naively, I concluded that a chain drive would be better. I gave Paul the figures, involving the motor's power (7.2kW) and he recommended a tooth pitch of 3/8ths-in, I think. Then, based on that, and a 5:1 gear ratio, a suitable large gear size came out at around 30cm diameter. EEK!. I had to say, uhm, that's way too big, can you go smaller, and he said, well yes, however you have to reduce the gear pitch. I thought to myself, I *feel* that's going to be a problem, but I couldn't tell why. Basically I think it means that the chain link size has to be smaller, therefore it might snap, under load from a 7.2kW motor... whoops. So, back to the straight gear arrangements.

Anyway. It looks like each gear-set, at 4:1, or 5:1 will be 100 quid, and around 6inch for the larger one and 1.5in for the smaller one. Yes, the large gear can fit onto a 60mm diameter shaft. I haven't told Paul yet that the diagrams I was reading from Lemco Ltd's site were actually for the LEM-170 yet :) None of the diagrams show the width of the shaft exactly, so I had to measure on-screen, on the jpeg image. I picked the wrong one...

Telephoned Lemco Ltd, left a message, to see if I could get some info on the motor shaft sizes, rather than trying to read them off the screen!

Plan B... hmmm...

Haven't heard back from Lemco Ltd, must call again.

Emailed Mackay, am actually not expecting to hear back from them, I think I'll have to write them off... which is a pity: I have a lot of respect for Mackay's them being a well-established family firm.

On the brighter side, just outside the house we're working on in Cambridge, I saw this beat-up old kit-looking car, sounding like a 5 litre monster on steroids. Talked to its owner (it actually started out - the car, not the owner - as a 20 year old Ford Escort, morphed into a Jeep, then the wooden body died on that (!) and got replaced by kit car parts) as, I figured that if he can do cars he could probably do a lot more.

And yes, he works at Cambridge Regional College. Yes, he could probably wangle access to the Engineering Dept by pretending it was his project, or maybe I could either get him interested in it, or better yet, as a couple of people have suggested, get the CRC interested.

He said he'd think about that one:)

I want to build! I want to do! V. frustrating.

Seriously considered a 5-leg (no middle one) SpiderBall to save weight and money. Then I spoiled it by looking up LEM-170 motors and using 10% larger leg diameters..

4QD's page advises that the Schiller Group have a design for a very powerful motor. I emailed them and got a message back, cool! Helmutt designs motors and licenses the designs - no manufacturing. ... So I would have to find out how to manufacture a motor!

Helmut Schiller sent me some diagrams. Went to visit an Engineering (CNC Tools) company yesterday, v. exciting. Could produce enough motors from this design to fund the project!