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Blog
Tis the Seas'n to be Sneez'n
Sunday, June 03, 2007
Hey fellow Hayfever sufferers, it's that time of year again (well it is for me, applogies if your season started sooner). Stuffy nose, runny eyes, and all that lovely sno ... anyway I shall move on.
Hope you've seen the Christopher Reeve foundation link on the front of my site, and been and bought your tags? If not, why not? Talk about a hard sell, well actually no I'm sure if you want to support the foundation you will :) I got my tags a few weeks ago, and wear them all the time at the moment. It's amazing that I ordered them online from the USA on a Friday afternoon, and they arrived the Monday morning?!?! How good is that, I can't order stuff in the UK with that quick a delivery!!
Thank goodness for Air Conditioning, my little office is starting to get a little warm now, just giving it a good run to bring it back into service.
I've also been practicing with my new Honey Bee King RC Helicopter, which I got a few months ago, but have not had the greatest of weather to use it outside. I'll post some piccies soon, and possibly a video or two of me crashing it :)
Hey everybody, it's been a while!
Tuesday, March 27, 2007
September 2006?! Good grief have I not blogged since then? What have I been up to you may ask, well in answer to that ... not a great deal. I've been working hard, doing some DIY, thinking of projects to work on, and relaxing (all at the same time ... impressed?).
Actually, it's been a few months of not really wanting to do much on the computer after a day at work, and finding the inspiration to get going again.
Things I've done in the last few months:
o I've started back at the Gym (today)
o Bought a new car, Grand Cherokee (then Gordon put the vehicle tax up!)
o Booked another Skiing holiday for next year
o Done a few more designs and drawings (on paper) for projects
There are other things, but I'm getting bored listing them already. Anyway, I hope everyone who cares, are well and happy. I'll update the site sooner or later, I promise!!!
TTFN
Never buy anything from Microdirect.co.uk
Friday, September 29, 2006
Ever had problems with returning a faulty item? Ever had the run around from said company? Ever been so frustrated with them that you felt like driving to their offices and camping out in their reception just to be heard?
Well don't wait, call 0800-ARRRRGGGGHH now!
That's better, helps to vent. I bought a Vivitar 390H-DVR from MicroDirect.co.uk in November last year, and it's been great. Until about 2 months ago when it started corrupting data on the 20GB HDD and trashing my photos and video. I managed to determine there was a definate fault and that it was reproducable (the best kind).
I went onto the MicroDirect.co.uk website to obtain an RMA number, which was simple and straight forward. I had to return the camera at my cost (£7.60), but wasn't too worried about that. I sent the camera off on a Wednesday (next day) and it arrived on the Thursday. After receiving an automated email from MicroDirect saying they'd received it I was happy, and awaited the replacement camera.
One of their Customer Services people called on the Friday only to tell me that the camera had been tested and no fault was found! I had previously (in my RMA request) provided exact instructions on how to make it fail, but apparently the only testing they had done was to take a couple of photos, a "short" video and copied them to a PC. They hadn't tried downloading/uploading 100Mb+ of data as I requested, so hadn't seen the problem. What's the point of having a 20Gb camera if you can only take a couple of pictures at a time?
Anyway, I explained at great length to this guy how to make it fail and that they need to do more testing, as I wasn't about to pay £10 + P&P to have it back faulty.
Basically this company doesn't communicate AT ALL. You might get the occasional automated email, and if you're lucky a phone call. It's taken 6 weeks to get a replacement, not a new one which I was promised on 2 occasions, but a damaged refurbished item.
After 2 hours of phone calls, about a dozen phone messages for someone in charge to call me, and countless emails, I finally have had a response to get a refund for all the agro this company has given me.
Get this though, they offered me a refund of £99 for something which I paid £200 for originally, but what's worse they changed the price on their website! The price yesterday was £182 and this morning after receiving their email it's gone down to £99 "Special Offer". They had the cheek to say we'll refund at the "Todays unit value".
Anyway, I've gone back to them so we'll wait and see what they have to say. I would have been happy with a £100 as it's nearly a year old, but to have the cheek to say that £99 is the market value when it was nearly double that yesterday got my goat!
Bushcrafting - Taught by the best
Monday, September 25, 2006
Hi ya,
Just got back from 6 days bushcrafting in Midhurst, West Sussex. We had an amazing time there and learned lots of basic skills for staying alive in the wilderness. OK so we were still in the UK, but I wouldn't have wanted to be anywhere else until I'd learned what I've learned.
The people we went with are Woodcraft School for Bushcraft & Nature Awareness. You can find more details on their Website.
The company is run by John Rhyder and Caron Buckingham, and John was the Chief instructor for the now famous Ray Mears. Nick Ward was our other instructor and together with John gave all of us a week we will never forget.
I have uploaded some pictures we took with our new Canon Digital 350D-SLR into the gallery so you can take a look and see what we got up to.
I am also adding some pages to the website giving more detail about our week at Midhurst.
A big thank you to John, Nick, Clair and Caron for the most enjoyable course I have ever taken.
Gaining weight
Tuesday, August 29, 2006
I have rebuilt M.U.P.P.E.T from scratch using Aluminium instead of the MDF which makes him (decided it's a him) much more robust. In the process, he's gained about 4Kg in weight and I'll see what this has done to the performance in a few days when I finish off the little bits that are outstanding.
I've re-engineered the driveshafts, mountings, side panels and have included the Odometry hardware, which just needs the controller programming including. Am waiting on the final material I need for one of the driveshafts, but that should be here tomorrow and I'll get that done in the evening.
Probably won't get any video up for a while, as I had to send my digital camera back as it's developed a nasty fault of corrupting the data on it's Hard Disk as and when it feels like it (a Vivitar DVR-390H).
I've also added a second battery to provide more power to the motors, as I think they're gonna start drawing more Amps when I get him back on his feet and the single battery was going to be a bit over stretched.
I'll snap some pictures using a different camera in the meantime and upload those soon.
A rolling wheel gathers Odometry Ticks
Sunday, August 13, 2006
Managed to complete the test rig for the Odometry stuff this weekend and with a bit more tinkering and time to get my thinking cap on for the software, I should be in business for some proper controlled locomotion.
The Spoked wheels are available on the Internet, but I couldn't find anywhere in the UK that sells them, so ended up making my own. Using Photoshop, it wasn't too difficult and I'll make these PSDs available for download in the M.U.P.P.E.T section of the website when I get around to it. The Spoked wheels were made from the thin plastic from a DVD case, which was easy to cut but flexible and strong. Am sure they could be made from dozens of other materials, but these should do for now.
I'll be uploading some pictures of the test rig, which was made using a small 12v geared motor (similar to those used in the Line Following Robot) used to turn the Spoked Wheel, and an Osciliscope to see the wave form output from the circuit. Some simple pulse counting software on the PIC microcontroller and an LCD allowed me to see the number of "Ticks" and the RPMs. Doing some quick math on the scope, the number of pulses and the time between pulses accuratly measured the RPMs of the rig at 123.75 RPMs. My motors on M.U.P.P.E.T are rated to 120 RPM, so this should be more than OK to keep track of it.
I've just got to take a look at the formula for calculating PWM speeds based on actual and required RPMs, and then hope I can get M.U.P.P.E.T travelling in a straight line (for a start) and then be able to plot an accurate course around the garden using measured distances etc.
And in the Yellow corner ..
Monday, August 07, 2006
... weighing in at a cool 20Kg it's M.U.P.P.E.T!!!!
That's right he currently weighs about 20Kg, with a fairly minimal set of batteries and the temporary MDF chassis. The motors handle the weight with no problems and the new H-Bridge controllers can now handle the current needed by the said motors.
The new H-Bridges now share a common circuit board design, where as before they each had their own design which were pretty similar, but weren't interchangable.
Now, there are just a couple of connectors which can be added or removed as necessary, but only one PCB design is required. Makes things a bit simpler (and means I can have a spare board on standby which will work with either damaged board).
I've also mounted the new H-Bridges in a decent Aluminium box at the rear of the chassis, which gives better access when needed, and also means all the power distribution (for the locomotion) is handled in one box.
Next on my list is some Odometry, so that we can drive in a straight line, or work out how far we've travelled etc etc. I've already built a prototype board for the electronics, and am now writing some PIC code to do some basic Odometry calculations.
I'll post more details of this as I do it. Just got a bit of engineering to sort out now, for connecting the Opto-Interruptors and Slotted Encoder Disks to the drive shafts and making it reliable.
More to come ...
Feel the Burn
Sunday, July 23, 2006
Well the second test was pretty successful. Programmed the PIC with some directional changes to make sure that M.U.P.P.E.T turns OK and he/she appears to work fine.
I tried doing a 360° turn on the spot, but tried it on grass to start with which was a little to hard for it (and I was only giving it about 10% power to be safe). Decided that a sheet of Ply would be a good platform for the test, and 360° donuts worked a treat! Should have taken some photos, but was too excited watching it burn rubber that I forgot :) ... next time!
After a few tweaks to the speed/power parameters I got it turning at a pretty good speed, fast enough for manoeuvring when it's working normally. One thing I noticed was that the tires I'm using provide plenty of traction and was worried that too much friction was gonna stretch the H-Bridges to their limits.
No sooner thought than done! I reduced the "run-up" time (time from zero power to 40% power) and did another test on the ply ... everything died!!
Turns out that the MOSFETs were ok, but the PCB I'd designed wasn't up to handling the current both motors were drawing. Bit of a design flaw really, and when I look at it now it's obvious. I've patched it up and it's working again now, but I'll need to make a V2.0 board for the next build so that it can handle more current. I've designed the H-Bridges so that their on separate boards, so I don't have to redo the whole thing if one decides to burn out!! Only problem was that I had a single connection to the battery and a track on the PCB was supplying all the power to both boards, hence the melted track and burned PCB.
Take a look in the Gallery for a couple of pictures of the burnt PCB.
M.U.P.P.E.T Is mobile
Thursday, July 20, 2006
Finally he/she (gender undecided as yet) moves!!!
Good news all round, the new motors, wheels, bearings, motor control circuits and H-Bridges all performed perfectly yesterday during my first mobile test.
Was a little worried that the new H-Bridges would overheat in this temperature (was 34°C outside!) but they performed beautifully and didn't get more than lukewarm. The new MOSFET H-Bridges are now rated to 30A on each channel and as the motors draw 18A at stall, we should be fine.
I put a quick test program together on the PIC controller and used up to a 50% Duty Cycle (half power) which moved M.U.P.P.E.T easily at walking pace. Haven't got the room for a full power test, but suspect it would move at a jog if it were allowed to. Can't imagine it would be going that fast for a while, as it's gonna be enough work controlling it at slow speeds let alone jogging speeds!
I need to work on the frequency of the PWM signal now as it's audible when low speeds are used, I've got it in the 3kHz range at the moment, so will tinker with that next time.
I'm also going to get some pictures and video sorted for the site, now that my camera is working again. It decided to corrupt all the existing data on the internal disk a few days ago, so lost some of the recent images of the Solar Panel too :(
The next thing to try will be some directional changes, gotta see how well it deals with turning as this will add a load of force to all the aforementioned bits and give the H-Bridges some work to do.
Until next time. Same BeakZ time, same BeakZ channel....
Hot Hot Sun
Wednesday, July 05, 2006
Well it's been a scorcher here for the last couple of weeks, the old Aircon is getting a good work out.
Making the most of the hot weather I've been spending some time working on a Solar Water heater for my inlaws-to-be. You can see some details about it in the Other Projects section.
I've also been working on some new motor controllers for M.U.P.P.E.T, and should have those sorted in the next week. It's a busy time :S
We've also just purchased an iRobot robotic vacuum cleaner, which is fantastic. You can see some pictures of "Bob" at work in the Gallery. Check out the iRobot Corps website for more details.
Back soon ...
It's been a while
Tuesday, June 06, 2006
Hi all,
Sorry I've been a little busy of late working and building other projects, so have not spent as much time on my Robotics as I would have liked.
I am currently working on updates to the site to include details about the other projects I'm working on. Take a look in the Projects menu for the Solar Water Heating Panels that I'm building as a trial for my in-laws to be.
Also, if you have a robot of your own that you would like to show off to hundreds of visitors a month, please feel free to add it to the Robot Showcase.
I'll update the Blog as I have more content available.
Talking the Torque
Tuesday, April 25, 2006
Well my first mistake is well and truly under my belt. The two motors I obtained a while ago, before starting M.U.P.P.E.T are ... well ... weedy to say the least. I think I got my figures wrong when I came to work out how much power/torque they would give my robot.
When I say "think" I mean "I Know" I got it wrong. Anyway, calculator in hand I worked out what I really needed and found a supplier that sells motors that are used in mobility products. In this case 2 12V 120RPM 150W motors with enough grunt to move a horse!
My existing chassis still works, and I've only had to remake the mountings for the motors and gearboxes. The batteries I am using, were in series (for 24v) so I can now use them in Parallel to give me more Amp-Hours at 12V, so no great loss there. My speed controllers will work at 12V as well as 24V so that's fine too.
I've sucessfully installed one of the motors and made the connecting driveshaft and, being the impatient person I am, given it a quick try. Works quite well on three wheels too!
Now all I need to do is make the other motor connecting driveshaft, put the idler wheels in properly and connect the driven and idler wheels with the belt pulley and we are in business.
More to come ...
It's Alive!!!
Monday, April 10, 2006
After a very enjoyable day Snowboarding (no broken bones, just bruses) and a couple of days to recover, I've got back to M.U.P.P.E.T. Take a look in the Random Stuff gallery (towards the end) for a couple of photos of Snowboarding (if you're interested).
I managed to make some progress at the weekend and now have something which looks more like a base for a Robot than a pile of odds and ends.
Decided that the easiest way to prototype the chassis was to use the Aluminium L-Shaped bar I aquired and use MDF to make the mounting points for the bearing mounts and the base. This was easier as it saved messing up lots of aluminium whilst I got the exact positioning of the mounts correct. Once it's all working I'll replace this with Aluminium to reduce the weight and make the panels a bit thiner (the MDF is a little fat in places and could do with being 2-3mm rather than 9mm).
The motor mounting ended up being two bits of L-Shape aluminium bar bolted to the front of the motors, which is easy to move around between the top and bottom rails of the frame.
I've got the pulleys and drive belts on order so they should be here mid-week sometime. Once I've got these I can start positioning the motors more accurately. I've done some math and got them in about the right place, for the correct pulley size and belt length, but I know it's gonna need "Tweeking".
The robot is about 600mm long by 300mm (without wheels) wide. Big enough to manhandle the batteries and electronics, small enough to be able to move it around without needing a crane.
Have a look in the Gallery at the M.U.P.P.E.T library for the latest images of the constructed base.
Wheels Wheels Wheels
Monday, April 03, 2006
Well been tinkering again! Have ordered the aluminium framework for the chassis of the robot, so in the meantime I've been completing the wheel hubs which I started a while ago.
I'll post some pictures tomorrow maybe, and I'll update the M.U.P.P.E.T progress pages with details of the hubs and how they've been constructed. Been a productive evening and I hope that in a few days I'll be able to get started on the chassis.
Also off to learn how to Snowboard on Wednesday so fingers crossed no broken bones! Will post some pictures of the days events if I have time to take any pictures.
The Robot Man Cometh
Monday, March 20, 2006
Have started drawing up some ideas for what's required for M.U.P.P.E.T ... finally!
I tend to work this way, brainstorm, come up with loads of ideas no matter how good or bad and then work on the ones which I think I can actually achieve.
Here's what I thought:
Drive Systems
o H-Bridge Controllers (Already built)
o Motion Control circuits
o Loopback Speed/Distance Odometry
Sensor Inputs
o Ultrasonic Proximity
o Ambiant light level measurement
o Video input/processing (a bit ambitious for now)
o Digital Compass for navigation
o Internal/External Temperature
o Digital Tilt Sensor
Output
o Serial Telemetry
o Radio Telemetry
o Audio Systems (for alerts etc)
o Visual interface, LCD Display, LED Indicators
As I said it's just a start. Got lots of things buzzing in my head at the moment, so will hopefully get some more down on paper soon and get it up here.
Welcome to the new look BeakZ.NET
Sunday, March 19, 2006
Well it finally happened, I got my arse into gear and started work on the next incarnation of the BeakZ.NET website. Hope you like it!
It's gonna be full of my development notes for building robots, photos, stories and plenty of random stuff along the way.
The site is a complete rewrite using dotNET and is also a place where I'll be playing with some of the new web technologies (if I get round to it!).
Check out the gallery as I've uploaded a load of stuff into there already. The Robotics section might be of interest for those who like robots and maybe even for those who don't but fancy a peak anyway.
Have fun and look around.
BeakZ
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