Author Archives: James

YOLOv8

I have been playing with Yolov8 for about 3 weeks now, I have been curating a British number plate tracking dataset. Using videos from youtube I trained a basic model and used this to help me label subsequent datasets. This takes the pain out of labeling every image manually. I have been using labelImg, anylabeling, and python scripts to extract the annotation section and view plates and perfect the dataset. This is the result so far which I am surprised how accurate it is. I have had to use a small batch size of 3 because I am training on 4k resolution images using a rtx3090.

as you can see above it still makes errors however, this was when I turned the confidence down to 0.02 to allow for more training data labels to be created, I then manually delete the false positives predictions by hand, which are not to numerous. This is easier than during the box labels.

Here is the result of training a segmentation model yolov8n.pt on the data set that I have. For most characters I am getting good recognition results. in the 60% yo 70% except for letters that have ambiguity like B and 8 and D and 0 as these are very alike. I have about 10 of each letter in the training data. I will see what results I get by adding more examples.

Jasmine’s makes it 1 kilometer raising money for Macmillan

Jasmine completed the 0.5 kilometer trail twice round as the Thameside Nature Discovery Park https://www.essexwt.org.uk/nature-reserves/thameside on the 10th of September. We are very proud of Jasmine, I’ll be honest I did not think she would make it twice round the trail, given the heat today. We also tried to raise funds for charity and the sum exceeded all our expectations. I also believe she could be the youngest to complete this event at 14 months, she only started walking about 2 and half months ago, Amazing. https://www.justgiving.com/page/jasmines1ktoddle?fbclid=IwAR2_LAmDn3JwtfXu24xNXBse71VPTFvzpL6p1huEDLAExgXZdbZnl3Mwr60 So Lucy and I would like to thank all those who supported her.

Jasmine receiving her medal.

Jasmine Cordell

Jasmine Cordell 1 Day old

Lucy gave birth to Jasmine on Friday the 8th at 7:20am. She went into strong labor at 5:00am. I called the hospital and described the situation, they asked to speak to Lucy but holding a phone call was a stretch too far at the moment. We quickly got in the car and made our way to Basildon hospital with very little traffic. It was a beautiful sunny morning when I stuffed the car diagonally across the disabled area (sorry) but no one else was there 🙂

Lucy’s water broke as she literally got out the car and we made out way to the maternity unit. After knocking on various doors and walking, what seemed like lengthy corridors, we were ushered in by the nursing staff. Lucy was monitored for 30 minutes where we could also hear the relief of that heart beat, which was at 160bpm at that point then dropping to 140bpm. The first midwife was Jepu Lungie whom was part of the night staff. She handed over to Rebekah who was there until the birth. After the initial 30 minute observation Lucy was given NO2 (Nitrogen oxide, gas and air). This relieved the contractions that were coming. Then, after what seemed like no time, Lucy was told to start pushing. Fifteen minutes later Jasmine was born.

Lucy and I would like to give a massive thank you to every one who has sent cards and gifts, we are very grateful and appreciate the support.

Ford car 6000cd radio hack

Have you ever wanted to just plug your phone / audio device straight into a car radio. Here are the details to connect a 2.5mm audio jack or Bluetooth receiver into a standard car radio. The car is a Ford focus 2003 the radio model is a 6000cd. The pictures below show the solder points. there are 4 points that represent each speaker. So if you had a quadraphonic input source you could have it control each speaker individually. However, I am using a stereo Bluetooth output device so I paired red and white and black and red (thicker) together.

There are 4 connectors solder point inside the radio that will amplify a standard line signal.

Viceroy Lathe details. T.D.S 1 S.C.L

Imperial gearing thread chart.
Metric gearing thread chart.

Here is a gearing program that runs on Linux (wine) or Windows that can be used to deduce other gear combinations. Note that the 127/100 compound gear is not used. This magical gear is what makes the lathe exactly metric. The lathe, like most, has an 8 TPI imperial lead screw. The 127/100 effectively allows the imperial lead screw to have a 100 metric divisions. This is because 1 inch is equal to 25.4 mm and therefore 50 inches is exactly 127 centimeters. Therefore, 254 / 2 is 127 and 127 is prime. Which means its not possible to get a smaller gear that will divide exactly.

lead screwinchesmmequivalent teeth
on theoretical
compound gear
8125.41016
41/212.7508

As you can see the table above lists theoretical gears with impractical numbers of teeth. This is made practical by another compound gear the 72 / 18 which is a ratio of a 1 / 4. 12.7mm / 508 is 0.25 which provides the metric basis to work with. The other gears provide ratios of on this.

This is a link to an online gear calculator.

http://bilar.co.uk/cgi-bin/change-gear-calculator.pl

Solar Evacuated Tube Collector (ETC) technology

Over the weekend we have almost perfect sun shine. So I collected some data on a 20 Tube solar collector. Here are the results.

Temp inTemp outdifference
33.637.64

The pump rate was at 6 liters per minute (0.1 liters second). So give this its possible to work out how much of the suns energy was being captured. We just need to know one more thing. The specific heat capacity of water. Which is 4.2 Kj / Kg / degree C. That is 4.2 kilo Jules per kilogram per degree C.

So the calculation turns out to be.

Total Energy per second = (Specific heat capacity of water) x (Liters per second) x (Temperature difference)

1.68 kW = 4.2 * 0.1 * 4

Microwave repair

It turns out that a microwave can be easily fixed. The symptoms are luke-warm food.

Here from the image above you can see the cracks in the magnets. These develop because the heating and cooling of them over time fatigue the fragile compound they are made from. I therefore, bought a new Magnetron (love that word) and plugged it in. It has now been working for over a year without issue.

Quad copter designed for flight longevity

The specification of the quad are as follows.

Battery
Load: 10.64 C Voltage: 14.28 V Rated Voltage: 14.80 V Energy: 62.16 Wh Total Capacity: 4200 mAh Used Capacity: 3570 mAh min. Flight Time: 4.8 min Mixed Flight Time: 16.9 min Hover Flight Time: 32.9 min Weight: 452 g   15.9 oz
 Motor @ Optimum Efficiency Current: 4.68 A Voltage: 14.55 V Revolutions*: 4886 rpm electric Power: 68.1 W mech. Power: 59.3 W Efficiency: 87.0 %  Motor @ Maximum Current: 11.18 A Voltage: 14.21 V Revolutions*: 4274 rpm electric Power: 158.9 W mech. Power: 129.1 W Power-Weight: 508.3 W/kg   230.6 W/lb Efficiency: 81.2 % est. Temperature: 43 °C   109 °F  
Wattmeter readings Current: 44.72 A Voltage: 14.28 V Power: 638.6 W
 Motor @ Hover Current: 1.63 A Voltage: 14.71 V Revolutions*: 2027 rpm Throttle (log): 26 % Throttle (linear): 44 % electric Power: 23.9 W mech. Power: 19.4 W Power-Weight: 77.1 W/kg   35 W/lb Efficiency: 81.2 % est. Temperature: 28 °C   82 °F specific Thrust: 13.05 g/W   0.46 oz/W  Total Drive Drive Weight: 1069 g   37.7 oz Thrust-Weight: 3.5 : 1 Current @ Hover: 6.51 A P(in) @ Hover: 96.3 W P(out) @ Hover: 77.8 W Efficiency @ Hover: 80.7 % Current @ max: 44.70 A P(in) @ max: 661.6 W P(out) @ max: 516.2 W Efficiency @ max: 78.0 %  Multicopter All-up Weight: 1250 g   44.1 oz add. Payload: 2541 g   89.6 oz max Tilt: 71 ° max. Speed: 40 km/h   24.8 mph est. rate of climb: 5.0 m/s   984 ft/min Total Disc Area: 58.58 dm² 907.99 in² with Rotor fail:

RCTimer motors 5010 motors 360

17″ Carbon fiber propellers blades.

Carbon fiber frame

Here is the eCalc link to an online calculator that can be used to approximate the build and estimate its flight capabilities.

https://www.ecalc.ch/xcoptercalc.php?ecalc&lang=en&cooling=good&rotornumber=4&config=flat&frame=750&tiltlimit=90&weight=850&calc=bat&elevation=500&airtemp=25&qnh=1013&batteries=lipo_10000mah_-_45/60c&chargestate=0&s=4&p=1&battdisc=0.85&esc=max_20a&motor=rctimer&type=54%7C5010-360&gear=1&propeller=0&pconst=1.13&tconst=0.88&proptwist=0&diameter=17&pitch=5.5&blades=2&project=JC%20quadRCtimer5010