Category Archives: Uncategorized

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. 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

Roland dg dxy-1300 firmware exploration

I have extracted the ROM images from the two 27C512 chips inside the DXY-1300. I then passed them though a disassembler. This produced the asm files respectively below.

RolandDG_R15209223_LH53140H_8949E is the more interesting because it contains z80 code that starts at 0100h.

The asm files have beep passed as all code. However they need to be separated into data and code. As there is HPGL data starting around E000h in the R15209223 file and likely numerous other sections. This HPGL is the test image that is drawn when the device is powered on holding down the enter key.

boot sequence log

The goal for me is to use my Z80 ICE debugger from Tauntek http://www.tauntek.com/Z80-In-Circuit-Emulator.htm to analyze the memory until its booted.

An objective is to change and find how the pen speed works. As I have a laser burner I want to mount on it.

0100h is the default place the z80 jumps to for execution and called the ORG. I also expect Ill be able to use the boot test image at location “000e0e0” to print out back engineering debug info.

RolandDG_R15179881_LH2357H9_8943B.asm

RolandDG_R15209223_LH53140H_8949E.asm

RolandDG_R15179881_LH2357H9_8943B.BIN

RolandDG_R15209223_LH53140H_8949E.BIN

I am waiting until I receive some new 27512 chips in the post as it appears the originals in the plotter are ROM or in some way not writable by my EEPROM programmer lt866cs.

here Is a simple analysis of the most used sub routine calls within the code. I believe it identifies the main execution loop.

FPV in stanford-le-hope

Hi

I woke early today to test video recording with the Raspberry pi. Using the camera module. Here is the video below. It is quite shaky but it was also a bit windy. I would have liked also to use a gimbal to position the camera. I intend to do this using the two extra channels on the transmitter.