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woofy

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Posts posted by woofy

  1. Hmm! curious device, it has a light shining on a 128x1 pixel array with the amount obscured by the filament indicating the width, but I'm not quite seeing how it works.

    Does that work with translucent filaments?

    Also, what happens if cross sectional area is consistent but it comes to an oval shaped section? Presumably it will increase or decrease the flow depending on its orientation.

    Does the modified Marlin also track the distance from the sensor to the nozzle and, with the filament speed, calculate when in the future to vary the feed rate to compensate for the width change?

    Personally I never change the filament width. I'd rather get good quality filament in the first place.

     

  2. gr5,

    It's not painter's tape, its Kapton tape. It was Super Grover that mentioned painter's tape. I dip a rag into Acetone and wipe it on an old failed ABS fragment to bring a little ABS onto the rag. The Kapton surface is wiped with that and it puts a fine ABS film onto the Kapton (but make sure you do it cold). It sticks like s**t to a blanket when hot and releases reasonably well when cold. The bed is heated to 110c before printing.

    I know that direct to glass printing is possible but there have been a few people on the forum mention the glass surface chipping, so I felt the Kapton would also spread and stress forces on the glass and protect it.

    I didn't use a raft. That's brim and support your're looking at in the pic.

     

  3. I think journalists just want something moving for the camera. Look at

    of the TCT show. At 1.05 you can see a nice example of air printing. Presumably the HEPA filter works by inhibiting filament flow :rolleyes:

     

  4. Didier, I was thinking the same thing last night. I was at the TCT show yesterday and spent some time on the E3D stand, Their V6 hotend looks interesting. The default uses a 12v heater and the UM2 24v. They can supply a 24v heater but its 40w against UM2 25w. Its only another 625mA, I would hope the UM2 power supply could cope with that.

    They use a thermister for temperature sensing, the UM2 uses a PT100. Farnell sells a http://uk.farnell.com/ist-innovative-sensor-technology/p0k1-161-6w-b-010/sensor-pt100-600-c-class-b/dp/1266922 that looks as if it could be clipped to the block.

    Then there is the mechanics of fitting it. There are some designs on thingiverse, I'm not sure if any of them are suitable for the UM2.

     

  5. They have a lot of very interesting technology there. My first reaction to the locked in filament was a way to rip-em-off!

    However looking at their spool prices its not too bad at 41.50/kg compared to the 49.71/kg I pay for OEM filament for my UP printer.

    Its way more that the 27.27/kg I pay Faberdashery for my UM filament though. (All prices are GB pounds).

     

  6. Take off weight is 0.8 kg. I have no idea what the flight time will be with 1300mah. There might be space for two batteries with a few changes but its quite cosy in there. I will continue using it as a practice machine.

    I have a better https://www.hobbyking.com/hobbyking/store/__56052__HKPilot_Mega_2_7_Flight_Controller_USB_GYRO_ACC_MAG_BARO.html on order. I think I will eventually need a better radio as there are not enough switch options on the one I have for mode selection on the new controller.

     

  7. I decided to have a go at building the waterproof quad I illustrated earlier.

    These are the parts I ordered for it:

    Hobby King 2.4Ghz 6Ch Tx & Rx V2 (Mode 2)

    Thunder QQ Super - Multi-Rotor Flight Controller

    Multistar 2212 - 920KV Multi-Rotor Motor Set w/CW and CCW Threaded Shafts (4pcs/box)

    MultiStar 10-4.5 (CW Rotation) Multi-Rotor Prop slot (DJI) Style Hub (pack of two)

    MultiStar 10-4.5 (CCW Rotation) Multi-Rotor Prop slot (DJI) Style Hub (Pack of Two)

    Afro Slim 20Amp Multi-rotor Motor Speed Controller (SimonK Firmware)

    Turnigy nano-tech 1300mAh 3S 45~90C Lipo Pack

    This turned out to be a bit of a poor choice. Firstly the motors are fitted with 3.5mm bullet connectors and the ESC's has 2mm bullets. Next the ESC's did not have a built in UBEC so I had to order:

    2mm Gold Connectors 10 pairs (20pc)

    Turnigy 5A (8-40v) SBEC for Lipo

     

     

    Finally built I was ready for my maiden flight, this lasted for about 6 seconds. I gently lifted of about 0.5 meter and the quad began to drift towards a brick wall. I mover the rudder to correct and guess what?

    The rudder on the Tx is reversed and I accelerated into the wall - crash. I released the throttle and it fell to the concrete - crash. Poor thing has two broken legs. I now have a programming lead on order for the Tx.

    After a repair I was ready to try again. The next flight was much longer - around 10 seconds. I had decided to take it onto the back lawn. It took off and again started drifting but this time I was ready and corrected it. However it then started to drift down again so I gave it a bit more throttle. My finger slipped and it powered upwards - and I mean really powered upwards. Phenomenal acceleration. It hit a high branch of an apple tree and flipped over. I released the throttle in a panic and - crash. This time with much more damage, broken legs, arm and back. Also damaged a prop. It's now grounded until I can get more props.

    quad5.jpg

    I'm down, but not out :)

     

  8. Why would be there a performance loss?

     

    Because if you define it as a variable, it is stored in memory. The processor has to go and fetch that value before it can use it. That's another instruction cycle which takes time. Not much extra time, but in critical code - it matters.

    When it is a #define, the value is known at compile time. The compiler can build the value into the instruction so it does not need a separate fetch cycle.

     

  9. @SanderG

    That was my first thought and I looked at a screwed together shell, this is the original arm:

    quad3.jpg

    quad4.jpg

    This has to be designed to be 3D printed, so the narrow end studs have additional support. We need 28 screws and studs which adds up to a fair bit of extra weight. According to Cura the cost of the glued design is about GBP9.78 using Faberdashery clear (uses 410g including brim and all support) . I think that's pretty good against a ready made shell such as this one which costs $119 and is also effectively a one piece design.

    Also I think the design is likely to be fairly fluid. If it does get damaged there are likely to be additions or changes I want to make anyway, so I'd print an updated shell.

    What do people think, glued or screwed?

    @Conz

    Yes, that's exactly what I want to do, have a waterproof quad that can land on water and dip a camera underwater. I don't want to fly in the rain. Ultimately I'd like to be able to move the quad around gently without using the flight prop's.

    Biggest problem is that I don't own a quad and have never flown one, so I'm coming at this very raw indeed.

     

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