Another DNA 20 Mod

[ecat]

Having had 2 out of 3 commercial VV units fail within 5 months of purchase I decided it was time to get hold of a hopefully more reliable DNA20 board and to make my own VW. A gripper design measuring about 64x80x25mm it's just big enough to include a micro USB charger, shown here with a sawn-off SparkFun but will take a dna board, and 3 Turnigy 1000mA Li-Pos.

Still work in progress, it's hopefully off to be anodised this week and since I was taking some photos...

... I thought I'd take the time to ask the all important question: Should the + and - buttons go on the spine, the front or the rear? Lol, I cannot decide and I'm so sick of polishing out little marks I decided the final choice can wait until after the anodising toughens up the surface.

The design file for this (.stl) should be compatible with most CNC software for milling or 3D printing and I'll make it available under an open-source non-commercial license once I know that everything does actually fit. If there's any interest I'll also investigate making a version available through Shapeways.

Apologies for the poor photography.

 

[Visus]

Pic #2 looks like the oscars trophy guy face
It would be sad to not see a flat chromed rotary dial up top there with master on/off in center lol hack innokin vtr styling
cellulose touch button on inner contour of paw grabber.
wow sharp
nice mod

 

[davidegee]

That's a thing of beauty! Looking forward to seeing the final pics

 

[rolf]

just finished ny first dna 20 ..after using other boards there is no comparison love the dna 20 ...everything on the readout is right there with out going throw all kinds of menues . and it fired up the first time .also love that it stays on for a while after .
nice mod you are doing . have fun .

 

[xpen]

Hey rolf, this ain't just another DNA20 mod.. It's a masterpiece! My hat off, sir ;-)

Personally I'd put the +/- buttons on the rear, close to the display, or even better some sort of dial (potentiometer).

Can't wait to see the final look of this..

 

[Jzaelke]

I think a dial that you could use with your index finger would be awesome.

 

[DrMA]

That's a great looking box. I'd love it if you could post it on Shapeways.

 

[ecat]

Thank you for the kind words and great suggestions.

My thoughts on the buttons so far:
On the spine (display) side I think it will be too easy to push them by mistake?

Front or rear face, a little ugly, especially as the buttons would have to be somewhere in the top 10mm. I did find these almost flat things Single membrane push button FT 01 SCHW. Without mechanical pressure point N/A 24 V 50 mA - Your order confirmation an interesting option if rebated into say the rear face.

On the gripper I again worry about accidental presses.

I love the idea of the rotating dial + push button combo at the top, something like these Panasonic AV462461J Super Miniature Switch30 Vdc 0.5 A IP40 - Your order confirmation make it quite easy to implement though they may not provide much in the way of tactile feedback.

The case is with the guy doing the anodising, I'll rig something up when it is returned and get a feel for the various placement options.

 

[bapgood]

Thank you for the kind words and great suggestions.

My thoughts on the buttons so far:
On the spine (display) side I think it will be too easy to push them by mistake?

Front or rear face, a little ugly, especially as the buttons would have to be somewhere in the top 10mm. I did find these almost flat things Single membrane push button FT 01 SCHW. Without mechanical pressure point N/A 24 V 50 mA - Your order confirmation an interesting option if rebated into say the rear face.

On the gripper I again worry about accidental presses.

I love the idea of the rotating dial + push button combo at the top, something like these Panasonic AV462461J Super Miniature Switch30 Vdc 0.5 A IP40 - Your order confirmation make it quite easy to implement though they may not provide much in the way of tactile feedback.

The case is with the guy doing the anodising, I'll rig something up when it is returned and get a feel for the various placement options.

The membrane switch looks interesting, however 5n is not very much. I like the clicky tactile switches with 200-300n for actuating force, not to firm but you know when its supposed to firing.

 

[Mike88]

That thing looks awesome! If you don't mind me asking where did you find the 510 base your using?

 

[ecat]

The membrane switch looks interesting, however 5n is not very much. I like the clicky tactile switches with 200-300n for actuating force, not to firm but you know when its supposed to firing.

Indeed. The higher actuating force also lessons the likelihood of accidental button pushes so a good solution all round. At the moment all options are open.

That thing looks awesome! If you don't mind me asking where did you find the 510 base your using?

Thank you.
All questions are welcome. The 510 base is a Tank Airflow Controller , cheap, looks good, nice size and easy to solder to after just a little work with a file.

 

[Rafto]

The design file for this (.stl) should be compatible with most CNC software for milling or 3D printing and I'll make it available under an open-source non-commercial license once I know that everything does actually fit. If there's any interest I'll also investigate making a version available through Shapeways.

That's the box I've been waiting for! I have DNA20 for a while, but didn't like any of available project boxes. Once you'll make available the design file, I'm going to find someone with CNC nearby and get my own gripper style mod done.

You've done some good work creating the design file. Thank you

 

[lauderdog]

This is absolutely gorgeous...I would buy it!

 

[ecat]

The guy doing the anodising sent me a link via his facebook site to the finished case...

... https://www.facebook.com/Customanodising.co.uk

They arrived here this morning and yes, he has done an absolutely wonderful job. The balls back in my court, I'll update with more pics and some progress hopefully

 

[ecat]

Just spent a day using the mod with the first test installation of all the bits. N.B. all wire routing and insulation is temporary at this time.

Looking promising if I do say so myself.
Now onto the +/- grrrrr

 

[retird]

Looking good........look forward to seeing completed......will be interesting to see the placement of the +.- and usb charging port....

 

[ecat]

The charging board is in. Bottom left of the battery, that red wire with the insulation tape loops right over the top of it

As for +/-, I may have something special up my sleeve...

 

[Rafto]

As for +/-, I may have something special up my sleeve...

I'm waiting impatiently to see what it is

Besides, where did you get the fire button?

 

[ecat]

The little silver fire button is from one of my dead tube mods, it looks sweet. Add a short length of plastic tube and a nice Omron tactile switch and Bob's you uncle.


Well, progress...

Yes it looks messy and I think it's going to be a tight fit but it works

The twiddly bit centre right is a switched rotary encoder: it clicks like a normal switch but it also rotates and generates a signal to say how far and which direction the rotation took place. So, click to fire, rotate clockwise to increase the Watts, counter clockwise to decrease the Watts.

Of course things are not quite so simple, the encoder will not interface directly with the DNA board. The little blob in the top right is a microcontroller, it decodes the rotation information and effectively pushes the buttons on the DNA.

The encoder above is this one https://www.sparkfun.com/products/9117 . You can buy quality ALPS and Bourns models for around the same price or less but I could only find one place with all the bits I needed so sparkfun it was. They are also available in smaller sizes, something I may need to investigate.

So the good news is no more holes, the bad news is it's back inside the case to modify the mounting bracket... And a knob, I'll need a nice click and twiddle knob, not too big, not too small and silver or black.

Edit:
Something like this http://uk.farnell.com/alps/ec111012010h/encoder-self-return-11mm/dp/2065018?Ntt=EC111012010H could be connected directly to the DNA, no need for the microcontroller even if it is a more expensive solution. I may get one sometime to try it out.

 

[ecat]

The little controller doesn't look quite so frightening when built on a proper board

as a bonus it also fits

I've written the software to keep the controller asleep for as much time as possible. A rotation wakes it up but to try to avoid accidental adjustment it ignores all movement for the first 2 seconds after which the Wattage changes in real time. If there is no movement for more than 20 seconds it goes back to sleep. Early usage suggests this works quite well though I'd still consider the simple self return switch I mentioned in my previous post as an easy to implement all in one solution.

KnobTreck: The Search for Switch Tops.
The click switch on the encoder has a very nice feel, not too hard, not too soft. At the moment I'm using it naked and apart from the look it's fine. The most appealing knob I've so far found is this: 505.613 - MENTOR - KNOB, ALUMINIUM, SETSCREW | Farnell United Kingdom , 12mm diameter sounds a good size and chopped down to around 6mm high could work.

Just about all done, I'll try to get the design I originally promised posted some time this week. Thank you all again for the feedback and support.