Tarot T-2D Mounted to Rotorbits Hexa

There are a lot of brushless gimbals out there, and there are a few videos takITen by Rotorbits based multirotors out there that were obviously shot using a gimbal. I have yet to see a video where anyone actually showed HOW they got it mounted or what brushless gimbal was used. With all of the possibilties out there, I settled on a Tarot T-2D, and I would worry about the "how" once I had it in hand.

I spent most of the day today trying various shapes and sizes of composite plates, numerous lengths of nylon stand-offs and finally found a good combination. There were a few goals in mind. It had to be easy to swap out (nice to use one gimbal for multiple copters)

1. Mounted to the center of the copter rather than cantilevered 2. Easy to swap out (nice to use one gimbal for more than one copter!) 3. Sturdy and stable (can't have the camera plummeting to the ground) 4. Adjustable (in case I want to run with two battery packs for longer flights)

Using a combination of threaded nylon standoffs, carbon fiber arrow shafts, and composite pre-drilled plates, some double sided foam tape, screws, and threadlock here's what I came up with.

5.6mm x 25mm M3 threaded stand-off 5.6mm x 20mm M3 threaded spacer 5.6mm x 20mm M3 threaded stand-off

all adds up to 55mm when stacked together and female ends on each side.

a 7.5mm O.D. carbon fiber arrow shaft, approximately 5mm I.D. This will yield a tight fit, gently press the assembled nylon spacer into the shaft. This will strengthen the assembly.

4 - 40x40 mm square composite plates, 10mm on center holes 2.5mm dia. 40x40 mm composite - Available at HobbyKing

Using the standoffs/spacers, and carbon fiber shaft, create 4 rods. Then take two of the 40mm square plates and screw them into the the Tarot's mount, for this I used 2.5mm flat head screws and their companion nylon washer and a nylock nut.

I needed to enlarge the holes in the 40x40 plate from 2.5mm to 3mm to accommodate the screws for the tapped spacers.

Putting it together looks like this.

Now, let's check the alignment with the Rotorbits hex base. I'm running a + configuration rather than an X but it works either way. The flight battery will hang between the gimbal mount and the frame base, running perpendicular to the Tarot's mount plate.

Here is the mount, testing fit on the copter.

Some double-sided foam tape on the other two 40x40 plates. This will secure the plate to the Rotorbits frame base. I may drill a couple of holes through the plate to utilize the leg socket holes to secure the top plates more solidly. However, currently the booms are friction fit into the sockets as drilling through the carbon fiber booms weakens them due to splintering of the fibers on the inside. Though I've found that the Dremel attachment for engraving works quite well to "sand" a hole through rather than using a drill bit that uses a shearing/cutting action.

...and here's the final installation, of the gimbal, some cable management is still in order of course! :)

Samsung 204B Repair - Part 2

Update! I got all the parts in from Mouser yesterday and performed the repair. A word of advice: if you don't already have desoldering wick, get some! I figured my solder sucker would be adequate...what a piece of junk! I had to resort to the ol' heat and pull method.

Anyhow, the repair went well and the monitor is once again instant-on, bright and crisp. just like when I got it 5ish years ago :)

Time to repair: About 1 hour

Samsung 204B Repair

If you have one of these monitors and it's starting to lose brightness, or flicker, or maybe the power button light is blinking and there's no picture. The cause is likely some blown capacitors on the power board. Good news! You can fix this for less than 10 bones, if you're willing to take apart the monitor and wield a soldering iron for a few minutes.

*disclaimer - start* I cannot be held responsible if you electrocute yourself or break anything that wasn't broken before you begin. Unplug the monitor and leave it alone for a few hours (a day if you're paranoid) this will allow any built up energy to dissipate from the capacitors, there's one in there that's a doozy if it bites ya! *disclaimer - stop*

1. Take the monitor off the stand, there's two screws holding it on.

2. Tear down the monitor housing, this can be done with an expired credit card (you will fuck it up, so don't use a live one). Simply slip it between the seams of the black plastic covering of the monitor and slide it from end to end, you should hear clicking/snapping. Work with it for a few minutes and you should expose the juicy innards. Be careful not to rip or otherwise mutilate the ribbon cable running from the control board to the button array on the front of the monitor bezel.

3. Remove the shielding, there's four (4) screws one on each corner, and two black screws. Total of 6, take them out.

4. Gently pull the cover off.

5. You will now see a few more screws, 3 black and 1 fat silver one. Get your screw driver and drive! (them out)

6. Carefully disconnect all the cables you see from their boards. There are two of them, we're interested in the one with the power switch and electrical socket on it.

All the capacitors that I'll be replacing are marked in red.

In the full size image you can see the 3 caps at the lower edge of the picture are bulging. these are definitely bad. I could stop there and only spend about a dollar (before shipping) to fix it. But why stop there!

The board I have is marked as 204B-VE REV0.1

A list of the caps:

680uf 25v (2) 100uf 450v (1) 47uf 50v (1) 330uf 25v (1) 820uf 25v (2)

Mouser Electronics - Cart of items

Total cost of the caps + shipping < $12 (shipping's a mother...)

If you really want to get off cheap you can if your 450v cap looks good, that's about $4 by itself. The only caps of mine that appeared damaged were the 330uf and the 2 820uf. I went ahead and ordered replacements for all of them.

Part 2 coming soon!

Glass Board Writing Surface...DIY style

So let's say you want a stylish looking white board, there's everything out there from flimsy standard issue office supply store boards that stain, to high end porcelain boards that you'll have to shell out major bucks for one that's larger than a couple of feet. I was faced with this dilemma not too long ago, and being the creative sort of person I am, I decided to design my own.

What sort of surface material would I use, I thought.

Metal? - chrome plated would look snazzy, but too expensive and heavy.

Plastic? - too "low-end" looking, stains, scratches easily.

Glass? - non-porous, rigid, sexy, inexpensive. Oh yeah! glass it is!

So with my surface material locked in, the next piece of the puzzle was to determine how exactly to fix it to the wall. Several days of bewildered home improvement store workers and internet research later I had found it, sign standoffs. Conveniently located at http://www.signstandoffs.com/

I would be using what are called "through standoffs" ,aptly named, as they are designed to go through the material you are mounting.

All of this in retrospect, and to you the reader, may seem quite obvious. However there was a lot of research into the types of glass to use, edge distances, hole diameters, and surface stresses before just going ape and drilling holes in glass. This thing, after all, is going to be hanging on a wall and being used daily so this is not something you want breaking, it could chop your hands off...or worse :) Respect your building materials!

I happened to have a couple of glass companies near by, I'm sure you probably will too, check the phone book or the interwebs. The company I used mainly deals with table tops, windows, and picture frames. So when I said I wanted a 3 foot piece of glass with 4 holes drilled in it you can just imagine the conversation.

me: yeah, how much would it cost for a thirty-six by thirty-six inch sheet of glass with four holes drilled in the corners?

glass man: ...holes?

me: yeah...four of them. three quarter inches in diameter.

glass man: is it for a table top?

me: nope, it's going on the wall.

glass man: huh? why do you want to do that?

me: to use as a white-board ...made of glass.

glass man: ...never heard of that before...weird...hang on I'll get you a quote...

There were several such exchanges like this during the various points from ordering to dropping off sketches to picking up the glass. They thought I was out of my mind then, now they just ask how many I'll be making and what size :)

Glass:

  • 1/4" thick - don't go any thinner or you'll be sorry. You can go thicker to say 3/8" but remember: glass is fracking heavy! (about 3lbs per sq/ft for 1/4")
  • Annealed (think guillotine rather than beads). Why not tempered? There are additional constraints when dealing with tempered glass when you want to put holes in it, also, the edges are exposed and tempered glass is weakest on its edges.
  • Polished edges - the edges are exposed and blood is bad mkay

Standoffs:

  • at least 1" diameter, the length is up to you. Keep in mind the further from the wall, the less weight your anchors will hold. You'll need 4 to 8 depending on the width of your board

Anchors:

  • I like Toggler® SNAPToggles, they hold crazy amounts of weight (356 lbs in 5/8" drywall)

My first board was 36x36 and utilized 4 standoffs and looks quite nice. Total materials (glass, standoffs, anchors) about $130. That may seem a bit steep for a 3ft square board but it's totally non-porous it will never stain. You use any old dry erase marker and eraser, and if you have something you'd like to keep around without the fear of accidental erasure, bust out the sharpie permanent markers. Go ahead, it's alright, a quick blast of rubbing alcohol and it comes right off :) great for drawing grids and such!

The real cost savings comes when you go big. Total cost for an 96"x48" (8 feet by 4 feet) $250 in materials. Labor is another thing, you're going to need about 4 friends, 6 if your friends are scrawny weaklings to mount that beast, but what you're left with is nothing short of impressive.

To date I have designs for: 36x36, 48x36, 36x72, 48x72, 48x96

Several months later I found a site (wish I'd thought of the domain) http://www.glasswhiteboards.com That sells a slightly more fancy version of this with a white enamel painted magnetic back with tempered glass and edge standoffs (not as cool as through standoffs!) they are nice but their prices are also about 10 times higher than my DIY solution. Even if you go with a thicker glass and tempered you're still only about doubling the cost of mine, so about $500 for an 8 foot board.

I've attached the sketches, check them out, have fun! I welcome any and all comments of course :)

Here's a shot of the 8 foot behemoth!