After flying briefly (my first 3 short flights ever) holding the transmitter, and with a neck strap, I decided I didn't like that at all and made a tray to hold the transmitter.
If you look around the web you will find many styles of transmitter tray and it hard to know what make since one doesn't know yet what exactly is preferred. One of the locals uses a large lump of molded polystyrene that has aluminum strips for the vertical supports. I thought that would be a bit much for a quick build so I went simple. Just a flat plate with eye bolts sticking out. I didn't have thick plastic plate handy, so used some 3mm sheet with some strips added to stiffen it up (and I may add more). The vertical bars are M6 allthread rod joined to some eye bolts for the loops. I would gladly have just used long eyebolts but no-one here stocks such an item.
I made the length of the tray to suite my arms by holding my arm at a right angle, elbow comfortable next to me (not pushed back) and putting the tx on the raw sheet of plastic and marking where the handle would go. After that just mark around the tx, draw straight lines to cut to, then smooth the edges with a file or belt sander (don't let the plastic melt).
The piece that holds the tx in place was just a scrap of 6mm thick perspex. The hole is tapped M6 but you could embed a nut instead. The groove was made on the drill press. Clamp a plank to the table at the right distance, raise the table to get a 2 or 3mm deep cut with a single flute countersink bit, set the speed to 2000 rpm. Now slowly slide the part along the plank to cut the groove. If you want to, you can move the table up 1 or 2 mm and cut again to get a deeper groove. Just make sure it holds the tx handle securely.
The neck strap was harvested off my camera and sits absolutely perfectly, and since it has rubber thread on one side, does not slip at all.
In use I find I can just forget the tx and how it is supported, and concentrate on flying
After I took the photos I soldered a strip of brass into the groove in the bolthead to make it a wingnut. I then stuck some self stick weather stripping to the tray under the foot of the radio so it could no longer slide sideways.
I am rather gratified that this tray is so good that one of the local chaps immediately wanted to try it out. I had initially thought I'd made the clamp bolt way too long and was thinking of shortening it, however when we fitted his Futaba T12 we found that since it has a thick plastic handle, the bolt was only just long enough to hold it, so I think I will leave it so that others may borrow it.I'll need to drill a hole in it to allow buddy box working but other than that it is complete.
On 2 Nov 2009 I reworked the tray a little. I wanted to make it a bit stiffer since I thought the 3mm sheet may well take a bit too much strain from the upright bolts. I used some 6mm sheet to make 2 strips that replace the original edge strips. These ones are wide enough that the uprights bolt right through them. The whole is much stiffer now, but not much heavier, and works well.
The tx is held onto the tray by this simple hold-down device. The groove was made using a counter sink bit in the drill press. I clamped as strip of plywood to the table as a fence, and slid the plastic along that to create the groove (despite owning a router and router table for this sort of thing). The pen marks are from the planning stage and will eventually get cleaned off.
I ran the strips past the router with a 45 degree edging bit before mounting them. By moving slowly I got a nice frosted finish that I decided not to polish.
Pondering the problem if being able to carry less, or at least be able to carry it in one hand (so the other can carry something else, saving a trip to the car), when I go flying, I considered various ways of fitting the tx tray into a flight box. My current flight box is a cardboard apple box that takes two hands to carry, thus preventing carrying anything else at the same time even though it is not all that heavy. Any box that can take the tx tray is necessarily large, even if it does have a handle for single handed carrying
It came to me suddenly in the night, FOLD the arms!
So, I have spent a few hours in the workshop this week making hinges that allow the arms to fold down against the panel, yet can only fold up to 90 degrees and can take the weight of the tx plus my lazy arms resting on it.
Pix to follow after flight testing