Aviatik 30.40

JohnFitz · 31 January 2009, 07:58 AM

Time to complete the l/g. The GTM struts are 1/4" too narrow so I am adding 1/64" ply fairings. I am using a 1/4" seamless stainless steal tube for my axle which will be JB Welded inside one of GTM's aluminum wing struts. The ends will be 9/32" brass tube which the wheels will ride on. A couple of washers and a cotter pin will hold it all together and keep the bungee in place.

Lucky Dog · 1 February 2009, 07:03 AM

Hi John,
Looking very nice!

A question though. I was wondering how you keep the brass tubing in place? Can you solder brass to stainless?

Thanks.

JohnFitz · 1 February 2009, 07:16 AM

Hi Mike, I will CA the brass to the stainless tube but there will be two cotter pins thru it as well. One will hold the wheel on before the wheel cover and the other will be outside with a washer so it looks like the full scale. I don't trust just using a washer and cotter pin on the outside of the styrene wheel cover to hold the wheel on. Hope you get the picture? I will post pictures when I get there.

The PIPE · 1 February 2009, 09:38 AM

Dear Mike Bealmear:

The PIPE here again...you were asking if it's possible to solder stainless steel to brass...well, I've done it with the "Stay-Brite" solder before, and hopefully you've seen those pre-packaged "Stay-Brite silver solder" blister packaged "solder kits" before, complete with a length of the special "silver solder", and a small squeeze bottle of the required "Stay-Clean" liquid zinc chloride solder flux packaged along with the solder...just as many RC modelers use for soldering music wire landing gears, after binding the pieces to be soldered with the usual bare copper wire wrapping...

...but DID you know you could get the "Stay-Clean" flux SEPARATELY, in a much larger volume bottle than the solder kit has in it, and use a special "silver-BEARING solder", that is essentially what the "silver solder" in the Stay-Brite "package deal" is, is ALSO available from plumber's supply vendors???

One website I've seen the larger, separately-available bottle of the Stay-Clean zinc chloride flux (about a 4 oz. bottle) available for something like $6.00 from one Ace Hardware store, just "on the Web" at J.W. HARRIS SCLF4 "STAY-CLEAN" LIQUID SOLDERING FLUX 4Oz. - 40002 .....

...and for the "plumber's solder", you would need to get the sort (or something VERY close to it) of 95% tin (abbreviated "Sn"), 5% silver (abbreviated "Ag") solder that's in the Stay-Brite kit, that IS also used for soldering copper plumbing lines meant for drinking water in people's homes, and therefore has NO LEAD (abbreviated "Pb") in it, to avoid contaminating drinkable water supplies. It's ALSO okay if the "SnAg" plumber's solder has either small percentages...say, a percent or two...of copper (abbreviated "Cu") OR bismuth (abbreviated "Bi") in the solder...these metals ARE also found in "plumber's solder" sometimes, and are ALSO non-toxic for drinking water lines in homes, and also would work well with the Stay-Clean, and also should allow easier soldering of stainless steel to brass.

I'm mostly mentioning this, because sometimes some of us RCers might have need for just what the Stay-Brite "silver bearing" solder kit DOES have in it, but either cannot easily get it from a local hobby shop, or might have need of a considerably larger quantity of what is in the Stay-Brite kit, but does not want to be bothered "cleaning out" a hobby shop's entire supply of the Stay-Brite soldering kits, and spending a lot more money than they had planned on doing.

Hope this helps...I've not yet had need for getting larger quanties of the unleaded "silver bearing" solder in the Stay-Brite kit as yet, but I wished I DID have places that I could get more of the Stay-Clean liquid zinc chloride FLUX, as I've run out of it in the past before from the kit's smaller bottles...

...hope this tip helps you out!

Yours Sincerely,

The PIPE!!!

JohnFitz · 6 February 2009, 12:44 PM

Ran the cable guide tubes and finishing up the l/g. Wanted to see how she looks off the bench. I am also working on getting all the instruments sized correctly.

JohnFitz · 9 February 2009, 08:13 AM

Next task I will tackle is making the instrument panel. Thanks to Koloman Mayerhofer for the full scale drawings and photo's as well as sharing his expertise. I also can't thank Henri Kaper enough over at RCSB for resizing and printing everything out for me. Henri lives in the Netherlands and has been very kind to lend his skill and expertise. If anyone would like a copy of these re-sized instruments just let me or Henri know and we'll do our best to share them.

JohnFitz · 19 February 2009, 07:15 PM

I am starting to work on the wing. You can see that the spars for these ribs are wider apart than the drawing and that's because I am using ribs that ere originally made for the Pfalz D. XII and Bob Holman cut these for me. I had to modify them a little but they are now close to the Aviatik rib shape. I didn't have any way to duplicate the Aviatik wing ribs and this is good enough for me. The leading edge will be carbon arrow shaft as I feel it makes the strongest, straightest and lite leading edge. The spars are bass wood 1/4"x1/2" and I will web them with 1/8" ply. Oh, I will build the wing as one piece but one half at a time since it is longer than my building table.

JohnFitz · 26 February 2009, 06:12 PM

Just putting the finishing touch on the wheels and tires. It is obvious that the tires were not black so this is what I did and what I used. Glued the tires on with the Loctite that stays flexible.

womenfly2 · 27 February 2009, 05:04 AM

Great idea John, how well does the vinyl paint adhere to the rubber tire?

Glad to see you post on the project again, missed it. How is the wing coming along.

Cheers,
WF2

JohnFitz · 27 February 2009, 05:58 AM

Thanks WF2, It's not really my idea. I have read that other people have done it with good success. This product seems to have worked very well. Should not be much wear flying off grass and dirt and it should be easy to touch up if necessary. I'll be working on the wing again today. Want to get all the webs cut and glued in and the leading edge done. Need to buy a couple of more carbon arrow shafts. Haven't decided how to build the ailerons yet with the washout. Stay tuned.