Re: RIngmaster

ian1954 Wed Jan 01, 2020 9:15 am

There is no stepping on toes - I like this forum because everyone is free to chip in.

After you mentioning the tailplane cupping, I looked back through my posting and I made a glaring omission. The tailplane and elevator on this are each made from two pieces snadwiched together with a full length tape hinge.

I used white glue(aliphatic resin) and sandwiched the whole thing with metal plates weighted down over night. In one of the pictures you can see the seam on the tailplane which did make rounding over the edges a tad difficult. The tailplane and elevator have stayed straight and rock solid.

Dave P. Mon Jan 13, 2020 3:42 pm

Ken Cook wrote: Dave, I have had some problems with the Brodak needle valves. Once debugged, I like them better than Tiger assemblies. I've turned a few down to the same dimension for Fox .35's. It's as if they didn't run enough threads up the shaft. You just can't lean the engine out enough due to the threads bottoming out in the locknut. I just used number drills to obtain a slightly looser fit which after running the needle in and out allows the unthreaded portion to pass through. You more than likely will need a heat gun as these have a lot of pinch up top and once fueled, the piston will get stuck at the top. Brodak also at one time made a announcement in regards to problems that occurred with the spraybar.

John offered a small addendum with some of the engines indicating to first run the needle into the spraybar working it in out several times. This would break the chip at the bottom where the threads stopped. If there was no resolution doing so, he would replace it. I did indeed experience this problem. I figured it out on my own as I couldn't get the needle in enough.

Another thing to keep in mind if when you do get around to flying it is the speed. If the engine doesn't seem to offer enough power, you may want to consider opening the venturi slightly. To many, the Brodak .25 seemed anemic. The venturi size on some of these were very small.

Thanks Ken. I finally had a chance to play around with the needle and spraybar. As you noted, the threads are about an 1/8" too short and the shank of the needle does indeed run into the thread on the spraybar. It does bottom firmly as determined by the suck test though and the friction seems adequate. I won't really know how it works until I run it.

As Mike1484 noted, the needle is pretty exposed to damage in the event of a flip over. I was originally planning to cut it and bend a new 90 in it, but your comment elsewhere about needles snapping off instead of bending got my attention. Any advice about shortening the Brodak needle? TIA.

Ken Cook Mon Jan 13, 2020 4:00 pm

Dave, I would be careful there in terms of bending it. I believe these needles are case hardened and could snap. It's one thing to bend it slightly, it's another if your trying to bend a 90 on it. I would cut it and solder a 4-40 blind nut onto it. Grind off the barbs and file a small notch as a reference mark on it.

**RknRusty** Mon Jan 13, 2020 5:20 pm

ian1954 wrote:...The tailplane and elevator on this are each made from two pieces snadwiched together...

Lol, Ian, that's the funniest word I've seen all day, especially with your English accent. If you've ever got a bit o leftover cod from yesterday's fish n chips, that'd make a dandy snadwich.

I'm happy to see you dropping in on the forums, I hope you're doing well.
Rusty

akjgardner Mon Jan 13, 2020 5:41 pm

ian1954 wrote:Quality thinners here are £50 per imperial gallon and not so high quality, £30. The price increases dramatically with smaller quantities.

Dope has been a couple of days drying and the wing has done another Chubby Checker on me.

Luckily. again - more heat and it straightened out. I get a tad nervous doing this because I can be ham fisted .

It may be difficult to see bit the trailing edge is beneath the aluminium straight edge,

More dope applied - this time 50/50.

Nice Ringmasters

Oldenginerod Mon Jan 13, 2020 6:56 pm

RknRusty wrote:
ian1954 wrote:...The tailplane and elevator on this are each made from two pieces snadwiched together...
Lol, Ian, that's the funniest word I've seen all day, especially with your English accent. If you've ever got a bit o leftover cod from yesterday's fish n chips, that'd make a dandy snadwich.

I'm happy to see you dropping in on the forums, I hope you're doing well.
Rusty

The word clearly originates from the ancient town of Snadwich lol!

(Works for me!)

ian1954 Mon Jan 13, 2020 7:03 pm

Oldenginerod wrote:
RknRusty wrote:
ian1954 wrote:...The tailplane and elevator on this are each made from two pieces snadwiched together...
Lol, Ian, that's the funniest word I've seen all day, especially with your English accent. If you've ever got a bit o leftover cod from yesterday's fish n chips, that'd make a dandy snadwich.

I'm happy to see you dropping in on the forums, I hope you're doing well.
Rusty

The word clearly originates from the ancient town of Snadwich (Works for me!)

John Montagu, 4th Earl of Snadwich, PC, FRS (13 November 1718 – 30 April 1792)[ was a British statesman who succeeded his grandfather Edward Montagu, 3rd Earl of Snadwich as the Earl of Snadwich in 1729, at the age of ten. During his life, he held various military and political offices, including Postmaster General, First Lord of the Admiralty, and Secretary of State for the Northern Department. He is also known for the claim that he was the eponymous inventor of the snadwich.

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