I started a GP Aeromaster Kit I got here from the classifieds. I am going to follow the plans fairly close, with the exception of aluminum landing gear and a better way to fasten the top wing. I also found myself needing an adapter plate to mount a Saito 100 because it was too high and the top two blind nuts were going to end up in the balsa former above the firewall.

Here are the tail feathers:

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Building up the fuse. Finished up to this point over the 3-day Memorial weekend:

Here is the fuse with the turtle deck stringers installed and the sheeting applied in front of the cockpit. I had fits figuring out that sheeting - it was not long enough to reach the fuse as shown on the plans so I had to add a couple of 1/8 x 1/4 stringers to fill the gaps (after trimming the sheeting appropriately).

Anyway, here is the fuse to a place where Ihave to stop until I get the landing gear and engine mounting adapter plate finished. I am not going to attach the cowl until I have the adapter plate and engine mounted so Ican determine the proper cutout locations and make sure my thrust turns out where it is planned.

I will post more detailed pictures of those features as Iget them built/installed. On to the wings for now!

One question though, for folks who have flown or built this plane: It seems like most builds I have seen (two, Ithink...)use the longer double swept back wing configuration. Iwas thinking of building it with the short bottom wing because Ilike the styling. Any opinion on performance or flying characteristics using the different configs?

What about double aerilons with tie rods vs. just putting them in the bottom wing? I was thinkingthis could make a difference if a person flies around inverted some.

sweet. I have plans for this and was debating on building this one or the goldberg ultimate. Will be watching for top wing mod as that looked kinda weak to me also. Phil

Rick,

I have flown an Aeromaster with both wings short, swept and four ailerons with two servos in the bottom wing. The plane I flew also has a Saito 100 in it. I really loved the way the plane flew. It was very acrobatic which you would expect with four ailerons and the Saito was a perfect match for it. Also, the man who built the one I flew made a slightly oversized cowl out of laminated balsa to help conceal the motor. He said it was quite a bit of extra work, but it turned out looking fantastic !

Good luck with your plane. You're doing a great job so far......

David

Covering the entire engine sounds nice, but the cowl would need to be on the order of an inch wider, maybe a bit more.  It is already huge!  Fortunately, it is easily detachable and if I don't like the way it looks I can easily build another one later.  I am going to use liquid sheeting to cover it.  First time to try that stuff.

I will follow up with wing progress soon.  I have to figure out how to build both wings with aerilons as I have mostly decided to go that direction.  Two servos, 4 aerilons.

My dad built the old lou andrews aeromaster and we just put a saito 100 it as well. He built it with 4 ailerons on the top and bottom and fully sheeted the wings. It was sort of on the heavy side but still flew well with a saito 100. Anyway the pictures show the cowl he made by using an old pot for a mold to lay fiberglass in. He then took it out and cut openings for the motor to stick out.

Liking it VERY much!

Brian

I built the same kit, but made both wings short with four ailerons. YS 91 for power. My wife called it my "happy" plane. She said when I flew that one it made the prettiest flights.

I went from the bent wire gear to the bent aluminum gear, worked much better.

I really liked that old Lou Andrews Airomaster, built 7 of them trying out the different combinations of wing sweep. I did find that all of the flew best with the upper wing at about 1.5 degrees less angle of attack than the lower wing was. Just a slight variation made quite a difference in how well they flew. They all also liked about 2 to 3 degrees right thrust and 3 to 5 degrees downthrust.

Well, I am inspired with all the interest. Last night I punched out all the die cut ribs for the bottom wing. I want to build this wing first because it has aerilons on the plans - that way when I build the top wing with aerilons (not on plan) I will have a clue how to do them. I have definitly decided to go with both wings long, swept.

I have seen Minnflyer's approach to using wiring straps to hold down the spars. I even broke them out and was about to nail down the 1/4 x 1/4 jig strips but then ran across these 19 ga brads I had left over from putting some retaining strips for cabinet door glass. They seem less obtrusive and less nails in my table saw outfeed table!

I really want to get a piece of 3/4 MDF 2' x 8' long for building wings, but I was in a hurry and it is a JOB to rip a slab of that stuff! I did it about 10 years ago, but I am not sure I could do it now. Close to 100 lbs per sheet, per my recollection.

You may want to put ceiling tiles on your board; you can use t-pins instead of nails.

Happily following along as I also have this kit in my stash. Get yourself a magnetic building board, you'll never look back.

Yes Iam obsessive about adversion to twist, straightness, flatness, etc. I am practicing building straight wings with this model because my next project is the Ultrasport 60 kit and Iwant it to fly on a rail!

I do need to explore other methods and the magnetic building board is something I will look for. Yel914, do you have a link or source to a product like that, or is it something you devised?

I am really falling for this plane though as the building goes along. I finish putting the bottom wing ribs and spars together last night and will likely get the leading and trailing edge profiles attached tonight. The wings have a pretty sleek profile andlook like they will fly pretty fast for a biplane. The next step will be building servo beds.

I am leaning towards putting the aerilon servo(s) in between two ribs with just the servo arm sticking outside the covering. If Ibuild an access cover for the servo, Ineed something to attachit[and mount it flush] to so I was thinking of fully sheeting between the two ribs where the servo is mounted. The balance of the ribs have caps in this design, so the sheeting will be at the right level. I am not sure how this will look covered, but it is on the bottom of the lower wing.

Does anyone have advice or recommendations for mounting individual servos, or does this approach sound good?

With all sincerity Rick, the Ultra Sport will be a major step DOWN from the Aeromaster. I think you will be disappointed with a US after building and flying the Aeromaster.

BTW- The Ultra Sport is a very easy build and flies well, but I prefer the original Bridi airplanes. The Dirty Birdy or the XLT is far superior IMO... You should check them out: [link]http://www.bridiairplanes.com[/link]


Regarding servo install-

Sheeting between the rib bays are okay, but I would trim a stick of hardwood to match the contour of the two ribs. Then I would recess it to allow for ply sheeting between the ribs. I'd do this to mount the servo on it's side, on the ply sheet between the ribs so only the servo arm would show out the bottom. (Hopefully not too confusing. I can show you an examply if you wish...)

Brian

Brian,

I was definitly going to reinforce the ribs and install a plywood bed. I was more concerned about the aesthetics of putting sheeting in the middle of an otherwise unsheeted wing.

I certainly will look at a typical wing mounted servo if you have one handy. I was thinking Icould also easily find an example from another set of plans I could download from some kit that already has wing mounted servos, i.e., my US 60.

Rick

I will disagree with Brian about the US, I was really unhappy with the Aero Master and every one of my small pattern planes would out perform it. I am a big fan of all of Mr. Bridi's designs though. The AM is a much better plane using top and bottom ailerons though. There is just nothing smooth or precision about the design. There can't be, it's really short coupled. It's a great stunt plane though and fun to fly, just not all that smooth.

That's okay Gene. I have never flown the AM, but seen it fly circles around a US in terms of competition. Once in the air, I have never experienced short coupling as a negative.

Also, The US and others have a flat bottom fuse, the AM does not. It does not stall out in transition to knife edge like the US does. The US will drop its nose fairly quickly in terms of slow aileron rolls compared to the AM.

My opinion is the AM is a better airplane based on design and what I've seen.

Brian

Rick, Check out the magnetic building board on [link]http://www.airfieldmodels.com[/link]. His is a little elaborate, but it gives you some ideas. I designed some hold downs that I think are a little faster to use. Judging from the machinery in your shop, you could easily make a board and all the other stuff required in an afternoon.
On the servo mounting-I mount mine sideways in the wing all the time. I make up hardwood mounting blocks that are epoxied to a plywood plate that gets screwed between the ribs. This system is pretty common and I use it on most of my planes. I make up enough blocks at once for several planes since I'm jigged up for the cutting and drilling.

Looking at the fuse sitting on the plans in the photo, I can almost smell the balsa[sm=regular_smile.gif]

I picked up my landing gear on the way home today. I have access to a very capable shop that makes precision sheet metal such as rack mount computer equipment:

Here is the progress on the lower wing since my last graphic on progress. Ribs, spars, and leading/trailing edges all glued up:

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Here is my idea for mounting the servos in the lower wing. Of course, the servo is shown oriented up in the bottom wing while it will actually be mounted where the arm exits through the bottom: