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Building a 1/3rd Scale Piper Tri Pacer

At last all the inside stuff is now completed and I can finish covering the fuselage. I'm going to use natural colour Solartexand will cover the sides first followed by the top. I'll leave the bottom covering off until I have finally balanced the plane in case i've got to move batteries or add tail weight.

The fabric covering on the sides extends forward to a line just forward of the cabin where there is a transition to aluminium sheet which I hope to duplicate with fibreglass.

 

All done Solartex is lovely stuff to use and can make us all look good.

I'm going to glass the nose with 3/4 oz cloth which I'll hit with a coat of grey primer that I can sand down with wet and dry to give me the smooth finish that will look like the aluminium skin of the full size.

 

 

My technique with using 3/4 oz glass cloth has evolved over the years and one of the things I find absolutely essential is to have a set of sharp scissors and I mean sharp. The cloth is so thin and unstable in the weave that you can't afford to pull it in any direction when cutting to shape.

Once I've placed my over size piece on the plane I tack it down the middle, stretch it out to the corners and tack it there. I then use a small, cheap disposable roller to roll on the resin then, using a dry roller run it over the area to absorb any excess, works for me and gives a nice consistent finish. The rollers cost about $3 ea and can be cleaned with metho but the metho used to clean them costs nearly as much as the roller.

 

The plans suggest scale opening doors but I was concerned that they would have weakened the structure too much so with the exception of the luggage door I settled for simulating the cabin doors by packing off thin G10 fiberglass sheet with 0.3mm ply strips.

Next was the window glazing. The side windows were a piece of cake to make as they are all flat, the windscreen is another matter. The plans have a template of the screen but I must say I only thought it would be good enough to be a starting point so I photocopied the template onto ordinary 80 gsm paper and cut it to 6mm oversize. I fitted the paper template to the aircraft and was pleasantly surprised to see a near perfect fit, a bit of trimming around the wing root and removing the oversize resulted in an accurate template that I could transfer to PET sheet.

 

 

A bit of accurate scissor work and you beauty, a really good fit. I didnt believeit was going to be as easy as it was. Thanks for the template Wendell, it sure saved a lot of stuffing around. I can now fit the forward braces and lay a coat of primer on all the glassed bits. After I paint the anti glare panel I will be able to glue the windscreen in place.

 

Masked up for priming on the nose, U/C legs, doors and hatch

 

The windscreen is now on and I've included a 1/3rd scale map on the dash of Garrigal Park in case Happy the pilot gets lost. The cabin is now sealed and the dreaded paint job is getting close. The base coat is Daytonna White and then after some pretty extensive masking  a decorative coat of Cadilac Red.

I've managed to find one last bit of the build that gives me the opportunity to delay the dreaded painting. The wing struts on the Tri Pacer are operational and have to be properly engineered to take the strain of a 15kg plus aeroplane pulling G forces.

I'm going to make them out of several lengths of 3/8" x 1/4" spruce that will be laminated around and over the end fittings. I have always envisaged that the struts would be permenantly fixed at the wing end and then bolted to tangs fixed to the undercarriage plate at the fuselage end. To do this I required swivel joints at the wing / strut junction. Google came to the rescue and after a search found 3mm rod ends at the extraordinarily named site "Bangood"

   

   

   

   

A 3mm diameter threaded rod is epoxied into trenches on the wing ends of the struts for the rod ends. The rod ends will give me about + or - 3mm of adjustment. The fuselage end consists of a shaped plate sandwiched between two aluminium sheet pieces to form a flat fork that will go over the fuselage tang and be bolted through.

The front strut is made up from 4 x 3/8" x 1/4" pieces of spruce and the rear strut 2 x 3/8" x 1/4" spruce. All gluing was with Hysol.

Belt and braces meant that I had to drill and tap and fit three 1/2" 4-40 countersunk screws through the strut and aluminium plates at the fuse end.

I've put heatshrink tubing over all the ends to give me the look of cuffs, I hope, after all is painted

Well, that's it, painting to go, wish me luck

Cheers

Stan

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