Scale Wendell Hostetler 30% Piper Cherokee Glass Fuselage Build.

The Siato FG61TS has a funky Walbro WYD carburetor from the factory. It has the typical Walbro features such as the pump and diaphragm but the venturi looks more like a Fox 60 carb with a spray bar. There is no choke, to prime the engine the plan is to screw a long rod into the barrel and pull barrel open, this opens the spray bar. This operation is done through the cowl. Once primed the rod is removed and you start the engine. The instructions recommend that you simply start the engine with an electric starter and don't worry about priming. The problem is I sold my my electric starter in 1992! Morris Mini Motors offers a conversion kit to a Walbro WT 962 carb. Been looking for a lathe/ mill project so I bought a knock off WT 962 to do the mock up. The bore on the WYD carb is .410 while the WT962 is 13 mm or a 1/2". The bolt spacing is the same however the pulse pressure port is clocked differently. Decided to whittle out a new insulating space out of 3/8" G10, the existing is either G10 or micarta, both have similar thermal properties. Even get to use the rotary table. The kit from Morris is about $120 and at the end of the day I will have about $80 in the project but look at the fun.

The insulator is done. I glued the first one onto a piece of aluminum, when completed I was unable to break the bond, I used thin CA and probably too much, soaked it in acetone for over a hour. The second one in the photo was glued onto a piece of 1/4" plywood four small dots of medium CA, it came off after soaking in acetone. Lesson learned. I have a genuine Walbro WT carb and correct size velocity tube on order. I plan to remove the intake assembly and port match it to the new insulator. Could have just bought the kit or modified the stock insulator but this was a fun project.

Since I had the center to center dimensions committed to memory, decided to cut the gasket critical dimensions on the mill and use scissors to cut the OD. 1/32" thick gasket paper was used, should provide a good seal. Used hollow punches to drill the holes, took about 20 minutes and they fit perfect.

Very Nice, Been thinking about making my own carb gaskets with the laser cutter recently.

pawnshopmike said:

Absolutely amazing work brother.

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WHAT HE SAID!!!!!

I love working with my mill.

AKNick said:

Very Nice, Been thinking about making my own carb gaskets with the laser cutter recently.

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That would be a great way to make them. How long have you owned your laser?

Have the anti-servo tab cut free. Put 2 layers of carbon on the both the trailing and leading edges. Fitted the tips on. The tab will be top hinged using two DuBro quarter scale hinges two per location. I do not plan to split the tab like the full scale but there will be four hinges in the center, Need to make a fixture to cut the hinge slots.

TonyHallo said:

That would be a great way to make them. How long have you owned your laser?

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About a year now. Been learning mostly on 3mm ply. Upgraded my CAD software (DSM Creator) to allow the dxf files to be manipulated and processed. Laser cutting kinda reminds me of the 3DPrinting when it started to become reachable to the hobby industry. Fun Stuff!

When I started my self directed IRA after I retired about 7 years ago 3D printing was a hot topic in the business world, kind a fizzled out, wonder if AI will do the same? EV were the same, took me a while to figure out what ICE stood for, now only Tesla remains as a profitable company.
Back to the Cherokee, the hinge knuckle is .115" diameter and the leaves are .045" thick. I want the knuckle flush with the top of the stabilator so a piece of scrap aluminum was milled with a .035" step, this was clamped to the stabilator to guide the cutoff wheel to cut through the carbon fiber. Worked well.
Was surfing the web this morning and came across a discussion about the Walbro spiral spring diaphragm, found the part number for the WT carb and ordered one, another $25 to the conversion cost.