Spar Question

[Acroeric]

Re: Spar Question

yep- me too. Pretty easy to make on a lathe. I seem to remember having to make 2 long pieces then cut them to the correct length carefully. All you need is a drawing. The ones I made were for the old Harer STC which may differ from the stock BC12-D-85.

[Jim Herpst]

Re: Spar Question

What material to buy and where? Also we need the dimensions ... I will get him to order the STC...its not a stock 85 although I want to go through his logs.....

[Guest]

Re: Spar Question

What material to buy and where? Also we need the dimensions ... I will get him to order the STC...its not a stock 85 although I want to go through his logs.....

Its phenolic rod as I recall and its used in the electrical industry as well as others.

I believe that the common usage is electrical is as an isulating rod.

Try Grainger or that other industrial supply whose name escapes me. ahh!! McMaster-Carr

Dave

[Guest]

Re: Spar Question

Order the STC it has all the dimensions that you need.

Dave

[Larry Lyons]

Re: Spar Question

OK; dumb question, do standard spars have the inserts? The spars I bought from Eric have them. Not sure if that is standard BC-12 or for the increased gross weight or something else. If interested I may have enough material I can send you to make another set of inserts. I would have to check. I got mine from McMaster Carr. Larry

[Ray36048]

Re: Spar Question

Main spars, yes. Rear spars, no.

[Guest]

Re: Spar Question

English spars had them in the rear spar too.

Dave

[RoN43220]

Re: Spar Question

My IA wants inspection holes put in my BC12D to see the inboard spar attach points. Does anyone have measurements on the optimum location for these?

Thanks, Ron

[Robert Lees]

Re: Spar Question

http://www.taylorcraft.org.uk/insp-rings.pdf

Your IA cannot insist upon inspection access at the points you describe, since they are hidden by the wing tank(s), and there are no access holes required on the original drawings.

However, the wing bolt attachments are visible by removing the wing bands.

[RoN43220]

Re: Spar Question

Great answer. Thanks Robert!

Ron

[Jim Herpst]

Re: Spar Question

Larry, Yes the Standard Taylorcrafts have the Bushings on the front spar. When one up grades the Gross weight (see Terry Bowden if interested...I will be...) Then the bushings are LARGER then the standard ones. I understand Terry sells the STC for a Gross Weight increase to 1260 or 1280 I forget which with the non electrical 85 and higher (F-19) Gross weight With the 85 electrical. I need to check with him to see if one can then STC a non electric 85-8 up with the 0-200 crank STC. That(in a "light" 1260 gross Taylorcraft ) will put the plane in the Homesick Angel catagory

[shipljl]

Re: Spar Question

To plane the root ends of the spars I used a router like shown in this Monocoupe restoration link at http://gobinkley.com/spars.htm. He shows a simple wood jig to hold the spar and control the router depth. The one shown is for a tapered spar repair but I just made a flat one. I attached some photos of my jig. After the required amount of wood was planed off each side of the spar, I used a wood chisel to feather the step transition, then sanded only the transition, not the flat where glue was to be applied.

Be careful to measure the required thickness per your strut attach fittings. I didn't think to measure and found them too thick, had to plane off the plywood and thin the spar some more. Give an allowance for the glue thickness, the varnish thickness, and root rib overlap thickness.

[Steve Green]

Re: Spar Question

I also used a router. The only difference is I used a round bit (looks like a straight bit in your pictures) that put the curve in the end of the cut for me. Set the depth (plunge router) and tested it on several pieces of scrap. I clamped a straight edge to the spar as an end stop going inboard. Worked really well, quick and minimum fuss once I got the set-up done.

[mulwyk]

Re: Spar Question

Another router setup, single stop. I used that little block plane to lightly dress the cut. Start cutting at the butt end and work towards the stop.

[Pearson]

Re: Spar Question

Bob did you borrow my router? I have that exact model. I was wondering what did you do to smooth out the little furrows in the spar after routing? Can you just belt sand it smooth or do you plane it? It seems it would be hard to plane up close to the inner end of where you routed.

Also Steve can you post a close up picture of the bit you used? From what you wrote it sounds like you did it so that there is a curve up to the original surface of the spar where you stopped routing.