Hey all,

I've started building a Fancherized twister to be powered by a LA .46 and I have a few questions. My first question stems from the fact that the leading and trailing edge supplied with the kit were bowed. In the Fancher article he replaced the leading edge with spruce. I just purchased arrow straight basswood for the leading AND trailing edge. This will add 1.8 oz over the kit wood. I am also newish to control line and may have some unplanned landings, so the added strength may be desirable. Thoughts?

Question two:
What do I use as an installation tool for these and do I need to sink them further than flush with the surface? Should I epoxy them?


Question three:
I am using this type of gear for ascetics and for ease of replacement after botched landings.

Do I need to add a hardwood mount between the ply doublers. The ply seems a little soft and I would hate to elongate the mounting holes with a hard landing.

Thank you for any and all input,

Jim

Best option is to design it to be easy to repair.  The bass wood isn't a terrible idea and it will be more robust. Not sure why you want the threaded inserts?
I use that same gear on Flite Streaks and Ringmasters it works well. I suggest you do use hardwood bearer for the gear ...  Twisters fly well and are fun if you keep them light.

I've heard that inserts are better than blind nuts for engine mounts. I've never used them, I'm open to others experience and advice.

Jim

Al Rabe uses the threaded inserts on his Bearcats.  Good enough for him, good enough for me!

I don't know Glenn?

Those things need more material removed to be put in place.

"T" nuts or "blind" nuts, until something better comes along, I'll continue to use them.

Washers and lock nuts if you want less material removed.

IMHO

I have used the threaded inserts when I changed engines and had different mounting holes.  Plugged the old holes and drilled for inserts to avoid swiss cheese engine bearers. 

Hi Jim,

I just finished my Fran Twister last week. Haven't been flying yet, field is covered with snow. I didn't try the brass inserts but may on my next build. Everything went pretty smooth once Sig sent me a new fuselage, the first one had a pretty bad bend in it. On another note i'm using an OS 35FP. I'm not hte most smartest guy on these boards but the LA46 may be a little too much engine. The Twister is not the biggest profile out there and they don't come out too heavy. I used the 35 on a Dare profile Smoothie last year, it is about the same size as the twister and it was plenty of engine. I have a LA46 but I'm saving it for my next build which will be a pathfinder or Cardinal. Thes two have a lot bigger wing and fuselage.  I'm not trying to change your mind, but I would ask someone with more knowledge than me about your choice. An overpowered ship can be a pain to slow down.

good luck,

Rich

Rather than using inserts or having clearance holes for the bolts in the motor mounts, just tap the maple mounts directly.  Use a 2 mm drill for the tap drill then rub candle wax on the tap to lubricate and go at it.  It's the lightest (no blind nuts, no inserts, slightly shorter bolts) and easiest way to mount an engine and the bolts never loosen.

I really like that idea, but installed the inserts about half an hour ago. Will keep it in mind for the next build.

Jim

The Twister is a great model for only 49.00. Sig has them on sale.

Will you post photos of your Twister build?

Charles

Just a note for the next build:

When using blind nuts (which have worked fine for me), I usually use hard, but thin plywood doublers. These will crush the balsa inward on landing gear attachment; so I usually insert 1/4" harder dowel through the balsa, before laminating the plywood, although epoxying it through the plywood afterwards should work fine. This takes only a few minutes. Then just drill through the dowels for the 4-40 l.g. attach screws.

I never took a photo of this process on a fuselage (I do it on elevators for the horn attach), but the photo below shows two approaches. The top fuselage has two CF extrusion inserts all the way through the plywood. I haven't finished that plane and don't know yet the wisdom of this approach - might not be the best way to do things. The lower and current fuselage has one l.g. hole through the hard-wood engine bearer and the other yet to be drilled through a dowel just below the center line. That fuselage is finished now, but only fit to wing and stab - not yet glassed and attached. The second shows how easy it was to do this for an elevator.

SK

If you decide to use "t-nuts" or "blind nuts", use DuBro. The cheap ones can pull apart. I prefer T-nuts over the threaded inserts, because they leave more wood in the beams. Tapping the maple is an interesting idea, tho.  Steve

4-40 bolt with nut and jamb nut.

I use 6-32 bolts with brass tubing inserted into the hub.   I've had too many 4-40 bend locking up the wheel. 

Did you see mine? Did you see mine? I just finished it the other day, and cannot go flying due to snow, cold and wind, So, I scratchbuilt a profile P-40 from plans, and am now finishing a Sterling Flying Fool, to keep me busy, 'til the weather gets on the right track. See of they'll stick here...[/img]

What's best to use for an axle on this type of gear?

     I have been using 4-40  hardened engine mounting screws for many years on the Skyray and so far, they have taken a licking and kept on ticking.

    Brett