isf2008

Elevatorbuild:

I'm assembling the elevator tonight and it is going very well. Part fit is excellent. It is almost like building a plastic model - just trim the little nubs off the parts and glue them in.

One of the unique construction methods that Hobby Lobby uses is locating mating parts by a pair of holes in the parts, and sliding the parts over two nails, each imbedded in a piece of MDF. Installing the nail in the MDF causes a little ridge on the back side of the MDF around the nail. This prevents the parts from seating flush against the MDF. A little trimming with a knife fixes that problem (as shown in pic 1 below).

- The first thing I did in building the elevator was to laminate the hinge pocket ribs using the registration pins (afancy name for the chunks of MDF with the nails through them). I was skeptical that this would actually work, but as the photos show it works quite well. Place the first part on the pins and slide down to the MDF. Put a little medium CA on the second part and put it on the pins and slide down onto the first part. Same again with the last layer. Works like a charm. One small issue is that excess glue builds up on the nails. I removed it with the back side of my hobby knife.
- After the hinge pocket ribs were built I laminated the elevator leading edge together on a 4' level. I use a variety of objects to weight down assemblies while they dry. These range from machinists' 1-2-3 blocks to bags of lead shot to boxes of shotgun shells to batteries from my cordless drill.The idea is to keep the parts straight, so whateveris handy gets used.
- The elevator is assembled on a plate much like the stab. Once the leading edge was dry it was glued to the elevator plates and clamped to the level to keep it straight.
- The basswood elevator joiner plate was glued to the plate and LE.
- The ribs were added next.

I'm taking pictures of half the elevator to show detail. Note that the tail spans 52"...

That's it for tonight! Next post will finish the elevator assembly and move on to the fin and rudder.

As far as lifting capacity goes apparently the bomb bay that is included with the kit will hold 7 lbs of candy or whatever. With over 3000 sq in of wing plus the lifting stab there is lots of lifting capacity available. Target weight of 32 lbs puts the wing loading at roughly 26oz/sq ft. A cargo of 18 lbs (AUW of 50lbs) would put the wing loading at 41 oz/sq ft... This might require the use of flaps for thetakeoff run to be reasonable, but would not be out of the realm of possibility. The DLE 85 and 26x8 prop slated to go on this plane put out 50lbs of thrust at 80% power, so as long as the airframe holdsout I don't think cargo carryingcapacity is an issue.