Frequently asked questions:

8-17-99

Question: Related to the StardusterToo:

Slave struts, do I install the new forward of hinge line type or the old behind the hinge line type? Do I need to remove the old behind the hinge line type and install the forward of hinge type? Can I install spades to help my roll rate on the behind the original behind the hinge line type? Can I install spades on the forward of hinge line type slave struts?

Answer:

The Starduster Too was originally designed with slave struts behind the aileron hinge line. Slave struts are that streamline tubes that connect the lower and upper aileron. Hinge line is the aileron pivot point at hinges connecting the aileron spar and rear wing spar.

Why is there a question as to rear and forward mounted? Flutter is the concern here. To minimize flutter, control surfaces must be balanced or close to balanced. With the slave strut located behind hinge line it adds weight to rear (heaviest portions) of ailerons. They serve to unbalance ailerons. By moving them forward of the hinge point it serves to add balance to ailerons. This helps minimize aileron flutter. To my knowledge there has never been a case of aileron flutter on a Starduster Too. As I understand, the faster you go flutter is a larger concern. I believe fabric helps dampen out flutter.

What this means is if you have the original style slave struts and they are working, do not worry about them. If you are recovering or building your plane, consideration to move slave struts should be made. Other reason to consider moving locations is that spades cannot be used on the original rear mounted slave struts. They will continuously want to snatch and are very uncomfortable to fly. The forward mounted slave struts will accept spades and they work well. Rear mounted slave struts are installed at an angle and are made of streamline tubing. This tubing, if turned at the slightest angle will want to fly, resulting in a heavy wing or feed back into the stick. Ever notice the stick wanting to move and you did not do anything? The slave strut just moved slightly. Several fixes have been tried - installing a welding rod on one side to prevent the flying, rubber or leather fill pieces at rod end bearings and use of round tubing in place of the streamline. There are many hundreds of these flying, and remember, if it isn't broke, don't fix it.

Forward mounted slave struts are mounted straight up and down and help prevent the flying part. There are problems with this type also in that the struts still move some, they do not affect flying, but move. One fix here is to install the rubber or leather in the rod end bearings. We are working on a rod end bearing for the lower connection with a double row ball type bearing to eliminate all movement. Another advantage of the forward mounted strut is it can be filled with lead to balance the ailerons completely. Adds weight to the aircraft, but flying is a dream. We are now installing a 3/8" x 3/8" x .035 square tube inside the forward slave struts. It adds rigidity and weight.

How do they fly? I have about 2,000 hours on my Starduster Too with the original rear mounted, streamlined slave struts. I changed them to round, 5/8" x .049 and have about 600 hours with the round. I liked the round better than the stream line because flying was more consistent, wing heaviness never varied or even existed at any time with the round after re-rigging was completed. Re-rigging was necessary as result of changing from streamline to square. After a total rebuild, recovering etc. I now have 138 hours in my aircraft and another 30 in another Starduster Too with forward mounted slave struts. I do not believe you would know difference in forward versus rear.

There are other things to be done to ailerons for major handling improvements. I went from the bushing type aileron hinges to ball bearing and from gaps in leading edges and sides of ailerons which varied from 1/16" to ½" depending on where you measured. I set up 1/4" clearance at the nose of ailerons to rear a spar aileron fillet. I set up approximately 1/8" gaps at all ailerons to wing end fittings and have installed gap seals. Results are outstanding. Before you could get ahead of the stick as it was moved to right or left. It seamed like the pressure built up a little and about ½ way point would increase substantially. If you shoved it to the side fast you would get in front of the ailerons and have to wait for them. They now are very solid from first to full movement. You do not get ahead of them. Pressure builds evenly from start of movement to end. Roll rate has improved, but I haven't had a chance to time it yet.

Question:

How do I know if my aileron hinges are good or worn out? This also applies to elevator and rudder.

Answer:

Move the aileron up and down with you hands over each hinge. This movement is not an angular type of movement but a straight up and down. If you notice none or very little movement things are good. If you notice movement, 3/32" or more there may be problems. Check this movement and document as you complete or buy an aircraft. Check periodically and at each annual check with log book to see what wear has taken place.

Question:

I have a Starduster Too with the bushing type hinges and want to change them to bearing type. How do I do this?

Answer:

Very carefully check the edge distance as given on plans. If you have this much edge distance, or more, all you have to do is to drill the holes out to size below 5/8" (0.625) and ream holes to 0.625. One way to do this when brackets are still mounted on aircraft is to use a unibit and a hand drill. Make sure the hand drill is lined up so you drill straight through bracket, not at an angle. Break all edges and inset bearings. If they are not very tight remove them and use epoxy or T-88 to hold bearings in place. Coat inside of hole and outside of bearing. Push bearing in place and wipe off excess glue. Install washer between bearing and aluminum angle, on front of aileron spar, at both sides of bearings. This allows the bearing center bore to be locked into aileron when attach bolts are tightened. You do not need to use the bend up locking tabs as before. A nylon lock nut or castellated nut with cotter pin will work.

We have the bearings in stock at reasonable prices.