|Matt Throckmorton's ("DocThrock") Team Rocket F1 EVO Kit Plane Construction Pages|
Team Rocket F1 EVO Elevator Page Last Modified: Monday, 25-Dec-2006 06:14:29 EST
On This Page: Skin Stiffeners Elevator Spars Right Elevator Left Elevator Trim Tab Servo Counterbalance End Caps Hang Elevators
While the HS was near completion, I had already started the
Rudder. The Elevators are constructed nearly the same way as the
rudder, at least as far as the skin stiffeners are concerned. I
determined that I could do a batch of skins and stiffeners at the same
time, so now I'll begin the Elevators.
The Elevator skins have to be stiffened. They are just too flimsy. So the idea is to use formed .025 angle and cut it to length and taper each piece so that they fit the taper toward the trailing edge. You need a bit of clearance at either end of the stiffeners, so the plans tell you to leave upwards of 1/8 inch from the stiff to the spar or the joggle in the trailing edge. You have to put the spar on and line it up in position, then draw a line on the skin to locate where the spar interference could begin. I marked a big fat line along the spar, then removed the spar until later.
Notice in the pic above a barely visible green line has been drawn across the stiffener. At the spar end of the stiffener, you'll note a red cross mark. That spots the first hole at the spar end of the stiffener. You place the cross mark in conjunction with the hole in order to maintain interference clearance between the end of the stiffs and the joggle and spar. When you're actually attaching these stiffs to the skin, you can't see them. So you have to mark them along the rivet line and a cross mark at the first hole. Rather ingenious little trick. My hat goes off to all the guys and gals who have come up with handy little processes like this!
You can't see it in this pick, but the angle/stiffener is
under the skin between the two boards. You spot the red mark on the
green line and drill, then cleko, the first hole. Then rotate the skin
until you see the green line in all the other stiffener holes and drill
the trailing edge end. On the shorter stiffeners I didn't bother to
cleko any other holes, just each end, prior to drilling.
**TIP: If you want to get a really pretty skin on your
F1 (or any
riveted surface), I highly recommend that once you get the skin drilled
and clekoed in place that you GLUE or BOND the skins down just prior to
riveting. Pick the side you want the prettiest and glue that side to
the skeleton and cleko it for about 24 hours. On a side that you may
need to leave open until very last, you can still glue it prior to
assembly and get a better than average looking surface. Just wax or use
releasing agent on the mating surface of the skin and glue it down. The
next morning, just remove the clekos and pop the skin free. When you go
back to rivet it down, you will still get a better surface than if you
just bang rivets in bare metal parts. I'm kind of heavy handed and it
shows. I have puckers and deformations that aren't particularly pretty.
I wish I would have done this trick from the start. In the case of the
elevators, one side is definitely the bottom. that makes it easy to
choose the pretty side. Glue down those stiffeners and the spars on the
top skin prior to riveting. You'll thank me later on, believe me. It
sure makes a pretty and smooth result.
After I D&D the skins, I'll back-rivet the stiffeners on,
proceed with assembly of the spars and other components.
I got back to work on the elevators after completing assy of
the main bodies of the rudder and the HS. Both are out of the jig and
getting closer to being finished. I'm going to roll the hinge side of
the skins all three control surfaces at the same time so I can use the
same process and materials in one "batch".
I went ahead and threaded the rod ends in the spars and test
fit them to the HS. COOL, it FITS!
This was the end of the Labor Day weekend '04. I still had time for a big motorcycle ride and even found time to have a few beers. It was a nice long weekend, and I got lots of building done around the festivities. Now it's back to the dull routine. And I have to find the time to build those wooden elevator fixtures!
I went ahead and rough cut the counterbalance notches in the
Elevator skins. That was a waste of time and a couple dremel cut off
wheels. Turns out that after I added a bracket and clekoed the
counterbalance to the elevator spar, the notch was still too "shallow".
Had I to do it over, I probably would just wait until I could attach
the spar-c/b assy and then mark and cut it REAL close the first time.
Last night I ceremoniously disassembled my HS jig and got it
out of the way. That took a while. Now I seem to have tons of room. I'm
contemplating moving the fuselage from my garage into the basement. I'd
have better lighting and more room. Better heating and cooling, too.
Just don't know if I want to negotiate my fence bringing the fuselage
around the back of the house and through the French doors. No matter
what I do, I can't get the tail through ANY of my doors, so I'll have
to disassemble the empennage anyway. (Turns out that the fuse fit
through a standard fence gate just fine!)
After clearing out some working room, and hiding the HS under
my work table, I got out all of the elevator skins and the trailing
edge doublers. I went ahead and clamped them and drilled them per
plans. This is pretty brainless. You just have to make sure everything
is flat and straight. I used lots of clamps.
OK, the center bearing on my HS was a smidgen off center, As
Mark Frederick likes to say: One change begets 30 others! Well in this
case maybe not 30, but I thought I was in a heap of trouble!
I was getting the ribs, spars and skins ready to put in the
wood fixtures and drill. I decided to check everything on the bench
before final drilling. What I found was that due to the center bearing
being offset, I could not get the root rib of the right elevator to
center up with the pre-punched holes on the skin! CRAP!
I hand re-bent the weldment, filed out and smoothed the poor quality weld and everything aligned beautifully.Right Elevator
The wooden block fixtures for the elevator were easy to make
per plans. I used my scrap 8 inch particle board shelving again. I
removed the rudder boards from my beam and used the end set of brackets
in place. I measured out 38 inches on center and screwed down the
second board and verified the dimensions. I had some shelving angles
laying around, and screwed everything down to my laminated beam.
I put the trial fit R elevator assembly on the bench and
measured the counterbalance skins for rivet drilling. I made sure all
the flange centerlines were visible through the pre-punched holes and
made sure all the parts were properly aligned per plans. I then drilled
using a #40 bit, clekoing as I went along.
I unclekoed the R elevator and removed all of the parts from the fixture. I D&D'd the bare parts, scotchbrited them and used a self etching primer on them. I filed the edges of the skins.
I woke up a tad early today, so I decided to go ahead and
D&D the R elevator skins. I started using my cordless screwdriver
deburring tool, but decided on these massive flat arrays of holes its
just faster and easier to use a drill bit with some duct tape wrapped
around it and twisting it with my fingers. I then used the trusty C
frame to dimple the skins. I used the same mallet, choked up on it a
bit and used about 1/2 force on the blows. It's kinda hard to ease up
when walloping these things. But you have to, otherwise it's VERY easy
to distort the sheet metal. Use about half the force you think you
need. Around the perimeter, you might even be better off using a
The Elevators are like the rudder in that you have to rivet the counterbalance (c/b) skins to the elevator skins prior to dropping the assembly in the fixture. There is a row of rivets below the counterbalance rib that is not accessible to buck when the assy is together. So you have to "unfold" the counterbalance skin and back rivet it to each side of the elevator skin with all three pieces folded out all over the bench top. A little cumbersome, certainly not impossible.
After back riveting both skins to the c/b skin on the table top, I set the skins in the fixture. I went ahead and riveted the R elevator spar to the c/b rib and home made bracket. I set the skeleton inside the skins in the fixture and clekoed the perimeter in every 3rd hole.
I started riveting at the 4 rivets on the leading edge of the
c/b and worked back to the trailing edge. I used my Main Squeeze and
the thin nosed yoke at the apex of the trailing edge. It was hard to
get in there because of the flare of the outer edge of the elevator,
but I was just barely able to get these rivets set.
The trailing edge doubler is best riveted on the bench.
Instead of alternating the rivets like in the rudder, I determined
which surface was the top and set the manufactured rivet head on top. I
used two cup sets so that the shop head would be slightly rounded. This
works well on the elevators, but not so well on the rudder.
The R elevator went back in the fixture and I stared at it a
bit. I have to roll the leading edge of the skins and rivet them
together in a curve (where the rod ends bolt/swing on the HS). Plans
say to us duct tape or cleko a 1" pipe to the skins and roll them until
the pre-punched holes line up. I didn't have any 1" pipe, but I did
have 3/4 PVC and copper. I decided that PVC might be too flimsy, so I
used the copper.
I ended up drilling and clekoing every hole. I used two pairs of Visegrips to grab the pipe in the area where the rod ends are screwed into the spar. The rod ends get in the way, so I removed them. I started at the outer edge and only clekoed one of the three segments at a time. That makes it much easier to roll.
The little outer segment was easy to roll and was good practice. I left that area clekoed, then moved to the center segment. That took a lot more coaxing. Then I moved on to the inner segment and worked it all by itself, but left the pipe inside the rolls of the other segments.
Every hole on the flat skin side has to be clekoed. the skin would buckle and bow if they weren't completely attached. It was a bear to roll the second skin, mostly because the first side (flanged) really gets in the way. I finally used my bare hands and rolled the flanged side out of the way so I could really get in there and roll the flat side all the way to the spar.
After rolling the skins most of the way, the holes still did not line up. I removed all the clekos and massaged the rolls the rest of the way by hand. I had to press the skins together and coax them almost completely down to the spar. Unfortunately that scratched the flanged skin as the holes in the flat skin scraped along the surface. Next time, I'll debur the holes, and maybe tape the underlaying skin to avoid the scratches.
All that's left is to shoot some pop (blind) rivets in the now passively aligned holes and then modify the shape of the rolls when against the HS during mounting.
The Right elevator is completed!
The plans seem to be missing a few pages or something at this
point. All of a sudden we jump to the access panel and doubler for the
electric trim. So be it!
I drilled all of the attach holes on the doubler through the
skin. Then I took everything apart and deburred it. I dimpled all the
holes in the skin and I tried to dimple the doubler. I ended up
countersinking a wee bit in the dimples on the doubler to get the
rivets to sit flush. And of course for the nutplates you have to
machine countersink the rivet holes.
I went ahead and used my Main Squeeze and set the #3 flush
rivets to hold down the nutplates. I went ahead and primed the skin
where the doubler will attach. Then I clekoed the trim servo doubler to
the skin. I hand squeezed all of the attach rivets for the doubler.
I took the Left elevator spar with the weldment clekoed to it
and set it in the skins. I had already set up the counterbalance and
the c/b skin, as well as the hand made bracket to hold it to the spar.
I already primed the bracket, too.
Getting the counterbalance to set right is a little tough. I
would move one area, then of course it moved another area. I used a
dozen or so cleko clamps to hold things tight, and it was still a minor
battle. But I finally got the skeleton, with centerlines already drawn
on the flanges, to sit the way I wanted in the skins. I drilled a few
holes to cleko the parts together.
At this point the E-006 trim tab/hinge spar is not in place.
I worked on it all by itself after the left elevator was completely
drilled and clekoed.
Finally the perimeter of the left elevator was all drilled @
40 and clekoed. At this point I did things a little differently.
I took the E-006 spar out of the assy and took it to the
bench. I got out the appropriate hinge material and rough fit it to the
spar and the corresponding area on the elevator.
plans aren't very specific on the location of the hinge, and I
ruminated over the location of all of these parts. What I ended up
doing is consulting Pflanzer's Pflying Pfactory and got some ideas on
how to proceed.
tacking the trim tab hinge to the elevator spar, I cut it to size and
smoothed it off. I then pinned the other half of the hinge to the trim
tab skins and eyeballed how they would look in place. I determined that
the hinge goes on the spar (and the skin) precisely as they look like
they should. The round part of the hinge is below the level of the
skins and the edge of the spar goes right to the edge of the flat part
of the hinge. Easy. Turns out both sides just need to be set so that
they look clean and flush.
The trim tab is actuated by a rod from the servo on the bottom of the elevator. You have to put a bracket consisting of two pieces riveted together and riveted onto the trim tab. Both pieces are supplied and cut very close to shape. I used one existing skin hole and one new hole for the small piece. For the larger actuator bracket I had to drill all new holes that also go through the root rib. You also put one rivet in where the tabs of both brackets mate together.
The Trim tab was fun to assemble. After D&D'ing the entire left elevator parts pile, I clekoed the trim tab components and set various sizes of #3 flush rivets, and one #4 rivet in the actuator arm brace. I set all these rivets by hand with my new Main Squeeze. So far, that thing works VERY nicely. And is more kind to my delicate hands/fingers. And the quick change feature using pneumatic type yokes is great. Anyone want to buy my Tatco squeezer?
left elevator main body is riveted like the other control surfaces.
There is an area of rivets that is not accessible after you close the
skins over the skeleton. Therefore you have to rivet a partial row of
rivets on each skin to the counterbalance skin.
time when riveting the counterbalance skin to the elevator skin, I used
a hand squeezer instead of back riveting. I clekoed EVERY hole common to
all three parts and flipped the assy with the stiffeners face down just
off the edge of my table. I removed each pair of clekos and squeezed
the one rivet in the bottom row (the top row goes into the skeleton.
the skeleton to the skin assy is pretty straight forward. I used a hand
squeezer for this process, and consequently the chore took about 1 hour
longer. I was trying to see if I could get the skins smoother. It does
look a little better, but I don't know if it was worth the extra time.
completion of the riveting on the elevator, I couldn't wait to trial
fit the trim tab. I tried to slide the pin in and it wouldn't go all
the way through. Manhandling with my palms was useless. I put the hinge
down against the table top and "coaxed" it a little to line the hoops
up better. That got the pin all the way in fairly smoothly. Then I
found out that the trailing edges did not line up very well.
I must have gotten in a hurry and riveted from end to end instead of
from the middle out (but I don't remember doing that), and that must
have caused the darn piece to end up catywompus. Even though during
the trial fit it was straight.
OK, it was REALLY bugging me... so I went home on my lunch hour and
drilled out the trailing edge rivets and pinned the trim tab back on
the elevator. Still bent. Palm and thumb this way on one end, that way
on the other, and VIOLA! Flat as a pancake. Now the clekos and IT'S
BENT AGAIN! DRAT! Coax again...FLAT! Oh, so it's going to be THAT way,
it it?! Sure enough, I had to "coax" the trailing edge (by manhandling
the entire piece) in between every rivet to keep the trailing edge
flat. But IT WORKED... so far. ( I didn't glue it together before
riveting, and it would have been much easier if I had!)
I suspected, even riveting the "in betweens" wanted to cause the bow to
return. I did a few things to fight this. I ran a drill bit through the
holes biasing the direction I wanted to put pressure. I also tried to
hold the trim tab with the twist I wanted (untwist, if you will...).
And when I squeezed the rivets, I tried to press them the direction I
need to bend or correct the trailing edge. It worked. With a little
more coaxing, of course. Matt Happy!
the trim tab dilemma was under control, I grabbed the hinge pin and
rounded off the outboard end. I slid it through until it stopped
against the far end, then marked where the inboard hinge stopped. I
took the pin to my vice and put a 90 degree bend in it. I inserted it
in the hinge again and marked where the web of the spar was, pulled the
pin and made another 90 degree bend so that the pin was flat against
the spar. Now I had a pin that would fully insert and lay against the
spar web to facilitate retention (and keep it out of the way).
the forward side of the left elevator was pretty simple. The
pre-punched rivet holes are exactly the same right and left, so I was
able to use the same, now pre-drilled, piece of copper pipe. I clekoed
it in, then rolled one of the three segments at a time. I started
on the straight side, not the bent side. That made the job easier.
Time to mount the electric elevator trim servo under the left elevator. The access cover and bracket are already D&D'd and primed. I had to hand bend them a bit to get it all to sit flat. Unfortunately, I can't find the proper nutplates to put on the bracket to screw down the servo. I'll have to find four more K-1100 nutplates so I can get this part finished.
I didn't have the correct nutplates to anchor the trim servo, I decided
to complete rolling the leading edges of the Right Elevator and the
Rudder. This is pretty straight forward. I used my copper pipe, clekoed
every hole and rolled one segment at a time.
fiberglass tips were just gathering dust, so I decided to do some
preliminary trimming. I'm not sure how the trailing edges are supposed
to line up, so I'll have to look at some RV's and maybe a rocket or two
(if I can find any) and see how they "terminated" the trailing edges.
The elevator caps aren't too bad to fit. I took a dremel drum and finished out the edge that mates against the metal, as well as trimmed the mold flash from the center. Then I used 220 (although 180 or 150 would probably go a little faster) sand paper (I know, that's not PC anymore) to rough sand to shape. Gonna need a bunch of filler to smooth these babies out.
took the scrap strips I cut off of the HS skins and used them as
doublers under the caps. One set was about 1 1/8 wide. I cut 4 18 inch
strips, rounded the ends and held them in place under the fiberglass.
used the NAS tack rivets to hold the doublers to the fiberglass. I
could have used #3 soft rivets, as well. Either way, my intention is to
screw on all of my tips. In the case of the elevator tips, the screws
and nutplates will hold the fiberglass to the metal, so the strength of
the rivets isn't that important.
Trim Tab Servo
finally got back to working on the trim tab. I didn't have the correct
nutplates, so I made an order for #6 screw "end" nutplates. Once they
were in hand, I grabbed the trim tab bracket and riveted the nutplates
with #3-3.5 flush rivets. I screwed down the servo and riveted the
bracket to the cover plate with #3-3.5 flush rivets. This was kinda
the servo bracket and cover were in place, I played with the activation
rod a bit, just to make sure it cleared through the hole.
The other thing that I found out was that I did not have full travel of the trim tab. The actuator bracket on the tab was bumping the elevator skin and rivets. So I took a dremel and cut the edge of the bracket down at an angle to allow for more clearance. Then I finished the bevel with a hand file. Now I have more clearance for the trim tab to swing through it's full spectrum of motion. I'm sure it will never need this much travel, but at least it won't bind at the bracket, either.
counterbalance weights finally came from Van's. 6 of them. I ordered
the E-614-020 weight for .020 skins. Kinda pricey to get lead bars
shipped from Oregon to Indiana. The FED EX guy was not happy. He stated
that it felt like a box of lead. He just shook his head when I told him
that was exactly what it was. I got a chuckle out of it.
of the weights set in the left c/b (the heavier one with the trim tab
and servo) did not even budge the elevator on it's hinges. I had the HS
off the edge of my work table so I could test the elevator weights, of
course. Three weights at the location of the existing hole would move
the elevator, so it was enough weight. But it didn't seem overly heavy.
in mind that when I actually complete the balancing, the left and right
elevators will be mated. So perhaps I'll need less weight on the left
elevator, because I can compensate on the weight in the right elevator.
I got home from work today, I was going to go to the electronics depot
and start collecting some switches and things. But I made the mistake
of looking at that sad HS and left elevator on my bench. I thought
"what the heck" and grabbed my end caps and went back to work. I had
already put on the doubler strips in both the HS caps and the Elevator
caps, so set about getting more toward finishing them. These parts seem
to be taking forever.
I centered up the caps, used a file to dress the edge where they mate to the skins and got the best fit I thought possible without making major shape changes. I marked the drill holes and started drilling #40 from the center outwards. I clekoed as I went. After drilling and clekoing one side, I flipped the whole thing over and did the same thing on the other side.
I have the fiberglass pieces clekoed in place. I assessed how they sat,
and figured I had some filing to do. That made them sit better.
I got out my cling wrap and selected a piece longer than the caps I was working with. One piece for each cap. I removed the caps pulled the wrap loosely over each cap, then inserted the cap back into the skin. I pulled the wrap smooth and even, then clekoed the caps back down.
went to my epoxy room (well, the shelf that stuff is sitting on) and
selected the correct blend of material ( I only have West System). That
means, one pump 105 and one pump 206. After mixing it thoroughly with a
tongue blade, I added about an equal volume of micro balloons.
Now that I've "buttered her up" we'll she if she takes a shine to me. Hopefully, once she's all set, I can get my hands on her and really smooth out her curves. Ooooh la la!
My friend Bruce brought over his welding equipment and a digital set of lab scales. My Van's E-614-020 lead weights are now confirmed at a NOMINAL 830 grams. I think that is precisely what Mark calls for with the rudder in the plans. So now I have confidence that I can use all 5 of the other weights in the elevators when I get a little further along. Still trying to find out if I have to cut one of the weights in two.
In retrospect, glassing over the fiberglass parts with micro balloons, at this point, was a waste of time. It was necessary to used the micro to reshape some areas anyway, but for filling pin holes and finishing it's pretty worthless. After sanding I found SO many pin holes to fill, it's depressing. I wish I would have gone straight to the auto body putty and pin hole filler. It would have saved me time and materials just to do most of this shaping and filling with "bondo".
.It's a year and a half since I started this project. The Elevators were constructed months ago, and put away in storage. I brought them out and dropped them into place on the HS. 2 AN3's in each one and an AN4 between them at the horns and WOW, it looks like a real tail ( no fiberglass caps, though...) .
Kinda Hard to get the entire tail in the pic because I have so little room in my basement. I'm just surprised I can get the tail on at all down there!
Now that the elevators are pinned in, time to hook them up. To start with, I got out the big diameter push tube, marked and cut it at 64 and 3/4 per the manual. Then I drilled it for the 8 pop rivets. I drilled it #30, cleaned it up, slathered JB Weld on both mating parts and inserted the end cap into the tube. 8 pop rivets and a bit of clean up and this part was set aside to harden.
Time to drill the elevator horns. The manual sez to mark 3/8 in from the lower forward "corner" on each horn and drill them for an AN3 bolt. I can't wait to see how much gap there is between the elevator horns for the rod end bearing.
First off, per plans, you neutralize the elevators. I used wooden screw clamps over the counterweights and clamped down to the forward spar. I also used a spring clamp to keep the trim tab from flopping around.
When I marked the left horn for drilling, I used the very forward leading edge, not the back of the stiffening bend, to measure the 3/8 in. I hadn't realized it, and I was going to drill these horns off the ship, but you actually drill them together in place. And I'm the guy who can't drill a straight line. So I started with a #40 bit and tried to stay straight and level. All the way through the right horn. Then I incrementally stepped up each size drill bit through #12 for the AN3 bolt. I think it turned out OK.
Randy Pflanzer riveted 1/8 inch aluminum spacers on the horns to take up the slack. I'm going to do the same thing. After that, you really only have room for a washer type shim. I could even eliminate that by sandwiching in an extra thinner layer. Symmetrically of course. OK, so now the elevators come back off the ship. Turns out that there is a very nice piece of 1/8 that comes with the ship. It's meant to use to bolt down the battery contactor, but I decided to cut it up for spacers. The way I riveted it is overkill, but I like symmetry and I can buck AD4's much better than 3's any day. This little gem is just to keep you from having to fumble with too many fasteners back in the emp when you're bolting in the elevator push tube. I probably didn't even have to use flush rivets, but they are clean looking and cool.
While the elevators are off the ship, I'm also going to go ahead and trim the elevator skins back to the rib in the lower area near the rudder horn. There is some potential interference with the emp deck, so I'm going to max the clearance there.
Elevator Control Tubes
I took the big assed aft elevator control push tube with it's end cap and rod end bearing and slipped it into the fuselage and back to the elevators. The rod end has a little slop in it when between the elevator horns. Note to self: JB Weld a thin AN3 washer to the inside of each e horn spacer next time the e's are off the plane. That will keep the fumbling down to a minimum. Probably going to do the same thing with the big fender washer at the bell crank (JB the standard washer to the fender washer). Too may parts to work with in a tiny uncomfortable position.
I climbed back in the fuselage and bolted up the re-re-remade bell crank (back to stock) and hooked up the rod end for the aft tube. Oh, forgot. Have to clamp the elevators to neutral, and neutralize the control sticks. Hmmmmm.... When you start this, with the sticks neutralized, the bell crank is supposed to be vertical. It's not. The intermediate tube is set up too long. Drat. So I disconnected one end and tuned the rod ends all the way in. Drat. The tube is STILL too long. The center tube is holding the bottom of the bell crank too far aft. Not much, perhaps an inch, but it's at the bottom of the bc, and that's the place where you have the most likelihood of contacting the bulkhead of the plane. Not good, could restrict full stick movement and full (adequate, anyway) elevator deflection.
I was able to get it all hooked up, but you have to remember, if the intermediate tube is too long, the ALREADY CUT aft push tube is going to be too short. So I adjusted the rod ends on the aft control push tube and basically had to max out the threads. I still have a couple turns to play with, but they are certainly not centered like you would like at the beginning. Not much margin for adjustment.
So the elevator control system was in place, but with errors. The center tube was too long by about 1 inch, I would say. That's how far back the bell crank appears to be displaced, and that's how much I seemed to have to crank out the rod ends on the big aft tube.
I climbed back in there and took a speed square with me. Well, at least the bell crank isn't as far off as I thought. It is an optical illusion back there. The top of the bell crank was only off about 1/2 inch or so. Really pretty minor, and I probably could go ahead as is. But the sticks aren't vertical, and neither is the bc. It was REALLY bugging me.
The problem with the control system never surfaced. It's close enough that I could go with it as is, but I finally decided to finish the aft elevator push tube, and order a new rod end for the intermediate tube. When the new rod end gets here, I will cut one end off the middle tube and put a new end on it. By the time I cut the old end off and clean out the JBWeld, the length should be just about right to solve my problems. So a shorter intermediate tube will allow me to get the bell crank back to vertical and neutralize the sticks as well. Were talking less that 3/4 inch to solve this problem.
For the time being, I went ahead and marked drilled, prepped, epoxied and blind riveted the other rod end cap on the aft elevator push tube.
That was a fun little project. I put the aft tube in the emp, released the clamps on the elevators and checked the travel. I get about 28 degrees down, so I'm good to go there. I only get 17 up, though. Regrettably, that's because I forgot to cut the emp deck panel right after I put the angle bracket back there to hold the VF. But the bell crank does NOT hit the bulkhead so that tells me I'm really in pretty good shape with the control system. Waiting for the part, and on to other things....
The stock length of the rear elevator push tube works great. Assuming all my control parts are in the correct location, the only thing that needed changed was the intermediate tube. I shortened it to 42 7/8, down precisely one inch from the plans. I don't think I could be off and entire inch, so I think there's a typo in the plans.
Since I was setting up the elevator controls with the push tubes ("rods"), I decided to make my lifer a little easier and bolt on the counterweights I bought from Van's a year or more ago. The kit has 6 lead blocks, pre-drilled for AN3 bolts and shaped to fit the pre punched RV 8 controls (I think). You use 5 of them on the elevator and 1 of them on the top of the rudder. Instead of cutting one of the elevator counterweights (CW) in to two pieces, for now anyway, I just bolted three weights on one elevator and 2 on the other. One weight goes INSIDE and the orientation is to put the thickest end from the bolt holes forward. This orientation gets the most weight to the end of the elevator CW and allows a lot of adjustability down the road. Of course when you bolt three weights onto one side, you will have some hardware sticking out beyond the edge of the skins. And of course you have to do this outboard, and it will be covered by the end cap anyway.
In final assembly, I will get at least one thread showing on the nuts per aviation practices. At this point I am considering leaving all 5 blocks in the elevators in tact. If one side ends up light, I will switch the weights side to side. If the elevator CW isn't heavy enough, then I will cut one of the weights and bolt each half to the forward bolt hole in the elevator CW. I'm not going to worry about that until after I have the parts painted and ready for final install.