T.R | Title | User | Personal Name | Date | Lines |
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1276.1 | The secret is... | DIENTE::OSWALD | Randy Oswald | Fri Dec 21 1990 11:20 | 20 |
| Jeff,
To fabricate multiple ply parts get yourself a supply of good, thin,
double-sided tape. Not carpet tape or the foam stuff, just good cellophane.
Make a ply-tape-ply-tape... sandwich. Lay out your cuts on the top ply sheet
and band saw them large. Then on a disc sander with a solid table mounted
exactly
90 degrees to the disk sand down to the line. Drill small holes as needed and
enlarge cut out spaces with a scroll saw if you've got one or a hand held
jig saw. Again, don't cut right to the line. Leave a little extra wood and
sand down to the line, either by hand, or with a drum sander in a drill or
moto-tool. This process is the most precise I've found and you get really nice
parts.
The maximum size of the stact is the maximum depth of cut of your most limited
machine, usually a scroll saw. Mine allows a max cust of about 1.5" so I could
get only say 12 laminations of 1/8 ply.
Hope this helps,
Randy
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1276.2 | Band saw will work fine. | SELL3::MARRONE | | Fri Dec 21 1990 12:40 | 21 |
| Jeff, re -.1, I have a band saw that can do the major cuts to a depth
of 5 inches, so there is a good chance I'll be able to use this
technique easily. If there is a need for accurate scroll work, such as
cutting very small radii or intricate details, we will also need access
to a scroll saw with a deep enough cutting height to accommodate the
size of the stack. But since I have been doing a lot of band saw work
with a 1/8" blade, I haven't had to resort to a scroll saw very much.
I think that using the 1/8" blade will do just fine for the kind of
pattern I envision for the fuse parts.
My only concern about the sandwich technique is that from past
experience, it may be fairly hard to separate the layers after the
cutting is completed. How do we insure that it can be disassembled
easily enough to prevent damage to the parts? Is there some
trick-of-the-trade other than brute-forcing the layers apart that makes
it easier? Like heat, solvents, or whatever?
When do we get started?
Regards,
Joe
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1276.3 | Ya Ya, you betcha | DIENTE::OSWALD | Randy Oswald | Fri Dec 21 1990 13:24 | 13 |
| Try a 1" woodworkers paring, not mortising, chisel. This, with care should do
it. Also get a tape thats fairly, but not extremely tacky. You don't want 'em
bonded for life! A trick I've used with success to reduce the tack of tape for
masking is to take a strip off the roll and stick it to a piece of glass. Lift
it off, check the tack. Repeat until the desired level of stick is achieved.
Just as a disclaimer, I 'aint never done this with airplane parts. And you all
thought I knew what I was talking about. Silly you.
Actually, this is a fairly common woodworking practice and there is no reason
why it won't apply here as well.
Randy
|
1276.4 | It can be challenging | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Fri Dec 21 1990 13:43 | 19 |
| Re .- a couple
You'll still need the scroll saw for the internal lightening holes. If
I understand the design, you need lightening cutouts in the sides which
don't have access from an outside edge. You need to drill a hole and
feed the blade through the work which isn't possible with a bandsaw
unless you really enjoy welding blades ;^)
My suggestion would be to saw the bandsaw stack and then split it into
smaller stacks that the scroll saw can handle. I've done this in
making wooden toys where I have several children to make the same
series of toys for. Carpet tape works well but sometimes you want to
use less than a full width strip (or adjust the tack as suggested)
Don't go overboard on trying to stack too many blanks together. Bandsaw
blades can wander if the tension isn't extreme and the wood has some
significant (and in plywood, sometimes hidden) grain patterns which are
almost parallel to the cut.The most important thing is to get each
person a pair of matching sides.
|
1276.5 | Here's some additional ideas! | PEE47::COX | So Speedy, how do we get zeez brains? | Fri Dec 21 1990 14:19 | 30 |
| I just finished kitting up 4 "Tamecats" for members of my club. The
Tamecat appeared on the cover of Model Aviation last year. Here are
some of the lessons learned:
1. Find a GOOD source of wood, the best I/ve found is by far Superior
Aircraft Materials, run by Sal and Mike Taibi. The Tamecat is mostly
light ply fuse and build up wings. Using Superior as a supplier the
total price for all of the wood was about $15.00 per kit, not bad! Try
doing that at your local hobby shop!
2. When sawing stacks of wood on a band saw or scroll saw only saw in
one direction, ie counterclockwise. That way if the blade isn't
exactly perpendicular to the table, you won't have one end of the stack
bigger than the other. Figure it out!
3. A good way to clamp and saw light ply is to use those little black
binder clips. Use a bunch and remove and reposition them as you move
around the piece.
4. As mentioned before, cut to near net shape and sand the rest of the
way using a disc or belt sander. This works particularly well on
stacks of wing ribs.
That's about it for now but I can say that it turned out to be so easy
that I'll seldom ever build from a kit again. Particularly when you
compare really good wood from a supplier against the junk they put in
kits!
Scott Cox
|
1276.6 | It flies! Club kit completed! | N25480::FRIEDRICHS | Keep'm straight n level | Wed Jul 31 1991 12:57 | 46 |
| Well, I guess I should have kept this up to date...
A total of 12 kits were made. I ordered all of our balsa from
Lone Star. With a bit additional for Jim Reith, the order was almost
$300! We used 2" insulation foam bought at Grossmans for the cores.
OK, back in February (?), Jim Reith helped me cut 24 wing panels using
his automatic cutter. We did this in one marathon evening session. We
learned a lot about cutting foam (which I believe is documented in
other notes).
I glued up the 48!! sheets of 1/32 balsa for sheeting and sanded them.
Al Ryder used his vacuum bagging system to sheet all of the cores.
Lamar Phillips cut out the firewalls and stab sheeting.
Joe Marrone and Mike Stains did a marathon session of cutting out all
of the 1/8" ply. They did a super job! The quality was better than
most kits.
We got together one night and distributed all of the pieces to
everyone in March (I think that was about the date).
Our club president, Butch Bason, built his Eindecker quickly. He does
not like foam cores, so he built up the wing from scratch. It was
covered and painted, but didn't have a landing gear, engine or servos.
To this day, he still hasn't finished/flown it.
About 6 weeks ago, I started to build both of mine, side by side. I
finished them about a week ago, and finally got out to fly one of
them yesterday. It flies pretty well! All of the trim changes were
within trim levers. My first flight was cut short by engine failure,
my second flight went well, then my dead ni-starter ended the evening.
Overall, it appears to fly much like the original.. A bit squirely on
the ground; nice loops; slow rolls (rudder only!). I haven't played
much with slow flight yet, but the washout that was cut into the wings
appears to be sufficient.
Thanks again to all that helped... Not only were we able to make 12
kits, a lot of us learned a lot! Perhaps Joe Marrone will share his
experiences about cutting the 1/8" ply stacks...
Cheers,
jeff
|
1276.7 | Jeff, You Shamed Me Into This! | CIVIC::MARRONE | | Thu Aug 01 1991 13:51 | 63 |
| Thanks for the lead-in Jeff. I guess with that introduction, I'd
better reply or else...
Mike Stains and I got together for one marathon 6 hour session one weekend
followed by another one almost as long a week or two later. I them
finished up the few odds and ends in one final two hour session. All
told, I'd say we invested about 12-15 hours in cutting out all the lite
ply and balsa parts.
The technique we used was to first make a cardboard pattern of each
part from the plans by gluing the blueprint onto the cardboard using
F77, then cutting it out on the band saw. The plywood was then stacked
12 high and thin nails were driven thru the stack to keep it together
and alligned. The cardboard pattern was used to transfer the outline
to the plywood stack, then to the band saw where we carefully cut out
each pattern. WHerever there was an internal cutout to be made, such
as the lightening holes in the fuse sides, we first drilled holes at
appropriate positions, such as the corners of rectangular cutouts, and
then used the Dremel jigsaw to cut out these blind areas. Where
matched pairs of things were required, such as the two fuse sides, the
wing saddle cutouts, etc, we carefully taped these parts together to
keep them from getting mixed up. This extra effort greatly enhanced
the quality of each individual kit.
Once all the parts were cut, we removed the nails from the stacks,
sorted the parts into piles, numbered each part with the appropriate
designation, and then taped and bagged each set. It went like mass
production.
I'm about half finished with my kit, and it has gone together very well
so far, but if I had to nitpick, I would make a few procedure changes
if I do this again in order to make things fit even better. For one
thing, despite our care in laying out the dimensions of each part, all
my formers came out with slightly different widths, necessitating some
trimming and sanding to get them all the same. If I were doing it
again, I'd cut a long strip of ply to the required width, then cut all
the formers out from this piece. That way they'd all be the same, and
not extra trimming would be required, thus speeding up assembly.
I really has a ball doing this project, and along with Mike, felt
personally gratified at how well it turned out at the kit level. Since
this was my first experience with scratch building, it also served to
break the ice on this method of building, and gave me the confidence to
think about a sctatch built project in the future.
If anyone has any specific questions on any of the techniques
discussed, or has any ideas as to how to do things better, please fire
away.
A special thanks to Mike Stains for his knowledge, experience, and able
assistance in this project. I learned a great deal from working with
him.
I'd also like to thank Jeff for getting us started on this project, and
to Alton and Jim for their work in making the wings. Boy, are they
STRONG!
Like I said, this has been a blast, and I can't wait to get mine
airborne.
Regards,
Joe
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1276.8 | Another Eindecker Takes to the Air | SELL3::MARRONE | | Tue Aug 20 1991 14:24 | 60 |
| I finally got my Eindecker finished last Friday after several weekends,
nights, and vacation days of marathon building. This club kit made
from sctatch was really very easy to build, and I think I set a new
personal record from start of construction to maiden flight, all-in-all
about 4 weeks. But I'm getting a little ahead of myself.
Construction was straightforward, as I said, especially in light of the
fact that the wings were already fabricated and only had to be attached
at the root and glassed. The fuse offers no surprises and builds
quickly. Tail feathers were built with lightening holes and tapered
for additional lightening in and to add more of a scale look. The
biggest job was building the cockpit area and turtle decking over the
wing. The original problem was that the two wing halves were not
cut exactly alike, so when they were glued together to achieve the
identical washout at the wing tips, the center section was slightly
skewed. Although this was no problem to fix with some spackling, it
did leave the underside of the wing still warped with reference to the
wing saddle. This necessitated making some filler strips to glue onto
the wing saddle, then blending the contour with sandpaper before the
wing sat squarely on both surfaces and was level.
Then work on the cockpit began and went pretty fast except for the
actual opening, which I guessed at since the plans are not explicit on
this. Next the landing gear. I bought one of those hex-shaped wire
benders for 6.95, and although it came in handy, it's not any panacea
by a long shot. Bending all those compound angles was a b**ch. All
else went along without a hitch. Covering is red and white Solartex (I
love the way it shrinks and stretches around curves), engine is a K&B
40 with Perry carb. All up weight came out at 5 lbs 2 oz.
Now for the BIG surprise. I put it on my balance jig, and to my
horror, it was so tail heavy it required 14 oz on the firewall to
ballance! Couldn't believe it. But, determined as I was to get it in
the air last weekend, Friday night I build a mold in the shape of the
firewall around the engine mount, and molded a 14 oz weight from lead
shot and epoxy. Next morning I bolted it to the firewall, made a last
minute ballance check...perfect...and packed up to head to the field.
Mike Stains whos been my trusty instructor took it up for the maiden
flight, and it flew great! I took it up for three additional flights
and did some practice bomb drops and baloon runs, and really enjoyed
flying it. Although my Taube was originally going to be my primary
plane at Rhinebeck, one flight of the Eindecker has me convinced that
they will trade places. I'm going with the Eindecker because it flies
much better than the Taube for the Mission event, and I just plain like
it.
So....another Eindecker lives and flies in Merrimack!
Thanks to Jeff for organizing this club kit project. The fruits of the
many hours of scratch building the kit have begun to pay off, and in
addition to having a first class plane to fly, I learned a whole lot
about scratch building and have greatly improved my building
experience.
Now if Mike Stains could only get his two Eindeckers built and in the
air.....but that's another story.
Regards,
Joe
|
1276.9 | Eindecker Trims Off the Fat | SELL1::MARRONE | | Wed Aug 21 1991 18:28 | 19 |
| Re: -.1
An update to the nose weight is in order. When I was cleaning up last
Sunday, I noticed that Jeff's Eindecker didn't have a battery, or at
least I couldn't see it. I asked him where the battery was, and he
pointed out that he had tucked it away under the rounded section just
behind the firewall. Brilliant I thought. Why didn't I think of that?
Mine was at least 4-6 inches further back, adding to my tail heavy
problem.
So, when I got home, I moved the battery to this location and was able
to trim almost 5 oz off the big weight and still get it to balance. That
felt good, and now that my Eindecker has gone on a weight loss program,
I'm sure it will be even better.
Thanks for the tip, Jeff.
Regards,
Joe
|
1276.10 | publicity for Jeff's project | ABACUS::RYDER | perpetually the bewildered beginner | Fri Jan 03 1992 07:13 | 6 |
| A picture of this model is on page 193 of the February 1992 issue of
RCM. (If you can get your eyes past the cover. --- What do
waterfalls, rocks, and scantily clad girls have to do with modeling?)
The photo (inside the mag, not the cover, Dummy.) shows Mike Stains
from our club with the Eindecker; Mike took second in Mission with
this plane at Rhinebeck.
|
1276.11 | I read it for the articles 8^) | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Fri Jan 03 1992 07:29 | 7 |
| Re: the cover
Would probably be a great way to boost membership.
Funny, RCM is the one mag that I can send my wife in the store to pick
up. (Hey hon, pick me up the mag with the women on the cover while
you're in there) Works every time 8^)
|
1276.12 | Maybe I'll finish mine someday..... | MICROW::PHILLIPS | DECtp Engineering TAY1-2 DTN 227-4314 | Fri Jan 03 1992 08:29 | 5 |
| I'll have to pick a copy up. Maybe it(the picture of Mike's plane) will provide
me with the insperation to finish mine...... That is, after I finish building
the Pulsar, the modified Spirit, the Panic, etc... :^)
-Lamar
|