Carlson Skunk Works

Well, the past couple of weeks has seen the assembly of the wing rear spar frames and the webs for the rear spars. Therefore, progress continues to be made.

The webs for the rear spars were scarfed last week and the assembled spar frames were sanded. This was a bit of a project since my wife has banned any further sanding in my basement work room. Therefore, I had to bring the spars up to the garage for sanding, then clean them off and bring them back to the basement.

Here are some pictures of the wing rear spars during construction:

This is the long view showing everything ready to be glued. I built two of the spar frames like this and will apply the webs to opposite sides so that I end up with right and left spars.

This shows the filler block for the jury strut attachment.

This is the root end of the assembly. I put a stop block at this end to provide a good reference point for other measurements.

Here is the center of the spar where the strut will attach. I cut the filler block a bit long and ended up having to fit the compression strut fillers at rib position 8.

Of course, the tip end of the spar. I ended up using a piece of left over 9mmX18mm material from the front struts to make the end of the spar. Once the glue had cured I sanded it down so that it is now level with the rest of the spar.

Once both of the rear spar frames had been glued and the glue allowed to cure, I cleaned off all of the wood blocks from the spar table. I then took the web material and laid it out for gluing. I left the parchment paper and one layer of wax paper on the table. I ran one web down the left side of the table and the other down the right side of the table.

Before I scarfed the web pieces I marked them so that I would know which pieces went together and in what orientation. That way I made sure the grain was running in the right direction.

I went over to Menard’s and picked up a bunch of clamps. Then I started at the root end and clamped the first piece of plywood to the table, scarf side up to accommodate applying glue. I worked on both webs at the same time, so the joints lined up as I went along.

Then I fitted the next piece of plywood so that the scarf joint was nice and level and smooth. At this point I clamped the second piece of plywood to the table. Next I lifted the end of the second piece of plywood and applied the glue to the joint. When I had glued the first joint of both webs, I laid a piece of wax paper across them, put a short board across the table and clamped the board over the joints. This should apply an even pressure across both scarf joints.

Then I moved on the next joint and continued working my way toward the tip end of the webs. As I moved down the web I moved any extra clamps along with me. I tended to use lots of small clamps to keep the web pieces from moving while I glued the joints. I ended up with four scarf joints in each web.

Unfortunately, I forgot to take any pictures of the process. I will try to get a picture of the fully clamped webs for the next post.

Progress is continuing to be made. Steady by jerks as my grandfather used to say. However, doing a little bit each day during my lunch break is really helping to keep things moving.

The two front spars for the wings are now complete and the two rear spars are in process.

Sunday afternoon I spent a few hours cutting and planing the Douglas fir parts for the rear spars. All the material is now ready at hand.

However, the spar table still needed to be cleared off from building the front spars and prepared for building the rear spars. Therefore, my Monday lunch time was spent clearing the table. I pulled the blocks that held parts in place, removed the wax paper and the parchment paper. New parchment paper was rolled out and stapled to the table and a reference line was drawn the full 16 feet of the table. Then on Tuesday I drew out the rest of the spar full size on the parchment paper and overlaid it with wax paper.

The table now has most of the part for the first spar on it and I have stapled blocks of wood to keep things in place until I can glue them up. Hopefully I will be able to get some pictures of the spar as I build it, but I haven’t had a chance to do so yet.

Here are some pictures of the front spars as the plywood web was installed. As noted in my last post, there are four pieces of 2mm plywood for each web. The middle joint was lined up with the filler blocks where the struts will attach to the wings, therefore, I used a but joint in this location as there is a lot of solid wood on each side of the joint. The other two joints on each wing were scarf joints. The next few pictures show how I laid out the but joint and the finished joint.

First I marked the center of the filler block:

Then I laid one half of the web in place so that it crossed the center mark and marked the end of the web:

Here you can see how much wood is on each side of the joint:

Then the glue is applied, the web is positioned and I stapled everything LOTS!

Here is the scarfed joint toward the root end of the rib, notice that most of this joint just happens to fall across the filler block for the jury strut.

Here is the scarfed joint toward the wing tip. This joint has less support from filler blocks.

All the stapes were removed and this surface scuff sanded before gluing up the other half spar and clamping it in place. The scarf joints required more sanding than the rest of the web just to get all the excess glue off.

I will try to get some detail pictures as I build the rear spars and put them in the next post.

Here is a special picture to round out this post. Saturday was the Antique Aircraft Association local fly-in at the Minden, NE airport. Our EAA chapter was asked to serve breakfast and lunch, so I spent the day watching airplanes. One of the planes is this PT-19 owned by my flight instructor, Ed Nelson of Nelson Aviation in Sidney, NE.

Well, I made a bit more progress this morning. Yup, this MORNING! My son had to be at the hospital at 4:00 AM to do a job shadow thing and, since my wife works close to the hospital, she went with. By the time they left I was awake and the coffee was ready.

What to do? Grab a cup of coffee and build airplanes!!!

All the half spars are basically done, but there are a couple that still need a few parts to be glued on. That is where I started. I pulled the finished half spar from the jig and replaced it with another one that still needed the spacer blocks for the compression struts and the aleron pully mount. I fitted those parts, then turned my attention to making my first ever scarf joints.

I had already cut the 2mm plywood strips for the spar webs, but they needed to be scarf joined to turn them into a single piece of plywood for the spar web. Scarfing is simply tapering the ends of the plywood at about a 12:1 taper. Since the plywood is 2mm thick, my scarf joints will be aobut 24mm wide.

On each piece I measured back from the edge of the plywood 25mm and drew a line to show where I was going to do the scarfing. Then I grouped the pieces by which end and angle the scarf would have to be made. I had two groups of four pieces of plywood each. The pieces were stacked such that they were back 25mm from the edge of the piece immediately below. Once in position I clamped them together and proceded to make the taper.

I started with a block plane and roughed them down at least half way. Then I switched to a sanding block and 60 grit sandpaper and proceded to make dust until the taper looked pretty good (to me anyway).

Each sheet of 2mm plywood is comprised of three layers of wood. The middle layer has its grain running perpendicular to the two outside layers. As the sanding removes the wood the layters show up as different colors. With each joint being 24mm wide, each layer of wood will show up as a color band about 8mm wide. The surface of the scarf ideally should have all parallel lines. I think I came reasonably close.

Here are a couple of pictures of my efforts:

The only problem that I had was that one of the pieces got inserted into its group backwards and I ended up scarfing the wrong end of that one piece. This is not a big problem because I can just scarf the other end of this piece and re-cut the end that I scarfed by mistake.

Once I shook all the dust off of the pieces and myself, I selected a couple of pieces to be my first ever attempt at gluing up a scarf joint.

The final step for the morning was to put wax paper underneith all the joints that I am going to glue. Mix up a batch of T88 glue and start smearing it on. The parts on the half spar are pretty easy to do ( I have now done quite a few of these). Then I lay a piece of wax paper over each joint and drive in a staple or two to hold things in place until the glue cures. I also laid a piece of wax paper under the scarf joint and proceded to smear the joint with glue.

Getting the plywood to lay still while I adjust it to be straight was a bit tricky. I finally put another piece of wax paper over the joint and put a staple through the joint near one edge. Then I took my long straight edge and made sure the two pieces of plywood were straight with each other and put a staple through the joint near the other edge. Then I added a couple more staples in the middle to make sure that everything was being held securely and evenly. I also did a second scarf joint.

Later today (lunch time) I will put the last piece of fir on the last of the half spars and glue up the other two scarf joints.

Well it has been quite a while, but progress has been made. Jeremiah and I found some time to rip the strips required for the wing spars and plane them to size. Then I finished the spar table, covered it with parchment paper and drew out a front spar full size. Then I laid on some of the strips that we had cut and fastened wood positioning blocks to hold things in place.

I now have four of what I am calling “half spars”. The next step is to cut the 2mm plywood web strips.

I also ordered a formal Airplane Builder’s Log book which should be arriving any day now. It is coming USPS, so it could be a few more days.

The fitting of the web pieces is a bit confusing, so I called Jerry for some advice. He thought that my plan for fitting the web would work very well. I will add more detail of that step when I get to it. For now I have some pictures of the last

Well, here is my first article on the topic of woodturning. It has been well over ten years since I have attempted to turn irregular shaped wood into round wood. Therefore, I would classify myself as a beginner.

So far I have checked out some books from the library and read them completely. I have located several blogs regarding this subject and have gone through them pretty completely. I purchased the book by Keith Rowley and am reading through that VERY carefully. I am part of the TurningAndTalking email group.

The equipment that I have is fairly limited, but should get me started.

I obtained a lathe via barter, so there was no expense there. However, I did need to buy some material and build a stand for it. Here are some pictures of the lathe and stand:

Here is the finished stand with the lathe mounted on it. The lathe is held onto the stand with six four inch lag bolts.

This is a pretty basic lathe. It does not have a Morse taper on either the headstock or the tailstock. It does, however, have a live center on the tailstock and a 1×8 thread on the headstock. I slid the tailstock up to the headstock and the points met! That was a real surprise! I had expected that I would need to do a bunch of shimming or grinding or fitting to be able to use it.

Here you can see that I have unscrewed the spur drive from the headstock. There is a faceplate that screws onto the headstock in place of the spur drive. With the 1×8 thread on the headstock I might be able to justify getting a four jaw chuck at some point in the future. Well, I can dream can’t I???

This unit has four speeds that are chaged via moving the belt across the pully sets. This could be the most difficult part of this project. There is no easy way to loosen the belt for movement. The screw holding the motor in place needs to be loosened by means of a socket and extension. The lowest speed is listed as 1100 rpm and the current setting is 1600 rpm. If I start by doing some work between centers I should be ok where it is for a while. I am sure it won’t be too long before I will need to learn to adjust the belt.

I also purchased a used bench grinder on eBay for $11.50 and have ordered new abrasive wheels for it. From what I have read, the first thing that people do when they buy inexpensive new grinders is to replace the wheels, so I don’t think I am any worse off going this route than buying a new grinder. When this one wears out, I will have a much better idea of the type of grinder to look for, plus I will have become such a good turner that I can justify an expensive sharpening system.

My other purchase was a set of woodturning chisels from Penn State Industries. I got their six chisel set, item #LCSIXW. From what I can tell, they seem to be a very good set of tools, at least for learning with.

My current project is building a sharpening jig. I will try to post more pictures when I get it closer to done.

That is it for this time.

Have a great day!
Roger

Well it has been quite a while since I last posted to my Maranda blog. Progress has been slow, but there has been progress. The main thing that got in the way was building a new dresser for my wife and myself. The one we had been using was bought at an unfinished furniture store well over thirty years ago. So it was time.

The dresser is made from white oak that was cut on my father’s farm in Minnesota. He has been cutting saw logs and having them made into lumber, then he stores them in some of his sheds to dry. So to give you a peek at my handiwork, here is a picture of the finished product.

Now on to the topic that you are really interested in; the Maranda.

As I mentioned on the Maranda list, I am getting ready to build my wing spars. Since I am building the 14-H model, the wings use built up spars. Built up spars require some type of table or jig on which to build them and since each one is about sixteen feet long, the kitchen table will not work. Therefore, I decided to build a special table just for making the spars on.

With a long time of consideration I came up with a way that I could build the table out of one sheet of plywood. Well, there are a few additional scraps of wood that will be incorporated, but for the most part it all comes out of a single sheet of ply.

Starting with a nice, clear sheet of 1/2 inch plywood, I cut two strips that are 11 1/4 inch wide and 8 feet long. This width was chosen because that is the widest that my table saw will cut. One of these days I will invest in table extentions, but that is what I have now. After these two strips were cut, I cut the remaining plywood into strips 4 inches wide by 8 feet long. In this picture you can see the strips laid out to show how they will be assembled.

To assemble these, I first laid two four inch strips end to end and laid a third four inch strip on top of them so that the third strip was half on each. Then I used one inch long sheetrock screws to fasten them together. I drove some of the screws from each side of the assembly.

Next I turned my attention to the top. The top is comprised of the two 11 1/4 inch strips fastened end to end. To fasten them together I scrounged around in my garage and came up with a piece of left over half inch plywood about six inches wide and two feet long. I marked a line along the center in both directions on both sides. Then I marked the center line of the long strips on the bottom for a bit over a foot on each one. These lines are used for alligning all of the parts. Then, with the top pieces laying bottom up on the floor, I screwed the small plywood board to them. Now there are only three pieces.

The next step was to set the four inch strips upright, place the top on them, and screw them together. I made sure the uprights were snug against the center patch, then measured the distance to the edge of the top. I addes 1/2 inch to the measurement and marked it on the top to show where to place the screws. This works for the four feet on each side of the center of the table.

The next step will be to get some more material to build some legs and a bit of reinforcement for the finished assembly. However, even at this stage it is quite solid and stiff.

That is how things are going at this point. Hopefully it won’t take so long to post my next update.

Well, even though it has been quite a while since my last post, things have been getting done on the plane.

The most progress has been made on the engine. I had two core engines that were both “stuck” and was trying to get at least one of them “un-stuck” to use as the base for the finished engine. Unfortunately, neither engine would give way on their own, so we had to resort to taking them apart the best we could while they were still frozen.

The engine that I had been working on the most is the one that was on my engine cart. I had pulled the valve covers, the rocker arms and push rods. Then I pulled the spark plugs and filled the cylinders with kerosene and let them soak for about three weeks. Still not luck with getting it to turn!

Well, a bunch of guys (about six) from church wanted to do something as a group project, so on Saturday, March 1st, they came over and we proceeded to tear down both engines. Between 9:00 am and 2:00 pm we got both engines completely torn down. Now I am going through the parts and selecting the best ones to build the new engine from.

When we pulled one head on the RL core about two cups of very fine sand poured out of one cylinder! No wonder we couldn’t get that engine to turn.

There was essentially no oil in either engine, so there was very limited mess during the disassembly process.

Out of 12 cylinder/piston assemblies there were 7 that were not frozen. The others are VERY rusted. I am hoping to clean up all 7 of the good cylinders and have them bored.

The crank in the RL core appears to be factory nitrided! This is good news if it is solid otherwise. It will still need to be magnafluxed to ensure that there are no cracks in it, then it will need to be evaluated to see if it needs to be reground. I am a bit concerned about this crank as some of the connecting rod end bearings look like they may have spun. This tag on this engine said it came from a car with a Power Glide transmission, but the bell housing was for a manual transmission and the pressure plate was still in place on the engine, so I don’t think that the crank had the 4 degree offset.

The cam shafts all looked good, but I will need to trade up to an OT-10 to get the proper performance.

I cut down one of the bell housings to make the front end cover for the new engine. I used a power scoll saw with a hacksaw blade in it for most of the cutting. This worked quite well, but the blade wore out before the job was completely done. I finished up with my hand hack saw. Now I need to do a bunch of filing to finish the edges the way I want them.

The cylinders are pretty rusty on the outside. I have started cleaning them up with a wire brush, but it will take a lot of brushing to get them ready to paint this way. I am going to make use of some of the stuck cylinders to experiment on ways to clean them up. I am thinking of trying sand blasting, naval jelly and electrolysis. And I might need to get a bench grinder and fit it with a wire wheel.

On the fuselage end of things I have been pulling staples from the ribs and looking for wood. Lowes in Lincoln has some very nice Douglas Fir but the longest lenght is 12 feet, so that would require scarfing every longeron for the fuselage and most of the really long pieces for the wing spars. I checked out both Menards and Builders Warehouse and came up with nothing. However, I just happened to stop at Foster Lumber and they can order anything that I want, so I am going to have them get me a quote for Douglas Fir in 16 foot lengths and Sitka Spruce as well. I can probably even have them deliver it to my house.

That about wraps it up for now. I don’t have any picture updates today.

Have a good one!

Well, there has been progress on the airplane and on the engine and on the shop and on the bathroom and …

What I am saying is that I have been busy!

So, the airframe is progressing in that all of the long ribs have been assembled. The first of the short ribs has been assembled as well, so we are onto the production of the next set of parts. Therefore, here are some pictures of the airplane parts.

One of the small improvements that I made to my work area is to add “stilts” to my work table. I used some pieces of 2×4 and built extensions for the table legs to sit on. This raised the working height of the table top from 29 inches to 36 inches. This is a real back saver!

Now, on to the engine! Progress has been made on disassembling the RH engine. Most of the external parts have been removed and we are waiting for the arrival of a nut splitter in order to remove the heads.

I got the book “The Classic Corvair” by Bob Helt. In his book Bob suggested using a piece of 2×4 to make a parts holder for use during the engine rebuild. This was a fun and easy tool to build. I decided to make mine a bit bigger than what Bob had suggested and I think it looks rather impressive. It is really fun to have a nice place and method for keeping the parts from the valve train organized. I have a largish nail to hold each of the rockers, balls and nuts for each valve. As I removed each piece I put it on the holder in it’s place. I drilled a 3/8″ hole for each of the pushrods. I do think that one of my pushrods is bent.

Here is where the prop will be installed eventually.

Here is the back of the engine. If you look closely you will see some of the white aluminum oxide that I am finding to be quite common in this core. I will need to be very meticulous in cleaning it up.

But I did mention the shop improvements as well. I needed more workbench space and I needed to start organizing the shop better. So I built an additional workbench. This one is fastened to the wall and is eight feet long. The shelf under the bench top will be used primarily for power tool storage. Right now I have my belt sander and some hand tools under there. I am busy using the scroll saw to make gifts and some tool parts like handles for pusher boards for doing small work on the table saw and router table.

Speaking of the router table, it is done and it works! I still have to finish the fence, but it is usable in its current configuration. This is being used to build the doors for the bathroom cabinet. One thing I discovered is that I really need to have the vacuum port on my fence. Without the shop vac handy there gets to be so many shavings that they get under the part that I am currently working on and it can climb up and throw the cut quite a bit off. Anyway, here is a picture of the router table.

The router table is a homebuilt unit from a magazine article. It was originally intended to be clamped in a bench vice for use, but I don’t have a proper woodworking bench vise, so I build some legs to go under it. I mounted a switched outlet under the table on the left side. This is a switch and single outlet that is a single unit and fits in a regular switch box. I might replace this with a double switch box and put in a double outlet and a regular light switch so I can turn on both the router and the shop vac at the same time. It was a fun project and is proving to be very helpful. I expect that I will be making quite a bit of use of the router table for shaping parts for the airplane.

Now the background project that I have been “working” on since March! THE BATHROOM!!!

Ok, so you can only see the toilet. My camera doesn’t have a wide angle lens and there isn’t enough room in there to get a good picture of the rest of the project. However, the new floor is in, the pedestal sink is in, the recessed medicine cabinet is in, the trim is installed and the cabinet is in. The only thing left is the doors for the cabinet and you can see the parts for them on the workbench if you look closely.

Well, that brings things up to date.

My wife and daughter will be at a women’s thing at church tonight, so my son and I are expecting to get a few more short ribs done. I will post more as progress is made.

It has been a long, busy summer, but some progress has been made since my last post.

Enough of the long wing ribs have been built for one wing. This weekend I will be building ribs at our EAA Chapter 1091 fly in here in Kearney. If you get a chance, come on out to see us. With the amount of time and being focused on building ribs I am hoping to have a significant number of ribs completed by the end of Saturday. Just to be sure that I have enough material to keep working on ribs, I ordered more 1mm plywood. It should be here tomorrow.

The big news is that I have finally located some engines that I can use to build the engine for the Maranda. The pictures show the condition of the engines at present. Before long we should be tearing them apart and cleaning things up.

The engines I am using are Chevrolet Corvair engines. The first one was from a 1963 model and had only 145 cubic inches of displacement. According to the manual I needed a 164 cubic inch engine, so I called the gentleman I bought it from and he said I could trade up. He went through the engines he had and came up with two complete engines that were “stuck” and one block, crank and cam unit. I exchanged the small engine I have for the larger ones and bought a gallon of penetrating oil.

This weekend I was able to put together a stand to put one engine on while we work on it. This gets it up to where we can comfortably get at things and see what we are doing. The stand has wheels so that we can roll it to a convenient location for working on it and then roll it back into storage when we are done.

Take a look at the pictures. I will try to keep the images updated as work progresses.

A Rib Is Born! Well at least the first rib is assembled.

I finally got time to assemble a rib. Things went well. Jeremiah helped me and even took some videos, so I am posting them today as well. The videos are in AVI format. My Windows media player doesn’t do much for them, but my Quick Time player shows them very nicely.

We built the rib as a team. I applied the glue and Jeremiah stapled the gussets in place. Jeremiah got a bit carried away with the staples in some areas, but by the time we finished he was doing very well.

Here is the video of getting started on the first rib:
Building the rib

Here is the video of me showing off the finished rib:
The completed rib