“No bird ever flew nonstop from New York to Tokyo, or raced 15 miles high at triple the speed of sound.
But birds do something else.
They do not conquer the air; they romance it..”
Some decisions in life are bare of any obvious logic.
Some people called me nuttzzz. Some people buy a porche when they get into the mid life crisis age. Other people take a second wife. Others get depressed. I decided to start building an airplane. A what ???? Yes, an airplane ! I skipped the phase of building the small plastic versions with glue and paint and went right into the real thing. My time is precious now so let's cut the obvious questions upfront. I heared them too many times already so here is the -mandatory FAQ reading- if you plan to visit my workshop.
"You're building an airplane?" : Yes, I am.
"A REAL airplane?" : Yes"
"In your garage?" : Yes. "
"One you can actually fly in?" : Yes!
"You can do that?" : Yes!!!
If you look at history, it's been thousands of years that people have dreamed about flight and it's only in the last 100 years that we have now the opportunity to build our own airplanes and fly. The current project work is the results of years of deliberation, evaluating and planning. I took the advice of other builders very seriously. The better you plan upfront, the less problems you encounter later. The type I have decided to build is the Van's aircraft, RV-7. I will motivate my choice in one of the subsections of this site.
I hope you enjoy following my building adventure and that you will return frequently to check on the progress. The latest activity will always be posted on the main page. You can also subscribe by RSSfeed. This will send you an email each time I post new progress. For subscription, click on the RSS icon in the bottom of the left menu on this page.
For people that live nearby, feel free to come and have a look. Don't forget to bring a six-pack. The most frequently used lubricant in my workshop is called "Jupiler", bring some as I'm frequently running out of stock.
In the previous articles I mentioned that my engine mount brackets had insufficient edge distance lengthwise.
I have been doing some research lately on articles and found that edge distance is more forgiving on steel parts then on aluminum parts.
Since I couldn't really measure the exact amount, I decided to take of one of the engine mount which I thought was in the worst shape in order to get a good measurement on it.
I was able to drill out all rivets without doing any damage to the material underneath and all holes remained nice and snug after removing the rivets.
Fortunatly I did drill them out because the results were bad... very bad.. So I decided to remove also the other side engine mount.
Part of the reason for this mess up is that the upper leg of the engine mount bracket was not clamped against the inside of the longeron.
The distance on the horizontal face of the longeron is in principle ok because I measure that according to the plans.
This is the looks of the right side bracket. The edge distance is not sufficient but still reasonable here. From the edge of the bracket to the side of the hole I have 0.107" where is should read minimal 0.1875"
You see also that the last hole on the bracket is useless as it's drilled lengthwise near the end of the bracket. There is no way I can fix that as the hole is already drilled in the longeron and there is insufficient space between the 2 last rivets to put one in between. I guess that last hole will not be critical if all the rest has good edge distance.
Here is the left side. This side is even more dramatic. Have a look at the bottom (rear) of the bracket). I'm so happy I took these off and checked.
Only 0.049" from the edge to the edge of the hole. That's definitly not enough.
Will order new brackets soon and in the meanwhile I'm going to experiment a bit with some aluminum bar the same gauge and test how far I can get with edge distance with proper clamping. Hopefully that will be ok because I don't feel like replacing longerons.
Here is what I think - after all this - is the correct procedure for drilling the engine mounts.
1. Do not rivet the upper engine mount brackets to the firewall yet when the manual tells you to do so. Keep them clecoed so that you can remove it later on to check your brackets after drilling.
2. Do NOT drill the side legs of the engine mount bracket to the fuselage side skin F-770 when the manual tells you to do so. Leave it open for now.
There is plenty of space on the vertical leg so edge distance after drilling here is no problem to do this later and it will give you more flexibility on positioning later. If you do decide to drill now, make sure the upper leg is clamped really thight to the inside of the longeron angle.
3. When you drill the gussets pilot holes length wise: do not evenly space the distance between rivets using length between first last hole. Do not followed the pattern on the plans. Instead, make a smaller spacing between the first 11 holes because those are where the engine mount comes underneath. Layout and check with the engine mount that you have sufficient edge distance at the end. Then divide the remaining distance for the other holes. The spacing will be slightly larger there. That's what you want.
3. Since you didn't rivet the engine mount yet, remove it from the structure and first drill the firewall gusset plate to the longeron and upper firewall angle. (just the aluminum parts) User pilot drills and enlarge for precision. Align the gusset length wise first. make sure you have the minimal edge distance on the inner side of the longeron. This will give you more edge distance on the engine mount as you move inward. Check this first with test fitting and drawing holes on the longeron. Then drill .
4. Now cleco the engine mount bracket to the firewall with all cleco's.
5. Remove the firewall gussets and thightly clamp the engine mount bracket top leg to the inside of the longeron. Check underneath that the vertical leg of the mount sits underneath the top one so that it's fully clamped to the inside corner of the longeron. Then drill through the longeron holes through the steel of the engine mount.
6. Remove and check edge distance.
7. recleco the engine mount top and front and drill the holes on the vertical leg (side) through the F770 fuselage side skin. Peel back side skin and dimple.
WARNING: I made a mistake on drilling the gussets... will explain the correct method "according to me" to drill the engine mount brackets and the firewall gussets in a future article (see 14/07/2017 article).
Continued on the fuselage gussets. In the last session I drilled them to the longeron.
I was not able to nest the forward side nicely on the firewall angle so I decided to make a slight bend in the gusset triangular from the corner (actually corner - width of longeron) towards the inner side. Even with the bend, the gusset doesn't touch the firewall angle but with slight pressure it nests well.
This made it possible to have the part where the rivets are to sit flush with the firewall angle.
Clamped and drilled. As you can see in the image below the gusset now sits flush agains the firewall angle and towards the corner bends up towards the firewall.
Another view fully clamped.
Here you can see the location of the small additional bend in the gusset
As I mentioned earlier, I had serious doubts about the edge distance on the top leg of the engine mount bracket.
A closer look already reveals the problem... The upper leg is lengthwise not flush with the inside of the longeron angle, instead, it's angled inward towards the end which makes edge distance smaller and small towards the end.
Major head scratch...
I tried to measure the edge distance but it's almost impossible to get a good reading while the mount is attached. As it is already rivetted to the firewall, removing it would be a drastic operation on the firewall structure.
I will have a night sleep on this and evaluate further tomorrow.
Removed the gussets and took this picture to illustrate the extra bend.
As a next step I deburred and cleaned the shoulder harnass attach brackets (F636, shoulder harness anchor).
The anchor is attached to the longeron using AN3 bolts.
To position the anchor, you have to draw a lengthwise alignment line 1/8" from the outboard edge of the longeron. Then measure a horizontal line at 17/32" from the front of the F708 bulkhed. The most backward line is my reference line perpendicular on the front of the F708. The second one (forward) is the one where the bolt will be centered.
Clamped the anchor parallel to the lengthwise line and showing the forward line through the back hole of the anchor.
Drilled and clecoed 3/16.
Good edge distance overall.
Here's a view with both passenger and pilot side drilled.
Deburred holes on longeron, gussets, canopy deck, F757S, aft deck F714 and F636 anchors.
Next I noticed that I forgot to dimple the vertical line where the F-728A channel attached to the F706 bulkhead. I rivetted the channel and angle at an earlier stage so all I had to do left was to dimple the holes for #30 and rivet it together.
Don't rivet the row on the left side (in the picture) just yet as the F787 stiffener web will attach also at that location.
Tried to rivet the connection of the bellcrank channel with the 706 and I set two rivets. I tilted both of them. Started cursing and called it a night... I'll get back to this when my nerves cool down.
Vans mentions in the plans that this is a difficult location and allows CS4-4 pop rivets in the lower three holes and that's probably what I'll end up doing.
Continued on the canopy decks and the F-757-S for sliding canopy.
In the previous session, I drilled these to through the forward side through the holes in the F-721B canopy deck.
Next step was to mark the locations as mentioned in Detail A of plan DWG25.
The detail A doesn't mention any dimensions for distances. You will find these on the detail image for cutting F-757-T for tipup canopy.
9/32" are required from the side of the longeron for edge distance and then you measure 1/4" from the aft end of the F--705-F channel.
This requires to remove the F-757-S temporarily.
From that point, measure twice 1" 7/32. I guess the positioning here is not all that critical as long as sufficient edge distance from side and aft end of F-757 is ok.
Clamped back in place and drilled the first hole to #40.
Then continued with the rest at #40 and finally used some new drills I bought from PANAM from #40 to #30.
These special drills are really great The tip is a pilot drill of #40 and the drill enlarges to #30 in a single step. They also have them in larger sizes and there are even reamers with this step principle. Really cool stuff.
Here the 3 holes are drilled to size.
Repeated the same on pilot size and then started working on the F-695 forward fuselage gusset.
Earlier this week, I made some measurements on the part to lay out the rivet pattern.
WARNING: I made a mistake on drilling the gussets... will explain the correct method "according to me" to drill the engine mount brackets and the firewall gussets in a future article. (see 14/07/2017 article)
Measured 5/8 lengthwise from the front and then divided the length until end - edge distance by 13. This gave me the length for spacing to get 14 holes.
Well, this was my first mistake of the day... but didn't know that yet
What you should do, is take a bit less spacing on the first 10 rivets as these are the ones that also go through the engine mount bracket and you end up with an edge distance problem on the engine mount bracket end if you measure my way.
So make sure to check edge distance of the 10th hole with end of engine mount before drilling.
Steel is more forgiving on edge distance but better to measure differently if you still have the change.
I also question if the 7/16 distance from the length side is a good idea. You could go wider here ensuring that you still have enough edge distance on the other side (inner side of the longeron). Having less there will give you more spacing on the engine mount bracket. You'll see why in a minute...
In my case I drilled and now my hole in the longeron is defined which gives me no more possibility to correct unless I re-order and repeat all the work on the longerons. Which is a big NONO...
In the picture above, you also see a line on the firewall side. This is the part that I need to grind off in order for the firewall to rest flat horizontally against the firewall.
Then I drilled the holes and copied them on the other gusset.
I clamped and made some markings of the holes with the pen and removed it again.
The edge distance on the inboard side looked great but in all my enthusiasm didn't think about the engine mount brackets.
I also had to make a triangular bend horizontally to ensure the forward end was laying flat on the firewall top angle. Without the bend, the gusset was too high and couldn't touch the firewall angle on the outboard side.
Then clamped the gusset bacj in position and drilled all the holes to #31 and finished them with a #30 reamer. Use lot's of boelube and slow speed as you will be drilling through steel.
Bottom view... Damn... those holes in the engine mount look really close to the edge...
This is where I realised that I would have needed also to clamp the engine mount bracket top flange and pull it inward against the longeron.
I'll have to inspect that more closely and cold sweat breaks out...
I learned by now that if you feel you messed up, you need to step away and come back with a fresh mind... which is what I did at this point. I'll re-evaluate tomorrow morning.
Started working on the F-721B canopy decks. These were drilled earlier to the longeron after it had been bent and now needs some more modification to fit with the F-757-S plate.
First I modified the F-757-S as per the plan DWG25 for a sliding canopy. The part comes without the cutout so you need to mark the dimensions on the plate and then make a 2 inch radius cut out on the inside corner.
Best is to draw a line in the length direction to mark the 1" 13/32 mark.
The 2 inch radius will not extend to the side so it's hard to estimate that your radius doesn't pass the 1"13/32 mark.
I used a fly cutter in the bench drill and aligned the extend of the knife to the 2" 3/8 mark and then aligned the piece so that the other part of the radius didn't pass the 1" 13/32 line.
Worked fine and just needed to grind away the last bit on the front to make it straight. Worked fine.
The next step is quite complicated as well. You need to cut a sleeve in the canopy deck between two marked points. This is where the F-757 will slide in.
It sounds simple but cutting a straight line with a dremel tool and a cutting disc is always a challenge for me.
I scratched my head for a while and then decided to clamp a wood block on the canopy deck in order to guide the disc while cutting.
This worked very well. Just slide the front of the cutting bit against the wood and keep the dremel level. This ensures a straight and quite clean cut that doesn't take away too much material.
This is how the cut looks like. Uncleaned directly after the cut.
And here it is after cleaning it up with some key files and sanding paper.
Then did the same for the one on the pilot side.
Installed it on the canoe.
At first, the F-757 wouldn't fit very nicely in the longeron. I rounded the top edge as the manual suggests and now have a good flat mating connection of the F-757-S to the longeron.
The forward side also butt's nicely in the longeron. Ready to drill, but that's for the next session.
Oshkosh is to you like Mekka is for a Muslim.
If you haven't been there at least once in your life, you will NOT go to heaven !
From Belgium, it's quite a trip but in the last five years of building, we managed to go twice to Oshkosh.
Nothing beats the experience of Oshkosh air venture in Oshkosh Wisconsin.
The first time we went, I visted sun'n fun in spring and decided to also visit Oshkosh. On sun'n fun there were rv's but the experimental parking there is kind of isolated and more difficult to make contact.
So my idea before arriving in Oshkosh was, 'wel I hope there will be some RV's'.
There are hundreds !
Most even camp next to their airplane and it's a real family style setting which is very inviting to go and have a chat to the owners.
I strongly recommend it to anyone, anywhere around the globe. Anything GA related will be represented at Oshkosh and it's definitly the only location in the world for home builders in the world where all info, resources and suppliers are availble at your fingertips. Wanne play with the next Garmin G3x hands on ? and some minutes later compare it you the Dynon skyview touch ? well... only at Oshkosh. Strongly recommend also the local hardware vendors where you feel like a kid in a candyshop having all those rivets, bolts, tools laid out in front of you. (small side remark: travel light, you will return heavy). There are often also the best discounts and deals to be found during the Oshkosh week when you buy there. Some even send it later at same price when you order there. I bought my VPX, aeroleds and lots of other stuff there.
I can also recommend the vansairforce.net gathering which takes place every time after the show in a house just outside of the airport. There 's hundreds of vans of builders there.
Another good tip: plan ahead ! there's hundreds of workshop, celebrity appearences, shows, movies, honourings, lectures, .... You will not be able to do all. Let me rephrase that: you will only be able to see a fraction of it, so it's very important to plan your trip ahead. The full agenda is available upfront and they even have a smartphone app. But save yourself the trouble in the evenings of your visits and plan ahead. You will be tired from walking all day, busy with late evening show or events so you just don't have the time for it. Do it at home, The agenda is fixed months upfront so plenty of time to prepare.
Vans aircraft has a tent withsome planes at Oshkosh, so it's a good opportunity to meet some of the well known names from van's support in real life. If you're lucky you can spot Van himself and take a picture. Also the vans dinner is a good moment to meet fellow builders but it's kind of like a static setting where once you sit, you are with the same people around your on your table.
Fir the vans dinner, you have to reserve and pay upfront via the mothership.
The vansairforce.net keg party is more like beer drinking thing in a garden outside of the house and gives much more possibilities to walk around from group to group. Ask on the vansairforce net forum for the exact time and location as it sometimes varies. Doug will be glad to help you. You will also meet some of the more famous builders like the members of the teamaerodynamix.
When organising your visit, make sure to book a student room in the local oshkosh university. Rooms are much cheaper than in the local hotels and if you book late, you might end up in cities far away from airventure as hotel infrastructure is very limited in Oshkosh itself. If you want a room in the university, book couple of months after the last airventure ended as they also sell out quite fast. The university campus will be full of aviation enthousiasts and there is a nice beer-terrace just outside of the parkinglot where a lot of them gather in the evening. Very nice place to get to know new people that share your passion. Busses to airventure are organised from the campus to the Oshkosh airfield and run in 15 minute intervals.
If you have some spare time, the Oshkosh air museum is defenitly worth a visit as it has some of the original RV's on display like the prototype RV-1 and early versions of the RV-3 and RV-4.
Visit airventure website for details on schedule.
Did you find my blog helpfull or do you want to support my project. Feel free to make a small donation using paypal. Any gift is welcome. Every cent helps.
At the Oshkosh airventure 2013, I took this cool shot with Richard VanGrunsven, founder and CEO of Van's aircraft. We had a short chat after he came out of a presentation where he attended putting the young eagles project in the spotlights.
Richard -usually known as "Dick" or "Van" was born in 1939 and became an American aircraft designer and kitplane manufacturer. These days his kits are so popular that the number of VanGrunsven-designed homebuilt aircraft produced each year in North America exceeds the combined production of all commercial general aviation companies.
Some advice on reading my log for fellow builders !
In some articles, I made corrections at later date on the original article to rectify my own stupidities or faults. Read through the entire article if you intend to use my findings/experiences on your own project !