V - Witt / Witts V

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Little Scrapper

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The rib has 2 solid blocks. Here are the templates/patterns and the blocks.

I simply shot a piece of Sitka stock through a planner to get a 1/2” thickness and with a sharp pencil I drew all the blocks with the aluminum templates. Cut them oversize and sand to fit tight per rib.

Everything is made to fit as I build each rib. Nothing mass produced ahead of time. It’s more fun a peaceful this way for me.

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Little Scrapper

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Sections of the rib have a doubler on the capstrip. I just spaced the cams away so one can works for all ribs and I either put a spacer in or the double capstrip in. That’s how I solved that issue. You can see a massive spacer (number 2) which holds the front spar vertical member in place. Couple reasons for this.
Some ribs are different because of plywood reinforcing on the spar so the jig needs to be adjustable to compensate. Also, once the gusset is on it’s really hard to remove a cam under it so this just makes it accessible to release the rib from the jig.
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Little Scrapper

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Lastly, as far as the jig is concerned, there’s one thing worth mentioning. I’m not saying it’s smart and it will work but I did one thing that could set me up for success once the ribs are built.

In these two photos you’ll see a nail in each one. These are stops for the blocks and the gussets. I basically insure that the blocks and the gussets on the leading edge and trailing edge of the rib gently kiss those nails. On a V-Witt, near as I can tell on the plans, has a Sitka Spruce board that is glued and screwed on to both trailing and leading edges. Assuming my spar openings are accurate (rib jigs job) these should all align perfectly so everything makes up as it should.

Well, it might not but I figured it would get me closer to a successful outcome. It will probably still need to be adjusted but this is what I did so we’ll see shortly.

What you see in all these photos is my first sample rib to test out my jig and verify the accuracy etc as well as the adhesive. If things work out I’ll be making this sample rib this week yet.

I’m also working on the fuselage but ribs and wings are fun winter work.
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Little Scrapper

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Actually, this is probably a better photo explaining the cams under the gussets. Clearly it’s tight. The last gusset on the trailing edge completely covers the rear cam so that cam won’t be tight, just snug enough to hold the cap strip piece on the spar opening and nothing tighter than that.

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Little Scrapper

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Was looking forward to gluing up a wing rib but my scale broke. Ordered another one on Amazon Prime so this is as far as I got.

Pretty self explanatory. Drilled the aluminum gussets so I can accurately mark nail holes. Set the nails in the gussets so they’re ready, nail tips slightly protruding to prevent sliding on epoxy. Acid brushes for application trimmed short so they are stiff for spreading thick epoxy. Jumbo epoxy sticks from dime store cut in half for mixing A&B. Postcards (small) for weighing A & B and large postcards for mixing. Jig board waxed.

I’m at a standstill until new scale arrives.

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Little Scrapper

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Edit: with weighing I can get the exact amount I need with no waste. Otherwise I’m limited to volume sizes pre determined like a pop can or a plastic shot glass etc. Syringes work I guess but weighing is just easy peasy.
 

jvliet

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This is Jim Vliet checking in. I can answer most questions about the V-Witt, Sonerai-1 and history of Formula V air racing 1977-1999. A couple of safety recommendations - 1) please always wear a safety helmet when flying a V-Witt. Out of about 10 that have been flown, 3 were involved in fatal accidents where the pilot attempted an off-runway landing, the aircraft flipped and the pilot (not wearing a helmet) struck his forehead against the wing wire support truss just forward of the cockpit. 2) Don't use the Solex 32-PHN-1 sidedraft carburetor that Steve used on his prototype #1 V-Witt.... that carb is verrrrry prone to icing. Steve solved that problem by taking air into the carb from downstream of his oil cooler, hence running constant carb heat which decreases power.

BTW FV air racing was very successful in the early 1990's but ended due to 9/11 when FV lost all the pending corporate sponsorship AND lost the use of our training airfield in Indiana... I am currently converting some VHS videotapes of FV races to digital and will be posting on YouTube in the next few months.
 

Little Scrapper

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This is Jim Vliet checking in. I can answer most questions about the V-Witt, Sonerai-1 and history of Formula V air racing 1977-1999. A couple of safety recommendations - 1) please always wear a safety helmet when flying a V-Witt. Out of about 10 that have been flown, 3 were involved in fatal accidents where the pilot attempted an off-runway landing, the aircraft flipped and the pilot (not wearing a helmet) struck his forehead against the wing wire support truss just forward of the cockpit. 2) Don't use the Solex 32-PHN-1 sidedraft carburetor that Steve used on his prototype #1 V-Witt.... that carb is verrrrry prone to icing. Steve solved that problem by taking air into the carb from downstream of his oil cooler, hence running constant carb heat which decreases power.

BTW FV air racing was very successful in the early 1990's but ended due to 9/11 when FV lost all the pending corporate sponsorship AND lost the use of our training airfield in Indiana... I am currently converting some VHS videotapes of FV races to digital and will be posting on YouTube in the next few months.
Jim, I love it when you check in, thank you! Any advice on the build & concerns about safety are very much appreciated. Thanks for the safety notes in your post!

Mike
 

Little Scrapper

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Glued up one side of a test rib, went very well. I’m not gonna post many detailed photos of the rest of the ribs because it’s boring repeated photos but I will post details of tonights session.

Not many people mix T88 by weight which is unfortunate because it’s very easy and extremely quick and pain free and absolutely dead nuts accurate. Here is how I approach mixing by weight.

T88 by volume is 1 to 1 but by weight it’s 100 parts A to 83 parts B. I used a scale I bought on Amazon Prime. I calibrate it before and after gluing just to keep it honest. I calibrate it with 4 pennies 1 at a time. Pre 1982 Lincoln pennies weigh exactly 2.5 grams so it’s easy to calibrate and check anytime you want.

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I have 2 sizes of cheap note cards. Small ones for measuring and large for mixing. I cut the small ones to fit the scale and pour part A on, whatever I come up with is 100% and this dictates everything. I started out estimating the size and it turned out perfect. The random squirt of part A came out to 4.150 grams. Because T88 has a weight ratio of 100/83 I simply took the 4.150 x .83 and that gave me 3.444 as a goal for part B. I put a piece of card on and squirted it to 3.410 which is razor close.

took my cut in half jumbo popsicle stick and pushed it clean off the small card on to the large mixing card. My goal was to mix enough for 1/2 of 1 rib side, so two separate glue mixes for a full side. As you can see I ended up with almost no waste.

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It’s really a clean way to deal with epoxy. Zero waste.

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Then mix.

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Little Scrapper

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I spread the bulk of the gussets with the stick and then push it smooth and consistent with a acid brush cut with a scissors so it’s stiff.

The rest of the photos are pretty self explanatory.

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Little Scrapper

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The estimate for quantity of epoxy for the front half was good. Very little waste left over so I wrote it on my wall for later reference.
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Little Scrapper

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For the 2nd mix I just repeated the same process. I labeled the post card so you can see the “goal” vs the “actual” in weight. Because I wasn’t sure and didn’t want to run short I mixed a little on the heavy side. I ended up with some waste so I went back to the white board and made notes on the second half. I now have a set of numbers to mix and it’s tea easy to do.

mixing by weight is very very quick and accurate and the process is extremely clean.

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Here’s the final rib with just one side glued and nailed. I finished this at 8:00 pm so it will be ready to pop out, flip and repeated tomorrow night at 8:00 pm.

I’m sure it will check out fine so I’ll be putting together ribs for the next month or so. I won’t be posting many photos because it’s all the same but just wanted to explain to those who have never use the weight method how I approached it.

Mike

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12notes

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Nice job!
A bit about little scales and weighing, you may know this stuff, but others may not. An accurate lab scale that measured down to .001 grams has to be encased in a box, as small air currents will affect the measurement, and by small, I mean breathing anywhere in the vicinity is enough. The small, inexpensive scales like the one you used often get returned "because they never settle down" if they accurately show that digit, so they frequently dampen the response by only changing the value by 1 every few seconds, only using 0 and 5, locking in the first value, or just using a random digit. Some small ones are accurate, but will drive you crazy if you try to be that precise.

Good decision to not chase the third and fourth digit. I've seen people waste time and epoxy trying to make it unnecessarily "perfect". We only use the milligram scale for dye concentrations that are measured in parts per million. Something that I did for mixing chemistry which might help is to weigh one drop of the most common monomer from the dispenser we use so I know what level of precision is possible, in my case, one drop is .03 grams. If I'm less than that off, it's not worth chasing.
 

Little Scrapper

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Pulled it out of the jig and checked everything. She’s plumb and square to the world. All the numbers are good.

Gonna cap the other side, start steaming some cap strip and move forward with the rest of the ribs.

I tried to make the photos interesting and fun but let’s be honest, it’s a rib, not much to do with it it looks like a rib should look. Haha.

Going to try and make ribs every day 7 days a week until they are done. I maybe won’t do a rib a day but I’ll do something rib related each day until they are done. I won’t be posting many photos of the process on the other ribs because it’s the same as I did in these last few posts. See you in about a month or so.

Mike

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Dam that’s a narrow looking rib!

I’m so excited to be back working on airplane stuff. It was a long road to get here. I finally have my weekends and no more working 7 days a week. It’s almost weird typing this on a Saturday at noon. I’ve worked Saturdays and Sundays for decades. It just feels weird. Regardless, I feel so dam centered now. Such a good feeling to work on fun projects with literally zero pressure to something else or feel like you should be working. I should have done this years ago.
 

jvliet

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Mike, seeing the photo of the wing drawing reminded me of something that happened when I built my wings - I ordered four sheets of 1/16th thick 45 degree aircraft mahogany plywood from a reputable east coast vendor, and when the crate arrived by truck, I was upset to find that they had shipped me four sheets of 3/32nds 90 degree plywood instead. Using the 3/32nds would have added a lot of weight, which was unacceptable for a racer. I called the vendor up and they said that either 1/16th or 3/32nds was called out on the plans, I answered "what plans", they replied "Tailwind". I replied "As I told you on the order form, I'm building a V-Witt, not a Tailwind". The original W-Witt wing drawing did not state plywood thickness and type, I had the plywood specs. directly from Steve verbally. It was a hassle to return the plywood as the trucking co. had to return to pick it up, and the trucking co. complained that they don't originate shipments from homes without a loading dock. So I returned it and eventually they shipped me the 1/16th plywood that I had originally ordered.

And then, another story.... in 1987 EAA had a feature activity at the Oshkosh flyin for all Wittman-designed aircraft. I got permission from EAA to trailer my V-Witt there. As we were pushing it into a parking spot on the row of Wittman aircraft (mostly Tailwinds, of course), some guy runs up and yells angrily "get that **** casooot outa here! This row is for Wittman aircraft!". I calmly informed him that it wasn't a cassutt, but a Wittman V-Witt. He stormed off, still fuming, and I then moved my #33 further down the row nearer to Wittman's V-Witt which was at the end of the row nearest the runway. Several days later all the Wittman aircraft flew in the flyby pattern prior to the afternoon airshow. While Brian Dempsey was flying #33 in the flyby, the canopy popped open and he had to hold it down with one hand while circling back to land it... The canopy frame had bent just enough to dislodge the front latch pin.
 

Little Scrapper

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Mike, seeing the photo of the wing drawing reminded me of something that happened when I built my wings - I ordered four sheets of 1/16th thick 45 degree aircraft mahogany plywood from a reputable east coast vendor, and when the crate arrived by truck, I was upset to find that they had shipped me four sheets of 3/32nds 90 degree plywood instead. Using the 3/32nds would have added a lot of weight, which was unacceptable for a racer. I called the vendor up and they said that either 1/16th or 3/32nds was called out on the plans, I answered "what plans", they replied "Tailwind". I replied "As I told you on the order form, I'm building a V-Witt, not a Tailwind". The original W-Witt wing drawing did not state plywood thickness and type, I had the plywood specs. directly from Steve verbally. It was a hassle to return the plywood as the trucking co. had to return to pick it up, and the trucking co. complained that they don't originate shipments from homes without a loading dock. So I returned it and eventually they shipped me the 1/16th plywood that I had originally ordered.

And then, another story.... in 1987 EAA had a feature activity at the Oshkosh flyin for all Wittman-designed aircraft. I got permission from EAA to trailer my V-Witt there. As we were pushing it into a parking spot on the row of Wittman aircraft (mostly Tailwinds, of course), some guy runs up and yells angrily "get that **** casooot outa here! This row is for Wittman aircraft!". I calmly informed him that it wasn't a cassutt, but a Wittman V-Witt. He stormed off, still fuming, and I then moved my #33 further down the row nearer to Wittman's V-Witt which was at the end of the row nearest the runway. Several days later all the Wittman aircraft flew in the flyby pattern prior to the afternoon airshow. While Brian Dempsey was flying #33 in the flyby, the canopy popped open and he had to hold it down with one hand while circling back to land it... The canopy frame had bent just enough to dislodge the front latch pin.

Jim, stories like this are great!!!! I’m not alone when I say people here enjoy aviation stories. I’ve searched the internet pretty deep for anything V-Witt related and there’s just nothing. Please, if anything pops up in your head related to this airplane, history, home building or racing feel free to post it here. In fact, make as many posts as you can. The only chance the younger generation has to learn about the past is from those who have done it and experienced it. Even a simple conversation with Steve is worth noting because far too many people have not recorded this stuff.

Again, thanks for posting!!!!

I’m in my shop right now working on wing ribs. I’m not really good with technology in fact I’m just horrible with it. It took me some time to figure it out but I connected to my shop internet my iPad and figured out how to stream the old Jimmy Stewart movie “Spirit of St Louis”. Then I figured out how to hook it to a big speaker. I feel like I’m in heaven right now working on ribs on a casual Sunday just having fun. I feel so fortunate to have my health and my passion back for fun things like this.

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Have a great day!
 
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