B-Model conversion
Posted: Sat May 26, 2018 7:33 pm
by fastj22
Everyone got the Sonex email about discounts for the B-model conversions, 10% off. Looking at the price, it might be something I want to do, under $10k. And I really like the look of the B. Has anyone converted a flying legacy model to it yet? Can you do most of the fabrication while still flying your Model A then come winter, do the swap? Lots of things I’d like to do better turtle deck forward. Sure like 20gals up front. I’d probably still do a tilt back canopy.
Re: B-Model conversion
Posted: Sat May 26, 2018 8:34 pm
by thomas
Hi John,
I believe Leroy Brandt’s B-model was a conversion. Here’s his thread:
viewtopic.php?f=58&t=4039&p=30901&hilit=leroy#p30901
I hope you’re not too much in a hurry to convert as I would regret not getting to see your famous “speed cowl” at a fly-in some day!
Paul
Re: B-Model conversion
Posted: Sat May 26, 2018 9:36 pm
by sonex1374
Since the B Model conversion kit is pretty much new parts forward of the seatback, you probably could build most of it as a unit, then make the swap all at once. Plus, your plane is running really well, so it’s about time to tear into something, right? (I know, I know, stop egging him on!)
Jeff
Re: B-Model conversion
Posted: Sat May 26, 2018 9:53 pm
by fastj22
Interested in what changes to the wing rigging. The Model A bolts go through the vertical supports. Since these move outboard? Is there some gusset or other flange to keep the same holes?
B-Model conversion
Posted: Sun May 27, 2018 7:08 am
by n307tw
fastj22 wrote:Interested in what changes to the wing rigging. The Model A bolts go through the vertical supports. Since these move outboard? Is there some gusset or other flange to keep the same holes?
I’m building a b model and can send you some pictures if interested of the build and plans - nearly done with the fuselage. Let me know what you want and I’ll email them to you. All the best.
-Tim
Sent from my iPhone using Tapatalk
B-Model conversion
Posted: Mon May 28, 2018 11:43 am
by Lbrandt
fastj22 wrote:Interested in what changes to the wing rigging. The Model A bolts go through the vertical supports. Since these move outboard? Is there some gusset or other flange to keep the same holes?
John
The skins of the wings are trimmed to match the shape of the new fuselage. Basically from nothing at the trailing edge to about 3” at the leading edge. New machined wing mount blocks are included and used to replace the 1” angle with solid aluminum blocks that we fabricated for the Legacy wing mounting. These have pilot holes for tre wing bolts and the installation went well. If I remember correctly there were new root ribs but not all new ribs. I formed new ones for the items that were not in the kit.
I’m very cramped in my fuselage because if the lowered seat. I felt much more comfortable in the Legacy model.
I did appreciate however the added firewall area for installing all the goodies for the UL engine.
For anyone building the B model (the windshield is attached to the aluminum skirt while laying flat on the bench), I sure wish I would have known that.
Now that our turf runway finally firmed up I should be able to start flying more this week. I only was able to get three short flights last winter.
Hope this helps a little.
Leroy
Sent from my iPhone using Tapatalk
Re: B-Model conversion
Posted: Mon May 28, 2018 7:56 pm
by fastj22
Lbrandt wrote:I’m very cramped in my fuselage because if the lowered seat. I felt much more comfortable in the Legacy model.
I did appreciate however the added firewall area for installing all the goodies for the UL engine.
Leroy,
Curious if the above statement is accurately typed. Do you find the B-model more cramped? I fly my waiex center most of the time and have the lowered seat. Flying left seat is a bit cramped.
B-Model conversion
Posted: Mon May 28, 2018 10:40 pm
by Lbrandt
fastj22 wrote:
Lbrandt wrote:I’m very cramped in my fuselage because if the lowered seat. I felt much more comfortable in the Legacy model.
I did appreciate however the added firewall area for installing all the goodies for the UL engine.Leroy,
Curious if the above statement is accurately typed. Do you find the B-model more cramped? I fly my waiex center most of the time and have the lowered seat. Flying left seat is a bit cramped.
I do feel that because of lowering the seat that I’m cramped. The center stick hits my leg where with the dual stick my knees could spread. I can’t use my rear leather seat cushion because it pushes me too far forward. Others may fit in the airplane differently than I do however.
I tried sitting in the middle but I’d didn’t care for it.
Sent from my iPhone using Tapatalk
Re: B-Model conversion
Posted: Sun Jul 08, 2018 7:09 pm
by fastj22
Preliminary clearance from the home ATC to pursue a B-Model conversion approach. Now I gotta go to OSH to sit in one before executing it.
Re: B-Model conversion
Posted: Thu Jul 26, 2018 8:06 pm
by fastj22
So I pulled the trigger and bought the conversion kit at the show. I won’t be documenting the process on these inner tubes as you jackals will rip me apart, but I will periodically report in on something noteworthy. Once you sit in a B model, you will follow me, unless you have much more self control than I do. Nice winter project I hope.
Re: B-Model conversion
Posted: Fri Jul 27, 2018 9:58 am
by N111YX
That’s great news, John. It was great to see you at OSH. Sorry to have been so busy and working with such short time. Keep us posted on that conversion!
Re: B-Model conversion
Posted: Mon Oct 08, 2018 7:15 pm
by fastj22
Received the kit today. No damage!
Did a cursory inventory.
Cowl looks great. Big improvement from the old one.
Glare shield pre-bent (correctly)
Lots of machined fiddly bits. All match laser holed.
Panel is HUGE! Compared to the A–
Aileron push rods are now aluminum tubes instead of welded steel.
Seat pan looks like its riveted to the floor stringers. Stiff but will probably need to cut access holes for stuff.
Got a complete set of plans for building an entire B-model. Replace my ratty old ones. I kinda forgot how horribly wonderful they are. Everything you need to know is there, its your puzzle to read each page 15 times to understand what they mean! Just kidding Sonex. They are fine. Just not really a step by step manual. Its been like 5 years.
Also looks like there will be little fabrication of parts, unlike my A-model was. I will also need to create a hardware order as only rivets were included.
Reading the conversion notes, basically, everything forward of the turtleneck is new. Need to graft in some splice plates to my tail cone. But looks like I can build the entire forward section except rigging and keep my plane flying. Heck, might even try to preserve the old cockpit for the EAA chapter.
My A-model has been flying since 2013 and I’ve helped get another Sonex finished up, but I’m like a kid at Christmas. Can’t wait to start.
My plan of attack is to fully inventory the kit this week. I’m out of country for the next month which is probably good. Time to settle down.
Then start building, putting the entire forward section from F-18 to F-01. Get the B-modeled wired properly, then when I can’t do much more, take the A-model down, pull the wings, the engine and graft on the new fuselage. I can probably do the windshield but not the canopy until mated. Can’t do the cowl until I have the engine hung either.
Couple of other things I plan, replace my old Garmin xPonder with the Trig22 ADS-B. Add a second A/P servo to my MGL. Oh and a smoke system. Gotta have smoke. Just need to figure out how to fit in the tight spaces.
Stay tuned.
There will be a lot of spare parts from the A-model available at discount prices, if I don’t create a museum piece from the old a-model.
Re: B-Model conversion
Posted: Mon Dec 17, 2018 9:27 pm
by fastj22
Project update.
I’m back from Antarctica and have dug into the project.
Got the seat pan all up drilled and clecoed. Side panels are mostly done too.
Its good to be back into the building mindset.
So some comments.
The conversion kit is basically everything unique to the B-model. They expect you to use common parts/assemblies that are included in the A-model kit. If you have a flying A-model, you will need to either purchase these parts, fabricate them, or harvest them from your A-model. Initially I was a bit disappointed but understand the rational. I think Sonex might make some more coin offering a couple of conversion options. One where the builder hasn’t progressed beyond the tail, and one for a completed aircraft.
I’m now seeing the point where I must do major surgery on the plane. But every weekend the WX is good and I take the bird out for 30 minute yank and bank. Then work on the conversion.
Re: B-Model conversion
Posted: Sun Feb 17, 2019 7:32 pm
by fastj22
IMG_1668.jpg (15.69 KiB) Viewed 8366 times
Update…
Off with the old, on with the new.
I’ve had to pull back the vinyl to make clean rivet/bolt attachments. I’ll probably pull the entire wrap off, strip the paint (which I should have done anyways), and re-wrap. Going to attack the wings next.
Re: B-Model conversion
Posted: Mon Apr 22, 2019 12:19 am
by NWade
fastj22 wrote:
IMG_1668.jpg
Update…
Off with the old, on with the new.
I’ve had to pull back the vinyl to make clean rivet/bolt attachments. I’ll probably pull the entire wrap off, strip the paint (which I should have done anyways), and re-wrap. Going to attack the wings next.
John - Given how far you’ve gotten on your conversion, I was wondering: Do you think the new B-model style of lowered seat-pan and control-yoke/push-rod arrangement could be applied to a Legacy Sonex?
I can’t swing a B-model conversion, but as my bird nears completion I’m finding that I’m about 1" too tall in the torso to fit my legacy Sonex with the standard seat and a center stick. I really don’t want to put in dual sticks in order to accommodate the lowered seat mod; but the B-model gets both a lowered seat and the center stick, doesn’t it?
Thanks,
–Noel
Sonex #1339
Re: B-Model conversion
Posted: Mon Apr 22, 2019 8:41 am
by fastj22
NWade wrote:
fastj22 wrote:
IMG_1668.jpg
Update…
Off with the old, on with the new.
I’ve had to pull back the vinyl to make clean rivet/bolt attachments. I’ll probably pull the entire wrap off, strip the paint (which I should have done anyways), and re-wrap. Going to attack the wings next.John - Given how far you’ve gotten on your conversion, I was wondering: Do you think the new B-model style of lowered seat-pan and control-yoke/push-rod arrangement could be applied to a Legacy Sonex?
I can’t swing a B-model conversion, but as my bird nears completion I’m finding that I’m about 1" too tall in the torso to fit my legacy Sonex with the standard seat and a center stick. I really don’t want to put in dual sticks in order to accommodate the lowered seat mod; but the B-model gets both a lowered seat and the center stick, doesn’t it?
Thanks,
–Noel
Sonex #1339
Converting a standard A model seat to a lowered seat would require a fair amount of fabrication and rework. The C channels supporting the seat are smaller and the aft attach point for the pan is moved back. I could harvest the aft attach off my old A model and send it you if you’d like. Its going into the scrap heap anyways. Have you considered just flying your bird seated center with your feet on the outer pedals?
Re: B-Model conversion
Posted: Mon Apr 22, 2019 11:56 am
by NWade
fastj22 wrote:Converting a standard A model seat to a lowered seat would require a fair amount of fabrication and rework. The C channels supporting the seat are smaller and the aft attach point for the pan is moved back. I could harvest the aft attach off my old A model and send it you if you’d like. Its going into the scrap heap anyways. Have you considered just flying your bird seated center with your feet on the outer pedals?
John -
Thanks for the info!
If your legacy bird had the lowered seat mod then I may take you up on your very kind offer - let’s see what the next couple of messages bring, and if you harvest it then let me know (here or via PM). I am happy to contribute to your beer/flying fund as a thank you! 
After firing off my last post (and an email to Kerry), I found photos online of the B-Model seat supports and I agree with you that it would be a lot of work to change essentially the entire lower fuselage structure (and possibly have to purchase some expensive CNC’ed control-stick parts) in order to get a B-model seat into a legacy fuselage. Drat…
As for your suggestion: I am loathe to simply sit in the middle because it effectively turns my bird into a single-seater. I want the ability to fly with my wife (who’s also a pilot) and take folks up for rides. Also, I built the center-stick version specifically so I wouldn’t have to have a stick between both people’s legs. I got my PPL in a DA-20 and spend lots of hours in a glider cockpit, so I like having the stick in my lap for precision maneuvering. But I hate that it leaves me no lap room for a good-sized knee-board, a place to unfold charts, it can cause non-pilot passengers discomfort, it makes it a bit harder to get in and out, etc.
I tested my fit in the airplane a bunch of times during the build and never had a concern; but I never had cushions and a closed canopy before now (9 years into the process). Although my head is nowhere near the edge or top of the turtledeck/rollover structure, I’m finding that the inward curve of the canopy rubs the the corner of my skull with just a ~3/4" cushion on both the seat bottom and seat back. D’oh!
I tried scooting my tailbone forward on the seat and if I’m willing to lean back a fair amount (not unlike sitting in a glider) I can probably fit; but I’m not sure how comfortable it’ll be given the lack of shoulder/neck support in a Sonex. And at 6’ 1" it puts my knees up close to the bottom of the instrument panel… But I think maybe the best thing is to try some more seat-cushion tests in a more-reclined position and see if I can find a comfortable setup.
Thanks for letting me hijack your thread, and again for your kind offer!
–Noel
Sonex #1339
Cockpit nearly complete
Construction Album
Re: B-Model conversion
Posted: Mon Apr 22, 2019 10:33 pm
by peter anson
Hi Noel, you might not have too much of a problem. I am only 5’8" but recently took Gordon Turner for a flight in my standard seat Sonex. Looking at the photo (see link), it’s hard to believe he fitted in but he did. One thing I found is that you can’t have a bulky head set. I have a Bose A20 set which is pretty compact and clears the canopy easily.
https://www.instagram.com/p/BtYaWS4h6eJ/
Peter
Re: B-Model conversion
Posted: Sun Apr 28, 2019 7:31 pm
by fastj22
Wings have been rigged.
Thanks to Paul Vetter for coming down from Gillette WY to assist and keep me from making stupid mistakes.
The laser level failed, so went Roman with a water level. Worked great.
I will say, rigging the wings while the fuse is on saw horses and the firewall removed is much easier.
Now to disassemble everything, and start riveting. Engine mount is on order.
Re: B-Model conversion
Posted: Mon Apr 29, 2019 9:05 am
by GWMotley
Nice buddy.
Re: B-Model conversion
Posted: Tue Apr 30, 2019 8:59 am
by Kitfox93eg
John, any chance you have any pics of the wing rigging as this is the next step in my B conversion
Ed Grasso
Re: B-Model conversion
Posted: Sat May 04, 2019 9:47 am
by n307tw
fastj22 wrote:Wings have been rigged.
Thanks to Paul Vetter for coming down from Gillette WY to assist and keep me from making stupid mistakes.
The laser level failed, so went Roman with a water level. Worked great.
I will say, rigging the wings while the fuse is on saw horses and the firewall removed is much easier.
Now to disassemble everything, and start riveting. Engine mount is on order.
Outstanding!
Re: B-Model conversion
Posted: Sun Jun 23, 2019 8:28 pm
by fastj22
For those of you considering a swing back canopy on your B-model, here’s a video on the issues I faced. It can and will be done.
Re: B-Model conversion
Posted: Mon Jun 24, 2019 1:05 pm
by racaldwell
John,
Thanks for posting the video of the swingback canopy. I’m curious why you didn’t use the slide lock plates from the A version.
I am in the middle of installing the swingback on my Xenos A project. Just finishing up a mechanism I came up with for a keyed camloc on the exterior for locking it closed from the outside.
Rick Caldwell
Xonos 0057
Re: B-Model conversion
Posted: Mon Jun 24, 2019 4:41 pm
by fastj22
racaldwell wrote:John,
Thanks for posting the video of the swingback canopy. I’m curious why you didn’t use the slide lock plates from the A version.
I am in the middle of installing the swingback on my Xenos A project. Just finishing up a mechanism I came up with for a keyed camloc on the exterior for locking it closed from the outside.
Rick Caldwell
Xonos 0057
The B-model uses a boxed channel for the longeron instead of the angle of the A-model. and the sliding mechs are machined to go over the side of the box and into a set of pins that stick out the side. Those pins were catching on my swing arms. The B model also uses 1 inch angle for the bottom of the canopy frame so when you can’t really go through the center of the box.
Re: B-Model conversion
Posted: Sun Jul 07, 2019 7:20 pm
by fastj22
Canopy, windshield, glare shield and fuel tank installed!!!
I left some DNA getting the tank straps set. Boy was that fun! NOT!
Here’s a video…
https://youtu.be/Hl7QHtRtKzY
Re: B-Model conversion
Posted: Sun Jul 07, 2019 7:50 pm
by Sonex1517
Looking great!
Re: B-Model conversion
Posted: Sun Jul 07, 2019 8:35 pm
by fastj22
Sonex1517 wrote:Looking great!
I’ve been vinyl wrapping the stuff as I complete it. it really helps motivation, to see the final product. It might not be smart as I already will have to go back and touch up stuff, but I see the light at the end of the tunnel.
Re: B-Model conversion
Posted: Mon Sep 02, 2019 10:23 pm
by fastj22
Been getting a little sidetracked and distracted lately. I did put in my autopilot control rods this morning.
I’ve been towing for the glider club every Friday and flying at least one of the other weekend days in a club plane.
Soaring season is coming to an end but we are getting some gold metal days lately. Here’s a clip from today’s trip into Tiger Country. We rarely dropped below 16,000ft and did 600km in 5.5 hours. This was a Duo Discus with a national champion coaching me from the back seat.
https://www.youtube.com/watch?v=3e987La_3w8
Re: B-Model conversion
Posted: Tue Sep 03, 2019 1:19 am
by NWade
fastj22 wrote:Soaring season is coming to an end but we are getting some gold metal days lately. Here’s a clip from today’s trip into Tiger Country. We rarely dropped below 16,000ft and did 600km in 5.5 hours. This was a Duo Discus with a national champion coaching me from the back seat.
Nice flight! Who was it in the back seat? I’m a competition Soaring pilot and as you know, it’s a small community.
I’m distracted right now myself between finishing my Sonex and buying a DuoDiscus so that I can do more XC mentorship - it’s something the sport badly needs more of!
Can’t wait to see both the B model and some more long glider flights.
—Noel
Sonex #1339
ASG-29
Re: B-Model conversion
Posted: Tue Sep 03, 2019 9:38 pm
by fastj22
NWade wrote:
fastj22 wrote:Soaring season is coming to an end but we are getting some gold metal days lately. Here’s a clip from today’s trip into Tiger Country. We rarely dropped below 16,000ft and did 600km in 5.5 hours. This was a Duo Discus with a national champion coaching me from the back seat.
Nice flight! Who was it in the back seat? I’m a competition Soaring pilot and as you know, it’s a small community.
I’m distracted right now myself between finishing my Sonex and buying a DuoDiscus so that I can do more XC mentorship - it’s something the sport badly needs more of!
Can’t wait to see both the B model and some more long glider flights.
—Noel
Sonex #1339
ASG-29
Bif (Marvin) Huss who sold his discus 2b for the duo in prep for his new 18 meter competition plane being built. He plans to use the duo to train saps like me how to race.
Re: B-Model conversion
Posted: Wed Sep 04, 2019 9:10 am
by dbdevkc
Hank Nixon (former nat champ) does the same thing here in NYS - mentors and teaches sailplane racing to junior members and other interested parties by using his ASK-21 in the “bus class” in local competitions.
Re: B-Model conversion
Posted: Sun Oct 20, 2019 8:17 pm
by fastj22
Running out of stuff to do.
Seat pan is riveted in. Boy that was a nervous moment. The B model has a riveted seat pan. You better dang well make sure you have everything perfect and access holes cut in the right places before doing this. Good thing is its rock solid, unlike the piano hinged seat on the A model. Jury is out on if this actually an improvement.
Panel riveted in. Wiring is nicely sheathed. Electronic smoke test successful. Had some issues with the flap travel, but I think I’ve got it close enough.
Started the engine this afternoon after almost 10 months of being mothballed. Came alive and produced heat in all cylinders. Only idled as I was in the hangar.
Re: B-Model conversion
Posted: Wed Nov 06, 2019 7:37 pm
by pfhoeycfi
fastj22 wrote:Canopy, windshield, glare shield and fuel tank installed!!!
I left some DNA getting the tank straps set. Boy was that fun! NOT!
Here’s a video…
https://youtu.be/Hl7QHtRtKzY
Hi…
I am ready to install my B model glare shield but the plans do not show any dimensions or measurements, ie where along the longeron, X inches from y, is the end of the shield or instrument panel suppose to end up…it seems that the glare shield is just pushed up to the firewall and drilled. Is that the case? On the firewall end the plans say to trim, on the panel side no spot or measurement called out. I’m gonna climb in upside down to drill and I want to get it right.
thanks,
peter
SNB0021
Re: B-Model conversion
Posted: Thu Nov 07, 2019 3:55 pm
by dirkverdonck
Hi,
About the tank straps, I replaced them right away with homemade SS straps that join in the middle, so easy to install!
And about the glareshield, I added an inspection panel to get easy access to the back of the instruments for inspection, replacement or repair.
Dirk
Waiex-B 036
Re: B-Model conversion
Posted: Sun Nov 24, 2019 9:39 pm
by fastj22
The Super Bee flies!
Did two sorties today. First one brought me back to the runway after a loop around the dog patch due to an uncomfortable climb rate. Traced it down to a loose ignition on one of the 12 ignition cables at the distributor.
Second sortie was good. Took the plane up to 10k ASL and orbited the field for an hour. Got some trim issues, the MGL radio kept going Tango Uniform, lots of ventilation from the canopy bow. CHTs were very low. The side cowl exits are more than enough. But Oil temp was too high. Need to create more flow me thinks. MGL AHRS was all over the place as was the compass. I mounted these under the seat pan. Not sure this is the issue. But I’m back in phase 1 to figure it all out. The new Trig 22 xponder came alive but couldn’t receive ADS-B position from the TN-72 GPS. So I have that too. This is experimental aviation right?
Re: B-Model conversion
Posted: Sun Nov 24, 2019 10:54 pm
by Sonex1517
Awesome John! Way to go. Congratulations!!