axle/hydraulic brakes assembly

[1labelloj]

I have the hydraulic brake option. There are conflicting instructions in the original plans vs the plans sheet that came with the upgrade parts. The original plans say to use 3 AN3-15A bolts (3/16 diameter) through the main brake body (calipers) and the wheel pant plate with one thru the eye/tip at the bottom of the axle.
On the inserted plans sheet it calls for ONLY ONE fastener thru the main brake body (calipers) and the wheel pant plate going thru the eye/tip. There it is calling for a MS20392-3C49 clevis pin which has a I/4inch diameter. The main brake body has pass through holes which at 1/4 inch. The eye/tip at the bottom of the axle has a 3/16 hole and not much metal which make me concerned about opening to 1/4 inch.

Any advice? I am concerned also with only using a single clevis pin as opposed to 3 clevis pins or bolts.

[WaiexN143NM]

Hi all,
This has been brought up before, i can suggest getting the steel backing plates from tracy obrien. Have them welded onto your axles., you will need to chamfer slightly with a large unibit the 3/4 axle hole. The holes in the backing plate to red caliper may need slight reaming. Dont drill the red caliper any bigger, internal oil gallies preclude that. You will be able to pick up 3 bolt holes. The single tab esp. With hyd brakes grabbing better , will be subject to breaking off. Good luck on installing your brakes. We like ours.

WaiexN143NM
Michael

[mike.smith]

I have the hydraulic brake option. There are conflicting instructions in the original plans vs the plans sheet that came with the upgrade parts. The original plans say to use 3 AN3-15A bolts (3/16 diameter) through the main brake body (calipers) and the wheel pant plate with one thru the eye/tip at the bottom of the axle.
On the inserted plans sheet it calls for ONLY ONE fastener thru the main brake body (calipers) and the wheel pant plate going thru the eye/tip. There it is calling for a MS20392-3C49 clevis pin which has a I/4inch diameter. The main brake body has pass through holes which at 1/4 inch. The eye/tip at the bottom of the axle has a 3/16 hole and not much metal which make me concerned about opening to 1/4 inch.

Any advice? I am concerned also with only using a single clevis pin as opposed to 3 clevis pins or bolts.

I saw no reason to use clevis pins at all. The start of my install is here:
http://www.mykitlog.com/users/display_l ... 164&row=18

I've had zero issues with my install.

[Waiex 49]

I have spent the last couple weeks having "fun" with the Sonex disc brake system.

It's a good upgrade over the mechanical brakes but I have found errors and omissions within the Sonex drawings and instruction documents. I've spent a good deal of time having to fix things that Sonex should have gotten right the first time.

Still, I like Sonex and I like the disc brakes. Just wishing this install was a bit easier.

I agree with both Mike's. The TOB torque plate is an improvement for mounting the brake housings. Using AN bolts to secure the brake housing is much better than using the pins. Having gone this way I can say that the brake housings now mount up very nicely.

Sonex could really make this disc brake kit a big win if they would do a Reality Check and get all the parts and drawings corrected.

My installation is documented at www.mykitlog.com/donbowen.

Best of luck with your project,

Don Bowen
Waiex 49

[jowens]

Agree with others the additional mounting bracket is a great/necessary add. Finding a TIG welder you trust is the only challenge. The c90 obrien bracket holes are not a perfect hole match. I made my own- a simple job with .070 4130 steel. I pilot drilled and then used a step bit for all the holes.

[chrisyk]

Greetings all. I am planning to install Sonex/Aeroconversions hydraulic brakes on my legacy Sonex taildragger. Sonex specs DOT 5 brake fluid. I want to use a stick mounted motorcycle type master cylinder, such as a Hegar. Someone must have done a combination like this. I need a master cylinder that is DOT 5 compatible. I called Hagar and they say to use ATF in theirs. I may have misunderstood but I thought he said you can"t use DOT 5 but you can use silicone fluid. I later found Silicone fluid is DOT 5. I sensed he wasn't real interested in talking to me as I am installing Sonex brakes instead of Hagar. Can anyone confirm that DOT 5 fluid is compatible with a Hagar master cylinder? Also what bore size is best for a Sonex setup?

[Waiex 49]

I used Hegar master cylinders and they told me DOT 5 was no problem.

I'm not using the stick mounted master cylinder rather I have toe brakes and left and right master cylinders.

I think you should be fine using DOT 5 with the Hegar master cylinder.

You might consider differential brakes. In my opinion this is much, much nicer than a single lever. Much better control on landings and taxiing. Just my opinion.

Good luck with your brakes,

Don Bowen
Viking Waiex N49YX

[chrisyk]

Thanks Don. I thought the Hagar master cylinder was OK. Now I'll go with it. I am tempted to put in toe brakes, but now I'd have to get down there and take it apart, get some welding done etc. Sonex doesn't recommend differential brakes, but I can certainly see it would be nice sometimes. A 50 ft turning radius is a bit much and a little more authority in a crosswind might be nice.

Chris Holloway
Sonex 1226. (still under construction after a 3 year hiatus)

[Waiex 49]

Hi Chris,

Not trying to influence your decision on the master cylinder, but wanted to offer you my thoughts.

The Sonex disc brakes work pretty well but the Sonex kit is crap. Full of parts that don't fit properly and the "instructions" are pretty much worthless. Written by a complete idiot.

I have the toe brake pedals from John Gillis (hope I spelled that right!).
I really, really like having differential braking.
The pedals are not difficult to install.
It is tight working down around the rudder pedals but it isn't that awful bad.
No welding is required.
Small tabs need to be installed on the rudder pedals.
This is done with pop rivets (I used standard Sonex supplied pop rivets).
You will need a smallish 90 degree hand drill and a smallish rivet puller that will fit inside the rudder pedal area. Got mine cheap at Harbor Freight.

I'm sure your single master cylinder will work nicely but it is really nice to have differential braking.
The only advantage I can see with the single brake lever system is that it is cheaper to buy.
The issue I have with Sonex is that too many design decisions were made to have things cheap.
Good airplanes are better than cheap airplanes, in my opinion.

I really like differential brakes, just like in "real" airplanes.
This winter I'm changing out the direct steering tailwheel in favor of a full swivel tailwheel from FlyBoy Accessories. Wow, just like a real airplane!

Good luck with your Sonex.

You can see my brake installation at www.mykitlog.com/donbowen

Don

[peter anson]

For goodness sake Don, stop beating around the bush and tell us what you really think!

Peter