Tail wheel suspension

[n144sh]

https://m.youtube.com/watch?v=LfbXxTLLnsk

This looks like a pretty nice idea. More info over on the supercubs forum.

[Battson]

Looks very high tech! Cool idea for the cub guys to go and try out.

Going straight to pros vs cons...My first thoughts:

• Looks great for soaking up major rough surface landings off airport!
• I wonder how it will stand up to all the rocks which jump up and smash into (and dent!) my big heavy my tail springs off airport? The main leaf looks quite delicate, as do the sliding dashpots / shock absorbers.
• Lots of moving parts to wear and replace, or even fail away from home base.

Great to see cool ideas like this being tested, and shared on forums. Cheers for posting.

[Blackrock]

I might have to order one and try it out. Weighs the same as the spring, about 5.5 lbs so not really anything to loose. Working with them now to see how the heavier BH weight will work with those shocks. Looks like they are the weak leak and will require maintenance. Not sure how they'll hold up to dropping in, etc. The spring isn't ideal but at least it is simple and only requires occasional maintenance. But I really like the idea of something absorbing tail wheel energy and rebounding it more slowly. I think with low pressure in bushwheels and one of these on the tail, the entire suspension will be a pussy cat and enable even shorter landings.

[n144sh]

Blackrock, do you know if the spring is the same spacing and this will bolt right up or will the mount have to be modified?

[Blackrock]

Pulled the trigger on one today. Ships after Christmas, lower shipping cost then. Looks like it pretty much bolts right up, but I'll know after the first of the year. I gave them all the BH plan dimensions and measurements from mine plus photos and they said it would be really close and they could get one right out. So I'll be surprised if there isn't some tweaking to get it on.

One thing I know will have to be changed are the steering arms coming off the bottom of the rudder. Cub arms bolt on, BH arms are welded and they will interfere. I'm willing to cut mine shorter and just not fly with steering cables to the TW. With Bushwheels, all steering is by brakes anyway so I doubt I'll even notice the change. I can cut the arms and leave enough remaining to bolt a set of arms back on on latter if I want them.

I'll post again after trying this out. Should be fun to try. I think taxing in this terrain will be much smoother with a suspension system:


Photo was lost when posted
​

[Blackrock]

[Blackrock]

There are some great before and after videos on the BCP forum, if anyone's thinking about doing this. One for 28M ships Monday. Can't wait to try it! I'll post my results.

[Blackrock]

It's here... Looks like I'll install it Saturday and hopefully get a test flight in this weekend, too.

My initial impressions are it is very well built and should hold up well. The shocks are of good quality; some rubber boots will protect them from dust and minor dings, etc. I'll have to bend or cut the rudder steering arms to get those out of the way and the 2-hole bolt pattern looks a little narrow so I may have to drill that out, but otherwise it should bolt on easily enough.

Stay tuned for more by early next week, weather permitting.

[geraldmorrissey]

Does it weigh the 5.5 pounds as advertised? If it does, I'm amazed, it looks heavier. Look forward to the flight report.
Gerry
Patrol #30 Wings

[Blackrock]

Yes, very close to 5.5 lbs. According to my scales 5lbs 9 ozs. The OEM TW spring is about the same weight. I didn't believe the spring was that heavy and like you, when I saw photos of the TW suspension, I thought it would be heavier. In the end, pretty much a wash weight wise.

[Bcone1381]

The next improvement on the tail wheel spring will be a mechanism that keeps the tail wheel king pin on a fixed plane as weight is applied to the tail.

[Blackrock]

That would be ideal to eliminate TW shimmy, or greatly reduce the chance of it. Every TW and spring I've used has shimmied at one time or another. Higher tire pressure helps.

[Blackrock]

Yesterday was the first chance to fly the new T3 Suspension. Even though I didn't get to try different shock pressure settings, I can tell this will make a big difference and will significantly reduce stress on the air frame from hard landings and/or rough field operations. I'm running 250 psi in the video and it was suggested I need to try lower pressures. These are very adjustable so I'll be trying different setting as weather permits, and I can get someplace with out snow to land off airport. More to come, but I'm already very pleased with how this performs.

In the attached video the steering is disconnected since I had to bend and then cut the OEM steering arms for the initial install. I'll be attaching new arms soon, They will come off the rudder at a different angle than the originals. Ground handling without TW steering works well, too as the video shows.

I'll post more info and photos as time goes on.

[Blackrock]

A second test flight with the suspension. This time I lowered the shock pressure to 200 psi and it really smoothed out the ride. I'm still trying different settings, so will likely be a while before I get it completely figured out. However, this is a big improvement from tail spring performance. I hope to get off field with it the next few weeks, but it is obvious this changes that game considerably. I'd never consider dropping the tail intentionally with a spring like in the video, but with the suspension, it is a non event. I'm very pleased with this mod so far.

I'll update when i get more time on this. The video volume may be a little loud after the first 2 drops in the hangar so you may want to turn your volume down after that.

[n144sh]

Wow, that looks really promising. I take it no problem with the heavier tail weight on the BH?

[Blackrock]

So far so good with the weights. I'm still trying different combinations of pressures and adjustments. There are 2 pressure adjustments to these and 2 manual adjusters, compression and rebound so it takes a while to try combinations. for now, I'm just adjusting positive pressure and rebound rate. Max pressure is 300 psi, I began with 250 psi and an empty plane. That was too much so dropped to 200 psi and added another person. That made the ride a lot better but still maybe too high pressure. I was worried that on compression, the tailwheel would shimmy due to the negative castor angle. But lots of compression at speed in the video without issue. I can go lower and will try that. With gross weight loads, I think enough pressure can be added within the 300 max range although that remains to be tried.