Front Suspension

[RICK MARTIN]

Alright Ron, You're right, not enough action here.
Last weekend when I went to Wauchula for another lesson with Dave Seace, I took my machine so that he could play with it a little. Unfortunately, after rebuilding the front end, I never really took it out on the street myself. As a result, when Dave went out to taxi, there was significant nose wheel shimmy. One wasted load-up/tear down. The difference was that during the rebuild, I had decided to de-couple the front fork from the pedals and try a more "dominator" set up. So I left the spindle free-turning except for a centering spring like a dominator. Now I see that I overlooked an adjustable dampening mechanism which I have designed and should be ready in a few days. I also installed a much heavier spring. Hopefully this will solve the problem before the New Year's fly-in. As has been stated here by Ralph, Doug, yourself and others, I would have been better off sticking to the original design at first. I was just so concerned about the small nosewheel "finding holes" on a grass strip and also about the abuse the frame would take without some suspension up front. This front end has been the one thing that has slowed me down and I'm about ready to order a stock Brock fork and wheel. We'll see. Anyway, here are a few shots after the heavier spring was installed but before the dampener is put on. Still need to paint.

[GyroRon]

Could you somehow link it to the pedals? Dominator style is nice but nose fork linked to the pedals may be better....

[gyropilot]

Rick,

To eliminate nose wheel shimmy, all you need is something to apply friction between the fork assy. and the frame... such as a plastic washer. I had to do this on my Bee's nose wheel.

Regards,

John L.

[RICK MARTIN]

Ron & John,

Thanks for the input.

Yes, I had it linked before and it was alright. But I'm attracted to the idea of having the nose wheel pointing straight even if I'm applying rudder upon landing.
Because of the bearing set up, I don't think I can use a washer for friction. The part I've designed is an adjustable clamp that will go around the spindle above the frame (yellow part).

[Chopper Reid]

Lovely looking nosewheel there but how much does all that weigh in at ??

[RICK MARTIN]

Brian,
I have not weighed the nose gear alone, but it's lighter than it looks. Yet I'm sure it is heavier than just a Brock fork and wheel. The machine has been hang tested and set up correctly.

[GyroRon]

I like it myself, because having some front suspension is a good thing and you need braking of some kind on a gyro and your disk brake set up looks sweet. Hopefully your machine will be flying by New Years so I can take it up and evaulate it for ya! ;)

[Doug Riley]

For some reason, the industrial-looking Bensen-Brock nose fork presents an almost irresistible temptation to construct something more complicated. Remember, we are building something that carries 50 lb. and seldom is on the ground at more than 15 mph. There's no need to turn it into something from an American Chopper episode; it's more like a glorified lawnmower wheel.

The geometry of steerable wheels is more complex than it looks. Pedal-to-wheel interlinks add to the issues already presented by rake, trail, shimmy, and camber.

The Dominator system addresses the structural problems of using a long gear leg to initiate the turn. Other than that, that system is something of a pain in the butt and much less precise than simply swivelling the fork directly.

IMHO, the most trouble-free setup is the original Bensen system. It used a separate steering bar on the fork, a plywood scrub brake, centering springs, a huge friction surface and NO interlink to the pedals. Some people found the steering bar difficult to master, though, hence the appearance of interlinks. These links can result in swerving right after flare if the link is not soft enough. Be careful with them!

[RICK MARTIN]

Ron, I was hoping you would say that. I'm working hard to make it ready for new year's. What are those microwaveable french toast things you said you like. I have to take care of all my test pilots!

Doug, As always, I so value your opinion/knowledge and guidance. I also believe strongly in the "simple is better" theory. Thanks for reminding me of the requirements of the nose wheel. By now I probably would have gone back to the Brock fork except that my seat situation keeps my short legs from reaching the traditional pedal location much less a scrub brake. But most problems can be overcome with careful thought. So don't be surprised to see me go back to the original design. Are you coming to the New Year's fly in at Wauchula? I'd love to pick your brain when we can look at the machine?

[Doug Riley]

Rick: Sorry, I won't be at Wauchula New Years. I live in northern Vermont and it's a wicked long trip.

Maybe B-Days. Good luck with that front end.

[RICK MARTIN]

Alright Doug, I'll try to catch up with you then. Happy Holidays to you and yours.

[GyroRon]

Rick as long as I got a place to sleep and use the bathroom and shower... That is more than enough!!! :)

[KenSandyEggo]

Letting some air out of the front tire will often eliminate a shimmy.

[RICK MARTIN]

Well then Ron, I guess you're covered. I only snore a little.

Ken, Thanks a bunch! I'll try it.

[Curran3]

Rick,
Thanks again for your hospitality over the holiday. You have a nice looking Gyrobee. Have you figured out what you're going to do with your nose gear? I'm toying with adding a prerotator at some point on mine. What length is your prerotator cable?
Curran in Jacksonville, FL

[RICK MARTIN]

Curran,
Sorry for not answering sooner. My email has been down for a few days and I just saw your message. I really had a blast at the fly in. It's late, so I'll measure and take some pictures for you as soon as I can. I believe my cable is a little too long. I don't like the way it conflicts with the mast. You can use my regular email: rmarti60@tampabay.rr.com or call 941 795-4668.

[RICK MARTIN]

Well,
As I hinted at before, I have made the decision to change my nose gear back to the original Brock/Bensen type fork. I ordered a fork, tire and wheel from Starbee and am having two nose blocks made (one steel, one solid 6061). I just don't feel secure with the design/strength of the spindle tube where it goes into the bearing surface. The tube is very thin and the gear was always sloppy and didn't align properly. I have to have peace of mind. My current plan is to take Doug's advice which is to leave the wheel un-linked and use a centering spring or springs. I'll just have to figure out a way to steer it (because of my seat, I may not be able to reach the front axle). As far as a brake goes, I'll either do a traditional scrub set up or a scrub that uses a tall push bar and contacts the front of the wheel. Sorry to do this, but you guys just aren't going to be able to laugh at my handle bars anymore.

[Brian Jackson]

you guys just aren't going to be able to laugh at my handle bars anymore.
Wanna bet? I can laugh at the handle bars all I want! :D

Actually I'm interested in the more esoteric elements of the design. The spring-loaded facet has been brought up many times previously. I've yet to adhere to an arguement that convinced me Mr. Taggart's design was inadequate.

Common wisdom dictates building the 'Bee to plans. Those that do end up with flying gyros. Those that don't are still "experimenting." While I love the experimental nature of this sport, we should ask ourselves one question: "What is my priority?"

The answer will dictate how soon you'll be airborne.

Regards,
Brian Jackson

[Brian Jackson]

Rick,
I just read my last post and I sounded a little rude and "preachy", sorry, that's not how I meant it. I was speaking more in generalities. A neighbor of mine likes to point out all the things wrong with my Bee, mind you he knows nothing about aircraft... he's a car mechanic. I just nod and tell him how many Bees are flying perfectly well by the plans, and don't need to be reengineered. I get a little frustrated with him sometimes. I still like your handlebars though! :D Now some little colored tassels on the ends...

Cheers,
Brian Jackson

[Doug Riley]

In many important respects, surface vehicles are the opposite of aircraft. Most of the screw-ups built into various amateur-designed gyros over the decades have been the result of applying car-mechanic reasoning to aircraft -- starting with bringing the center of gravity "as low as possible"!

[Brian Jackson]

In many important respects, surface vehicles are the opposite of aircraft. Most of the screw-ups built into various amateur-designed gyros over the decades have been the result of applying car-mechanic reasoning to aircraft -- starting with bringing the center of gravity "as low as possible"!
Agreed. Back in the early '90s when I was first introduced to Gyros I made the same assumption regarding CG, thinking the "pendulum effect" would somehow be more stable. How wrong I was. I'm thankful for the PRA and for this forum's members for the wealth of knowledge I've gained. What's funny is that the more I learn here, the more I realize I don't know.

Regards,
Brian Jackson

[RICK MARTIN]

Brian,
It takes a lot more than that to upset me (Like Ron's snoring in my motorhome). Believe me, there was no offense taken. Actually, I think you're probably correct, but I just have this thing about a crooked nose wheel upon touch down, or more importantly while I'm crow hopping. I've very much enjoyed your posts adn I hope to see you a Bensen Days.