Dave Wilshere

Didn't know your eyes were affected too!

dubd

I had to dremel a lot of wood away to get the retracts to fit. The struts are fine. I had to remove wood from the mounting rails as they are too narrow. I also remove most of the u shaped former that sits underneath the air cylinder. The same applied to the nose. You'll also need to either cut the steering arm on the nose gear or dremel the fuse to allow the steering arm to clear the fuse. It was a bit of a PITA.

DD

mtnflyer14

Wow. Might have been easier to use the C-ARF Behotec retracts and trailing link struts/wheels?
Regards,
Gus

ricardinho

i am using the bohetic retracts and got the dreamworks pinned trailing struts.. that was the combo i had on my classic flash... worked awesome... i am going to sell my airtech struts...i am also using the inairco wheels and brakes..

flyboymd

My Feedback: (1)

Well I maidened the UF today. Not the idea day 20+ MPH crosswind and mostly cloudy day but got it done...Not what the weatherman called either for but he rarely has a clue anyways. First flight was pretty good- got it trimmed easily and flew on rails- AND FAST.. Just needed a little up trim... Good 7 minute flight.. Super Eagle pushed this thing around like a foamie!!! 2nd flight I had the same experience Gus had with landing gear problems.... Only not only did a main not come down but the nosewheel kept coming down and getting caught on the front gear door. After several attempts to get em down I decided to belly land her... Glad I was on my grass strip... As perfect a landing as there is on those conditions and not a scratch... So I've got to trim some off the front gear door now and also work some more with the mains... I already knew this but no matter how many times you put excercise the gear on the ground they never seem to work the same way in the air... I am going to have to shim the gear down more than I already have with the 3mm spacers and washers.

Dave Wilshere

What gear set up are you using? There were three UF maiden flights this weekend in the UK and all had perfect gear operation. Five now flying here with three more being built.

Rob Westwater's UF on it's maiden yesterday

Dw

dubd

It would have been easier and I would have gone that route if I had known beforehand. Kinda sucks to spend unplanned hours on the plane when I have business school homework plus a full time job. [:@] My original Flash had the Behotec gear and I wanted to try something different, so I paid the price. As I stated, the end result turned out good so far. Hopefully none of my gear will get stuck in the air. Seems as though that is plaguing some of you guys.

mtnflyer14

Best of luck with your gear. I have been doing some work on my Bobcat, so haven't put the UF together to troubleshoot the main gear problem. I don't think it is bottoming in the wheel well, though so I'm not sure why the left main didn't unlock from the 'up' position.
Regards,
Gus

mtnflyer14

Good job on greasing it in gear up. I hope to do some troubleshooting this week or next weekend on my gear; I'll let you know if I find something definitive. Please let me know what you find as well.
Regards,
Gus

flyboymd

My Feedback: (1)

Thanks. Yes please do. I just came in from the shop. I shimmed mine a little more but the gear is not bottoming out... It spins freely... Mine seems to be my right gear. I noticed when I have 100psi of air in the tank it will cycle ok about 3 times but that right gear is always the last one down. After the 3 time and the pressure drops to around 60psi I have to push on the gear up just a tad and it unlocks and comes down. I always had Air Up - Spring down on my other models and never had an issue. Grrr these are giving me fits.

flyboymd

My Feedback: (1)

Dave,
Using the gear that came with the plane. The Behotec retact units and the newly designed struts we all had to grind and modify to get to work...

mtnflyer14

Your symptoms sound just like mine, except my problem is with the left. I'm wondering if some retract lubricant might help? I'll get our local hobby shop owner over next weekend and troubleshoot that.
Regards,
Gus

ricardinho

hello i had a similar problem with my hawk gear.. the problem i found was not the struts but the retract itself. check to see if there is any binding where the t is on the end of the cylinder rod is.. it may be hitting the side a little. my hawk was only getting about two or three cycles .. after finding where it was binding i could cycle them 8 times on 125 psi... you should easily get 8 to 10 cycles with 120psi.. my classic flash with bohetics would cylce all the way to 40 psi ... pat

Dave Wilshere

OK, sorry.

Behotec gear is very good, but you can check the freeness of the unit by "cracking" the gear and releasing the air. Then work the legs by hand. it should feel smooth.

Don't add lube in the cylinder, check the slider block and the actual pin, I add light machine oil to lubricate the pivot ( infact the BVM 1945 is good for that)

Dave

mtnflyer14

Dave,
Thanks, tonight I'll bleed the air and check the retract for smooth operation and go from there.
Regards,
Gus Grissom

mtnflyer14

Okay, I think I have solved my problem. I extended the gear and found a small rub on the inside of the left wheelwell where the aft part of the brake assembly was touching the inside of the wheel well when retracted. I filed a little off the aluminum and also took a little more out of the slot that the pin that holds the trailing spring, thus reducing the amount of trail. Those two actions effectively moved the wheel forward and it no longer touches any place in the wheel well. The other option would have been to remove the retract, plug the mount holes and move the retract forward, but I think I would have had to sand off some of the ply mount to get it to go further forward, so just filed aluminum. Hopefully the winds and temperature will cooperate this weekend and we can fly here in Colorado.
Regards,
Gus

indubitably

My Feedback: (14)

So what have been the most successful mods needed to make the retracts work the best. In 75 flights i have tried quite a few different methods of working the gear best. I had been reluctant to grind the strut where the lower spring retaining screw contacts the strut. Without doing this the strut has a knee bend to it. If it doesnt straighten out then it wont fit into the well well. (well well). I had a slight bent to the pin which hung me up. Field straightened it out and got by, but had a wheel up landing. I was getting used to these. Just rudder into the direction of the stuck wheel, and and opposite aeleron to keep the wing off the tarmac. It starts doing a circle as it slows, and the centrifugal force keeps the wing up until its barely moving, then brake. Walk over to it, pull the wheel down, and taxi back. I had trouble at the beginning, got it worked out thanks to all your help, then the bent pin. All in all very nice struts and gear. I will be taking more out of the knee for a fully straight strut. Any one getting away with not grinding this out? And any other mods? Just when i thought all was perfect, then a stuck down, followed by a stuck up.
I have the Shuii colors, and really like the visibility if this. The red, yellow really is hard to see. The blue against white on top stands out, as the white and red on bottom. Would get visibility over some of the prettier patterns, but i really like some of the colors i have seen.
The plane is a complete delight to fly. And for the most part landings are as good as any plane i know.

ricardinho

hello what retracts are you using... i never had any of these problems with my classic flash.. i used the bohetic c36 2 with dreamworks trailing struts.. the only thing i had to do was grind a little on the top of the strut, fit perfect and would cycle up to 40lbs... this will be the same set up i am using on the ultra flash.. is the wing that much differant? if anything if the wing was desighned and offset for trailing link that there should be no mods at all...crazy...so you got it all straight now i hope.... i am getting ready to start mine...

mtnflyer14

I think I remember an earlier post from Dave Wilshere that said the wheel wells were moved aft a little to accommodate the trailing link strut. But, in hindsight, I think I should have mounted the retracts in the wing so that the wheel fit in the center of the wheel well instead of centering the retracts and then modifying (filing out the strut where the pin sits) to reduce the trail to make the wheels fit in the well. Oh well. The wind is just howling this morning, so I won't be checking out my latest fix today! Guess I'll have to finish up my taxes - ugh.
Regards,
Gus

ricardinho

that stinks.. today 55 degree and sunny and 5mph wind...going to fly imac today...i am sure your problem will be solved.. my friend who is building my ultra said that is important to alighn the retract so it centers the wheel well.. thats the way he builds them... really if you think about how retracts work.. they eaither go up or down.. if they are getting stuck that is a binding issue...maybe later will be good for you to fly...hope eevrything works for ya....pat

Dave Wilshere

Took the UF out again today, took some agression out on it...think the guys were surprised how quick it is with a P-120SX.
Biggest thing is fast/slow difference...like 220mph!
Still perfect gear operation. Today there were four Flashes at the field three CF and my UF. All Behotec C-36-2 and either Jet 1a or AT (square) legs, all perfect gear operation as normal...

Dw

Flying shots by new cameraman Dave Bugz..good first try

mtnflyer14

all perfect gear operation as normal...
Stop rubbing it in!!
Regards,
Gus

indubitably

My Feedback: (14)

Ill buy your struts if you like. They are awesome. The spring is much longer, and does not seem to fatigue as the Dreamworks do. But i do like the large half inch socket, clamp better than the pin. The pin bends so easily. But then you can bend it back as well.

My setup has worked for probably 65 flights, and i usually do touch and goes for the last four minutes of flight, and as i taxi back, i can look into the main tank, and see the fuel level. And do 3-4 more touch and goes. We have Petromat, so the wheels dont wear out so much, but the ground under the petromat can be uneven, so you can really see the main gear work. I have done smooth landings, then see the plane launched into the air from a bump. So i know i am maximizing my landing experiences and stressing the struts to the max. But they hold up. I have the new Behotec retracts, and the new Behotec struts and wheels, as it came from Andy Kane. Totally stock. I just wish i could keep the struts, and have the Dreamworks retracts attach points. I have a machine shop, and would like to work out that solution with a spare set of struts. Im not sure if individual parts are available yet.

My builder had hogged out the retract well so as to keep the knee bend, but then the alignment was off. It is better to keep the retract mechanism straight as it allows for some toe in for landing stability. Then the strut pins can be ground flat surfaces all lining up. Easy to do with a vice and endmill. Other wise the flats on the pins are all over the place. It also keeps the wheels flat with the bottom of the wing, instead of off angle. By shimming the retract mount, you can bring the wheel down, and closer to the flat bottom of the wing, and it will keep the whee from jamming in the wheel socket.

In retrospect the problems i had in the beginning were due to over energetic mechanisms to modify what would have been simple if only the struts were aligned straight from the start. Grind that slot deeper so as to allow the knee to extend more. It doesnt take much grooving to do this, so go slow.

John

dubd

You're correct, the best method is to center the wheel in the well. We have rain for the next 10 days, so it doesn't look like I'll maiden the plane until April.

Dave Wilshere

I have NEVER bent a behotec pin, neither have the other guys around me. The Behotec pins are very hard. I presume we are talking about installation in an UF. It would help if people could list the equipment they are talking about, units, legs and wheels.

Dave