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Wheel ski design

Can't remember what Jean-Marc uses on the Datum skis but they are very strong. They'll pull a 2600 lb Bearhawk up on the ground. Maybe give him a call, you can even speak French!
 
I used the same actuators as thunderhead did. They say 800 lbs. They're made in China so who knows. With my 2 +2 and full fuel it takes 400 lbs to pull the plate under the tire, I built a contraption to measure the pull. I'll get a pic. Of them today and post it. I got them off Amazon

Tim

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After several years, I have a few techniques to make life easier for my Datum skis actuators. I try to not wheel taxi up to a berm and then make them pull they plane onto the skis while in effect climbing uphill, things like that. Keeping the telescoping tubes of the ski retraction mechanism cleaned and lubed (silicone spray is best) helps a lot, as does the slop or tightness of the tubes. The skis themselves seem to be bulletproof. Weight, cost, and power consumption are the balancing points between going way overkill on the actuators. Let's all remember.....Jean Marc of Datum deserves some credit for coming up with the concept of using linear actuators for the motive power, as far as I know anyway.
 
Bad Idea. Hand pump allows one wheel to come down by holding brake on opposite wheel. Hand pump also tells you if you if hydraulic leak. I have electric pump on my airless skis on my 180 hp cub. Hand pump on the C-2200 federal. I''ve had nothing but problems wit the electric and it has been r4placed 3 times. Poor quality control. 206 amphibious with electric pump was always flawless. It also had had pump which I only had to use once.


sandy
 
This is the actuator I use. Iv had them 2 winter's and many cycles no problem so far. Having said that I have a spare I keep in the plane. It would only take 5 minutes to change. The only problem with the better actuators made here is the weight, they weight is about 3 times of the ones I use.IMG_20201029_082850.jpegIMG_20201029_082845.jpeg

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This is the actuator I use. Iv had them 2 winter's and many cycles no problem so far. The only problem with the better actuators made here is the weight, they weight is about 3 times of the ones I use.

I've look rapidly but I can't seem to find them!

Do you know the approximate weight of those?


Thanks again
 
Bought a pair of Fluidyne 3000 Fli-Lite. I only need to change plastic bottoms and built some brackets so they fit my landing gear axles...

I don't like the idea of running oil lines and pump into the plane..
I've been thinking to run them electric and I would like to cycle them on the ground.

What electric actuators do you use?
Or a 12v mini double acting hydraulic power unit that I could mount outside the airplane?

Any issue or concern ??


Thanks!








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What's your concern with hydraulics? All that's inside (usually) is the pump. Most of us put the fluid reservoir on the engine side of the firewall. Very reliable.
 
What's your concern with hydraulics? All that's inside (usually) is the pump. Most of us put the fluid reservoir on the engine side of the firewall. Very reliable.

I do not like the idea of rooting messy oil lines and installing an hydraulic pump inside the plane, and remove all that when spring season comes.. Maybe there is a way to do a clean and simple setup??


Electric is very tempting, but looks heavy...
 
My hydraulic skis have been underwater several times. Once I got the airplane back on top they operated perfectly even in sub zero F temps. Electrics would concern me in that situation.
 
Hydraulic is not messy if you do it right. I like the reservoir mounted on the hand pump - less piping and convenient to maintain. The only things to remove in the spring are the skis and pump, but a lot of people leave the pump in. Done it many times. Eazy-peezy.
 
I do not like the idea of rooting messy oil lines and installing an hydraulic pump inside the plane, and remove all that when spring season comes.. Maybe there is a way to do a clean and simple setup??

for installation on a covered plane, I like to take a AN834-4 TEE https://www.aircraftspruce.com/catalog/hapages/an834.php and weld to inlet part of a AN832D (cut the nut half off) https://www.aircraftspruce.com/catalog/hapages/an832.php that makes it long enough to fit from belly metal(false boot strip) through floor, and put a nut onto of floor..... those 2 tees are the only thing you leave in the plane in summer....

just drill 2 holes.... much easier than plumbing under floor.... you cold also skip using TEEs and just do 4 separate ones if you wish to be able to only move one ski at a time... same method, just weld 2 strait bulkhead finings modified as above....
 
I do not like the idea of rooting messy oil lines and installing an hydraulic pump inside the plane, and remove all that when spring season comes.. Maybe there is a way to do a clean and simple setup??


Electric is very tempting, but looks heavy...

Take a light bulb and weight it when it's off, then weight it with it on. Lighter then oil.
My Datums only have a 22 gauge wire running to them

Glenn
 
Hydraulic is not messy if you do it right. I like the reservoir mounted on the hand pump - less piping and convenient to maintain. The only things to remove in the spring are the skis and pump, but a lot of people leave the pump in. Done it many times. Eazy-peezy.

What he said ^^^. I generally just removed the handle on the pump in summer and left the pump in place. Pumps don’t weigh that much, and there’s no mess.

MTV
 
I guess one thing that can be said about e power over hyd, is 2 switches on the panel take up less cabin room then a pump handle?
 
Quit trashing the dead horse. I have been in overflow with the 185 doing water surveys [under the ice] One way in one way out. Very experienced hydrologist in the right seat.-40 and I settled into the deep snow he was shouting water, water , water. I had the power to the fire wall trying to get to a spot that was no longer water.
I told him to find a place to do his measurements that usually take an hour as I tried to get the slush that is rapidly freezing off the top on the skis. it was over the top of the 8:50s and with my ax i was abe to only shape it into a smooth ? airfoil. Put on my snowshoes an started to top a track to a place where the was no water on top of the ice. Found a place that had only a skiff of snow on smith ice. I went back to the 185 to pack a ski stance with to get the plane to the good ice. He had finished his measurement. I told him to take the power head and augers up to the good ice but put them where I wouldn't run into them when we got the plane loose. Thank Cessn for the spring steel gear. { I had Titanium which was even more springie. He rocked the wings until the plane came loose and I was to the good ice in 5 seconds. I told him to snow shoe a 100' track that could freeze up while I went upstream with no snowshoes as mine weighed so much I couldn't lift them. I had another 200' and called to Richard that his 100' would be kore than enough. I moved the plane up and Richard and turned the plane by hand. the tailwheel was a glop of ice so there was nothing we could do with that. Loaded and we weren't quite off at 300' but it didn't matter as the plane was light on its feet and we were 250 k miles from home. Landed on the ski strip and were on ice skates all the way to the hanger. Into the hanger to unload and let everything melt off. Hot floor and water drain was great.
 
3.9 pounds is the weight of 1 hydraulic cylinder and hoses, no oil. I don't have lines, pump and fitting yet. Makes me wonder...


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