Jack for Tcraft

[VictorBravo]

Re: Jack for Tcraft

Rob just hit on a big one. Flat tire...uh, tyre... needs to be taken into consideration. Perhaps the little "stand" I mentioned could be an interim step... you bring it up enough to put the stand in, then move a pin on he jack to be able to take it up another level?

Obviously it would be easier if the geometry worked out so you had enough leverage and overcentering ability to do all of it at once.

[Darren Lucke]

Re: Jack for Tcraft

I agree - and what I had in mind for the axle stands - to work in conjunction with the gear jack -

At the moment, there is some small scrapes possible - hard to avoid for me at this time, however, a little ingenuity (by the aircraft owner) will save that paint - UNTIL there's a strong enough interest to get a special plastic wear pad for them (unfortunately at present I do not have any molding equipment). As Bob Waldron mentioned - the piece of inner tube / rubber will protect it as well as a thin piece of plastic - if you've got a show plane (recycle a milk jug possibly??).

Planes shouldn't be built with 70 year old jigs - people realize that I think - and mindset is changing from the past 70 years... I wonder how many poked holes or dented their struts from using a piece of wood to top of wing strut attach ???

Hehe... I love the interest in this tho!

hmmm... yeah, the flat tire. Are we talking a catastophic failure??? or just a slow leak / PITA type??? A bit of air will bring it on up where the jack will work okay - on the PITA one.. if you have a puncture that air won't bring up - what exactly were you doing anyway???

[Robert Lees]

Re: Jack for Tcraft

I suppose a flat's a fairly rare event.

We did have this at our airport a few weeks ago (with an S2 Pitts). There was no obvious cause of the flat, but the urgency was getting the thing off the runway.

They ended up finding a low trolley & manhandling the aircraft (do you know how heavy an S2 is?).

With your jack, Darren, you could lift the wheel off the ground & pull it off the runway easily (ground conditions depending).

The S2 flat was FOD-caused.

[VictorBravo]

Re: Jack for Tcraft

A $0.25 piece of wool felt padding attached with RTV will solve the scratching problem... that's a non-issue.

A jack will need to work in any situation where the tire needs to be removed, whether that is a catastrohpic flat or a slow leak. You can't sell a jack that is only useful half the time IMHO.

The more common "slow leak" means that when you have a tiny little leak on Saturday, and come out to the field next Wednesday to fly again, the tire is just as flas as if you had shot it with a gun. The value of this jack is that you can remove the tire from being totally flat, take the tire someplace else to fix it (your house, the FBO on the other side of the airport), then go back and put the tire back on.

You might have to put a longer handle tube on it, so you can pull the jack harder to raise the airplane from a fully flat situation. This also means the axle pad cup might have to be a bit larger.

I also recommend a "pip pin" or some other 10 cent pin to prevent the handle from slipping off the tab. This would be a failure mode that could damage an airplane or send the jack handle flying into someone's face.

[Darren Lucke]

Re: Jack for Tcraft

Pins are already slated for production - two pins - one in the handle to keep them (2 pieces) together and one through the foot attachment as mentioned - although I did design this to have a long clip inside the tube - and the angle appropriate that you never really pull on in that direction at all! Great minds here.... and the felt - I forget about the simple things sometimes - GREAT idea!

[Bob Waldron]

Re: Jack for Tcraft

Darren,

I suggest that you go to the local airport and find some of your original 'test' airplanes. Have someone let all the air out of the tire, and try your jack.

The original was designed (and has been used) to lift a blown J3 Cub tire high enough to change it on the runway. It is always nice to have a spare wheel and tire.

I suspect that your wonderful jack will work just fine on a flat tire.

[VictorBravo]

Re: Jack for Tcraft

Pins are already slated for production - two pins - one in the handle to keep them (2 pieces) together and one through the foot attachment as mentioned - although I did design this to have a long clip inside the tube - and the angle appropriate that you never really pull on in that direction at all!

Darren, if you're clever about it, you can use the pivot bolt (just to the right of the letter "F" on the prototype in your photos) to be where the end of your handle tube hooks over. I think all it would take is a notch cut in the end of your tube at the right angle, and a loose enough fit to put it on at an angle, then when you lift on the handle it gets tight.

The other pin would locate in the curved series of holes on the other end near the axle cup, which would allow you to raise or lower the jack height to fit almost any airplane in this category. My guess is that the extra CNC time and slightly larger amount of materials used on each one would not amount to much... maybe two bucks worth... and save you from having to design, build, manufacture, and keep stock on three or four different size jacks.

If you need to cut costs to the bone, you can eliminate the wheels and just have a rounded edge on the bottom of two "blades" that are the same distance apart as the wheels were. This can save some fabrication time and hardware. However it will create problems in soft dirt or grass.

[Darren Lucke]

Re: Jack for Tcraft - Gear Stand

Hey Guys -

I need a bit of help - anyone have accurate dimensions on the TCraft Tapered Axle????

Here's what I'm working on - would like to adapt for the TCraft Folks -

http://www.tufindustries.com/images/GearStand02.jpg

[VictorBravo]

Re: Jack for Tcraft

Darren you might be barking up the wrong tree IMHO. What could someone use the stand in your photos for? You can't change a tire with it because the stand has to come off before you put the wheel on.

Give me a couple of minutes and I'll make up a sketch of what I thought might be a better wheel stand...

[Darren Lucke]

Re: Jack for Tcraft

Just a stand, Bill... work w/ me... you won't need 2 jacks to take both wheels off at the same time (Read - Cheaper!).

[VictorBravo]

Re: Jack for Tcraft

Here's the idea I had for a quick and cheap jackstand for a light plane that would allow changing a tire without a jack, even in the field somewhere. This can be made very light with Titanium or Aluminum.... or very inexpensively with steel.

[Bob Waldron]

Re: Jack for Tcraft

Darren,

I understand the value of your stand. Tomorow I am removing the wheels on my Fairchild (one at a time) and will place the axle on a 6"x8" post and some 2"x4" scrap. I would feel a little more comfortable using your stand.

Good luck.

[Darren Lucke]

Re: Jack for Tcraft

Thanks Bob - let me know your axle type / height... I'll send you a pair for your plane!

A pair for both your Fairchild and TCraft (once I get the dimensions for the axle)!


Bill... your design IMHO - from a manufacturing standpoint - is flawed.

1) alum in that thickness & design would not be sufficient for side loads / bumps into the wing (what my stand is designed for while wheel is removed & so you can remove both wheels at one time - get your hands greasy once, clean up, and then reassemble)

2) ease of manufacturing - it would require specialty dies for bending and or a one-stroke double bend

3) design requires more welding / fitting than necessary for the job at hand

4) loads in the vertical would put undue pressure (psi) on the paint / axle (no felt would survive)

5) have you checked alum prices lately in thickness that would be remotely acceptable?

Anyhoo - always fun to see everyone's ideas -

[mulwyk]

Re: Jack for Tcraft

Well, Gee, Darren.
I don't even know if it works, or what it does, but I love the looks of your stand! I really like the "TUF" logo, the curved lines, red color. Beautiful! Go Darren! Keep 'em coming.

[fearofpavement]

Re: Jack for Tcraft

Darren, one suggestion for the stand, if it is used on a soft surface (not everyone has a hard surface to work on) It may sink into the dirt, gravel or whatever. Some type of larger "footprint" may make it more versatile.