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a great way to spend 45 dollars... put together a wing jack stand
I have been looking for a better solution to jacking up the wing for some time... I have been using a jack arm arrangement that slips into the axle but it is really a marginal solution; it is a bit pricey, takes way too much effort just to lift a wheel, and is in the way during maintenance. So, for a while I contemplated ordering a commercial wing stand... while they are pretty nice, they run around well north of 200 dollars plus shipping. Doing a bit searching on VAF there are several scattered examples of an inexpensive solution that I mined for ideas.
Parts that I used: From Harbor Freight, a 3 ton super heavy duty long ram hydraulic flat bottom jack for a whopping 40 dollars (I even had a coupon for 10% to level off the tax). From Lowe's, a 3/8-16 x 3" carriage bolt, lock nut, a 3-1/2" hose clamp, 1" steel pipe cap, and a single 10' stick of 1/2" emc for about 5 bucks. I had a good piece of plywood in the hangar to make a 18"x18" base, and I just used some #10 cs screws that were left over from the build. Set the jack in the center of the board oriented so that the pump arm is easy to access. Measure the desired length for the conduit support legs. Cut them and squeeze the ends in a vice, bend the ends to sit flat. Drill the base and supports, attach hardware... I used some gorilla tape at the top to cover any rough edges. ![]() I drilled a slightly oversized hole in the pipe cap for the carriage bolt to nestle down into and tightened down a nyloc nut so the cap will just jiggle. ![]() Thread the cap assembly into the tie-down. ![]() Jack away :) ![]() This works so well I really wish that I did it long ago... |
Good idea, but....
Just a thought here, but I would cut off the excess bolt length, as it will make it stronger.
There maybe little to no chance of this bending, but why give it any extra help?? ![]() With the angle shown, the longer the bolt unsupported, the weaker it is. Imagine what would happen if the bolt were a foot long:eek: |
Other than Mikes suggestion, I like this setup ! ... probably enough to make one of my own :)
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a lttle bit worried....
about just having that hose clamp around the top of the braces. Would not take much side load to make that slip, or make one of the diagonals slip out from under it.
Maybe pin the diagonals to the clamp somehow? rivet them? just thinking out loud here.... Is there anything fixing the base of the jack to the plywood? |
If you look carefully at the top of my jack I drilled a 1/2" hole about 1/4" deep. Then took a 3/8-16 socket head cap screw and rounded the head on a grinder to fit the hole in the top of the jack.
I stole the idea from a guy in KC about 6 years ago. I welded my braces to the ring at the top. |
I have three
made almost exactly the same as Stephens about 6 years ago for our Mooney.
To solve the problem of attaching the support struts at the top, I found a ring in the electrical isle at Home Depot with an ID big enough to just swallow the jack body. I think it even had four flats around the circumference to attach the strut tops with screws. Anyway, they work great. I countersunk the top of the jack ram to deepen the hole, and just use two cut off bolts in the tie down holes to provide secure jack points. Only improvement I might make is to buy some lock rings available from industrial supply houses like McFaddin-Dale. Probably safer if you ever have to leave the plane on the jacks overnight... ![]() |
Very cool tip! Thanks for sharing!
I love the innovation in our group. |
I made similar jacks. Work great. Lock rings are a good safety idea.
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I'm still an advocate for reversing the design approach of the jack ram to wing tie down point.
I use a 1.25-1.5" twelve point socket and bolt that to the tie-down hole with a standard hex head bolt. Put the ram of the jack into the open socket and there is no way that is slipping off. |
alternative Jack
in our hanger (two RV's) we use a HF motorcycle jack that has a flat platform top. One of the guys built a box to fit on top of it that extends it and has the appropriate contour to fit under the cockpit at the spar carry though. We use a furniture pad for additional padding.
It nicely raises the whole plane, and with slight adjustment, can lift just the nosewheel. Jim F RV-9A (220 Hrs.) |
The jacks are now listed on Harbor Freight for $54... :mad:
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Just finished the Tie-Down assemblies on the two Spars. Had no idea they were that strong!
- John Munroe Front Royal, VA RV-8 in progress |
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Went to visit local store, the jacks were labeled $39.99!! At the register, they were $54.99. :mad:
The manager honored the $39.99 price AND applied my 20% off coupon! :D Total price was just over $29 each!!! I'm gathering the other parts and will put my Frankenstein jack together soon. THANKS for the great idea! |
I built these a year + ago, have worked well for me.
I welded the jacks to steel plate, about 14" square, 3/8" thick. Bit heavier than the ones shown at the start of the thread, but totally no way they are going to tip over in normal use. ![]() |
Finished my jack project today. I am quite pleased. I used Greg's technique and drilled a hole in the jack shaft to accept the bolt assembly that screws into the tie down hole.
Anyone who wishes to borrow these jacks is more than welcome. I do charge Russians $20/weekend rental fee. :D |
Got mine done
The jacks are $54 now. I over did the bases a little, but very stable while jumping in and out of various RV's. The 3 inch exhaust clamp worked well for securing the 3/4" conduit to the jack body. My hanger always floods about a inch deep after a rain, so decided against the wood base.
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Another Harbor Freight Jack
I built a jack like this using the great ideas I read about here. Thanks to all you experts! I used 3/8" all-thread at the top for connection of the jack to the wing. I put a lock nut on either side of a gas line cap, then ground off the threads inside the cap to make the end of the all-thread smaller where it would fit into the top of the jack. The gas line cap is probably not needed, but I felt better with captivating the assembly over the top of the jack.
At the bottom of the jack I added one thing I hadn't seen here. I was concerned that the bottom of the jack might slip out and allow it to fall over. I used a jigsaw to cut out the shape of the bottom of the jack in 3/4" plywood. I bolted that piece of wood to the larger bottom support using bolts up from the bottom. The jack does not have any bolt holes to allow directly mounting it so this method traps the jack in the cutout area of the second piece of wood. Now the jack is secure at the bottom along with the supports at the top as shown by others. I used double hose clamps to increase the strength there. Pictures follow. ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
FWIW, I drilled holes in the base of the jack and bolted it down. I like the welded versions a lot, but have zero welding skills.
Greg |
Seems like the shorter, $18 bottle jacks would work just as well, assuming you made a taller stand. Any reason why not? I'd think 6" of lift would be more than enough?
http://www.harborfreight.com/4-ton-h...ack-66450.html |
Really cheap.
Mine are simply two concrete blocks with a flat piece of wood on top, then the usual bottle jack borrowed from my bench press.:)
Fred Flintstone kinda deal! Jack both my -6A and -10 with them. Best, |
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Greg |
resistance to overturning...
Beware of using a small jack on blocks, there is not much resistance to overturning with a small jack fully extended... It takes a surprising length of extension to get the wheel in the air and there is some positional movement of the jack point, especially with a tail dragger with the the tail on the ground.
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Jacks are...
$40 online right now. Might have to do this just as a side project, or to at least have the jacks handy for future use.
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From the number of people doing it I guess it is o.k. but are the two tiedown points strong enough to support the weight of the whole aircraft?
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Jim |
Jack stands
The idea has been around for a while ever since Harbor Freight has had the cylinder jacks available at a reasonable price.
I made these eight years ago, for use in certified aircraft that were significantly heavier than RVs. A little over the top but they will probably last as long as the cylinders will hold up. ![]() One accessory I did not add was some small casters on one end so that the stand can be tilted slightly and then rolled under the wing. They are pretty heavy to drag around. Dave A. 6A build |
This is probably a dumb question, but although I know jacking at the tie down point is common, is the tie down point strong enough to hold +/- 500# of plane all in that one point on regular basis? Usually it's one bolt on the jack going into the tapped extruded aluminum tie down bracket which, in turn is attached to the spar with nothing more than 4 AN3 bolts. Seems like a failure either in the treads, bolt, tie down bracket, and/or spar would be quite problematic. Just curious.
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I recycled a couple retired disk blades out of the iron pile with an 18" section of 2.5 x 2.5 x .25" angle and 2-3" muffler clamps welded together.
Makes jacking the mains a quick, simple job. ![]() |
I like your design with the welded angle. I have a RV3 and was wondering
if having just one jack would be sufficent and just jack up one side at a time for tire, bearing, and brake work? Thanks Jim Miller |
Why offset
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My modification/contribution to the design
One way to address the concern about the struts slipping out of the band clamp is to just rivet the struts to the clamp using an AN426AD4 rivet. (I found this solid band clamp at my local irrigation supply store, but I suspect most well-stocked hardware stores would carry something similar.)
![]() Thanks Stephen for the original idea. Under $50 for everything! |
The angle is welded offset so the jack is centered.
One jack will work just fine, just be careful of side loads as the weight is shifted to the opposite wheel. I had someone ask me if I have any extra blades so they could make one like it (he said he didn't have any disk blades laying around for some strange reason). I do have a bunch but they are heavy, dirty and 23" in diameter. I will be more than happy to give them to any one that wants to pick them up at BNW. Might be a good reason to come to RV day on 6/16. |
Jacks leak
Be careful. The jacks from harbor freight will leak over time. We were on jacks for a month getting some gear work done and placed saw horses longitudinally across thebfront and back wing spars. The leaknis not great but we needed a coupl of pumps each day. The jacks are a home run
Phelps |
There are some great ideas here, but I question using hose clamps to secure the braces that I see in some of the pictures. Would it not be safer to use something like a muffler clamp?
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When I saw this thread I rushed off to HF to buy jack and now have the
project done except for painting. I used ideas from the posted designs and added my some of my own. I will try to post a photo later and may need some help. Thanks Jim Miller PS: This jack may be a little tall for my RV3 and may require that I cut off the two inches of jack ram that extends above jack when fully retracted. Anyone out there using this jack on a RV3? |
This picture of a punctured Falco always reminds me to make sure the attachment point on the jack is well secured.
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I am going to try to post photo of just complete wing jack. It is
welded from 1 3/8 sq tube and a piece of 3 inch c-channel. Note the muffler clamps threaded thru 1/2 holes requiring no welding and easy replacement. Paint is John Deere green from Lowe's. |
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