Set Screws vs. Cap Screws

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I have a commercial project coming up that requires me to build a display table for a couple of scale model airplanes, one is the Antonov 124. The models actual wing span is approximately 56", nose to tail is about 53". The airplane has a single 8mm mounting nut and is elevated from a platform by that mounting nut.
I need to mount the airplane so that it will not spin while on display, that is one of the current problems.
I have the details figured out, I think. There will be an 8mm threaded stud coming from the airplane to an elevated post and will do down into the post 3~4". I plan on embedding a 1" long set screw rod coupling 1/2" into the mounting post. The 8mm rod will go through that coupling and down another 3~4" into the post.
Finally the question. A single 10/32 set screw, in the coupling, will tighten into the 8mm threaded shaft. Since this set screw is going to be used relatively often I have fears of a hex wrench eventually rounding out. My thought is to use a hex head cap screw instead, with a larger sized hex head.
Will the cap screw hold as well as a set screw or will a snug set screw hold as well as a cap screw that is tightened much tighter?
The job of the set screw is only to prevent the rod from rotating, the bottom of the hole will maintain proper shaft depth.
Thoughts?
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"Leon" wrote:

------------------------------------------------------------------ Set screw is a failure waiting to happen IMHO.
How about an 8mm lock nut that locks the 8mm stud on the plane to the mounting post below?
Lew
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On 11/2/2012 4:05 PM, Lew Hodgett wrote:

The airplane is mounted at a 30 degree angle. I thought about using a nut in the post but that would mean you would have to hold the >4' square airplane at an angle and spin it 16~20 times to mount and again to unmount. Actually I believe that it would be best if the airplane would spin if forced, which convention folk will do. I just don't want it to spin on its own or given a lite tough. Essentially the method you are describing will be used at the airplane to stud union.
Setting the airplane stud in the mounting hole quickly will be a great advantage.
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"Leon" wrote:

------------------------------------------------------------------------- Took a look at pics, Haven't yet figured out how the pooch is going to help.
Is he the job super<G>?
The following is based on you having access to metal working and welding.
Picture a pipe flange. It will give you an idea of what I'm about to describe.
Start with a 1" dia x 3" long CR1018 CRS and drill a 1/2" dia x 2" deep hole.
From the opposite end, drill and tap 8MM threaded hole, 1-1/8" deep.
This eliminates drilling an tapping the full 3".
Cut a 3" dia x 1/4" thick piece from CR1018 CRS.
Drill 12, 8 MM clearance holes, equally spaced on a 2-1/2" dia bolt circle.
Drill a 1" clearance thru hole on centerline of 3" dia plate.
Position 1" dia x 3" long piece in flat plate with 8 MM thread up and projecting 3/4" above plate, then weld.
Using white oak or similar hard wood, cut a 3" dia x 3" long piece, then drill a 1" dia thru hole. (Parallel to end grain)
Drill only one 8MM clearance hole x 1-1/2" deep on a 2-1/2" dia bolt circle.
Mount this white oak piece in table at a 30 degree angle as req'd.
Thread 8 MM lock nut and weldment onto plane stud as req'd.
Drop weldment into white oak piece and rotate until hole in weldment lines up with hole in white oak piece, then insert 8MM pin to prevent rotation.
Line up plane to final position and lock in place with lock nut.
Grab a beer and greet the world with a shit eating grin.
Have fun.
BTW, if you can't find CR1018 CRS (Cold rolled), use CR 1020 HRS(Hot rolled)
Lew
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For whichever set screw you use, file flat a part of the 8mm threaded rod where the set screw will contact. Re-die the rod, if need be, if the filing messes up the threads on the rod, for screwing it onto whatever. With a flattened side on the rod, either set screw would not have to be tightened so tight.
Sonny
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On 11/2/2012 4:20 PM, Sonny wrote:

where the set screw will contact. Re-die the rod, if need be, if the filing messes up the threads on the rod, for screwing it onto whatever. With a flattened side on the rod, either set screw would not have to be tightened so tight.

Thought of that too and the threads will not matter at that point. Filing would help but I personally will not be setting this display up over and over and the depth of the mounting stud "in the airplane itself" will be ever changing, which would change the location of the flat spot on the rod.
Now if only I could find a key way slotted threaded rod.....
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wrote:

where the set screw will contact. Re-die the rod, if need be, if the filing messes up the threads on the rod, for screwing it onto whatever. With a flattened side on the rod, either set screw would not have to be tightened so tight.

Make sure that the depth into the airplane will always be the same, or simply tighten the jam nut at the airplane AFTER the set screw is installed.
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Sign up the the Yahoo 7x12 minilathe group or the Yahoo X series mills group and ask. Someone will probably produce some for you. About a 5min job on a mill. If you were near me in the UK I'd do it for a couple of beers.
I've made sawdust a long time but a couple of years ago bought a cheap Asian 7x12 minilathe and a tiny X1 mill (Now have a much bigger mill/drill) and I've taken to making swarf too.
For so long there was the situation "what I need for this job is....". Now I just make it. Absolutly great. I can be completely free and imaginative about the way I can tackle projects.
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Stuart Winsor

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wrote:

the set screw will contact. Re-die the rod, if need be, if the filing messes up the threads on the rod, for screwing it onto whatever. With a flattened side on the rod, either set screw would not have to be tightened so tight.

DON'T use threaded rod. Use a good alloy steel "shaft" threaded to fit the airplane, and a close drop fit into the stand - with a flat ground on the shaft to take the set-screw.
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"Leon" wrote in message
I have a commercial project coming up that requires me to build a display table for a couple of scale model airplanes, one is the Antonov 124. The models actual wing span is approximately 56", nose to tail is about 53". The airplane has a single 8mm mounting nut and is elevated from a platform by that mounting nut.
I need to mount the airplane so that it will not spin while on display, that is one of the current problems.
I have the details figured out, I think. There will be an 8mm threaded stud coming from the airplane to an elevated post and will do down into the post 3~4". I plan on embedding a 1" long set screw rod coupling 1/2" into the mounting post. The 8mm rod will go through that coupling and down another 3~4" into the post.
Finally the question. A single 10/32 set screw, in the coupling, will tighten into the 8mm threaded shaft. Since this set screw is going to be used relatively often I have fears of a hex wrench eventually rounding out. My thought is to use a hex head cap screw instead, with a larger sized hex head.
Will the cap screw hold as well as a set screw or will a snug set screw hold as well as a cap screw that is tightened much tighter?
The job of the set screw is only to prevent the rod from rotating, the bottom of the hole will maintain proper shaft depth.
Thoughts?
Drill a slight shallow hole in the 8mm shaft for the set screw to enter. Problem solved. WW
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On 11/2/2012 5:04 PM, WW wrote:

Darn, I though you had it!. I will not be setting this display up but others will, over and over. They will be attaching the threaded stud to the airplane first and the stud would have to be clocked perfectly for the hole to align properly.
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http://www.flickr.com/photos/lcb11211/8148925134/in/photostream/lightbox /
http://www.flickr.com/photos/lcb11211/8148925104/in/photostream/lightbox /
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wrote:

To do the angles you might have to get Swingman to drag out the multirouter. Throw in your contrasting woods and I'd like it.
Mike M
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So here's my take on this If you make it able to rotate, you might do more damage on the far wing, or smaller plane if the larger plane swings into the smaller mount or plane.
But that is not my choice it's yours or your customer's.
I still think you would be better with a belly cradle (smallish) and use the stud to secure it to the belly cradle. you might actually use a piece of metal in the cradle to allow it to be tilted based on their preference , so the metal plate is rounded (conforming to the bottom of the cradle) and has an elongated slot across the cradle (not lengthwise) allowing the model to be leaned at their preference. Tightening the nut would tighten the position the model is locked at.
If you do decide to continue with the shaft and allow movement. Put an arm on the shaft and limiters to prevent the model from being able to swing if hit. Allow it to just remove the initial energy, but not damage the other model or itself.
Wish I were good at sketchup. Wish I could draw... nice work you and Swingy do w/Sketchup.
Now on to more important things.. Nice dog, but whats the cash of money doing on the table....??? Are you bragging???
On 11/2/2012 6:15 PM, Leon wrote:

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On 11/3/2012 10:13 AM, tiredofspam wrote:

I under stand your concerns. These airplanes are not exactly fragile but my biggest concern is twisting the nut out of the bottom of the airplane. They do break down, the wings and landing gear come off, and are shipped from show to show in very nice shipping containers about the size of a small refrigerator. The airplanes already have stands that they are displayed on but not at the angle that the customer wants. He wants more tilt to take up less display floor space. Any way I think a rubber washer between the airplane and the jam nut might allow enough give should one of the wings take a bump.

thanks! I probably spend 1/3 of my time designing, 2/3's building. A lot easier and less expensive to get it right on a drawing.

Now on to more important things.. Nice dog,
The one sucking the pillow? I swear she would smoke cigarettes if they were around.
but whats the cash of money

Payment for a kitchen job about 8 years ago, neighbor pricing. ;~(
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On 11/3/2012 11:05 AM, Leon wrote:

Yabbut, Leon .... you're not supposed to leave it on the table for all that time ...
Shhheeeeesh!
LOL
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On 11/2/2012 3:53 PM, Leon wrote: ...

Agree would be best to have a flat but probably won't matter too much...how much does the beastie weigh?
I'd suggest a regular hex set screw--they've got the cup in the base to grab the target already plus they're hard. If need be, ship the allen wrench w/ it in a little cubby spot...
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On 11/2/2012 5:15 PM, dpb wrote:

In display mode about 20~25 lbs for the big one.

Yeah, actually there seem to be about a dozen tips for set screws, Pointed, round, ball,
http://www.mcmaster.com/#set-screws/=jzs18u
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On 11/2/2012 5:27 PM, Leon wrote:

...
...
...
Yes, the pointed, round, ball work best w/ a matching reset, the cup w/ the little toothies will bite into your threads iff'en you don't want the flat or they ignore it.
I came to me this morning -- there's model-sizes of square and/or hex or octagonal telescoping tubing that would provide a specific orientation...
--
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Those conformable soft tip screws are very good for your purpose. They will hold well, but like others say, use the length of the hole and shaft to control basic setup height. I would consider a stop collar with the conformable soft tip if you want other heights. The collar would probably already have a screw designed for a flat.
http://www.mcmaster.com/#shaft-stop-collars/=k055cp http://www.mcmaster.com/#shaft-stop-collars/=k055p2
On 11/2/2012 6:27 PM, Leon wrote:

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