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Alum. Backpack Frame anyone?


TK765
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Hi all, I am fairly new to the board, have trooped in the past and I am in the process of finishing my Sandtrooper finally after a number of years sitting in the box.

I am digging into the backpack right now and have the cpvc kit which is ok but after a little boredom today I though "hey I could probably have our shop make the frames". They will do custom work for employees at cost, my buddy had them make a sailboat trailer.

So after a few minutes of goofing around I came up with this for a start. I am not in the eng. dept anymore but I try to do a few things once in awhile to keep my skills fresh.

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If there was interest I would be willing to put forth the effort to make these as accurate as possible before proceeding, get accurate cost from the shop and if cost effective do a run.

I would need help and input from anyone and everyone to make these as accurate as possible. Dimensions, tube size, radius's, # of cross supports, angles.

If there isn't any interest thats ok too, but I would still like to design one up and make it as accurate as possible so again any input would be appreciated.

Not in a rush especially since I broke my shoulder and will be messed up for awhile.

Thanks

Todd

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That's a nice start, but it needs a bar at the top and the middle, ideally at the bend. It also needs to be sized to a production seed tray, like what the Crashmann is making. I look forward to whatever you can provide. As for price, keep in mind that you can usually get the original boy scout frames on ebay for around $25. I just picked one up today, actually.

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The seed trays / main boxes should each be 2 1/4" tall, for a stacked height of 4 1/2"

The top of the seed trays are 7" x 11"

The base of the seed trays are 9" x 13 1/2"

umm Barley and Hops? Charlie? :unsure::lol:

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Ooh, pretty picture!

One of the challenges we had working with thin walled aluminum tube was that it would kink when trying to form a tight radius. Since you've got a real production shop, it would be no problem for them :)

I believe the tubes are 1/2" diameter. The radius of the bends in your drawing look good to me. I chose 22.5° for the angle in the middle since that is half of 45° :)

Here's some pictures of the CPVC frame I just glued together:

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When assembled, it is 12 3/4" wide and 18 3/4" tall

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I've seen conflicting information regarding the top of the frame. There are some screen grabs that show two vertical bars going a couple of inches above the top of the seed trays. Others show a rounded corner leading to the horizontal bar. I have no official information about the rest of the structure, since it was obscured by the seed trays.

Good luck with the project, and I hope you heal up real soon! (I hear barley and hops helps bones heal good :lol: )

Charlie

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I've seen conflicting information regarding the top of the frame. There are some screen grabs that show two vertical bars going a couple of inches above the top of the seed trays. Others show a rounded corner leading to the horizontal bar.

I'm pretty sure that none of the old, used ones on ebay are identical to the ones used in the Film. In the "Making of" book, one of the prop guys says specifically they used Boyscout back pack frames, but most likely a variant only made or sold in the UK. Over the last four years that I've been buying them off ebay, I've encountered at least three different designs. All of them had the foot, but all the cross-bars were different and none of them had that signature bend in the middle. I'm thinking they might have added that just to look cool with the seed trays. Who knows.

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Thanks guys, every little bit of info helps. So 1/2" od on the tubes, what would be the radius of the bends typically?

My first plan is to pattern this initially off the pics of the snow troops pack since there is so many variations of scout packs. I am going with the theory they used or altered the same type of packs for both movies.

On the 90 degree bend on the bottom, are the sides suppose to be angled in slightly?

Thanks for the thought, I had surgery yesterday and everything is tolerable right now, that is untill the nerve block wears off :unsure:

Got lots of drugs too, will have to wait for the barley and hops unfortunately :lol:

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  • 2 months later...

I'm pretty sure that none of the old, used ones on ebay are identical to the ones used in the Film. In the "Making of" book, one of the prop guys says specifically they used Boyscout back pack frames, but most likely a variant only made or sold in the UK. Over the last four years that I've been buying them off ebay, I've encountered at least three different designs. All of them had the foot, but all the cross-bars were different and none of them had that signature bend in the middle. I'm thinking they might have added that just to look cool with the seed trays. Who knows.

Pix of the different ones, sir?

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Hey there, I am also making a frame out of some aluminium pipes. I've already the right pipes here but I got one problem. I want to bend the pipe to the right degree but I don't know how to bend aluminium? I guess there are special machines you have to use?? :blink:

Salute! Kevin S.

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...how to bend aluminium? I guess there are special machines you have to use?? :blink:

Salute! Kevin S.

The Boy Scout frames are hollow and easy to bend by hand, using a heavy rubber mallet. You have to be careful though, too much bend and a "fold" or "crease" will develop. To overcome that, some folks in my garrison have filled them with sand, then bent them.

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The Boy Scout frames are hollow and easy to bend by hand, using a heavy rubber mallet. You have to be careful though, too much bend and a "fold" or "crease" will develop. To overcome that, some folks in my garrison have filled them with sand, then bent them.

Thanks for this good advise, I'm using a 15mm pipe which is 1,5mm thick. Hope It will work :lol:

I gonna post the result :)

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That's a nice start, but it needs a bar at the top and the middle, ideally at the bend. It also needs to be sized to a production seed tray, like what the Crashmann is making. I look forward to whatever you can provide. As for price, keep in mind that you can usually get the original boy scout frames on ebay for around $25. I just picked one up today, actually.

I got one for 20$ on ebay 2 weeks ago.

And wait for it to come home, so i can take off my pvc frame.

but i think its cool, crashmann, and TK765 make a frame run.

The vintage boyscout frames, can be hard to find from time to time.

Cheers :)

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  • 2 weeks later...

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