first prototype (patent not yet applied for)

[sloan]

Submitted for your amusement.

Helpful hints from anyone who has tried anything similar GREATLY APPRECIATED!

http://www.cis.uab.edu/sloan/heliconCag ... nCage1.jpg

http://www.cis.uab.edu/sloan/heliconCag ... nCage2.jpg

Materials: 3/4" PVC pipe & 8 3-way elbows, 2 15"x30" cargo nets, 16 9" bungee-ball loops.

Assembly time: 15 minutes from off-the-shelf parts.

Next step: better strapping, custom fit. The main issue is that ROTATION is not quite adequately controlled. But, for a first cut, this looks promising.

The idea is that this goes in a standard 3'x3'x2' cardboard shipping carton. This prototype would require significant foam padding to stabilize the bell - the next version (I hope) will keep the helicon completely (well, mostly) away from the sides of the carton. Prudence would probably require padding (particularly along the 4 smaller sides.

[tubaguy9]

I just wondered...what would you use this for?

[danzfat]

Shipping maybe?

[OOMPAH]

-

[skeath]

I'm not an engineer (not that type, anyway), but my thought is that to keep the instrument from swinging, you should add, halfway between the top and bottom (image 1), another crosspiece, all the way around, reasonably level with the instrument. Strap the item horizontally to those pieces, on all 4 sides.

A very innovative idea!

SK

[Art Hovey]

I applaud your creativity.
I suspect that the PVC pipe is the weak point. When the cage is dropped the pipe may break, and you know what happens next. Another possible problem is the fact that antique brass instruments sometimes have weak solder joints; the rope tension may yank something apart. But I see that you are avoiding that problem pretty well by using the netting.

Since you asked for suggestions, here is mine:
http://www.galvanizedjazz.com/tuba/BigConn.html

[sloan]

There's a tradeoff here: this design for the PVC cage is very compliant. This means that, if dropped, it tends to deform rather than break. My original (over?)design called for dividing all the 36" members into 2 18" members with 4-way elbows and additional cross-members (4 24" members in the middle of the small sides, and 4 18" members on EACH of the big sides, meeting in a 4-way cross). Given that the helicon has a hole in the middle, I even considered a 24" post in the very center of the cage. But, that feels like overkill AND it might make the cage TOO stiff - stiff enough to want to crack rather than bend when dropped. It also complicated the process of installing the helicon inside the cage (and getting it out!)

The meshes were mostly a matter of "what's easy to get off the shelf". I originally wanted fairly heavy-duty webbing in the central plane of the box, with the idea of strapping the helicon to that webbing. Alas, the folk who advertised EXACTLY what I wanted turned up their noses at my puny order (they have a minimum order of 30sq ft - a little more than 3x what I need. So, I decided to go with obviously inferior material just to see how it worked.

In the next version, I'm aiming for 8 adjustable straps (one for each corner of the box) that attach to <something> wrapped around the large tubing. My first attempt will use 1.5"x36" Velcro "cinch straps".
Note that this will fix the (minor) problem that the 36" members are a bit TOO flexible and are clearly bending under the tension. The stiffer design would fix that - but I'm hoping to avoid that. With the attachments (mainly/only) at the 8 corners, all of the PVC will be under compression (although it *might* be necessary to add a couple of attachments to the EDGES in addition to the 8 at the CORNERS - don't know about that...yet.)

Building the prototype allowed me to better visualize the proper position of the helicon in the box, and check the lengths (and accessibility) from the cage corners to the nearest large tubing. The bell complicates things just a bit - but I think the lines will work out.

As has been pointed out, one concern is pulling the helicon apart. For "normal" handling, the forces aren't big enough to worry about (as long as you stick with the large tubing - but for extreme handling I suspect I will need bracing (probably styrofoam blocks) everywhere that the instrument approaches the sides of the box closely. It might be easiest to simply line the box with a couple of inches of ... something. Better, but more complicated, would be to brace the bell and 3 places on the circle.

The goal here is to a) minimize WEIGHT and b) construct something that drops neatly into a commodity cardboard shipping carton and also lifts out smoothly and stands alone outside the carton - and goes back together for the trip home! This is supposed to be a round-trip shipping solution, not one-way. If the suspension idea works out, I can image building it into an ATA case (just specify some tie-down fixtures at the right places on the interior walls) - but I don't need a 300-trip case. I'll be happy to get 10 trips out of it (maybe only 2 round-trips per carton).

And, of course, I have no urge to ship a box completely full of foam. If you stay with a carton, 3'x3'x2' is just about the minimum you can get away with. With a helicon, there's a LOT of "void" to fill. Not only is all that foam heavy - it's expensive!



So far, this is turning out to be cheaper than my best "custom carved Styrofoam" design. I'll probably build one of those, too - but first I want a working version of this idea.

[David Richoux]

What shipping method(s) do you plan on? Air, (freight or checked luggage,) truck, Greyhound bus? The vibration and impact patterns for each of these will be a bit different (and each will involve different methods and amounts of handling.) I think your method will deal well with the smaller vibrations and shocks, but a drop from the back of a truck, or getting squished by other cargo should be a factor in your design. Fortunately, Helicons are not particularly heavy, so you should be able to protect it from most major impacts.

I shipped a BBb Helicon from California to the East Coast using Greyhound Freight. A big double layer cardboard box, soft foam chunks in plastic bags and some carefully placed bubble wrap worked just fine. The big problem was in the tracking and unpredictable way Greyhound decided to route the box ("space available" for a box this size meant a lot of time waiting for a bus in various depots.)

The box (and horn) arrived in perfect condition, BTW.

[sloan]

What shipping method(s) do you plan on? Air, (freight or checked luggage,) truck, Greyhound bus? The vibration and impact patterns for each of these will be a bit different (and each will involve different methods and amounts of handling.) I think your method will deal well with the smaller vibrations and shocks, but a drop from the back of a truck, or getting squished by other cargo should be a factor in your design. Fortunately, Helicons are not particularly heavy, so you should be able to protect it from most major impacts.

I shipped a BBb Helicon from California to the East Coast using Greyhound Freight. A big double layer cardboard box, soft foam chunks in plastic bags and some carefully placed bubble wrap worked just fine. The big problem was in the tracking and unpredictable way Greyhound decided to route the box ("space available" for a box this size meant a lot of time waiting for a bus in various depots.)

The box (and horn) arrived in perfect condition, BTW.

I'd love to get it SMALL enough to qualify for checked luggage (I mosly fly Delta, who have a reasonable - and well-publicized - policy for musical instruments) - but I"m not sure that's feasible. Air freight would be my next choice.

I believe that the PVC frame will make any sturdy cardboard shipping carton at least as "uncrushable" as any other packing method. IF the 3/4" pipe is too weak, note that it is available in larger sizes. I'm using "furniture pipe" (which people use to make, duh, furniture) and it is available in sizes up to 1 1/2" (I might have to get a bigger pipe cutter if I go that large). My original plans were to use large diameter pipe, but then I remembered that amateurs ALWAY over-specify and use much larger material than necessary - so I decided to start at the small end and move up as necessary (as opposed to starting large and wondering how small one *might* have gone...)

The box I have brought a different helicon to me from Nevada by train. When it arrived, the box looked exactly as if it had been sitting unmolested on a warehouse floor for 5 days. I think that the helicon *could* have been simply placed in the empty box and arrived unscathed. I did more damage to the box OPENING it than the trip did. But that box was filled with a diverse collection of padding/bracing/"void fill". This might not have mattered for train shipment - but it would for air freight.

On the other hand, the helicon pictured was sent to me nearly naked in a cardboard "carton" that had been cut down to a strange shape. Unsurprisingly, it arrived with a fresh wrinkle in the bell.

[an aside: has anyone else noticed the tendency for commercial packers to simply lay the product on the bottom of the carton, and then use air pillows to fill the void between the product and the top of the carton? This immobilizes the product, but doesn't seem to give much in the way of "drop" protection. And yet....most everything arrives at my front door in good condition.]


My goal is to have as much protection as a "box full of styrofoam", at much lower weight.

Also, have you checked prices for ATA cases of this size, with and without foam interiors? As I said in my last post - if this experiment is successful, it's tempting to order an ATA case "naked" - with a few tie-down fixtures added to the interior (this experiment will determine exactly WHERE those fixtures need to be, and how to lash it up. But, that really only makes sense if you plan on 300 trips. I suspect that *most* of the extra protection you get from an ATA case is .... for the case. I'm happy to throw away the cardboard shipping carton on every trip, if necessary. [and, of course, the design *could* be inserted into a naked ATA case just like it would be inserted into a cardboard shipping carton]

[imperialbari]

I'm going to have to warn my helicon about this.

I can just imagine my helicon walking through the woods (etc.) and one of these (painted in camouflage) trapping it.

Even if it managed to escape, it would be likely be late for the gig!

Yes, somebody is afraid of those Helicons Flying Over the Cuckoo's Nest.

K

[Donn]

I built bicycle trailers of PVC and cord, and carried tubas on them. V1 was actually PVC, V2 was made of the far superior black ABS plumbing. ABS is stronger and more resilient - I have no idea what it would take to break the 1 1/2 inch ABS tubing I used, but I quickly found out what it took to break my PVC. I don't think I've seen smaller diameters, but if it exists I think it would be pretty limber, possibly flexible enough to make a loop around that size. Bamboo would be another option - strength is a little unpredictable there, but I think small diameter doubled up would be pretty reliably better than PVC.

I didn't get what you're using for cord, but from the clearance, I suppose it isn't very elastic (or the contents would be displaced outside the envelope on impact.) If you need anything with more stretch, keep bicycle innertubes in mind - in my opinion, better than shock cord and if you have bicycles you get a certain amount of innertubes for free as they fail in ways that aren't easily patched.

[Donn]

Yes, the dark gray plumbing pipe is much stronger than the white or yellow...and (though you might have to go way across town to "that certain" plumbing supply place) not that much more expensive.

OK, that's another option, but I think it's still PVC. ABS is the really black stuff used for waste pipe. Larger diameters, not brittle like PVC, uses a different cement. Fun to work with, inexpensive, and for just plain strength you can't beat ABS (or break it.) For a stronger version of more or less the same pipe diameter as the prototype, grey PVC would be worth a look.

[sloan]

The current "cord" is 9" bungee-ball (a loop of bungee cord material joined by a plastic ball). This is NOT the final version. In this version, they are stretched almost to their limits, so there is a little bit of elasticity, but not much. This is just a preliminary lash-up, and it was entirely coincidental that the webbing and bungee I had on hand were close enough to right without any length adjustments. But, this version is nowhere close enough to actually ship (without a LOT of extra cushioning). It's mostly scaffolding to hold the helicon in place so I can measure and plan the final spiderweb.

In the next iteration, I'm looking for something with:

a) fewer connections
b) attaching at the corners of the PVC brick
c) ADJUSTABLE
d) much less elastic

Suggestions welcome! What I have on order are 1.5" x 36" velcro cinch straps. They are advertised as being able to hold 200lb. I'm a bit skeptical, but they are inexpensive and worth a try. These are inelastic. I think that 8 inelastic, but adjustable, straps will work just fine. If not, my next step will be to make a stiffer cage - but right now I think the "give" in the frame will be a plus (recall that this will be dropped in to fit snugly in a cardboard shipping carton). After that, it will be time to consider localized padding for the problem areas (bell + 3 points on the circle).

You mentioned bike trailers - I'm finding lots of interesting bits and pieces of hardware listed under "motorcycle tiedowns".

[Donn]

You mentioned bike trailers - I'm finding lots of interesting bits and pieces of hardware listed under "motorcycle tiedowns".

Yes, well, that's actually how I use the bicycle innertubes, as I regularly carry a bass tuba on the back of my Moto Guzzi. They're strong, elastic within a useful range, and knots hold very well, even a simple hitch. Great stuff.

What did you use for wheels...bike wheels...?? How did you attach them?

Yes. Wish I had a photo. The V2 frame had two internal cross members that each had a pair of Y elbows, such that two pipes stuck out on each side below the main frame rectangle. I cut holes in boards to match the pipes, so a pair of boards on each side, and cut notches in the lower edges of the boards to serve as wheel dropouts. Not a magnificent design, but it worked with ordinary, fairly high quality quick release 27 inch bicycle wheels. In V1 I tried to attach the wheels directly to PVC struts, not such a good idea.

The tongue of the trailer attached to the bicycle seatpost, and attached to the trailer frame with an ABS screw fitting - not because I wanted to be able to remove it, but thinking that would be a good place for a "break-away" that could relieve some catastrophic stress in a collision before the main frame broke. (I have a vague memory that this theory was tested and found somewhat wanting, as it proved difficult to extract the aged and distorted male threads from the fitting when this eventually did happen.)

A pair of reflectors should be mounted on the rear corners.

It was big, and tall. Most bicycle trailers you can buy are narrower, which is good if you care about people's cars you might pass parked on the side of the road, and ride a good deal lower to the ground, which is good for stability if it's narrower. But they're just about as heavy, and the ride is at least as bumpy.

A design goal I didn't satisfy very well is to present an angled surface to obstacles, because any trailer wider than your elbows will tend to snag things when you mis-gauge clearance. I also could have managed some kind of suspension fairly easily, I think.

[Donn]

You might find something to suit your application at http://www.industrialbicycles.com/.

[tofu]

(sorry to hijack your thread, Dr. Sloan, but we can probably talk diagonally across the table...no...??)

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I wonder if an old Schwinn Town and Country could just be modified to have its basket extend to the rear another couple of feet...That should accommodate most any tuba. After that, with the addition of a little 2-cycle engine and a friction roller, and one can be Mr. Urban Tuba Super-Nerd!

(much more serious than kidding)

talking diagonally now /

I have thought about bike trailering one of my horns as well. My trailer is tig welded aluminum and originally I set it up to haul two small kids (2 and 4) on a cross country bike trip. It is built like a roll bar cage in a racing car would be thus should the trailer roll the kids would be protected as they were strapped iin with 3 point harnesses and helmets. Also by using a ball to attach the trailer to the seat post should I go down the trailer would stay upright.

I used 700c tubes and tires since this was what is on the road bikes and simplified carrying inner tubes/spare tires on the trip. Since we were traveling through the mountains the trailer has brakes for added safety. The automatic braking system use Sturmey Archer alloy drum brake hubs which are actuated by a mechanism built into the tongue of the trailer. When the towing bicycle begins to slow or stop, the inertia of the trailer pushes it against the bicycle, thus depressing a rod in the actuator which in turn pulls the brake cables and results in a simultaneous slowing or stopping of the trailer. Since the kids are now too big it has been converted to haul stuff including an 85 lb dog so I know it can easily handle the weight of a tuba. It is 34 inches wide and the interior 30 inches in length. My concern is the pounding that a horn would take - especially if I hit a pot hole. I ride 4000 - 6500 miles a year so I know how no matter how hard you try to miss them a pot hole will usually find me. I will probably change the wheels to 26 inch with 2.5 mtb tires and have been thinking of ways to try to pad the trailer to cushion the horn, but am now also thinking of ways to suspend it and/or the horn perhaps in a fashion as Dr. Sloan has done.

[MaryAnn]

I seem to remember a reference (by me) a few years ago to a suspension system for packing tubas for airline trips. Of course I never went beyond the idea stage. This looks cool; doesn't MIT or somewhere have an annual "drop an egg from a two story building" container contest? The winning designs would probably morph pretty well into tuba-suspension designs.

I remember my problem with a custom flight case for my F tuba (that I sent back without using) was that the *only* thing held securely in place was the tip of the bell. To me, that was a recipe for disaster, and I could never understand why that maker had such a reputation for good products. Well made, yes, but stupid design.

I also remember a guy who had an F tuba like mine, who bought one of those large wheeled garbage cans, used spary foam to make the tuba-shaped well, and used it successfully for flights. Of course a helicon would not fit in one of those.

I love to see these creative ideas show up on Tubenet! I'm in the midst of using PVC ideas to make a chair-based adjustable stand for my euph, which needs just a couple inches above my lap (which is not tuba-sized, but pint-sized, making the chair seat option feasible.) One thing that I've found that works pretty well, is a package of that shelving liner stuff, that is non-skid and pretty cheap. I found a roll of it in black at my local Big Lots, and just folded it to size and tried it out. It works great, not slippery at all, and the people who spent hours making custom cushions for the same application, have showed a lot of interest, even if only to wrap their existing cushion in this non-slip stuff.

MA

[sloan]

I seem to remember a reference (by me) a few years ago to a suspension system for packing tubas for airline trips. Of course I never went beyond the idea stage. This looks cool; doesn't MIT or somewhere have an annual "drop an egg from a two story building" container contest? The winning designs would probably morph pretty well into tuba-suspension designs.

Many engineering schools have similar contests. One of my PhD students mentors groups of undergrads in the Engineering program - he says that this problem (construct a SMALL, LIGHTWEIGHT shipping container for such an oddly shaped object with some areas that can take some buffeting and others labelled DO NOT TOUCH) might make it as next year's subject for an annual design-contest course.
I'm considering giving them long-term access to the helicon pictured in my original post - and then bringing in my *other* Eb helicon as a surprise: "OK - you have 1 day to adapt your design to fit *this* one".

I have also seen cases where the bell is in direct contact with the case. The bell rim is special, I think. In some directions it is very strong, and in others very weak. Personally, I prefer a case which grabs onto the large tubing and lets the bell and the valve section float free - but I can believe that it might be correct to constrain the RIM of the bell from moving sideways (and also using the common idea of an airbag stuffed down the throat). Once I have the suspension system worked out, I suspect I will add those features to my PVC-cage design. Two mechanisms that each do half the job is often a better design than depending on one mechanism to do everything (belt, suspenders). Right now, I'm thinking of a bell-rim collar plus a half-inflated ball - but I'm also playing with the idea (inspired by an earlier post) of something that looks like a mute to transfer all forces in the area of the bell to the inside of the throat. Sort of a bell umbrella...

(im)Patiently waiting for my Velcro cinch straps to arrive, and trying to think of ways to minimize the number of adjustment points. 8 seems high, but I can't seem to reduce it.

Any advice on the right buckle/ratchet/Boy-Scout-Knot for the loads involved here?

[sloan]

The bungee thing is on the right track for damage control.

To prevent damage, the best approach is to SLOW DOWN movement within a defined area, rather than to prevent movement.

Moreover, if movement is COMPLETELY prevented, there might as well be no case (aka "defined area") whatsoever, as 100% of the force will be applied to the contents within.

Right. The main point of the suspension system is to avoid filling the voids with (expensive) foam. You can do the same thing with a custom molded case.

But...I'm trying to get both *some* elasticity along with *some* ability to adjust the (8, at last count) lengths of cord. Not to mention a reasonable "quick-release" mechanism.

a) soft wrap around the large tubing
b) precise length of bungee (with some stretch still available)
c) fixed attachment points (at the corners of the box)

I think a buckle/ratchet/Boy-Scout-Knot needs to go somewhere in the loop. (8 of them, at last count)

Also - note that the cardboard shipping carton does provide *some* extra protection against more casual assaults. And a convenient place to paste on the address label...

I suspect the final product will have 2" or so of foam lining the sides of the carton. As you say, the suspension system is simply to make sure the helicon is moving SLOWLY when it hits the foam.

[Donn]

My concern is the pounding that a horn would take - especially if I hit a pot hole. I ride 4000 - 6500 miles a year so I know how no matter how hard you try to miss them a pot hole will usually find me. I will probably change the wheels to 26 inch with 2.5 mtb tires and have been thinking of ways to try to pad the trailer to cushion the horn, but am now also thinking of ways to suspend it and/or the horn perhaps in a fashion as Dr. Sloan has done.

Maybe germane to the whole thread, I've been assuming that tubas can take a fair amount of punishment. Compared to, for example, a large saxophone.

When I carry a tuba on the back of my motorcycle, I put some "eggcrate" foam between the tuba and the rear rack, after observing some dents in the bell around that location. Impacts distributed over small areas like that, will cause a dent. Light but repeated impacts with hard surfaces will cause surface damage to lacquer or plating. But a little foam, plus the shock absorption of a bicycle wheel and tire (700C is better, right?), ought to be plenty?