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How can I make this barrel organ idea? Answered

So, I want to make a "programmable barrel organ" like the $1100 version below (called the Gloggomobil) but instead of using a xylophone to make the notes, I want to use kalimba-style metal rods that are plucked by pegs. My problem is, I can't think up a good way to do the barrel. The pins need to be strong enough to pluck these metal bars without breaking, but also secure in their spots so that they don't fall out when the drum is upside-down. The only thing I can think of that would be effective would be a metal barrel with threaded holes that you put screws into, but not only would drilling and threading hundreds of holes be impossibly time-consuming, programming a song would take hours and hours. I've been pondering this thing for the last week and I'm at my wits end. I'm asking the Instructables community to give me a hand figuring out what to do. Pretty much any material is at my disposal: wood, metal or plastic. I want this thing to look good though, so I don' want to do nails in a coffee can or something el-cheapo like that. Thanks for any ideas, I'll be sure to write up an Instructable once work gets underway.


This might be a bit of a long shot, but my thoughts on the matter (for what they are worth) are that you could use a large diameter piece of PVC or other building pipe/tubing for your drum (take your pick on material and size. It's your project, you pick the specs), and you can cut out multiple gaps from one end to the other the width of a screw/bolt (you'll understand why later). You may want to have end caps or the like, if so drill a hole near each end for every peg you want installed and cut from that hole to the corresponding hole on the opposite end. I would recommend having your drum 1-2 inches longer than your kalimba keys arrangement (I'll explain why in a little bit). You can then fit screws/bolts into the gaps that you have cut out of the tubing. Place the head of the bolt on the inside of the tube, and a nut (sp) on the outside. By loosening the nut you are able to slide the bolt along the slat to the desired key and then tighten it to hold it in place. By making the drum longer than the key arrangement you are able to store extra bolts out of range of the keys. In the event that you want to hit multiple keys at one time, you are able to move these bolts into the range of the keys in addition to the bolt(s) you already have in place. You can use end caps (or something similar, like a coupler, or a screw on cap) to attach it to your base and crank. There are a few ways to do this. Some offer more torque than others. The simplest way I can think of is to select a smaller diameter of tubing (the same material you used for your end cap) and drill a hole in the center of both your end caps to allow this rod to run out of each end by a few inches. Then use a bonding material (like PVC cement) to attach the rod to both caps. You allow it to run out the ends a few inches so that it can be attached to the base and also so that you can attach a crank on one end. I hope that helps. Let me know if anything is less than clear. I would be happy to clarify anything you don't understand. Happy tweaking. Sinisterly, The Not So Nice Guy

I like your idea. Its quite interesting, but this PVC pipe sounds like it would still be a lot of work to put together and program. How about this: A PVC pipe with small holes drilled in it, and an axle at the center. Around the axle is a bunch of cylindrical magnets. You insert steel pins through the holes, and they are held in place by the magnets. Then, to remove them you can just pluck them out with a pair of pliers.

I don't know how difficult it would be to program, but it could be finicky. I didn't think of the magnets idea, but I like it. You should totally do it and let me know how it works. I'm really interested. Have a good day. Sinisterly, The Not So Nice Guy

well, think of tinker toys. Assuming you drill holes a tiny bit smaller than the pegs, and you find either tinker toy style dowels that have a little give in them or like the kind of wood dowel pegs that are used for furniture construction, it seems likely you'd have a simple solution to being able to insert and remove the pegs at will. I think if your barrel is not hollow, this use of pegs would work better.

This thread is 3.5 years old. Here's what I ended up with: https://www.instructables.com/id/Build-a-Programmable-Mechanical-Music-Box/

Impossible is an ugly word, forget it and never pronounce it again.
Why not use a washing machine barrel/drum and its bearings, it is all drilled for your needs, if you look for a salvaged front-feeded machine drum you may just find one that fits without too much work.
Do the pegs out of regular screws, washers and nuts, maybe you can find a special with a nice rouded tip or use lug nuts that would be kind to your metal rods.
Punch/drill a hole in your flat rods, put them on a good resonating wood box, cover them with a thick steel piece, pull a screw through it and you´re almost done.

seems impossible, give up!

Leonardo Da Vinci actually came up with such a thing, and it's not very miniature. I had the great joy to play with a replica when I was last in Rome, so we know that such a thing can be don, and all in wood and nails so far as I could see. Would you like me to see if I can find you some schematics or at least a wee Da Vinci Drawing?

Sure. Thanks. The thing is though, its easy to do if you want to permanently mount the song on the drum, you can just use some small nails. But I want to make it interchangeable, and there's where it gets tough. I'll take a look for some Da Vinci work too.

Yeah I can see how that is a problematic ambition :) Best of luck looking!

Make the drum out of wood and use short drywall screws ?

Well, I could, but like I said, i want it to be re-programmable, so you can make new songs and experiment, and write your own music for it. Drywall screws would wear out the holes after a few uses, and would be a lot of work to screw in and out without a drill or something.

There are only 8 possible rings to place them in, and you could make new drums from logs for next to nothing, why worry about the wear. Setting short drywall screws by hand is dead easy anyway - say 20mm ones ? In wood, the screws would follow the previous thread, I don't think it would wear out very quickly at all - you could always use the next longer screws. This was only the interim solution, the best solution would be a piece of 6mm or 8mm aluminium pipe, and drill and tap holes as close as you can around the 8 rings. If you say what speed the drum is rotating, and you allow a certain minimum chord timing, you can work out the number of holes you need. Its a tedious job, I'll grant you, but it need't take that long. You MIGHT get away with self tapping screws - they won't wear the holes out.


8 years ago

One way to save yourself a little time is to use a nut-bolt combination for your striking points. Similar to AlternateLives' suggestion, but instead of threaded rod, just get bolts. Screw the bolt in from the side so it's thread comes out, and tighten the bolt on with nut. Make certain all the bolts are just far enough away from the keys that they just miss it. Now to "program" the song, you add cap nuts to the end of the bolts you want to strike the keys. When you turn it the barrel, only the bolts with nuts on the ends will strike.

Okay, now for my crazy-expensive version: Drill holds in the barrel for each rod, along with some support. Now attach the end of the rod to a servo mounted in the barrel. Attach the servo to a MicroController. Now you can program the servos to move the rods into striking distance on command. You can write a song in the software, load it up (or transfer over serial). Have a motor turn the barrel and you've got a music machine... Should only be about 160 servos + Microcontrollers + programming hardware... ;)

Make the drum out of some sort of plastic or metal can. now, cut lots of little rods out of threaded metal rod. make sure they are thin enough to not break the bars. now, buy some two-part epoxy. this stuff smells something terrible, but it is a great adhesive for just about anything. glue small nuts equal to the size of the threaded rod to the barrel. you should now be able to screw in individual pegs into the cylinder.

To make it look nicer, maybe use an old beer keg, and then Steampunk it.