Archive for January, 2012

Hacking the Roland HD-1, again

January 29, 2012

As mentioned in a previous post, I added a Roland TD-3 to my Roland HD-1 so that I can get more drum sounds, and so that I can attach the kick drum that I made.  It turns out that the TD-3 has triggers for all of the drums in the HD-1, plus one more, ostensibly for a second Crash cymbal; but of course that can be reconfigured to be any drum or cymbal.  I purchased a used Roland PD-7 drum pad for $25 on eBay, and wanted to mount it to the HD-1 system so that I could have a fourth Tom.

The two upper arms on the HD-1 that hold the cymbals do so with an innovative system that presses into the end of the arms.  I figured I could buy those fixtures from Roland as spare parts, and then mount the new drum pad in the same way that the cymbals are mounted, on the end of a metal rod.

I first tried to order parts through Roland, but they are impossible: they publish neither exploded diagrams nor parts lists, and you have to order the parts by having someone on the phone try to explain what each part is, and where it goes.  The parts I ordered arrived quickly, but were the wrong ones. BTW, Alesis is similarly brain dead: you can order either a “long screw” or a “short screw”, but no one (and I mean no one) has any idea how long either of them are.

With that option gone, I built a prototype of a block that would sit on the end of the arm and hold a metal rod on which the new drum pad would sit.  The wooden prototype looked like this:

The large hole goes through the arm, and the metal rod goes through the smaller hole.  Set screws keep the fixture from rotating on the arm, and keep the metal rod from dropping out.

My drum kit now looks like this, where the new drum pad is circled in red:

Here is a closeup of the new pad:

And here it is from the back, so that you can see how it works.  The “U” shaped metal rod connects the drum pad mount to the block of metal at the end of the HD-1’s Tom Tom arm:

And here it is at a different angle:

Having the fourth Tom Tom gives me more flexibility and variety when playing; and it was inexpensive and easy to add!

Thanks go to Brian from J&L Hardware in Fairfax, Vermont, for fabricating the U-shaped metal bar!

Hacking the Roland HD-1

January 16, 2012

I purchased a used Roland HD-1 drum kit after reading some of the reviews. They pointed out that the HD-1 has three weaknesses: 1) there are only 10 drum kits defined, with only 2 kits that are really useful, and with no ability to redefine the existing kits or define new ones; 2) the kick drum pedal does not feel realistic; and 3) the drum and cymbal pads have only one sensor zone.

There is an article here in which greydog describes how to use a Roland TD-3 to extend the voices for the HD-1. You run a MIDI cable from the output of the HD-1 to the input of the TD-3, after which you have access to all of the voices and kits in the TD-3, including reassignment of voices, changing relative loudness of each voice, and stereo voice panning. This works well, but you are still stuck with the HD-1 kick pedal.

The video here, towards the end, shows how to modify the springs in the HD-1 kick pedal to stiffen it up, but that did not seem like it would be enough. I build a wooden contraption to simulate the kick drum, and attached a regular kick pedal to the “drum”:

The kick input to the HD-1 does not accept a piezo signal: it will not trigger with that kind of input.  I discovered, by accident, that it will trigger if you just short the two signal lines together.  So, my original plan was to put a momentary contact push button switch where the beater hits the wooden panel, countersunk so that the beater just barely “clicked” the switch, and trigger the HD-1’s kick input that way.  I came across a free practice pad that had been converted into a DIY drum pad, and mounted that pad where I had intended to mount the switch. The only problem was how to get that piezo signal to trigger the kick drum.  By connecting the new DIY kick drum sensor directly into the kick input of the TD-3, I was able to get the best of both worlds.  I now have all of the HD-1 drums triggering the TD-3 sounds, and also have the new kick pedal triggering the TD-3 kick sound.  As a side benefit, I actually have two kick drums now, one on the HD-1 and one on the TD-3.

Quick and Easy Rope Plant Hanger

January 1, 2012

My girlfriend wanted to hang some plants in front of our picture windows, so we went to a local nursery.  For about $10 they sold a pot holder that would trap a pot in a web of ropes.  There was a large knot at the top and bottom, and a series of knots in the middle to hold the ropes in place, so that the pot would not fall out.  It looked simple enough, so we just bought some rope and went home to try to duplicate the design.  One reason to do this was to be able to customize the hangers for pots of differing diameters and to hang the pots at differing heights.

It turned out that tying all of those knots in exactly the right places was a frustrating process, so I tried to think of other ways to keep the ropes in place.  While perusing the web, I encountered some designs that used beads rather than knots. Having no beads of that size, we decided to try using washers, instead.  The result is a plant hanger that can be made in under 10 minutes.

To start out, cut four pieces of rope 100 inches each.  Fold them in the middle, to get 8 strands of rope about 50 inches long.  Tie an overhand knot about 3 inches from the top, where the ropes loop back on themselves.  We did not need to, but you could trap a steel ring in the top loop if you wish. This is what the top should look like:

You might think that a simple knot like this could shift, but once you pull each strand tight, it should be solid.

Insert washers from the bottom, trapping pairs of ropes.  The trick is to use two layers of washers, one of which traps pairs of adjacent ropes, with the next layer trapping pairs from adjacent pairs.  It is easier to show you than to explain it:

Note that one of the final washers has to trap one rope from the top and one from the bottom, to turn the whole thing into a cylinder.  This is what it should look like just before you tie a second overhand knot at the bottom:

The next part is tricky.  Put a bowl on the table, place the bottom knot in the bowl, and then place the pot on top of the bowl.  The bowl provided space for the bottom knot so that the pot does not fall over while you are working on getting the ropes arranged around the pot.

Gently lift the top knot to put a little tension on the ropes. You need to start out with all of the washers at the top, and only lower the first layer of washers down until they rest on the top of the rim of the pot.  Make sure that the washers are spread out evenly around the pot.  Then lower the top layer of washers.  These put some side tension on the ropes, pulling them so that the ropes that are holding the pot cannot slide sideways and drop the pot. It takes some fiddling, but after a few minutes, you should end up with something like this:

This design uses ropes in dynamic tension: once you have configured the ropes properly, you cannot let go of the ropes, or you will have to arrange them again.  Be prepared to hang the pot from some temporary hanger if necessary.

Here are some shots of two of the pots after we finished hanging them:

We like the flexibility of being able to chose the rope color and the hanger dimensions, as well as knowing that we’re only 10 minutes away from making another one, should we need one. Note that you can try it with 6 or 10 ropes instead of 8, if you wish.