Doug, I'm going to send my 100' roll of mylar down to you so you and Paul will have something to do in your spare time. I can see clotheslines strung all around the living room and kitchen. ;-)
I find this fascinating since I've thrown out a few belts after the silver has worn down. Now I find out that I should have kept them and cleaned more of the stuff off. So, where can one source the etching cream?
Thanks again for sharing your tweaks!
EDIT: a Google search will quickly show sources for the etching cream. |
Whut?!? No cryo treatment? BTW, I did find an etching cream that does not use some real bad stuff. A bit more expensive, but the add says it can be reused. Second row of product. etch all |
Thanks for the update, Mothra. My etching cream is on the way so I'll get to try this soon.
I think Doug and Paul could start a fashion trend there in CT. by wearing those HazMat suits around the house. |
Hey Doug, I'm sure you and Paul did quite a bit of experimenting but how many belts did you get from a 3 or 4 oz bottle of etching cream? |
How can you go wrong with a name like BigCrank! ;-) So far I've stayed with the jump start type battery packs that can be found at various places. I don't have an external charger and these come with one built in.
So, there is another item for the list for next time I get down your way. The Anvil, and my Jump n' Charge. Sounds like a game for kindergardeners compared with BigCrank! |
I finally got around to trying this over the weekend. This is a wonderful tweak and I give it the two key lime pie award! I believe this is getting us close to the realm of direct drive, at least as good as an idler.
My perspective on the improvements are similar but, since I listen to mostly rock (a little flab in the bass is not a bad thing), I thought I may have noticed things differently. But I've had some time to digest this overnight and I don't think I would disagree with anything anyone has posted about this new belt configuration. What I've noticed the most is the increase in micro-details. I'm hearing new sounds in the background and around the edges. Bells, wood blocks, chimes and such are not being smeared anymore so they come out to the front. The attack and presence of all instruments is greatly enhanced. I hate to use the cliche about veils being lifted, but there it is.
I found the process of etching the belt very easy. HINT, is it always the side that the mylar wants to curl to. The thought did cross my mind about trying this with an already spliced belt, but the worry of what happens to the splice tape prevented me from trying that. So I simply cut the old splice out and proceeded. This led to a belt that is about 2" shorter than what I normally use, and I'm left pondering if shorter isn't also better. This means that the wrap around the motor capstan isn't as tight so the belt runs smoother. There seems to be no chance of belt flutter with the shorter belt. With the increase in friction provided by the de-mylared surface I suspect that an even shorter belt may work better.
My belt may not be as tight as what Doug gets. I say this because I'm pretty sure I'm no where near tilting my Galibier's motor. I found that there is a point where an increase in tension causes a noticeable thump when the splice went around the capstan. So I backed off to the point where the splice was barely audible with no music playing. That should be good as I find the splices to relax a bit after running for several hours. There is still more tension than I ever ran with the stock mylar.
And that leads me to my only complaint. It is too bad that splice tape comes in beige and not clear! Watching that splice go round and round is disturbing, but I can learn to live with it. |
Oh, but it's white tape. ;-) Too bad they don't carry clear. |
Splicing tape is always white so engineers can more easily find the splice afterwards. They sure won't have any trouble seeing that splice come around on a clear belt. ;-) Frank_sm, just to clarify a little. The "metal" side has always been the side in contact with the platter and capstan. This surface required a certain tension, no more and no less, to perform at its peak. Over the course of a few weeks or months the metal would have worn sufficiently to cause slippage. So many of us would just make a new belt and sit in wonder at the improvement of a fresh belt. Little did we know that we should have gone in the other direction. But, had we found that Doug and Paul wouldn't have had anything to tinker with. With Paul's new trick there is no more slow erosion of the metal surface and it seems that this textured surface is superior to the old metal surface in every way. Someone else may have a better method but I'll share mine. I use a plastic pan that is maybe 14x12x8 to contain the etching creme and wear heavy pvc gloves (Home Depot). Remember, it is the side the tape wants to curl to. Since I'm right handed, I start with one end of the tape in my left hand. I dab on the creme using a 3/16" artist's brush to get the end. Then I load the brush, hold it against the tape and pull the tape past the brush with my left hand leaving the treated tape in the pan. You can see the metal vanishing while you're working. Then I take the pan, brush and gloves outside to the faucet to rinse. It really is easy, using a little caution, and takes only a few minutes. The curl is still there, but you won't have any trouble telling which is the smooth side and which is the textured side. |
Stltrains, the McCormick's item number is 6033665, 1/2"x100' holographic mylar. You're going to love this upgrade. |
I know the feeling having lived in S. Fla. for 25 years. If the forecaster's are close to being right it looks like this one won't be a major storm but they all spawn tornados. We'll be pulling for you guys down in the big Easy. |
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Thanks for confirming that, Doug, about the motor pod differences. That is the conclusion I reached based on what I remember your Teres motor pod to look like.
With the Galibier motor I find that if I go real tight with the belt it will almost immediately climb the capstan. So I start there and gently relax belt tension until the belt no longer climbs. That seems to be about the best tension.
And thanks for mentioning about the dust picked up by the belt. I neglected to brush the belt between plays for 3 or 4 sides. When I brushed the inside of the belt on the 5 side I was startled at how much immediacy came back. Maybe Paul's next breakthrough should be a way to eliminate or minimize the static buildup. ;-) |
You guys have fun out there in Denver! Anne and I just can't seem to work out the RMAF dates with our schedules. |
Thanks for the update, Doug. I've been wondering what I was going to do with that other 90-something feet of tape. ;-)
The tension thing is also different with the Galibier motor pod. With the extra girth and weight of the Galibier pod it is easy to over tension the belt. First you will begin to lose speed. I'm talking 5 to 10% drop. Make it a bit tighter and then the belt will practically jump right off the capstan.
Stltrains, I'm also puzzled why you had a problem getting the metal off. Maybe trying to be too frugal with the cream? |
Elbow grease. Really? Something doesn't seem right. I put the cream on with an artist's brush and the metal almost instantly disappears. No rubbing, scrubbing or anything. It just melts away in seconds. |
I'm really at a loss Stltrains. I use Armour as well. It does say "improved" on the label. I'm assuming we bought the stuff around the same time. Go figure. ;-) |
HI Emailist,
It is a slight difference to the touch. I find that the textured side will stick a bit when the mylar is allowed to freely slide on my finger. The smooth side just glides along. And, it is usually the side that the mylar wants to curl to. |
Socoaste,
I have an extra roll that I've used for a splice or two. The only slight downside, to me anyway, is that it is white.
Your desire to conserve is appreciated, but I can't imagine anyone using this etched mylar belt that won't need to make at least two or three per year.
Yes! They do wear and it is audible when you put a fresh belt on. The splicing tape will still make it eventually to the GPGP, one belt at a time. :-) |
Doug, do you mean a Galibier-like pulley? ;-) Socoaste, the wood pulley does sound like a cool idea and that's a great wood to machine. A good lathe is one tool I still don't have.
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Yes, Doug. Thom has the pulleys made with a flat surface with a small lip top and bottom. Much like a tape guide from R2R.
The easiest method I have found to locate the textured side is using a micro-fibre cloth. One side of the mylar will glide along, the other will grab the cloth.
I have gotten belt dressing on my hands plenty of times. I'm sure some folks are having good results, but I don't want that stuff on my table. The static is not an issue for me. |
Somewhere around 1/2" diameter bar stock, drilled for the motor spindle size, a couple of thousandths by ~5/8" landing. |
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Therefore the motor has to be able to handle the additional strain due to this tension, meaning more torque will probably be needed. I agree in general, however I don't find this to be entirely true with the Maxon motor that is supplied with my Galibier. I tension the mylar pretty high, probably more than most other Galibier\mylar users. The stock motor works just fine at speed where torque is not as much of an issue, but I always give the platter a push to start and I don't stop the motor anymore to change records. Starting the platter rotation is probably when the torque matters most with a belt drive. And there will also be the increased sideways pull on its bearings. True. However, the Maxon motor side load spec is much higher than I could ever get with the tension on the mylar. I've tried this and the motor pod tips before reaching the kind of strain that would approach the side load. I don't have a way to measure what the strain is at the tipping point but it does take a fair amount of force to deflect the belt. The motor/platter coupling one can achieve with the mylar is surprising. As Doug points out, the motor needs to be very quiet because this kind of coupling will transfer excess noise to a platter. |
