![]() |
Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ. |
|
In Reply to: 1st attempt at Rollerblocks posted by sober1 on March 5, 2003 at 19:31:34:
First, always listen to Barry's advice - he has a lot of experience with isolation and knows what works and what doesn't.Second, I'd shorten those blocks if possible. The taller they are, the less stable they'll be and the less effectively they'll isolate your equipment. If you're having trouble understanding the stability issue, just imagine making them ten feet tall - it would be very easy to tip them over at that height; the shorter they are the better they'll isolate due to increased stability. Keep in mind that you're trying to eliminate vibrations that the naked eye can't see, so seemingly small factors can sometimes have profound effects on sound quality.
Third, unless you believe the silicone you used is providing beneficial vertical isolation (I believe silicone is far too springy to achieve this), I'd lose it in favor of some high strength (slow curing) epoxy. Even though rollerblocks are isolation devices, they are also coupling devices. Essentially, rollerblocks combine the coupling qualities of cones with horizontal isolation. It's easy to forget about the coupling factors when experimenting with isolation.
Fourth - if you're worried about the stability of your equipment (thus the reason you've considered sandwiching the bearing between two blocks), I'd countersink the freeze plugs if possible. Once countersunk, the edges of the polymer base will keep your equipment from ever sliding off. Remember that the closer you can get the bottom of the bearing to the shelf/platform, the more effective your rollerblocks will be.
Fifth, I don't know much about freeze plugs, but I'm assuming they're made of common steel. You may want to look for a harder material to use as the cup in the block. I've had very good luck using ladles I found quite cheap at WalMart (yo8u have to make sure the ones you get are spherical - most of them are eliptical and aren't as effective). I do have to spend a little time cutting them down to size, but the SS is very hard a polishes up nicely. Corrosion is another reason I'd avoid common steel. Short of replacing the freeze plugs, do consider polishing the center where the bearing will make contact under normal use (this is a very small area, and therefore can be polished quickly and easily). When you have a good bearing surface, your bearing should oscilate for a full minute or more if you give it a flick while unloaded. In fact, you should be able to merely blow on the bearing and see it wiggle for several seconds. Do keep in mind, however, that under normal operating conditions, the movement of the bearing is microscopic, so how the bearing behaves transitioning from rest to micro-motion and vice-versa is critical. If your bearing's motion tends to become a little chaotic as the oscilations become small, then you probably need to polish your cup a little more (assuming good bearings).
Last, don't be afraid to ignore all advice and try out your own ideas. In the end the only thing that matters is that you get a smile on your face when you listen to your system.
Enjoy,
Pete
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- A few suggestions - pburant 10:38:55 03/06/03 (2)
- Re: A few suggestions - bdiament 10:57:08 03/06/03 (1)
- Re: A few suggestions - pburant 11:23:34 03/06/03 (0)