Building An Acrylic Turntable

Well, here is the response that I received from Polytek regarding acrylic casting so it looks as though I might be back to square one;

Technically we do no make "Acrylics", we do have a water clear Polyurethane series called Poly Optic 14 Series, I will attach info. To make an absolute bubble clear casting of any resin, you need to vacuum degas and or cast in a pressure pot. For the mold rubber, you could use a 74 Series rubber with 2300 mold release or, a PlatSil 73 silicone like the 73-25. I will also attach this info. In the end if there is not and molded detail in part, I would just get it cut out of Acrylic stock.

So where can I buy acrylic stock and will I then have to compromise with respect to size and weight?

Thanks to all who have responded so far, I will have to triple back through URL's, etc...

I wonder where carbon fiber might fit into all of this? Would this be a suitable alternative to using slate and can acrylic be used in combination with other materials in order to make it more affective?

Please reconsider, acrylic will not be the best choice. Talk to TT WEights, they could provide something suitable.

My only knowledge about sound advantages in choosing acrylic is that it does not resinate, the very reason why my ASR amp and phono stage are encased in acrylic. Please keep in mind that I'm not machining acrylic but rather casting it instead. The only machining would be to bore or drill holes but a diamond drill bit will cut clean through any material. I'll try to find out more concerning what type of pourable acrylics are on the market.

Thanks for the clickable link tip.

PTP stands for Peters Top Plate which is a steel top plate created and sold by a member of the LencoHeaven forum. It allows you to create a plinth with minimal cutouts for installing the Lenco bearing and mounting the Lenco motor. Slate has some very nice damping qualities due to it's natural layering. Its also quite heavy and relatively soft which makes it easy to work with.

03-27-12: Manitunc
Tpreaves
What is PTP? Is there an advantage to using slate over a slab of solid Delrin of the same thickness. The Delrin is expensive, but easier to machine.

I have no idea Manitunc, I just made the link for Andarilu.

Tpreaves
What is PTP? Is there an advantage to using slate over a slab of solid Delrin of the same thickness. The Delrin is expensive, but easier to machine.

Hey, thanks for the link! Both tables look like they can get the job done and that acrylic table surely came out nice. I forgot to mention but I'm planning to cast my platter and my plinth in a pourable form of clear acrylic. The 2 part polyurethane rubber mold will come from Polytek. This way I'll be able to make the plinth and the platter as thick, as large and according to any design I want, plus each piece will be solid.

Here's a clickable link. It's easy and quick to do. Read about markup tags below the "Post your response" dialog box.

http://www.lencoheaven.net/forum/index.php?topic=4657.0

I built an acrylic TT a few years ago. I created a double plinth of 1" Acrylic and mounted the motor on the bottom plinth for isolation. I used a motor from a rega TT. I fabricated the feet out of 3" diameter stainless steel cylinders.

I enjoyed it for many years until I built my current Lenco based TT. Here is a link to a photo.

http://www.lencoheaven.net/forum/index.php?topic=4657.0