Hello all!!! This is my first posting. I've been intently reading all the DIY TT threads, and the thought of making my own TT seems HELLACOOL
I need a little help in finding a good place to buy acrylic. Is it all the same? (quality, density, etc) Also how do you samich metal (ie aluminum, stainless) to plastic for a platter? Glue?Screws? Sheer will? thanks for any help
BEER
I need a little help in finding a good place to buy acrylic. Is it all the same? (quality, density, etc) Also how do you samich metal (ie aluminum, stainless) to plastic for a platter? Glue?Screws? Sheer will? thanks for any help BEER
McMaster-Carr has all. So does TAP Plastics. There are a lot of grades of acrylic available, both filled and unfilled. Horses for courses- there is no "best," only good and bad choices for specific applications and design tradeoffs.
There are a lot of options for metal-to-plastic attachment. Screws, certainly (though one has to be mindful of torque and design in a way of spreading out the force). Adhesives, too- being careful to allow enough compliance to not have failure from mismatch of thermal expansion.
There are a lot of options for metal-to-plastic attachment. Screws, certainly (though one has to be mindful of torque and design in a way of spreading out the force). Adhesives, too- being careful to allow enough compliance to not have failure from mismatch of thermal expansion.
Acrylic material selection
I highly recommend CAST Acrylic Sheet. That is what I use in my machining projects. Look for Lucite L Cast Acrylic sheet. If you have never worked with Acrylic, be careful, do not drill pilot holes and then chase them with larger drills unless you have the work held down securely, otherwise it will suck up and cause you injury. Acrylic will also crack if you don't have a good method of drilling. It saws easily and machines well, but you must have a good process in mind before starting the project. Good luck!
I highly recommend CAST Acrylic Sheet. That is what I use in my machining projects. Look for Lucite L Cast Acrylic sheet. If you have never worked with Acrylic, be careful, do not drill pilot holes and then chase them with larger drills unless you have the work held down securely, otherwise it will suck up and cause you injury. Acrylic will also crack if you don't have a good method of drilling. It saws easily and machines well, but you must have a good process in mind before starting the project. Good luck!
Drilling speeds/methods
I would perform a search on google to find specific speeds for drilling since I only deal in SFM to calculate drilling speeds and feeds on CNC equipment. I also use water soluble coolant when drilling/machining all plastics and metals.
Are you doing this project in a garage and using hand tools?
1 important thing that will help you obtain good entry and prevent chipping when the drill goes through the workpiece is to place a plate underneath the piece you are drilling. That will support the acrylic when the drill breaks through the other side and prevent chipping. Also, do not drill a small pilot hole and then chase it with a larger hole. You will chip the material as well as risk the drill sucking into the work. Good drill point geometry for the drill should be between 60 & 90 degrees. Finally, always make sure you have a sharp tool.
I would perform a search on google to find specific speeds for drilling since I only deal in SFM to calculate drilling speeds and feeds on CNC equipment. I also use water soluble coolant when drilling/machining all plastics and metals.
Are you doing this project in a garage and using hand tools?
1 important thing that will help you obtain good entry and prevent chipping when the drill goes through the workpiece is to place a plate underneath the piece you are drilling. That will support the acrylic when the drill breaks through the other side and prevent chipping. Also, do not drill a small pilot hole and then chase it with a larger hole. You will chip the material as well as risk the drill sucking into the work. Good drill point geometry for the drill should be between 60 & 90 degrees. Finally, always make sure you have a sharp tool.
here is a link
Here are links with some info on working with Acrylic.
http://www.eaa1000.av.org/technicl/acrylic.htm
http://www.plaskolite.com/fabguide/pg08.pdf
Here are links with some info on working with Acrylic.
http://www.eaa1000.av.org/technicl/acrylic.htm
http://www.plaskolite.com/fabguide/pg08.pdf
If anyone cares on my input here......LEXAN is the best acrylic to work with....it can be machined,threaded,formed and the stuff is bullet proof...I currently buy it for my designs at 200CAN for a 4X8 sheet...I have done pretty much everything with this product....nice thing about it also is it comes with a peel off plastic backing so it does not get scratched....it also comes in different tints as well as clear...the trademark is owned by 3M but there are other manufactures that have a similar product
Cheers!!The DIRT®
Cheers!!The DIRT®
Acrylic - Lathe versus Router?
Wow, great baffles!
I am looking at making a replacement platter for my Rega Planar-2 out of 1-inch acrylic from McMaster-Carr. The examples I have seen on the net are mostly done on a machinist lathe, but I was thinking of doing it on a router with a circle cutting jig (since I don't have a lathe).
The main issue I was worried about was chipout on the rim as well as the relief that I will have to machine out of the center.
How much of a concern should this be for me? Does anyone have recommendations about router speed and bits?
Thanks!
Wow, great baffles!
I am looking at making a replacement platter for my Rega Planar-2 out of 1-inch acrylic from McMaster-Carr. The examples I have seen on the net are mostly done on a machinist lathe, but I was thinking of doing it on a router with a circle cutting jig (since I don't have a lathe).
The main issue I was worried about was chipout on the rim as well as the relief that I will have to machine out of the center.
How much of a concern should this be for me? Does anyone have recommendations about router speed and bits?
Thanks!
FYI
Lexan is not acrylic but a brand of polycarbonate brand from GE. It is stronger than acrylic but more flexible and has less hardness (easier to scratch). This may account for its different damping qualities compared to acrylics. Lexan is more forgiving if your material is not clamped that well during machine work because it is less likely to fracture.
Offhand, I don't know what the dielectric properties of the two are, but I think acrylic holds more easily holds a static charge - this may be a consideration if you don't screw a grounding terminal to the plastic.
You can fuse acrylic to itself using a solvent cement called "Weld-On" from IPS Corporation, CA 90248. If you decide to use this liquid, do so in a ventilated area and make sure to read the MSDS before you start. Panels joined in this manner look as if the seam is not glued at all, but rather, as if they are just resting against each other.
ensen.
Lexan is not acrylic but a brand of polycarbonate brand from GE. It is stronger than acrylic but more flexible and has less hardness (easier to scratch). This may account for its different damping qualities compared to acrylics. Lexan is more forgiving if your material is not clamped that well during machine work because it is less likely to fracture.
Offhand, I don't know what the dielectric properties of the two are, but I think acrylic holds more easily holds a static charge - this may be a consideration if you don't screw a grounding terminal to the plastic.
You can fuse acrylic to itself using a solvent cement called "Weld-On" from IPS Corporation, CA 90248. If you decide to use this liquid, do so in a ventilated area and make sure to read the MSDS before you start. Panels joined in this manner look as if the seam is not glued at all, but rather, as if they are just resting against each other.
ensen.
I didn't have problem with machining that piece using router. I used regular wood bits, the one for cutting was 1/4" straight cutter. The speed was less than maximum by 25% I guess, but the best is to try on a piece of scrap material. Since the baffle was 2.5" I cut everything in two runs, it is better that way (if you unsure 3 mighty be even better. If you want to make it nicer afterwards you might use a template with a straight bit with bearing guide, but best finish is done by sanding and buffing.
I never liked sanding and buffing acrylic. it takes too long and i have never really been sastisfieed with the edges, I always just use a blow torch and pass it over the edge very quickly so as not to warp or disfigure the edge. Always worked pretty good for me and it leaves a very nice edge. Also alot easier to do on complicated edges.
Oh, and remove the paper backing before you try it
Oh, and remove the paper backing before you try it
I made 2 platters for my P3 recently, 1 from 1" ABS and 1 from LuciteL material. If you are planning on machining or routing use CAST Acrylic or LuciteL(same thing). It is less prone to chipping and more stable due to the manufacturing process.
I will post pics of both platters soon. I also machined a custom aluminum bearing/hub assembly. This made a noticable improvent since the stock plastic hub runs out anywhere from 0.005 to 0.01 which results in speed instability. It is basically a P9 clone except I am still using a ball bearing, whereas the spherical end of the P9's shaft is the bearing.
I do not use the felt mat with either the ABS or Acrylic platters. They measure 25mm thick with a large counterbore machined in the underside to clear the motor/belt assy. The Sheer audio platter is 9mm thinner than mine, FYI. Both were CNC machined and critically inspected with the hub assy. in place to verify concentricity.
The main problem with the stock plastic hub is that the surface is uneven and the plastic spindle cap is not pressed on straight which results in extreme runout. The bearing is also not pressed in straight to the plinth, mine is'nt too bad, within 0.002. YMMV.
I will post pics of both platters soon. I also machined a custom aluminum bearing/hub assembly. This made a noticable improvent since the stock plastic hub runs out anywhere from 0.005 to 0.01 which results in speed instability. It is basically a P9 clone except I am still using a ball bearing, whereas the spherical end of the P9's shaft is the bearing.
I do not use the felt mat with either the ABS or Acrylic platters. They measure 25mm thick with a large counterbore machined in the underside to clear the motor/belt assy. The Sheer audio platter is 9mm thinner than mine, FYI. Both were CNC machined and critically inspected with the hub assy. in place to verify concentricity.
The main problem with the stock plastic hub is that the surface is uneven and the plastic spindle cap is not pressed on straight which results in extreme runout. The bearing is also not pressed in straight to the plinth, mine is'nt too bad, within 0.002. YMMV.
static-dissipative (SD) plastic
Has anyone ever experimented or know about the use of static-dissipative (SD) plastic for a turntable platter?
http://www.professionalplastics.com/cgi-bin/main/co_disp/displ/prrfnbr/100146/sesent/00
I was pretty set on using acrylic until this caught my eye. I saw others talk about how the metal bearing grounds out the static in acrylic, but is this still the case if the bearing is mounted in wood?
I'd rather not fork out the extra $ for the SD plastic if simple acrylic will do me well
thanks
Craig
Has anyone ever experimented or know about the use of static-dissipative (SD) plastic for a turntable platter?
http://www.professionalplastics.com/cgi-bin/main/co_disp/displ/prrfnbr/100146/sesent/00
I was pretty set on using acrylic until this caught my eye. I saw others talk about how the metal bearing grounds out the static in acrylic, but is this still the case if the bearing is mounted in wood?
I'd rather not fork out the extra $ for the SD plastic if simple acrylic will do me well
thanks
Craig
Re: static-dissipative (SD) plastic
Hi Craig, FWIW, my shop is right next to SJ Airport and I buy almost all of my plastics from Pro Plastics, good company and good prices too. Anyway I would not pay the price for this SD Delrin, it is way too expensive. If you want to try a different but similar material, check out UHMW-Static Dissipative material. They sell it and it is very inexpensive. I looked into it about a year ago, got some prices to build a platter for a TT I haven't started yet.cscull said:Has anyone ever experimented or know about the use of static-dissipative (SD) plastic for a turntable platter?
http://www.professionalplastics.com/cgi-bin/main/co_disp/displ/prrfnbr/100146/sesent/00
I was pretty set on using acrylic until this caught my eye. I saw others talk about how the metal bearing grounds out the static in acrylic, but is this still the case if the bearing is mounted in wood?
I'd rather not fork out the extra $ for the SD plastic if simple acrylic will do me well
thanks
Craig
TT project machine work
Hi Vinyl-Addict
Thanks for the advice on plastics. I see on another post that you have had better experiences with ABS than with Acrylic. Do you think static is something I should be worried about? I confess I am researching like mad, but still quite new to TT design and was attracted to the static dissipating plastic based on a hunch.
Also, do you work with the public or do strictly business to business machine work? I am going to need the help of a machinest with my turntable project.
thx
Craig
Hi Vinyl-Addict
Thanks for the advice on plastics. I see on another post that you have had better experiences with ABS than with Acrylic. Do you think static is something I should be worried about? I confess I am researching like mad, but still quite new to TT design and was attracted to the static dissipating plastic based on a hunch.
Also, do you work with the public or do strictly business to business machine work? I am going to need the help of a machinest with my turntable project.
thx
Craig
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.