DIY acrylic platter

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First of all, a quick hello, as this is my first post to this forum.

I'm toying with the idea of manufacturing an acrylic outer platter for my acoustic research XB table. My plan is to use a plunge router pivoted around a central pin in the acrylic blank, and to swing the router around the centre at the various depths and radii needed to shape something that will fit over the iner platter.

Kind of a poor mans CNC :)

Has anyone on the forum attempted a similar project, and do you know of any pitfalls/snafus I can avoid with a bit of advice from those who have attempted this before?

Stay froody,
Joel.
 
Ex-Moderator
Joined 2003
A man who know where his towel is...

Welcome to the forum. I've used the plunge router on trammel technique as you suggest for cutting out and rebating holes for loudspeakers in 1" plywood. First comment is that it is easy to put a very large load on the router bearings. I fuggered my 1100W ELU router that way and bought a 2100W Hitachi industrial monster to replace it. Second, acrylic takes care to machine. Try to take too much of a cut and it chips, use too high a cutting speed and it melts. You'll need some spare acrylic for experimentation. Other than that, it should work.

I'm toying with the idea of using my two 16" plywood cut-outs to make a 2" thick turntable a la Altmann...
 
JVDM said:
First of all, a quick hello, as this is my first post to this forum.

Has anyone on the forum attempted a similar project, and do you know of any pitfalls/snafus I can avoid with a bit of advice from those who have attempted this before?

Stay froody,
Joel.

Welcome to the forum Joel.
I've done plenty of machining in acrylic and can say that you will have a challenge in keeping the cutting tool from "loading up" without using any lubricant. You also have to deal with the high spindle speed of the router. I don't think you can do it cutting dry, in fact I wouldn't even attempt it. The tool will load up and break, at worst you may need medical attention afterward.
 
you can cut acrylic with a router... it is good to use a liquid coolant, if you can, but if you can't use the thinnest router bit you can, and make very shallow cuts - ought to take you a long long time to cut it all...and you won't get a finished piece when ur done...

but ur best bet is to rough cut a blank... then find a local wood working guy with a wood lathe to true it up and make it round... someone with a shopsmith will also be able to handle it.

In a deep deep pinch you could fab a jig with a drill press and a "live center" or some other bearing point for the bottom end, and turn it that way...but that is somewhat dangerous, and you have to watch the surface speed on the perimeter.

Best bet? Find a local machinist who is sympathetic to your hobbyist aims...

_-_-bear

PS. acrylic isn't the only material to consider...
 
My experience machining acrylic with a router has had very mixed results, owing to the tendency of the bit to grab and therefore chatter (attached image shows an offset router base made of 1/4" acrylic - the machining is definitely rough). I think bear is quite right to suggest that you want to aim for only a rough cut to be finished by other means, although I suppose you could try to cut the outer perimeter roughly to an 1/8" or so oversize and then take it down by steps of 1/64" or so.

How thick a chunk of acrylic were you thinking of starting with?

Anyway, I'd advise a lot of caution and (you may have already done this, you don't say what your experience has been) playing with routing some other bits of acrylic first to get a feel for it.

Regards.

Aengus
 

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With some practice, machined acrylic edges can be turned into a nice polished surface with the correct use of a heat gun or propane torch with a fan nozzle. It takes a few tries to find the right combination of heat and nozzle movement, but once you have the right technicque you can produce some very refined results.

Cheers, Terry
 
Poindexter...

there are speciality acrylic makers out there that can cast acrylic shapes and machine them. But here are only a few, and cost per one off is high. In large enough quantity, they can be had near the CAD $160 mark + machining setup services.

another option favoured by the "Teres" people, are platters made of wood....
 
Re: Aengus, thanks for the invite...

Nanook said:
but I'm still at least 800 miles east of you! So "dropping by" to come have a listen is a little out of the question. There is a small chance I may end up on the left coast for a few days prior to Christmas...

stew



800 Miles!

Stew, that's a long way to mush your Dogsled:D

Best Regards,
TerryO
 
but I'm still at least 800 miles east of you! So "dropping by" to come have a listen is a little out of the question.

Hey, Stew, that's why I thought it was a safe invitation.

There is a small chance I may end up on the left coast for a few days prior to Christmas...

Whoops, maybe not as safe as I'd thought. :D

Seriously, though, if you're going to be out this way, PM me and I'll send you my phone number - if we can fit it in, you'd be more than welcome to come by for a beer and a listen.

[edit] Terry, you're not even that far away - the invitation extends to you as well. [/edit]

Regards.

Aengus
 
Aengus said:


Hey, Stew, that's why I thought it was a safe invitation.



Whoops, maybe not as safe as I'd thought. :D

Seriously, though, if you're going to be out this way, PM me and I'll send you my phone number - if we can fit it in, you'd be more than welcome to come by for a beer and a listen.

[edit] Terry, you're not even that far away - the invitation extends to you as well. [/edit]

Regards.

Aengus

Aengus,

I'm a little concerned about the "edit" notation above. Was the invitation added as an afterthought, or did you decide to "edit" it out and it didn't work.

Don't think I'll fall for you hedging on this, I just want a simple "Yes" or "No" answer!
:xeye:

Best Regards,
TerryO
 
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