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Old 23rd February 2013, 08:21 AM   #561
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Originally Posted by pinkmouse View Post


Gentlemen, let's keep the politics out of this please.

Ant, Val or MDF under the grille cloth?
Its valchromat. Made sense because its black so wouldn't need spraying to hide under the cloth. And its a somewhat thin cross section so mdf would likely break if dropped.
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Old 23rd February 2013, 08:22 AM   #562
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Thanks nick
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Old 28th February 2013, 02:17 AM   #563
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Hey folks,

I'm waiting on about 90kgs worth of lead that will be used to damp the interior walls of the Apollo cabinets but in the meantime I've been busy creating lots of tool paths for the 3 baffles used in the One.10, 20 and 30 models.

They'll be machined out of 100mm PU high density modelling block and serve as the master from which a silicone rubber mould will be made. Why go to all this effort? Well it will allow for some pretty wild experimentation with casting materials. I'm going to start off with a high density PU resin mixed with aluminium trihydroxide filler for extra mass, using this combination its possible to create a composite with a density similar to corian(around 1700kg/m^3) but without the huge price tag and hassle of laminating many 12mm sheets to build up the final thickness. I'll see how that performs but really anything is possible including concrete and epoxy with a wide range of fillers or reinforcement. Really excited about that part.

Extending this technique to the cabinet portions and not just the baffles would be something I'd like to do eventually too. It'd allow for some creative ways of tackling internal reflections. Probably the biggest advantage of casting the enclosure would come from it being formed from a single block of material with no joints. A nice side effect is you can go to town on the styling too.

Anyway that's a ways off and I'm going to focus on the baffles first. Here's the first half of the mould created from the master.
Click the image to open in full size.

One very handy feature of an integrated CAD/CAM package is the ability to create a model of the CNC and this can be used to check for clearance and collisions with hold down parts such as clamps and screws. I wouldn't say its fool proof but the simulation does let you see problems before they happen for real.

Click the image to open in full size.

Click the image to open in full size.
Attached Images
File Type: jpg one20 mold3.jpg (55.3 KB, 1465 views)
File Type: jpg One range Baffle Layout1.jpg (95.4 KB, 1451 views)
File Type: jpg One range Baffle Layout2.jpg (70.3 KB, 826 views)
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Old 2nd March 2013, 01:13 AM   #564
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Now that there's some hours on the CNC and things are bedding in I decided to spend the day stripping down and removing all the ballscrews and nuts carefully putting them back together getting everything as tight and aligned as possible. Result is there's virtually no bind anywhere now and it shows in the speeds and acceleration it can achieve. Those Leadshine AM882 are awesome! I could have gone past 16.5m/min but Mach was limited by my max 45k PP speed so I went and whacked the acceleration all the way up to 4000mm/sec^2 instead lol

Ps. I don't run at these speeds or accel as its overkill but its nice to see the effort from careful setup confirmed with a speed increase. For regular use I run at 10m rapids and 5m on the Z with relatively high acceleration. That's more than enough for me but its nice to know there's head room there because steppers do like some margin to avoid losing position.

Leadshine AM882 performance on CNC - YouTube
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Old 5th March 2013, 11:06 PM   #565
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Had another go at making a dust shoe and after picking up some cast acrylic this attempt came out much better. A week or so ago I did try to cut the same parts out of extruded acrylic and that stuff melted no matter what I did. Lesson learned - go with cast if the finish quality matters.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.
Attached Images
File Type: jpg Dust Shoe 01.jpg (170.0 KB, 631 views)
File Type: jpg Dust Shoe 02.jpg (164.7 KB, 629 views)
File Type: jpg Dust Shoe 03.jpg (159.5 KB, 632 views)
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Old 5th March 2013, 11:15 PM   #566
ScottG is offline ScottG  United States
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Originally Posted by ShinOBIWAN View Post
Had another go at making a dust shoe and after picking up some cast acrylic this attempt came out much better.

Click the image to open in full size.


Need a part.. now you make it yourself! I'm envious.
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Old 6th March 2013, 06:44 AM   #567
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Quote:
Originally Posted by ShinOBIWAN View Post
Hey folks,

I'm waiting on about 90kgs worth of lead that will be used to damp the interior walls of the Apollo cabinets but in the meantime I've been busy creating lots of tool paths for the 3 baffles used in the One.10, 20 and 30 models.

They'll be machined out of 100mm PU high density modelling block and serve as the master from which a silicone rubber mould will be made. Why go to all this effort? Well it will allow for some pretty wild experimentation with casting materials. I'm going to start off with a high density PU resin mixed with aluminium trihydroxide filler for extra mass, using this combination its possible to create a composite with a density similar to corian(around 1700kg/m^3) but without the huge price tag and hassle of laminating many 12mm sheets to build up the final thickness. I'll see how that performs but really anything is possible including concrete and epoxy with a wide range of fillers or reinforcement. Really excited about that part.

Extending this technique to the cabinet portions and not just the baffles would be something I'd like to do eventually too. It'd allow for some creative ways of tackling internal reflections. Probably the biggest advantage of casting the enclosure would come from it being formed from a single block of material with no joints. A nice side effect is you can go to town on the styling too.

Anyway that's a ways off and I'm going to focus on the baffles first. Here's the first half of the mould created from the master.
Click the image to open in full size.

One very handy feature of an integrated CAD/CAM package is the ability to create a model of the CNC and this can be used to check for clearance and collisions with hold down parts such as clamps and screws. I wouldn't say its fool proof but the simulation does let you see problems before they happen for real.
Very interesting! Im thinking of doing the same on my next speaker project! Where do you plan to get all the moulding material? And also the aluminium trihydroxide, im having a really hard time finding it! The only site that sells it dosen't seem to have it in stock.. I think i will order this kit: Silicone Mould Resin Casting Starter Kit with Fast Cast Polyurethane Resin - Easy Composites
To start experimenting a little bit! What do you think about maybe putting a layer of gelcoat before the resin to get a high gloss surface?

/Sebastian
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Old 6th March 2013, 08:43 AM   #568
sploo is offline sploo  United Kingdom
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Originally Posted by ShinOBIWAN View Post
Had another go at making a dust shoe and after picking up some cast acrylic this attempt came out much better. A week or so ago I did try to cut the same parts out of extruded acrylic and that stuff melted no matter what I did. Lesson learned - go with cast if the finish quality matters.
Watch your static build-up with that Ant. When I first set up something like that I noticed it was arcing small sparks to the router body after a while!

Now I have a cable connected to the metal wire in the hose, which is then earthed.
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Old 6th March 2013, 12:51 PM   #569
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Watch your static build-up with that Ant. When I first set up something like that I noticed it was arcing small sparks to the router body after a while!

Now I have a cable connected to the metal wire in the hose, which is then earthed.
Cheers. The spindle casing is earthed so I'll run a wire to that.
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Old 6th March 2013, 01:00 PM   #570
c12mech is offline c12mech  United States
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Good point about the ground wire. I've read a few articles about people using plastic for dust collection without grounding that lead to fires in the shop. Not something most people think about but it does happen.
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