BillFitzmaurice.info

Hi Folks,

as we all know... new house means new home theater speakers to suit. Well that's how my brain works anyway.
I just finished my "Tuba 18 stealth install" so I fired up the tools and delved into a 9 driver curved SLA to match.

I thought I'd post the build process because I made a few decisions someone else might be interested in and I used my new CNC router. Which someone might also be interested in.

First decision:
I wanted to mount the SLA on the wall. Not sit it on a shelf.
Mounting on a wall is an easy process. Just whack a french cleat on and away you go.
But with a depth of 15 inches I was worried about pulling the back completely off with the leverage.

Second decision:
I also wanted to keep the front baffle as "clean" as I could to maximise the WAF.
Could I hide everything except the cones? I.E. no visible mount or screws.

Third decision:
I didn't like the line where the bottom panel is screwed on. Could I hide that?

I designed and built as I went, so here's what happened...

Firstly, here is my home made CNC.
I absolutely LOVE this thing and I'm happy to chat about it if anyone wants to.

What on earth do I want with a CNC router?
Well, you can teach it to do this...

and then do that 9 times (while I watch the TV)

This means the drivers will fit in from behind. I was going to use tiny screws to hold them in but the fit is SO good I simply used hot glue.

Well it looks like you have all this under control... Jealous of your toys!

Next was the change to the carcass to eliminate the bottom line and strengthen the back.
Hopefully this picture tells a thousand words.

and cutting a long story short, here's the final product.

Neil,
That is very very nice work on a number of counts.
Well done!

Extremely nice finished product....
A CNC router is on my wish list...

I was looking at the XCarve recently.

http://www.inventables.com/technologies/x-carve

Yeah, I've got a few questions if you don't mind...

How difficult was it to build your own? Do you have a background in computers/CNC?

How do you control the stepper motors? (Software, interface, etc?)

What do you think your total cost was for the CNC?

Would it be easy to take the bed off to make it smaller and easier to store? I work in a multipurpose garage and would like to be able to store it when not in use...

Hi NukePooch,

Building it was a piece of cake. Getting it to run was another thing altogether...
I chose to build this model from a guy in Germany http://www.holzmechanik.de/solidis_eng.html
Mainly because I have plenty of experience cutting timber but none in metal.
Mine has a bed size of 600mm*600mm, which is twice as big as the one in the link and because the table moves (not the gantry) it takes up a bigger footprint.
The upside of having the table move is that the X axis is VERY stable. Downside is that the table is longer.

I do have a back ground in computers but that's not the hard part. The hard part was getting the correct electronics to all work together.

So my hardware chain is:

• My Laptop, running Mach4 and connected via USB to,
• A motion controller from PMDX. I have the PMDX-422. ->
• 3 stepper controllers ->
• 3 motors =>
• 3 ball screws and linear rails.
• A 1.5kw spindle with matching inverter (speed controller)

Cost(this might be scary, I've never added it up)

Hardware (all delivered to my house in Aus)

• Ball screws and linear rails: from China A$430
• Electronics kit and 400w Nema23 motors (from here http://www.hobbycncaustralia.com.au/ but kit no longer available) A$300
• PMDX-422 motion controller (because that's what Mach4 wants!): US$170
• Upgrade to 1.5Kw spindle and inverter: A$330
• Spindle mount: A$50
• Plywood: A$250
• Machine screws: A$75
• Misc: A$50

Software

• Mach4: US$200
• V-Carve desktop (CAD/CAM package): US$345

Total approx A$2300. So don't under estimate the cost of the software chain!!

Note: I upgraded my spindle. I started with a 300watt motor. It wasn't anywhere near powerful enough. I could only run very small end mills.
The new one is fantastic and very quiet.

I checked out the link you sent. Interesting. Small motors and spindle but if that's all you require it could be good.
I'll check out their software at some point as well, given they say it's free!!

Hope this helps.

Nice.

How come you didn't round-over the baffles?

Yeah, I thought about that but the distance to the edge is only 6mm and I liked the sharp look.
It might make a difference but I sure as hell wouldn't be able to tell

Yeah, the CNC sounded like a whole lot of work. That's where I think I'd lose my mind, trying to get all the electronic children to place nice together.. LOL. I've just started researching them and it will likely be a while longer before I can afford one...so I've got time to learn.

On the XCarve stuff: the software is free, but a bit simple from all accounts. I've heard it doesn't have a whole lot of advanced features that the Mach software has...but it's likely more than I'd use, at least to start. People have had luck designing in Sketchup and transferring over to Easel...
The XCarve has an option to mount a Dewalt trim router instead of the spindle, which is what I'd do. Reviews say it's worth it both in speed and the ability to run larger bits.

Having never used a CNC before, I'd probably be better off to go simple, until I figure out if I need more... It definitely got my mind spinning with possibilities...
Thanks!

That's where I think I'd lose my mind

Yep. I lost and found mine a few times during the build.
I had absolutely no knowledge of CNC before I started. I just tied on a blindfold and leapt into the CNC abyss.
I only stuffed up a few things on the way. A few bits of plywood here and there as I misread plans.
While learning how Mach4 works I accidentally plunged a spinning spindle into the table bed and dragged it sideways.
Result: Bent spindle

I'm much more careful now.