Working area 900 x 600 mm - LR2 or MPCNC

I would like to build a CNC for loudspeaker building - so cutting flat stock with grooves for fitting panels, non-circular roundovers, panel inbuilt waveguides (mostly not round) and wooden horn milling. The working area I need is 900x600 mm, which should cover 90 % of the projects in one piece. I could use Z height of up to 150 mm, but could live with 100 mm. It would be also used to mill prototypes from foamboard. Am I correct that a LR2 would be more stiff and exact in height - and therefore would be the preferred option? And if I am able to find space for it, the experience with the smaller one would be good for building a full sheet machine.

And my second question - since I would have to have my flats cut locally anyway (or do by hand routing:) - I noticed there were options buying the flats in EU - any actual recommendations? I can have the flats cut by water jet from Aluminium locally at a reasonable price, but would like to support the community as well. Overseas shipping and VAT/Customs would much more support our local government though - that is why I am looking for EU only. Thanks!

6 inches is a stretch for either machine. If you just need to get that high, not that deep, you can build a drop table to keep the machine shorter and let your workpiece sit through the table. Hope that makes sense.
As far as being exact in height, they are both about as good as your construction. The lowrider gets less stiff as it goes up, the mpcnc gets less stiff as it goes down. I think that might end up being more important to you.
At that xy size either machine is a contender.
My 2 cents on the lowrider plates : if you have the still to cut them by hand, they’ll work. If you ALMOST have the skill to cut them by hand, they’ll work long enough to make the lowrider cut its own damned plates, lol. Likely much cheaper than having any business cut them out of anything and you can use the saved /money saved to support any business you want.
You might even find somebody here close enough to knock them out for you from some off cuts in exchange for a beer or a smoked meat sandwich. That would be super cool.
Any chance you can show us examples of the work you want to do? Might help with insight on the advantages of each machine.


I would like to be able to machine things like the ones shown here: The thickest part of this horn is 150 mm - however it can be also made from 3 layers. If there is any benefit to it, I could live with 105 mm working height.

So far, I have been 3D printing similar stuff and I can model most of the things (if not all) I would need myself in Fusion360. Or buy plans/models by Joseph:) I am working on a multiple entry horn with 3D printed parts, but it would ultimately need foam or wooden extension.

I plan to use foam to learn how to machine things with CNC and also for acoustic measurements, where the foam is good enough, especially if surface treated. And finally, plywood or hardwood for looks.

The longest 1/8" endmill you will find is about 18-30mm. Can’t really cut any deeper than that.

For that horn, I’d match their construction, and make it from 18mm ply. Slice the piece up into 18mm slabs first, add some alignment helpers, and do the glue-up after you cut it all out. Then sand the piece when you’re finished. Someone here has a great pharaoh’s head they made for a local theater company that was made with this technique.

Ok, how does one make the horns then? Is that a larger spindle with longer bits?

Sliced up and glued together. And, uh, are people really buying those for 4500 a pair?

Layers, Still going to take a while. Each layer is a 3D carve, the finished product will be very accurate and good looking, but a lot of CNC time is involved.

I thought it was glued together first and then CNC’d. So one would first plane the hardwood pieces to exact thickness, then slice the model and do the carvings - aligned by holes and pins.

If I would be able to do this in foam and plywood, I would be happy:)

You only need one true side, the CNC will true the other. You could do both if needed with the CNC. Just to be clear that horn would be considered a very advanced project. The concept is simple the execution takes a lot of precise work. but saving $4500…I feel like I could get there in a try or two.


Yes, it is a challenge I am willing to accept. It is a hobby anyway - and I will definitely start with something easier first.

Edit: So LR2 or MPCNC or it does not matter?

I think either will be suitable. Hardwood can be tricky, and the lowrider only has one motor in the short direction. I’ve cut some small projects from mahogany on mine, but I’m much more comfortable with my MPCNC for projects that need precision. Most of my lowrider stuff is large signs.
Since we’ve gotten this far, I think somebody with more LR experience could offer some advice.

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Ummm… For reference, the construction of the $4500CDN/pair horns is specified as “stacked 18mm Baltic Birch plywood”, not hardwood. The renderings are… inaccurate. And I’m guessing the progress pic is a bespoke/commissioned piece.

Even for that, 4500…
I understand these aren’t free plans and a lot of work has (maybe) gone into engineering the shape. But I’ve got some old acoustic engineering books around here somewhere from an interest years ago. I wonder how much work it is to make something worth 100 bucks?

Speakers are often more magic than science. It depends on who you ask, but even the polk audio speakers that sold for $450 in 2000 were sold to circuit city for less than $100. The biggest cost is marketing and sales.

I remember you talking about early experiences in electronics retail on another thread.
Too bad it seems like I’m late to that party, though. Guess I’ll keep working the day job.

Put together a slick, clean website with some good buzzwords, and I’ll bet you could sell plywood at a 1000% markup based on Internet info…

Well, flat cutouts for a pair including the wood was quoted to me as ca 800 USD locally. And that would require glueing, lots of sanding and finishing. The price for the finished horns is not that high if you consider the work they need.

Anyway, that is a bit out of topic. I think I am decided to go for the LR2.

Free range, vegan, gluten free, no msg, made in the USA plywood!


Back to topic:) Is there any problem with making the Z axis long? Like having the Z tubes 500 mm long and 300 mm long Z lead screws? Even though I will use only the first 50 mm? I cannot think of any reason other than room requirements - and due to the construction, it should not be a problem, am I right? These would just hang down the table on the sides.