Gathering info for a 4x8 or 5x10 build - input appreciated

Hi All,

In the past year I've been rapidly developing an interest in woodworking - specifically loudspeaker design and building. I've come to realize that the design/build process would be much more efficient with an appropriate CNC. Not to mention the options for creativity go through the room. An added bonus would be the ability to cut projects for friends and family for fun / small profit to recoup expenses. Ideally I'd like to cut mostly 3/4" thickness of Baltic Birch, cabinet ply, and MDF for my speaker project. I'm not sure how feasible it would be, but the ability to cut light aluminum for amp/faceplate design would be great! 3 axis would be all I would need for now. Speed isn't of main concern, but accuracy and reliability would be.

I've been looking hard at the CNC router part CRP4896 kit. It seems to be well put together from what I've read on here so far. If possible, I'd really want to expand to 5x10 so I could cut 5x5 sheets of BB. My budget for building this machine would ideally be under 10k with a target completion date of December - including machine, electronics, dust collection, and computer/software. I will also need to build a workshed (with electric, lighting, dust collection) to house the machine.

Some questions:
-Do I really need the upgraded NEMA34 electronics? Are they worthwhile?
-What should I be using for design and generating CAM files? I've downloaded Mach3 to play with which it seems will just be generating the gcode from imported files, correct?
-Are my budget and goals feasible?
-What are some good resources to learn the machine and software?
-Clamping: How are you getting around wood that is warped in the middle without a vacuum clamping system?

Any tips and help are appreciated.

Thank you,
Andrew
Thornton, PA

I run CNCRouterParts machines probably 40 to 50 hours a week. I have a 5x8 and a 5x11 (for 2 5x5 baltic sheets) that we run and I am going to be adding in another of the 5x11 in the next couple of months. We cut mostly 1/2", but do cut 3/4 once in awhile. The Bosch 1617 router doesn't like to cut the 3/4 inch at all, but it does the job. A spindle would be much better for this.

-Do I really need the upgraded NEMA34 electronics? Are they worthwhile?
The Nema 23 will not cut the 3/4 in a single pass reliably. The 34 setup will go much faster and be able to cut deeper.

-What should I be using for design and generating CAM files? I've downloaded Mach3 to play with which it seems will just be generating the gcode from imported files, correct?
We use Vectric's software. It is easy to use and we use it to make our files. Not to mention Vectric allows upgrades for a minimal cost from their different software selection. Their website explains this better.

-Are my budget and goals feasible?
I built the 5x11 for around $8,000 with 34 setup. I got the electronics box that was ready to go.

-What are some good resources to learn the machine and software?
Vectric has a well maintained forum and videos on their software. Between Mach's website and here, you can find out most anything. Ahren is very helpful for setting up the machine and getting it running as well.

-Clamping: How are you getting around wood that is warped in the middle without a vacuum clamping system?
Screws into the sacrifice table. I program them to have the machine drill the holes. We haven't hit a screw in probably 2 years now. We tried to drill a screw that was in place though.

Sean

- - - Updated - - -

I run CNCRouterParts machines probably 40 to 50 hours a week. I have a 5x8 and a 5x11 (for 2 5x5 baltic sheets) that we run and I am going to be adding in another of the 5x11 in the next couple of months. We cut mostly 1/2", but do cut 3/4 once in awhile. The Bosch 1617 router doesn't like to cut the 3/4 inch at all, but it does the job. A spindle would be much better for this.

-Do I really need the upgraded NEMA34 electronics? Are they worthwhile?
The Nema 23 will not cut the 3/4 in a single pass reliably. The 34 setup will go much faster and be able to cut deeper.

-What should I be using for design and generating CAM files? I've downloaded Mach3 to play with which it seems will just be generating the gcode from imported files, correct?
We use Vectric's software. It is easy to use and we use it to make our files. Not to mention Vectric allows upgrades for a minimal cost from their different software selection. Their website explains this better.

-Are my budget and goals feasible?
I built the 5x11 for around $8,000 with 34 setup. I got the one that was ready to go.

-What are some good resources to learn the machine and software?
Vectric has a well maintained forum and videos on their software. Between Mach's website and here, you can find out most anything. Ahren is very helpful for setting up the machine and getting it running as well.

-Clamping: How are you getting around wood that is warped in the middle without a vacuum clamping system?
Screws into the sacrifice table. I program them to have the machine drill the holes. We haven't hit a screw in probably 2 years now. We tried to drill a screw that was in place though.

Sean

Quote:

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-Clamping: How are you getting around wood that is warped in the middle without a vacuum clamping system?

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Warped wood is the hardest thing to clamp with a vacuum hold down system. Even a $10,000 vacuum system will struggle with warped wood.
I'll second the advice to use screws.

Sean - thank you very much for a thorough and detailed response. I'm glad to hear your machines are working out well, especially under a commerical workload. That fact alone instills a bit of confidence for sure!

Nema 34 - Glad I asked, this will be a must-do for me now. I likely wouldn't cut anything under 3/4" except for making templates for friends and small stuff for around the house.

Router/Spindle - I use a handheld version of the 1617 now and would never attempt to cut 3/4" in a single pass. A number of the porter cable models seem to be popular though, anything you'd recommend?

Vectric - Will check it out for sure, seems to be popular on here as well now that I'm looking.

Table Size - Any reason you had to extend the table to 11' vs. 10' for two sheets of 5x5? If it works in the 5' width direction I figured double that would be fine for length at 10'? Most of the tables seem to have oversized cutting capacity by a few inches anyway, right? I'll be using BB quite a bit so this is important to me.

Time to go shed/workshop shopping I suppose!

Thanks a ton,
Andrew

The Portercable 7518 router would cut through the 3/4" in one pass, no problem. However, it would be loud as hell. It's their 3-1/4 hp router model.

You'd be better off using a watercooled spindle, much quieter.

I was going to go with the 7518, but have since changed my mind and will be going with a 4kW watercooled spindle, both for the fact that it is more quiet, and also that the RPM can be controlled via Mach.

If the table is only 11 ft, that doesn't leave any room for gantry hang over. You'd need to ad that amount for table total length to get to the 10' of cutting area.

Quote:

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Originally Posted by Falcon69

The Portercable 7518 router would cut through the 3/4" in one pass, no problem. However, it would be loud as hell. It's their 3-1/4 hp router model.

You'd be better off using a watercooled spindle, much quieter.

I was going to go with the 7518, but have since changed my mind and will be going with a 4kW watercooled spindle, both for the fact that it is more quiet, and also that the RPM can be controlled via Mach.

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Thanks for the input. Are you running one of the Chinese made 4KW spindles that are out there? How has been reliabilty been on those pieces? They certaintly are cheap enough. Would I be able to get by with single phase 220V service?

Also - thanks for the input on table size. That makes alot of sense.

Andrew

We're just putting our CRP4896 together now, so I don't have any experience with it, but I wanted to pop in here and say that I'm interested in spindles, too. At first we're going to be using a PC892 router.

I built a 48x48 crp machine. You can see the build thread here.

If I was starting over I would build it 5.5ft x 12ft.
I am cut alot of mdf and the sheet is 49 in wide. I can get it on the machine, but it is close on clamping.
Also some sheets come 5ft wide and I would love to just be able to stick that on the machine.
I would want 10ft cutting area with the extra 2 feet for other things.
I have a fixed auto z zero plate on my machine that takes up room that I would put in the extra 2 feet.
Also I would put a 4th axis (or room for one later) in this area mounted deeper into the frame parallel to the y axis.

It would not cost that much more upfront to make the machine bigger. Just longer rails, rack, 8020 and wire. The motors and electronics would be the same.
I have though about expanding my machine, but I would waste so many parts and wire in doing so.