Considering MM for sheets goods in GA

[cncnewb]

Hi all. I want to thank everyone here for their contributions, I have enjoyed reading them these past few days. This is more a less a x-post of a thread I made at CNCZone under a different handle, so if it looks familiar that may be why.

I am a residential contractor of sorts and have been contemplating a CNC wood router build that will be used primarily for sheet goods. Mostly .75" melamine and plywood. (Cabinets, closets, etc.) As such I need to be able to have a y-axis working envelope 60" or greater to accommodate both 5 x 5 and 4 x 8 stock. While I don't expect to replicate an Onsrud, this is not a hobby machine. It may only run a few hours a week, but it needs to be capable of processing a decent number of sheets daily if need be. (30ish, maybe 40??) Based on my research thus far I have the following requirements: (Which are probably all wrong!)

1.) It must be able to consistently and accurately make clean cuts in a nested routing application. (more on this later)
2.) Vacuum hold down system
3.) Pneumatic pins for positioning
4.) Air drill for boring as I anticipate having a single spindle w/o ATC capabilities
5.) AORN I am planning on a 3kw chinese spindle (water cooled?) with a good VFD (Hitachi?)
6.) My understanding is cutting speed affects tool life and it certainly affects the bottom line, so I want something that can cut decently fast and clean.
7.) Budget: Under 10k is the goal, but I have an additional 5k in the budget. (That I would rather not spend!)

I realize some of these are upgrades to the standard MM design, but I am pretty sure I have seen all of them implemented on way or another on MM on this board.

For several reasons I am leaning heavily towards the MM. My main concern is will it accomplish what I need it to? Specifically will it consistently and accurately perform nested routing applications? I won't be running 6 days a week 12 hours a day, but I do need a machine that is capable of what would be best described as a light to medium commercial duty.

I have read that there have been some concerns with the cut quality of sheet goods on the MM; specifically fuzzy edges on cuts. Is this due to poor build quality? Is it an issue with direct drive (I plan on gearing mine)? I don't mean to offend, as I have basically zero knowledge, but I would like some confirmation that someone is using their MM to route for cabinets on a fairly consistent basis.

As for my skills they are as follows: I have zero hands on CNC experience. My fabrication abilities are OK, but I have some friends who are very capable and I am not afraid to pay someone to do something I am not capable of. Anything beyond installing a ceiling fan or light switch is uncharted territory for me, so I will definitely need the Wiring for Dummies manual on this project! While I don't have any specific relevant software experience, I am not worried about learning whatever software is necessary.

One of the main reasons I am leaning towards MM is the active community. The other being it is a proven device. I just want to make sure it is proven in the application I will be using it most for. Given my level of expertise imo it would be foolish for me to branch out on a from scratch build.

Anyway, thanks all. I hope to interact with more of you in the future.

[darren salyer]

Welcome to the forum.
I'm a remodeler and using my MM in exactly the manner you are describing.
Its great to have a wish list, but things like alignment pins can be added after the fact.
For processing panels, a simple 1/4" high fence on two sides to butt sheets to will accomplish the same thing.
As far as cut quality, of course its affected by build quality, but just as importantly, its affected by operator, tooling and material quality.
Only you can truly answer if its right for you.

[cncnewb]

Hi Darren,

I was hoping you would reply, thank you. I have read your entire thread and you made several references to doing cabinet work with your MM. When you perform nested routing do you have to do any secondary machining to your panels? (that is to say specifically to processes that were performed on your MM)

Take for example your machine: I have seen the level of detail you have produced on some engraving and sign making applications. It seems intuitive that relatively simple nested routing operations would be a cinch for the machine. Could you give me an idea of what kind of time your MM would take for a typical nested route of 4 x 8 melamine/mdf of frame-less cabinet panels and stretchers?

[darren salyer]

I can process a sheet of cabinet parts in 15-25 minutes, depending on the sheet. I use a 1/4" endmill so I can drill shelf pin holes and cutout with the same bit, so times are slower because of bit size.
Parts are blown off, but that's the extent of cleaning up any panel edges.
I could go straight to an edgebander if needed.
I pocket hole everything on a separate machine and screw the parts together on a worktable.
Typically the machine is done with its sheet before I'm done with mine.
We make a pretty good team.

[cncnewb]

That's encouraging. I would be pretty pleased if I could match that type of performance.

[MetalHead]

Welcome to the team !!!

[IMMark]

Welcome Gabe.
Sounds like you have put a lot of thought into it already..that's a good thing. You mentioned going with gear drive...my suggestion would be to look into belt reduction.
Best of luck
Mark

[cncnewb]

I received the same belt reduction feedback on CNCZone so belt reduction it is.

After more reading on the MM forum I found a guy who seemed pleased with his MM and was running a 7 man cabinet shop in Canada. MM #88. That is way beyond anything I would be doing so I don't think machine design will be a constraint if you know what I mean.

There is more research to be done, but I think I have found my machine.

[timberlinemd]

My MM (#66) was built for cabinet panel processing. I'm still using a router, but the spindel will improve cut quality because of the ability to control speeds and not loose HP. I would recommend looking into 'Ger21' 2010 screenset for Mach3. It is set up for cabinet panel processing and w/o a ATC you get the closest thing to it for changing tool bits.

I use a 1/4" upcut for both shelf holes as well as thru cuts. I also do all of the dado and rabbit work on the machine with a bit that is a 1/64" bigger than 3/4". Works great. I've been cutting at 120-150 ipm with the router with no problems using the 7.2 geared motors.

[cncnewb]

Steve,

Thanks for the reply. When you process a typical 4 x 8 panel for nested cabinets, what is your average routing time?

Also, I have been looking at cabinet software and all I can say is man there are a lot of choices! Would you mind sharing your cabinet software experience?

[timberlinemd]

Route times vary depending on cut speeds and how you cut. I would never go back to pushing material through a table saw. Mach3 will give you a estimated time after you load the code for cutting.

My software is proprietary and not for sale. I have spent many years developing it for the way I make cabinets.

If I were to purchase a program, my first choice would be Mozaik (http://www.mozaiksoftware.com). It is developed by the same programmer who created CabinetVision, which is considered the best software for cabinet building. However, the cost of Cabinet Vision for a design to machine would be in the 10K range, Mozaik is $125 per month. For a very reasonable price ($70) you could consider Cabinet Planner (http://www.cabinetplanner.com). It has a very good design interface along with cutlists. It provides a panel optimizer and the DXF files. It is limited in that you would need to adopt your cabinet building methods to it and would also need to add some things to the DXF files so as to be able to have you parts come out. It does not come with CAD, CAM. You would need a CAM program at the very least and a CAD program if you needed to change/add entites to the DXF files.

Good luck!

[cncnewb]

Ok, so after hours of more reading I think I have some ideas of what I need/want. Naturally I have a few questions so here we go.

1.) Motor selection:

I have decided that belt reduction is essential on my machine. The consensus seems to be anywhere from 3 : 1 to 4 : 1 is optimal. Several people seem to be leaning towards the 4 : 1 for better resolution (I think) and I can get 4 : 1 kits from Mike (I think) so 4 : 1 it is.

As for the proper motor on a belt reduction setup, the consensus seems to be that if you need more power then go with the PK299F-4.5A, if not then get the PK296F-4.5A.

As stated I am planning a 5 x 10 with a 3KW, possibly 4KW spindle, primarily cutting sheet goods so the question is do I need the larger motors? Aside from the fact the smaller ones are cheaper I have read something about cut quality and "cornering" being superior on the smaller motors, so there's that as well. TBH I have no idea why that would be the case.

I think I have a rudimentary understanding of the power differences, i.e. Bipolar I am looking at 440 oz/in(4) PK296 vs. 880oz/in(4) for the PK299, but I don't know what that translates into real world application. Is 1660 oz/in enough for me? What would the trade-off be for double the torque?

[cncnewb]

Brief aside: I am planning on completing the electronics portion first. One, because I am the least familiar with it, and two it seems to be advisable to set up the kitchen table test first so I might as well get it out of the way. And by the least familiar I mean the MM electrical schematics (I purchased the plans and reviewed them) may as well have been written in Sanskrit.

Ok, for several reasons I am planning on incorporating a dedicated motion controller to my system. While I have researched several options, it seems that Ethernet SmoothStepper will best suit my needs for a variety of reasons. Not the least of which there are functioning MMs using them. Darren, for one iirc.

So this is what I am thinking for my controller setup.

Questions 2.) and 3.) are BOB related and Power supply respectively.

Dedicated PC
BOB - PMDX-126- It seems I may need additional PMDX daughter boards although I don't really know why, so more research is required here. e.g. Darren has a PMDX-134 in his, what is the purpose of this board? And I see that some people are using a PMDX-107 spindle control daughter board. Yet the traditional BOB PMDX-122 doesn't seem to require a daughter board for spindle control. Presumably the spindle/router is controlled without it, so why do I see people adding the 107 daughter board to the 134?
Motion Control - Smoothstepper (ethernet)
Stepper Drivers - Gecko 203v's
Power Supply - I don't know what size, or how to determine what size.

Also I have been reading up on wiring fundamentals itf and have ordered some ferrules and a dedicated trapezoidal crimper from ferrulesdirect.com.

Re: other electrical supplies, where is a good source for other misc. electrical supplies I might need? e.g. shrink tape, misc connectors, DIN rail, etc.? In my electrical fundamentals research I have become aware that all wiring is not created equal. I want to use quality connectors so I can do the most I can to ensure I have a quality wiring job. i.e. is ebay type stuff good enough for this, or is there a preferred vendor?

Thanks everyone.

[bradm]

Info on motor sizes in the extreme cases.

Note that if you are going with belt drives, you can use other motor vendors than OM.

Power Supply sizing

The PMDX-134 is a wiring shortcut; it replaces the wires you would normally run from the PMDX-126 with a printed circuit board sized to the spacing of adjacently mounted Geckos.

The 107 board provides an analog voltage output that can be used for speed control on a VFD. Simple run/stop can be accomplished without it. Or if you're electronically inclined, you can build the same function out of an optoisolator, a capacitor, and two resistors.

[pblackburn]

Brad nail most of this. I would further add that the spindle can be controlled through Modbus if your VFD is capable.

I have an assist Excel calculator posted here on the forum under power supplies. You can check that out if you wish.

[cncnewb]

Thanks Brad and Pete. I had not come across the thread "Info on motor sizes link". The first line of the link accurately sums up the impression I was getting from reading threads on motor sizing. To wit:

I keep picking up bits and pieces of info on why bigger steppers are not necessarily better...

Preach it!

re: PMDX-134 being a wiring shortcut; Ok. Makes sense.

As for the rest, more reading, but I think I have enough to keep going. I am pretty close to ordering some parts!