[honestak]

Hey guys, I have been doing my research for the last couple of weeks on jumping into the world of DIY CNC and have decided to go ahead and take the plunge. The machine needs to be able to handle 4x8 sheet goods including MDF and plywood and capable of producing good repeatability/accuracy results at a fair speed.

As a bit of background, I work in a architectural practice doing design and fabrication for some of our custom projects. This includes work on custom interior paneling, furniture and cabinetry. 3/4" plywood is the material of choice and most of the cnc work is simple 2d cutting. Most of this work has been outsourced in the past but our practice is moving into a new facility where we have dedicated shop space and I think I can open up a new revenue stream if we had our own machine. I would also like to be able to do some 3d milling of panels in the future.

I have talked with Ahren of CNCRP about buying a 4896 kit and have been real impressed with his knowledge, product and customer service. While it seems this is the best onestop kit, I cant help but think there might be better more do it your self options out there.

So, what do you think? If you had $10 grand to spend on a 4x8 router what would you spend it on? Custom build? Chinese machine? Used production model?

Thanks

here are some pictures of the last job we had cut

[vtx1029]

Look at MechMate CNC Router - Build your own with our detailed plans. I would think 12 could buy you a decent used router as well. While CNC router parts have nice stuff its not something I'd want in a Biz setting at least with the CRS linear ways. Now if you upgraded the ways to a nice Hiwin or other profile linear way then... (Don't take that as a knock on CRP heck I own one of their products and think its great for the $ you pay)

[Drools]

my 2 cents on the CRS rails.
Only one issue I had with them was, keeping them clean. Ahren now sells a rail sweeper that should keep the rails dirt free. Other than that they should be able to handle a production enviroment and if a bearing does break, replacing one is very easy.
If I remember correctly there have been other threads where CRS rails are being used in a production enviroment.

[dhanisch]

I have a CRP4896, and probably between $8k and $9k invested in it. Nema34, Mach3, Smoothstepper, water cooled 2.2kW spindle, KentCNC dust shoe, HF dust collection, CNCRP cable track kit, (5) 8' runs of t-track, IGUS flex cable, etc. I've even beefed up the bed with extra bracing to ensure the bed is square, as well as extra bracing for the crossmembers. The end result is a very accurate and very sturdy machine. I have no complaints about it so far.

In it's raw form, you have a lot of options. I personally made some changes in the bracing for my own satisfaction, mainly because I found the base was difficult to get into square by just using the supplied braces. I added flat braces on the bottom as well as (4) 45-degree braces at the extreme four corners. I replaced the t-bolt/nut used in the crossmember bracing with a t-track nut/allen head screw. Made for easier access. Being constructed from 80/20 allows for very easy modification later on if needed.

So basically, I was able to come in well below the $10k mark WITH improvements, and in the end, have a very versatile machine. Plus, Ahren's support is second to none.

[honestak]

Thanks for the responses! I have often read that the linear rails (hiwin) are the better option for linear movement compared to the cncrp solution. Is something that could be easily integrated into one of their kits?

also what kind of prompted this post was that I was planning on building a steel base for the machine and that is what kind of got my wheels turning, if I can build the base then why not fabricate the rest of the machine. I have some welding skills and have access to all of the metal working equipment I would need. Defintely would be more time consuming and probably more money but would it pay off in the end? Steel frame with Hiwin rails versus CNCRP?

[awerby]

The only problem with that is the weight of the steel, plus the fact that it warps when you weld it. While steel's great for the non-moving parts of the machine, like the table, most people like to use aluminum for the gantry and Z-axis, so the motors don't have too much inertia and momentum to overcome when reversing at speed.

Andrew Werby
www.computersculpture.com

[freecncplans]

I run two CNCRouterPart machines 40 to 48 hours a week. With dust collection and the rail sweepers we never have any issues. We cut 30-40 sheets a day of mostly 1/2" baltic birch plywood on the two of them. I do this with a Bosch 1617 EVS router on them. I cut the 1/2" with a downcut 1/8" bit in a single full depth pass.

We get pretty accurate parts (tape measure close to line width). The machines are easy to put together. The only suggestion I make is to add a few inches to the length and width to allow for clamping the material down.

Sean

[RossMosh]

The first thing you need to do is figure out what the $10-12k includes. Does it include just the router or does it have to include software, dust collection, computers, ect ect ect?

For $10-12k just for the router, you could probably start looking at a more refined linear drive system then the CNCRP kit. If you're looking at $10-12k for everything, I don't think you'll be able to go with linear rails. You could go with round rails but the benefits might not out weigh the cons.

The other thing you have to look at is the time and money invested in doing something different/new. Let's say you wanted to use supported round rails with ball screws for your machine. Well you've got to design and manufacture custom uprights. You have to design all the different mounts. You have to figure out all your clearances and there are a bunch of little parts that could take plenty of money and more so time to get right. Do you want to build a router to build a router or do you want to build a router to build your items?

If I were in your shoes, I'd go with a CNCRouterParts designed machine with a welded steel base, NEMA34 steppers, and a proper spindle OR hunt for a used ShopBot or something like it.