cutting capacity

[dlenox]

I make craftsman spininning wheels and some of my components are 1/2" and 3/4" oak plywood. Difficult and time consuming to cut by hand. Looking for a CNC wood router plan that has a work area of at least 15" x 25" that is up to the task.

Seen a lot of designs however they all talk about using a Porter Cable 7310 laminate cutter with 1/8" or 1/4" bit. I have more powerful wood routers, but they carry a bit more weight.

No one talks about how big the stepper motors need to be to to work with this thickness of material.

Any one have link to plans that might be acceptable?

Thanks,
Dan

[chuckknigh]

That's because it's complicated. It has to do with the drag you're going to encounter...it probably takes less force to cut through 3/4" thick oak with a sharp bit, than it does to cut through 1/4" balsa with a dull bit. That kind of thing...

And there are ways to reduce the power needed...cut in multiple passes, slow down the cutting head, etc...

OK, a guideline. BalsaMan was cutting out 3/4" MDF parts on a smallish homebuilt machine, which used 100 oz-in steppers that came out of HP LaserJet printers. There are dozens of threads about his exploits...look for the ones that concern "MDF Clocks" for some particularly good ones.

As for plans...it's hard to go wrong with the Kleinbauer plans. They're inexpensive at $30 or so, and they're well engineered. You'll want one of the larger machines, probably the Phoenix or Routezilla. His machines don't give .0001" accuracy...but considering that you're working in wood, that level of accuracy wouldn't be of any use, anyway! It should be "good enough" for woodworking, and if you want to upgrade your machine later, you can make the upgraded parts on *it!*

http://www.kleinbauer.com

-- Chuck Knight

[seansear]

I built one of these machines. I use a Porter Cable 6000 (6070 or some such router) series router. I often go through 3/4 and 1" solid Walnut using 1/4 and 1/2" bits. I also do other 3D machining with 4" thick Mahogony.
He has changed his design a bit but is still a great work horse of a machine machine. It is also capable of very detailed work.

http://www.campbelldesigns.com/


Bruce

[Cold Fusion]

How strong are your steppers sean?

[seansear]

I use Superior steppers. KMO92's at approx 600 oz-in.


Bruce

[dlenox]

Thanks for the info, contacted both kleinbauer and hobbycnc and both of them said that my goal of cutting 3/4" oak plywood was beyond their design capabilities.

However niether of them gave *any* explanation why...
not sure if it is stability, stepper motor size, router power, etc.

Still interested in building CNC router, but can only do it one time, and still not sure where to obtain an initial design.

Heck I do not even know if the Porter Cable 7310 laminate cutter would work on the wood that I want to cut!

[seansear]

Dan,

Did you check out the campbell designs website I listed earlier. I have no vested interest in this company or person. I just built one of his designs and it will work for what you want to do. 36 x 42 table with plenty of horse power. If I remember I did it for well under $6,000

[balsaman]

Any machine will cut oak plywood. Including the ones mentioned above. Question is, how fast do you want to cut it? In one pass?

With a 1/4" bit taking 1/8 or 1/4" deep cuts you will get through it, it will take some time.

How much do you want to spend? Are you able to work with aluminum? There are lot's of plans out there that will handle what you want to do with ease. The two machines you mentioned are "hobby machines". Easy to build and use inexpensive parts. They are meant for light duty work.

Give us some more details, and we will do our best to stear you in the right direction.

Eric

[balsaman]

Here is a nice machine for a pretty good price.

http://www.rcgroups.com/forums/showt...01#post1677101

Also a thread about the machine:

http://www.rcgroups.com/forums/showt...hreadid=160123

Eric

[ger21]

The PC 7310 will cut what you want, but you'll have to make multiple passes, depending on how fast your going.

Gerry

[dlenox]

ouchhh!

Have to keep price in <$850 range for wood cnc router.

Saw the Cambell site and plans alone were bit pricy, I am an experienced builder and have a mini-mill and mini-lathe at my disposal. What I am looking for are some initial guidelines for the cut capacity that I need, such as
screw size (sounds like 5/8")
wood router (if 7310 can't handle 3/4" in single pass)
stepper motor (oz rating)
minimim rail diameter (sounds like 3/4")

I do spinning wheels as a hobby, not profession. Can't make a real living at it, but it is fun and I am able to sell a quality product to a niche market. What I need is a way to make a couple of parts from 1/2" and 3/4" oak *plywood* that are labor intensive with a working bed size of about 18" x 30"

Dan

[balsaman]

Well if you have some time I would say to be in that price range you need to build a sturdy machine from MDF or aluminum, or both. Use Drillrod for guides and rollerskate bearings. Use 1/2" Acme rod for leadscrews in home made delrin nuts. Use a xylotex 3 axis board and 3 of his 116 oz steppers. Use a slightly larger router like the porter cable 1.5 HP 690 model.

I was cutting aluminum (slowly) and 3/4" MDF (three passes, 20" per minute, 1/8" carbide bit) with my home made MDF machine with similar components.

Eric