[seainsea]

Hello all,

I've been tasked at work with trying to narrow down a machine (cnc mill/router), that ultimately starts us off in a prototyping scale. I have spent the time to rake as much info as I can off the web, and have so many unknowns I just have to cover all of my bases for sake of selection narrowing and eventually decision making time.

My first goal was to find a small (roughly (x)2' x (y)2' x (z)4"+ cnc mill/router for this purpose.

So my findings were basically from the $2,000 - $30,000 and my budget was blindly guestimated @ $15,000.

I found a whole lot from this range.
So here are my questions/concerns if any of you gurus with experience or even a bright idea want to take a stab at it.

1.) What would be the accuracy of a kit purchased from say Build Your Own CNC Router Machine I know the accuracy is high on stuff coming from tormach, littlemachineshop, etc... mills, but what about the home/cheap hobby builds?

2.) My personal thoughts were why go small if you don't have to - bigger bits, bigger HP's, less time - I can always stick a smaller end mill in a larger router/spindle - am I right (FYI - we are looking at doing Architectural Concrete Formwork here not airplane parts)?

3.) Regardless of Real-Estate of the machine we ultimately purchase, what is the ideal work area around a machine assuming the material stock will be small for prototyping (understanding we are strictly looking for prototyping parts right now, we can assemble else where.)?

4.) [Noise] Would Investing in an HSD/Colombo Spindle be worth it here? I know a router running for any amount of time would drive anybody crazy.

5.) [Dust collection and cleanup] The unknown here is that we may want a non-shop environment to place this in (eg. Empty office - probably the biggest reason for the smaller footprint request). Would an enclosed box with a light vacuum do the trick, I really need some expertise here.

6.) Have any of you tried anything like this? What did you do? What am I missing for important considerations?

Thanks in advance

[seainsea]

Regarding #1.) I'm still unsure about the accuracy from a build your own style kit, but after some more study it seems to me that you can get pretty acceptable results for the hobby level. This of course is after scouring the web seeing what people have produced on home builds, and the care they have taken to use anti-backlash nuts, belts, chains, etc...

Regarding #2.) I'm still thinking bigger is better (Horse Power & Collet Size), but maybe not if I add noise consideration to the mix. My big unknowns here are:

i.) I know I can get mortising and beading (Ball End) bits on a 1/4" Shank that are 0.75" diameter.

q1.) I don't know what would be an acceptable plunge depth / RPM ratio on this size shank. I'm sure those of experience have some recommendations here.

ii.) I've re-checked my different options here and have come up with the following answers from a few manufacturers.

1.) All Routers Porter Cable, tech reported approximately 89 dB., Collet: 0.25"/0.5", $190
2.) Makita has an electric die grinder (GD0800C) @ 77dB., Collet: 0.25", $230
3.) Hitatchi's M12VC 2.25 HP Router @ 79.5 dB., Collet: 0.5", $140

Option #3 looks like it's the best all around for HP, Collet Capacity, Noise level/$, and speed control.

q1.) If I went with something like a Probotix Fireball Comet, they recommend a small trim router, do you think the z-Axis could handle the weight of the Hitatchi? I want to get your gut feel here, I'm always eerie of asking a sales person if something would be possible just to see them lie through their teeth, and end up with something that doesn't meet your expectations is all. So I wanted to ask here 1st.

Regarding #3.) I'm not thinking this is all that critical, because once we know what we want, we will make sure that we find an acceptable place to put it. Although your recommendations are still welcome, it may very well determine where we actually put our machine.

Regarding #4.) I'm really not comfortable with the knowledge base online about these things, it seems that there is a real lack of widespread knowledge here, that these items are extremely awesome, but touchy, and I don't even know where to start. It seems that most need special driver boards just to control them, and then from there, there are so many types, and it seems that there are very few places to buy them from.

HOWEVER: if you have some good guidelines for me to follow in terms of comparison of types, considerations, and where I should be looking to buy them from, I'm all ears.

Regarding #5.) I'm still struggling with this one, because I think this could be the one thing that could not only keep the dust levels down, but the majority of noise as well. If you know of good builds, or even off the shelf products for this one, please let me know.

Regarding #6.) Your experience is what I'm looking to draw from if any of you are willing to share it, so please do

I'm continuing down the road to figuring these things out, I guess my biggest fear is that if I don't stay transparent with the things I'm leaning towards, I'll hear somebody months later tell me I should have done a few things differently to save me time, money, and heartache. I'm really hoping that the experience of this community can do that for me before committing to this kind of choice making.

Thank you for any help you can contribute.