[mercaytor]

Hi all, working on my design for my first CNC mill, main use will be PCB isolation routing. I'm on a tight budget and have not yet purchased a spindle, so I saw this on sale for $60 CAD:
6A Electric Die Grinder | Princess Auto

Quick specs:
Type Heavy duty die grinder
Current Rating 6 A
No Load Speed 7,000 to 30,000 RPM
Variable Speed Yes
Collet Size 1/4 in.
Voltage Rating 120 V

From what I've read elsewhere, the 30,000 RPM would be suitable for PCB copper traces, correct? I know I've also seen recommendations against Die Grinders in other threads for bigger scale projects, but since my goal is just a 200mm x 200mm x 100mm work area and primarily used for PCB, is this a good starter spindle?

Will I run into issues with the 1/4" collet for engraving bits?

Thanks all!

[keebler303]

Die grinders are not recommended because they have loose, low tolerance bearings meant to last a long time while being abused in a shop. Those characteristics are contrary to what you need for a spindle. The smaller your work, the more important that is. I believe a die grinder is even less suitable for a small machine than for a larger one.

That said, it may work ok for you but it will never produce work as nice as what can be done with a proper spindle.

Matt

[mercaytor]

That's exactly the feedback I needed to hear, thanks! So is it possible to get into a more appropriate spindle for pcb routing within the same price range (ideally no more than $70)? If its not, then I may go ahead with the die grinder until I canafford a nice Wolfgang Engineering spindle assembly.

[keebler303]

I'm not really up to speed on the tiny spindles. The Wolfgang is likely the cheapest decent one out there. The die grinder will work, but you may find you cannot get the detail you'd like.

The only "real" PCB mill I have seen had a spindle like this on it, likely a $3-5k investment.

High frequency spindles and milling handpiece

[Bubba]

I got one of the original 3 spd spindles from CNC on a Budget : Inexpensive Technology and Engineering and it is USD90 plus shipping. It takes 1/8" bits and has worked very well for me.
Usual disclaimer.

[mercaytor]

I see that there's a sale (20% off) for the Wolfgang spindles... $219.99 USD
http://stores.ebay.ca/Wolfgang-Engin...p2047675.l2563

Would you consider this to be a good deal, or are there regular sales on this? Just don't want to over-extend my budget but I also don't want to miss out on a good price.

[Bubba]

I can't really comment as I have no experience with those units

[mercaytor]

Bubba, I've looked closer at the Paul Jones 3Speed spindle, which you mentioned you were using. Now you said you had the "original", is the current version changed significantly that you are aware of? Any reason that I wouldn't go for the current model he's selling?

Thanks for your input!

[Bubba]

When I bought mine, he had recently come out with the ER collet unit and that is what I thought I would get, but he suggested I get the "original" with the set screw and 1/8" hole. At that time, he did not have the larger motor unit available.
The original uses a 70 watt motor so your not going to be able to do a lot of hogging in many materials anyhow. ( I have done some engraving and light milling in brass and aluminum) If I were to do it today, I think I would look seriously at the newer unit with the bigger motor, (the black one in the pictures) as it looks like it will have a bit more power. IF I am drilling pcb stock with a "larger" drill, I have to slow down the feed rate or the motor will stall.
Best advice I can give is email Paul and as his advice. He seems to be a nice guy to deal with.

[mercaytor]

Yup extremely nice guy. Emailed him and got a very fast reply, so I pulled the trigger and placed an order for a 3Speed spindle. Thanks for the pointer, Bubba! I'll let you know how I make out, hopefully I have a good experience with this spindle as well.

[Bubba]

Good luck and look forward to hearing your experience

[mercaytor]

Well just found out that my 3Speed Spindle shipped earlier this week, so I'm guessing it might be here next week. Now I need to actually finish my machine so I have something to test it out on!

[Bubba]

Hope you find it as good as I have.
I also got a bunch of extra O rings on one of my orders to have on hand "in-case". A couple of time when I was pushing it in some brass, I stalled things out and "burned" the rings a bit so replaced them. Finding O rings in my town is like finding hen's teeth (matter of fact, there are probably more hens teeth:})
Good luck and let us know how it works out.

[doorknob]

Did you order the regular flavor or the one with the ER-11 collet and larger motor?

I noticed that the FAQ states, "The bearings are virtually identical to those you would find in a Dremel Tool." I would have expected that one of the advantages of the spindle would be better bearings than a Dremel leading to better runout specs. What am I missing about this spindle?

I'm looking for a spindle to use with my ShapeOko, and PCB isolation routing and drilling is one application that I'd like to handle. I'm not sure that I would need the bit size flexibility of the ER-11 collet (since I should be able to get both engraving bits and drill bits having a 0.125" shank), but the larger motor might be nice to have. There's a lot to read on his web page, so I'm not sure of what the current price of the ER-11 collet unit is, but maybe I'll just shoot him an email.

[Bubba]

Yes, the bearings may be similar or the same, but the dremel housing is plastic and this is machined metal! That is the difference.
I haven't measured the run-out, but based on performance, don't think there is a problem.
As my machine was primarily built for doing PCB work, the 1/8" shank is ideal. Its also easy to change tools as only the allen wrench is needed.
I agree that the larger motor would be nice as I have stalled mine when trying to drill the "larger" holes in PCB material. It was not available when I ordered mine or I would have gotten it. Also, he sourced a replacement motor for the original but apparently they no longer stock it at least the last time I checked. IF I have to replace mine, I plan on using an "outrunner" RC helicopter motor.

[doorknob]

Your mention of the RC motor reminded me that I have read some threads about using them with spindles.

A couple of them are at:

http://www.cnczone.com/forums/genera...dle_motor.html

and

http://www.cnczone.com/forums/bencht...dle_motor.html

One more thing to learn about - I'll put it on the list...