[Jesse B]

I'm going to be obtaining a Mini Mill within the next couple months (6"x4"x4"), and I need to find a spindle for it. I know most people use routers, but I have 2 issues with this approach:

1) Size: I think a router would be a bit large for this machine.
2) Noise: Routers are extremely loud from my experience, and I'd like to keep the noise down if I could.

So I'm not sure what this leaves me with. I've looked at some Drywall Routers, which are quite a bit smaller. The one I'm looking at is adjustable between 15k and 30k RPM. Would this be too fast? I plan on routing PCBs mostly, but will do some Plastic and Aluminum as well.

I'm open to any suggestions, but please try to keep the cost down. I'd be okay with fabricating something myself if anybody has any ideas.

Thanks,


- Jesse

[Teyber12]

dremel tool?

[Jesse B]

dremel tool?

I'm under the impression from my reading that Dremel tools have excessive amounts of run-out. I'm not sure if this is true, but if it is, it'd make manufacturing PCBs quite hit or miss, imo.


- Jesse

[jalessi]

Jesse,

Keling sells a 24,000 rpm spindle for $329.00

http://www.kelinginc.net/CNCSpindleandController.html

Jeff...

[Jesse B]

Jesse,

Keling sells a 24,000 rpm spindle for $329.00

http://www.kelinginc.net/CNCSpindleandController.html

Jeff...

Thanks. That's a bit more than I initially wanted to spend, but I will seriously consider it.

Just curious, so that if I run across something I can decided whether or not it suits my needs, what kind of RPMs should I look for for the following things:

PCB Boards
Plastics (Delrin, HDPE, etc.)
Aluminum

Thanks,


- Jesse

[packrat]

I've seen this use for PCB milling in a homebuilt PCBmill; http://www.foredom.com/foundations/s...=H.25&tab=docs

There are collets up to 1/4 inch I think. You would still need a flex shaft and motor but these things are really long lasting, much tougher than a Dremel.

cary

[Jesse B]

I've seen this use for PCB milling in a homebuilt PCBmill; http://www.foredom.com/foundations/s...=H.25&tab=docs

There are collets up to 1/4 inch I think. You would still need a flex shaft and motor but these things are really long lasting, much tougher than a Dremel.

cary

I've also seen similar pieces used (same company actually, just a different model), so maybe I'll look into that. The one problem with that is that I just have no clue what kind of specs the motor needs. Maybe somebody can help out

Thanks,


- Jesse

[packrat]

The web site lists a few different motors and flex shaft styles. There are different brands also.

The good thing that I see about them is, with the motor hanging from above, there will be a minimum weight on the z axis.

I've got one that was my grandpa's and he used it hard. It still works good, got to be over 30 years old. I use it when I don't want to fire-up my air compressor to just run my air die grinder for a few minutes.

cary

[Jesse B]

For a temporary solution, would something like the following work?

http://www.instructables.com/image/F...-and-motor.jpg

Thanks,


- Jesse

[Jesse B]

Well after looking at a few projects, I think that I'm going to make my own spindle. If I source all my parts properly, it shouldn't cost me too much at all. I have a Dremel that I'll use temporarily until this is done, but that should get my by just fine. All I figure I'll need is access to a Lathe, and I'll be in business (and I'm pretty sure I know somebody who has one).

I found 3 projects in particular that all have aspects of what I would like to achieve with my spindle.

http://www.mycncuk.com/forums/showth...e-design/page2
http://www.cnconabudget.com/PaulJonesPCBSpindle.html
http://babelfish.yahoo.com/translate...l.php&lp=de_en

I do have a few questions, however.

1) What size collet should I go for? I was looking at an ER-16 Collet for 1/4" Bits. That sound good?
2) Would a simple shank such as THIS work for what I'm wanting to do? If not, any recommendations?
3) Where can I purchase bearings for this project for as inexpensive as possible. They'll need to be handle fairly high speeds (20k-30k rpm).
4) Where can I purchase inexpensive pulleys/belts for the motor as well as the shank?

Thanks,


- Jesse

[jalessi]

http://www.vxb.com/

[jalessi]

http://www.sdp-si.com/estore/CoverPg/pulleys.htm

[packrat]

About 20 years ago I built a manual pantograph mill and used one of these for the spindle;http://www.parlec.com/pages/straight..._collet_chucks

It makes building the spindle super easy. The collet part is already made, just add bearings and a housing. If you look around you can find them used.

cary

[Jesse B]

http://www.vxb.com/
http://www.sdp-si.com/estore/CoverPg/pulleys.htm

About 20 years ago I built a manual pantograph mill and used one of these for the spindle;http://www.parlec.com/pages/straight..._collet_chucks

It makes building the spindle super easy. The collet part is already made, just add bearings and a housing. If you look around you can find them used.

cary

Awesome, thanks a lot guys.


- Jesse

[Jesse B]

Alright, been throwing together a rough design (not bothering going into any detail until I get something usable, so I know the CAD sucks), and I have a few questions. I got the rough dimensions of the Shank, as well as some bearings (rated for 15k rpm and cheap!), and the 550W motor I'll be using (I know it's small, but it's very powerful and very efficient).



Anyways, I have 2 questions as of now.

1.) Is there anything that I need to put on the shank, such as a clamping collar or something, to keep it from falling out of the bearings? How do I go about doing this, etc.?

2.) What is the top of the shank like, for connecting either pulleys or just a coupler?

Thanks,


- Jesse

[Jesse B]

That's pretty much what I'm planning to go with (rough design, will be refined one I decide on a few more things). Total footprint is about 6"x4"x3"; not bad for a 0.5kW spindle, imo

Still need to figure out the 2 questions listed in the previous post, but I've got pretty much every part picked out otherwise.


- Jesse

EDIT: Bit better layout and whatnot. Everything fits nicely, even the speed control.

[RotarySMP]

HerbertKabi has provided information here on how to make highly accurate, highly reliable High-speed spindles.
http://www.cnczone.com/forums/showth...t=12184&page=5

I am building a low quality lower speed lower reliability spindle here.
http://cnczone.com/forums/showthread.php?t=103610

[Jesse B]

HerbertKabi has provided information here on how to make highly accurate, highly reliable High-speed spindles.
http://www.cnczone.com/forums/showth...t=12184&page=5

I am building a low quality lower speed lower reliability spindle here.
http://cnczone.com/forums/showthread.php?t=103610

Thanks for the links. The first one has lots of information, but that seems like absolute overkill for what I need. I will not be running my machine daily, it will just be a "whenever-I-need-it" type machine. I'm liking your thread, as well as the build on /www.metallmodellbau.de. My design is actually highly influenced by his build.

One question however. Refer to the below linked picture.
http://www.metallmodellbau.de/pictur...SPINDEL-11.jpg

What are those brass-looking rings, and what are their purposes?

Thanks,


- Jesse

[RotarySMP]

Those are nuts. He threaded the inside of his spindle housing, and then made these nuts to retain the bearing.

[Jesse B]

Those are nuts. He threaded the inside of his spindle housing, and then made these nuts to retain the bearing.

Ah alright I just wasn't sure if they were some special vital piece or whatnot. Thanks for clearing that up.


- Jesse