CNC Routers

[craigboez]

A few teams have mentioned that they have a CNC router. My team currently uses a manual mill and lathe, and I'm wondering if a CNC router might be a good addition to our existing shop. One would come in handy for drilling evenly spaced holes in the chassis, making gussets, cutting curves in aluminum or polycarb sheets, etc. Another option would be a CNC mill, but I'm not sure we'd use many of the additional capabilities it has over a router, so it may not be worth the expense.

Can any teams with a CNC router give any advice on what to look for? Should we buy one, or are there good DIY solutions? Is yours as useful as you had hoped? What are the max sizes, thicknesses, etc of material (aluminum in particular) that you're able to work with?

Thanks.

[MichaelBick]

The best thing to use a router to do is gusset plates and polycarb. It's great to be able to do these things in house and is a good addition to a shop if you can't afford a full cnc. However, if you can afford one, a haas or even a tormach will beat it any day for speed and accuracy. The router typically has the advantage for size.

The cnc mill will give you the capabilities to do all of the things you mentioned. CNC mills are great for all robotics applications and if you have the money for one, I'm sure you will be happy with it.

I would recondite talking to the lead mentor of 973, Adam Heard. I know they built their own cnc router, and love it. For a better idea about the capabilities you will have with it, talk to him.

[rcmolloy]

Originally Posted by MICHAELABICK

The best thing to use a router to do is gusset plates and polycarb. It's great to be able to do these things in house and is a good addition to a shop if you can't afford a full cnc. However, if you can afford one, a haas or even a tormach will beat it any day for speed and accuracy. The router typically has the advantage for size.

The cnc mill will give you the capabilities to do all of the things you mentioned. CNC mills are great for all robotics applications and if you have the money for one, I'm sure you will be happy with it.

I would recondite talking to the lead mentor of 973, Adam Heard. I know they built their own cnc router, and love it. For a better idea about the capabilities you will have with it, talk to him.

Adam, the other mentors, I had a pretty decent discussion about gussets and polycarb last night and in terms of router capabilities. If you have an existing router or have the time and funds to actually make or buy one then great. However, I personally have and I know many other teams have gotten pretty decent precision with just matching a plotted printout to make the gussets in house with drill presses, bandsaws, and sanders. Granted they aren't as beautiful and super precise as some of the gussets we have created but they're still functional.

As for gear/sprocket spacing, we also decided that its obviously a more precise job to do on a mill. The process for large components (35 chain) wouldn't be too terrible but you would still have the manual mill to take care of that.

[MichaelBick]

I completely agree with Cory here. Last year we had our polycarb cut on a hand router and drill press with a plotted printout taped over. A bandsaw would have been better for the job though. You do not NEED a router, however if you get one it will be put to good use.

[craigboez]

Hey RC, what kind of precision can you guys get out of your router?

[AdamHeard]

Originally Posted by craigboez

Hey RC, what kind of precision can you guys get out of your router?

We make gearboxes on our router, we've never done any really formal testing to see what the actual tolerances we're holding are. Gearmeshes and timing belt exact c-c have worked out well.

[R.C.]

Originally Posted by craigboez

Hey RC, what kind of precision can you guys get out of your router?

Hey Craig,

We own a Techno 3024 and love it. Paton Group here on the WestCoast supports the Techno line for educational uses.

http://www.patongroup.com/product-12..._Overview.html

The pricing on the site is just the bare machine, no ATC and no vacuum table. I'd get the 4896 vs the 3024, the person in charge 4-5 years ago when we got ours just bought the cheapest one. Even a 48x48 would do.

I'd say we can get +-.001 C-C. According to the rep you can get better. We've made everything from Rails to Gearbox Plates to Manipulators on our router. Just add a mister and g2g to cut aluminum. If you have the money I'd totally recommend a CNC router.

-RC

[HumblePie]

We are fortunate enough to have access to a 3D printer. So, for smaller plastic and/or wood parts (smaller than the printer envelope), I find that a printed template, along with a pattern trim bit on a benchtop router table does a pretty nice job. You can rough cut the parts slightly oversize, temporarily affix the printed template (w/ double-sided tape or screws) and trim on the router table for accurate geometry and a nice smooth edge. Larger parts can be accomodated by designing the template pieces to be interlocking.

[Mk.32]

Originally Posted by HumblePie

We are fortunate enough to have access to a 3D printer. So, for smaller plastic and/or wood parts (smaller than the printer envelope), I find that a printed template, along with a pattern trim bit on a benchtop router table does a pretty nice job. You can rough cut the parts slightly oversize, temporarily affix the printed template (w/ double-sided tape or screws) and trim on the router table for accurate geometry and a nice smooth edge. Larger parts can be accomodated by designing the template pieces to be interlocking.

Why don't you just print a template on paper and then cut it out? A hell of a lot cheaper then 3D printing...

[Madison]

Originally Posted by Mk.32

Why don't you just print a template on paper and then cut it out? A hell of a lot cheaper then 3D printing...

There'd be no edge to guide the router.

[HumblePie]

Originally Posted by Madison

There'd be no edge to guide the router.

Exactly. The template only needs to be 2-3mm thick to give the bearing on the pattern bit something to ride on, so the material cost is small. It's also a good introductory CAD application for the students.

[craigboez]

Some great ideas in the thread. Thanks all. Perhaps it should have been called "alternatives to CNC routers".