Should we get a laser cutter if we already have a CNC router?

Is it a good idea to buy a laser cutter even though my team already has a CNC router? The only advantage I see in it is speed, but maybe someone can tell me something that will change my mind.

Setup and learning time is way less. Workflow is just Create DXF -> Laser Software -> Cut, which is much easier than setting up CAM. On the actual machine side, you don’t need to load tools or hold anything down- just throw the sheet in and cut.
Many teams use their lasers for prototyping, as the convenience of it encourages people to prototype with more iterations.
Whether or not you want to shell out the $$ for a laser for those advantages is up to you.

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Depends on a lot of things! What’s your budget for the laser cutter? What router do you have at the moment?

Can you clarify what you mean by speed? CNC routers and laser cutters are generally used for different things (sheet metal vs. prototyping), so the word “speed” is a little ambiguous.

As of now, we are using the CNC router for both prototyping and final pieces. I refer to speed as the setup time, and overall time to cut the piece.

We built our router from scratch, and it has a 5’ by 4’ bed. Our budget is currently ~$2000, but we will pay a little more for something that is worth the extra money.

Do you have any recommendations for a laser cutter?

Just check out the materials that you can cut with a laser… polycarbonate does not cut nicely, so you’ll want to explore other options such as PETG. Acrylic, which does cut nicely, tends to be too brittle for mechanical roles on your robot.

You’ll also find that the laser can do engraving that your CNC cannot do… burn away paint, powder coat, or anodized dye and you’ve got custom plaques. Grab some acrylic and make custom trophies. Unless you’ve got a 1/600" tool bit for your CNC, you’re not going to get that kind of resolution! I impressed some vintage car restorers by taking an old VIN tag, cleaning it up, spraying it 100% black, then burning away the paint that I didn’t want… basically a museum quality restoration in 30 minutes. (Well, someone at the museum would have noticed that my font choice was only “close” when they put it next to an original… let’s say “show” quality.)

Like anything, it’s always fun to have a new toy in the toolbox… you’ll definitely find that the laser complements your CNC nicely, but in no way replaces it.

Jason

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If you’re down to drop $2k, a Epilog Helix isn’t a bad choice, those are pretty great machines. I’m a little unsure about the value it would get you, especially if you have an effective and established CAM/machining workflow, but they’re certainly nice for quick prototyping.

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This is somewhat of a value statement… To better illustrate the results, here is a photo of an incremental prototype of our 2019 gripper, built from 1/4" and 3/16" polycarb as well as 5mm lauan. The structure of the gripper uses tab-and-slot construction and is held together by cable ties. You can see the scorched rough edges, and at least one area of yellow discoloration between a set of close features. These parts were cut on the 80W laser that Triple Helix designed and built. Yes, our system is well ventilated.

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We got a laser cutter and a CNC router last year. The CNC was great for producing aluminum plate parts way faster than we could on a mill. The laser cutter doesn’t do aluminum, but it’s phenomenal for:

  • Rapid prototyping in wood - it only takes a couple minutes to cut out (for example) an intake plate, so you can iterate through different versions almost as quickly as you can test them
  • Test-fitting. We cut out parts of our arm and intake out of 1/4" plywood, so we could stick bolts through them and make sure the holes line up. I’m unsure how much value this added, but we’ll probably continue to play around with it. When there are errors in the CAD, you’d rather find out from a 3 minute laser cut than after an hour or two of routing
  • Creating precise field elements, such as the holes in the rocket this year. Even for simpler parts, like “cut out 16 of these little rectangles”, it can run in the background while kids work on the robot, which is nice if you’re shorthanded
  • Stencils. We cut out a great stencil of our team logo from cardstock, and used it to spraypaint our new robot cart.

It took us most of the fall semester to assemble the routers, figure out appropriate feeds & speeds, and troubleshoot all its issues/user errors and get one student trained on how to use it correctly. In contrast, on the day the laser cutter was delivered, the mentors were already cutting wood, and it’s very fast & easy to train a student on how to use it. As someone mentioned, you don’t need a CAM to run a laser cutter part, just a drawing.

But what really made the laser cutter worthwhile for us was the rapid prototyping capability. One of our main team goals last year was to start doing more (and more meaningful) prototyping, and the laser cutter was a big part of making that happen.

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The biggest question is where else would the money go? The biggest value a laser cutter provides is a really fast way to cut designs out in wood and various plastic sheets for prototyping. If you want to make your prototyping system better I would definitely recommend it unless the money would be spend on something more valuable to your team.

We got a 4x8 lazer cutter last year and it has been so helpfull making prototypes and even some final products the hook on our climbers last year was 6 pieces of laser cut 1/4 in plywood glued together and covered in spray paint and and this year we probably had 8 laser cut pieces on the robot

+1 to being able to iterate faster with a laser vs a router.

We went through 8 iterations of the geometry of a part on our laser in under an hour and a half.

Here’s the part in assembly. Thanks to the laser, we only had to run this part once in metal as opposed to 8 or more times.

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We have had a 4x4 router for 3 years, and this year invested in a grant for a 4x8 laser from Lightobject.

It is so freaking easy to cut parts. Finished parts coming off the same day it was delivered.

With material stocked, I think I can have field elements out at Kickoff by the time our teams are coming out of round 1 game analysis.

Also looking forward to a bunch of business development stuff / team swag that is a time-suck to route but easy to lazer etch.

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@Jeremy_Germita what machine(s) are you running?

Laser is a Gwieke LC1390 similar to below:

CNC Router is a Shopsabre 3636

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