Laser / CNC Budget Laser Cutter or CNC for cutting fins?

[BigMacDaddy]

Was shopping last night for Christmas presents for myself. I want to improve my technological capability for cutting low-powered fins from 1.5mm-2mm basswood plywood but also maybe balsa and also larger sized fins in the future.

I was originally contemplating a laser cutter for this purpose but my late-night research seems to suggest a CNC machine will be more effective and flexible. I guess if I had a CNC I might also do centering rings, jigs, and other things from wood instead of 3D printing them. I also imagine I would use this to shape foam for some interesting (and lighter) rocket experiments.

Any issues or advice about this? Can a cheap CNC machine work well for cutting 2mm plywood (I cannot find anything specifically demonstrating this but it seems like it would work since it shapes and cuts many other harder materials)? I am not looking to spend more than a few hundred on this since this is just a hobby.

Considering this unit (possibly with upgrade kit to go to 300x400mm cutting area):
https://www.amazon.com/gp/product/B07P6K9BL3/
Sorry for the naïve question and I am sure this is answered elsewhere but too many search results are drowning out the useful information specific to this hobby. I saw some of the earlier threads on much more expensive machines but I can deal with a bit of periodic aggravation to save some $$$.

 

[Sandy H.]

A few years back, I built a CNC router from plans. It was made from wood! It used pipe, skateboard bearings etc. The 'machine' itself probably cost me $75-100, but the electronics ran another $200-300. Add in a nice high-end collet for the router itself and that was probably another $200 total.

It was fun to build and fun to learn how to use, but the skateboard bearing method was a maintenance nightmare. One thing to think about isn't necessarily that you have to tighten things often (routers vibrate, 3D printers and lasers don't) but when something loosens during a run, you ruin the part and/or break router bits.

I played with the machine for around a year and it could do some really cool things, but it was a toy, not a 'machine.' I saw the picture of what you are considering and at first glance, it looks nice. Once I saw how tiny the motor is, though, I think it won't do much. My biggest concern would be how the collet attaches to the motor, as runout makes cuts very inaccurate if there is too much. Also, the steppers are tiny, so it won't be able to take deep cuts and therefore you'd have to make multiple passes to cut through stuff, I imagine. The inaccuracy of the collet and/or dropped steps makes multiple passes less likely to succeed.

Having said all of that, if you like to tweak, tinker, learn new things and have the space, it could be a fun thing to play with and I can't think of any way I could do something that inexpensively, as you see my wooden one cost $500-600 by the time I was done with it. . .

If you go for it, be sure to start a thread about it, as it will help others and if you run into issues, maybe one of use can help as well.

Good luck!

Sandy.

 

[BigMacDaddy]

A few years back, I built a CNC router from plans. It was made from wood! It used pipe, skateboard bearings etc. The 'machine' itself probably cost me $75-100, but the electronics ran another $200-300. Add in a nice high-end collet for the router itself and that was probably another $200 total.

It was fun to build and fun to learn how to use, but the skateboard bearing method was a maintenance nightmare. One thing to think about isn't necessarily that you have to tighten things often (routers vibrate, 3D printers and lasers don't) but when something loosens during a run, you ruin the part and/or break router bits.

I played with the machine for around a year and it could do some really cool things, but it was a toy, not a 'machine.' I saw the picture of what you are considering and at first glance, it looks nice. Once I saw how tiny the motor is, though, I think it won't do much. My biggest concern would be how the collet attaches to the motor, as runout makes cuts very inaccurate if there is too much. Also, the steppers are tiny, so it won't be able to take deep cuts and therefore you'd have to make multiple passes to cut through stuff, I imagine. The inaccuracy of the collet and/or dropped steps makes multiple passes less likely to succeed.

Having said all of that, if you like to tweak, tinker, learn new things and have the space, it could be a fun thing to play with and I can't think of any way I could do something that inexpensively, as you see my wooden one cost $500-600 by the time I was done with it. . .

If you go for it, be sure to start a thread about it, as it will help others and if you run into issues, maybe one of use can help as well.

Good luck!

Sandy.

Thanks Sandy -- very much appreciate the feedback / advice / experience.

I read / watched reviews that said the spindle rate is too low and that the stepper motors could be upgraded... I mainly want to learn (and for my kids to learn) so it would not be bad to upgrade. Most common thing I would do regularly is cut rocket fins from really thin / soft plywood so should not be too bad if I needed to do a number of cuts and run things at slow speed. Also as you said, I do not think I could buy the pieces of this for the cost on Amazon...

I saw a hack online where you can use a 3D printed part to replace the spindle for this with a higher-speed Dremel tool that you can take on and off the machine. I do have a 30,000 RPM rotary tool that I could use in this way. Also for $30 you can purchase a 20k speed spindle. I bought a set of stepper motors to try to make a Sisyphus table so hoping to be familiar with using stepper motors and controllers in the future.

 

[Sandy H.]

Sorry to see that there aren't many others chiming in to the thread, as I imagine a lot of people would like what you are looking for.

As far as the Dremel tool option, from my experience, that will have limited utility due to spindle runout. I know I seem to be harping on that issue, but the bottom line is that runout for a Dremel or hand tool is not at all important, as the human hand is way more 'off' than that. But, once you start to try to move a tool that isn't running on center of rotation through material with tight guidance, it either wanders or breaks the tool. For low power solutions, often the choice is to move to smaller diameter tools and they are even more prone to break.

One thing I really like that is part of your thought process is to get something accessible for teaching your kids. Growing up in the 80's, a cutting torch and big hammer was accessible, but in more modern times, programming and software are important, but there is still great value in making chips (the kind you track in the house, not the kind keeping you from getting a new car).

I'm guessing that the Dremel upgrade might be logical, but at this stage, my best advice would be to take very light cuts at high spindle speeds with the original parts. I'm saying maybe 1/32" depth of cut, max spindle RPM and somewhat slow X-Y feed. That will minimize the chance of the tool grabbing and breaking and will also somewhat average out any runout the tool has. Sure, you'll cut a 0.08" path with a 0.06" tool, but you are less likely to break if the depth of cut is low. You will burn up tools more often, but check Harbor Freight for the used PCB cutter packs. Not sure if they still have them, but the PCB people (even in China) were smart enough to retire tools after X number of cutting feet. It wasn't worth risking a broken tool due to it being dull. Anyway, those tool packs were very small diameter (good for low power) and often were still serviceable for an hour or two on home projects.

Hopefully bumping this back up again will get some more involvement from the community, as desktop CNC is cool for rockets, education, home projects etc. It can be hard to learn with free tools, but it is worthwhile from my perspective and any other points of view can only help the community as a whole.

Sandy.

 

[BigMacDaddy]

Sorry to see that there aren't many others chiming in to the thread, as I imagine a lot of people would like what you are looking for.

As far as the Dremel tool option, from my experience, that will have limited utility due to spindle runout. ...

One thing I really like that is part of your thought process is to get something accessible for teaching your kids. ...

I'm guessing that the Dremel upgrade might be logical, but at this stage, my best advice would be to take very light cuts at high spindle speeds with the original parts. ...

Hopefully bumping this back up again will get some more involvement from the community, as desktop CNC is cool for rockets, education, home projects etc. It can be hard to learn with free tools, but it is worthwhile from my perspective and any other points of view can only help the community as a whole.

Sandy.

Thanks Sandy...

I also posted in the Hobbycnc Reddit group and got a number of replies. People suggested that an up/down compression bit would not likely work unless I cut into substrate too much, that I might be able to stack the 2mm plywood and cut 3 or 4 fins at once (and that then a up/down bit might work), and that I should just use some relatively standard 1/8" down-cut bits. Also some advice about holding down material with painters tape, glue, etc... that I really need to make more effort to understand -- I guess holding everything steady is essential.

Good advice about the Dremel. I had never thought about instability in these tools. Mine is actually a Wen brand tool and came with a flex shaft so I was wondering if I could just mount the flex shaft and leave the rotary tool off on side -- https://www.amazon.com/WEN-2305-Rotary-Tool-Shaft/dp/B003BYRFH8. However, I assumes, lots of inefficiencies, heat, etc... is likely created in that type of curved shaft so I will put these ideas on the back burner. I can also add a laser cutter to this setup but my original research seemed to find that sufficiently powerful laser cutters were much more expensive than the CNC and that the CNC could do more stuff.

I will definitely check at Harbor Freight. Also might buy some low cost bits at Amazon and Aliexpress so I have some options to test. I can see a rapidly approaching future where I need to buy more plywood even though I wound up with 40 sheets of 2mm sheets when a a package was lost, replacement shipped, and lost package wound up arriving a month later also.

My kids are really excited about this (well the older 9yo one). He does some 3D design already for the 3D printer and we made a nice stained wood box for a 3D printed trophy he designed for his Mom in Blender. He is excited to make presents for his teachers out of wood.

 

[moondawg]

If you are only cutting 2mm plywood or thin sheet materials like that, then a laser cutter is 100% the way to go. It will be far, far easier for a first-time CNCer to get repeatable, reliable, accurate cuts with a laser than it will be with a small CNC machine. Plus, you won't have to worry about tooling, sawdust, etc.

I have the Atomstack A5 and a K40 laser to use at our machine shop. the 20W A5 is a great laser, I bought it for one job (marking about 200 anodized aluminum plates) and it paid for itself. Buy a copy of Lightburn to go with it, and you have a nice, powerful tool.

For rocketry, a 3D printer and a laser cutter will do 99.99% of anything you'd want to do in the hobby, I'd think.

A laser cutter might take a few passes to cut 3mm plywood, but it *will* cut it, and if you can live with the burnt color on the edges, will absolutely give a result as good as a routed edge (as long as you don't want chamfers, etc)

 

[Long_Gone]

I ran in to the same conclusion with the cnc router I am happy to say a homemade laser is making me happy doing just what you say you want. I like the accuracy and repeatability of the laser. It also cuts whay you cant or absolutely hate like centering rings. I built mine but the 15w Otur lasers are a good place to start and I love lightburn.

Long_Gone

 

[Long_Gone]

My laser and a clone of a Centuri Alien Scoutship.

 

[BigMacDaddy]

I ran in to the same conclusion with the cnc router I am happy to say a homemade laser is making me happy doing just what you say you want. I like the accuracy and repeatability of the laser. It also cuts whay you cant or absolutely hate like centering rings. I built mine but the 15w Otur lasers are a good place to start and I love lightburn.

Long_Gone

Thanks -- so how much do 15w lasers run? Any recommendations about where to purchase or is it just Amazon or Ebay is fine.

 

[Long_Gone]

Amazon is fine here is what "I think" is good.
https://www.amazon.com/ORTUR-Laser-...G,B097H2KHJ3,B08K8Z1H4G,B08M96HHKW,B08N1KT4VS
https://www.amazon.com/ATOMSTACK-A5...G,B097H2KHJ3,B08K8Z1H4G,B08M96HHKW,B08N1KT4VS
Sorry the links are ridiculous in length.

L/G~

 

[FMarvinS]

Before you invest in a laser or CNC, you may want to research and visit a makelab in your vicinity. If its anything like mine, you'll have laser cutters, cnc machines and 3D printers available. The best part is the experience and classes that are offered which will accelerate the completion of your projects. One last note, if you build fiberglass rockets, the decent CNCs can easily cut 3/16th inch G 10 (for fins) or 1/2 inch plywood easily (altimeter sleds etc). The laser printers we use (40 and 75 watts) can cut 1/4 inch plywood well but G10 is incompatible with laser cutters. The same with aluminum.
Good luck!
Fred

 

[Charles_McG]

MPCNC from V1 hardware kit and Creality control board left over from upgrading my CR10S. Tool is a Harbor Freight cutout tool from my father in law.

 

[Long_Gone]

Nice

 

[Charles_McG]

It could just as easily have a laser on it - but it will be a while before I can justify the cost of a 5+W laser and the ventilation and safety measures.

The cutout tool with a 1/8 bit cuts birch ply at 15mm/sec, 2mm deep and barely lowers pitch. The MPCNC works pretty well - pen tests drew 100mm squares with diagonals about 0.1mm different. I manually square it each use. It’s harder to get the work surface flat than I would have thought.

I have a dremel mount too. It works -but loads up fast. 10mm/sec, 1mm deep, and it behaves like the brand new bit is dull.

 

[tjkopena]

For rocketry, a 3D printer and a laser cutter will do 99.99% of anything you'd want to do in the hobby, I'd think.

I would add a cutter to that list, like a Cricut or Silhouette. It's real useful to be able to cut vinyl for finishing rockets, either directly with adhesive vinyl, or indirectly with stencil vinyl. I'm not a materials engineer or similar, but my understanding is that you should not laser cut vinyl or other PVC stock unless you really know what you're doing (I know some commercial sticker printing companies user laser cutters). It releases gases that are very bad for you and for your laser cutter.

The high end version of those machines, e.g., the Cricut Maker or Silhouette Cameo 4, are quite capable of cutting thin balsa (up to 1/8" or so). Maybe basswood; not plywood. So for many rockets they're an all-around cutting option. They're commonly available for $200-300, with the deep cut knife necessary for balsa and similar stock. They're also fully assembled. I have not used a Silhouette personally, but that is probably my recommendation. The Cricut software is TERRIBLE, in terms of ease-of-use for anything but the simplest tasks and actively makes the excellent hardware an annoying chore to use, and that's before you even get into unfortunate aspects of the Cricut company's desired business model and so on.


The Ortul Laser Master 2 20W is an excellent intro laser cutter. It's affordable, easy to put together, and LightBurn's mostly a joy to use. With simple mods like an air assist it's very good at cutting thin wood stock.

 

[BigMacDaddy]

Thanks everyone for the feedback... I will post how things go with my exploration of CNC and laser cutters for rockets or other things.

 

[mjennings]

We just got the shilloette cameo 4. Only played with it a little haven't tried anything than card stock yet. But from everything I've read both it and the circuits "can" cut balsa with the right blades, but it's really at the limit of the machine's capacity. I'm going to try some matte board for some centering rings, especially if I can run down what the black stuff that FlisKits and others use.

 

[Long_Gone]

Love my 3D printer and my laser.

 

[BigMacDaddy]

We just got the shilloette cameo 4. Only played with it a little haven't tried anything than card stock yet. But from everything I've read both it and the circuits "can" cut balsa with the right blades, but it's really at the limit of the machine's capacity. I'm going to try some matte board for some centering rings, especially if I can run down what the black stuff that FlisKits and others use.

Cool -- the CNC machines (and laser cutters I suppose) also have attachments for hobby knives and you can setup appropriate settings in the software apparently. The one benefit of the CNC machines is that they have Z-axis control (albeit only with a couple of inches of range on the cheaper ones). Apparently having Z-axis control even makes a difference for laser cutting if you are doing multiple passes and I can imagine might also make a difference for blade cutting if you were doing multiple passes or cutting some thicker stock.

 

[BigMacDaddy]

Before you invest in a laser or CNC, you may want to research and visit a makelab in your vicinity. If its anything like mine, you'll have laser cutters, cnc machines and 3D printers available. The best part is the experience and classes that are offered which will accelerate the completion of your projects. One last note, if you build fiberglass rockets, the decent CNCs can easily cut 3/16th inch G 10 (for fins) or 1/2 inch plywood easily (altimeter sleds etc). The laser printers we use (40 and 75 watts) can cut 1/4 inch plywood well but G10 is incompatible with laser cutters. The same with aluminum.
Good luck!
Fred

Great to know that the CNC's can do more work in the mid-powered and higher-powered rocketry.

I have been 3D printing for a while now so pretty comfortable with the broader technology set (although definitely a learning curve for the CNC / laser cutter paths and parameters -- AND cleanup / mess / venting). My university has tons of this stuff that I can theoretically use for just the cost of materials but I need to go over to engineering building, etc... so a bit of a pain (also one of the alumni of my masters degree runs the accelerator programs at NextFab, one of the largest makerspaces in Philly so have been over there periodically -- although mostly for other events and not making stuff).

 

[tjkopena]

We just got the shilloette cameo 4. Only played with it a little haven't tried anything than card stock yet. But from everything I've read both it and the circuits "can" cut balsa with the right blades, but it's really at the limit of the machine's capacity. I'm going to try some matte board for some centering rings, especially if I can run down what the black stuff that FlisKits and others use.

I have a Cricut Maker and have used it to cut balsa for a couple low power rockets. I did not have any problem whatsoever with that. Took a couple passes, but not an excessive amount of time by any means and the results were all very crisp. I would use it a lot more for that purpose except the software is so clunky. I believe the Cameo 4 can exert more pressure than the Maker, so I'd expect it to be able to cut balsa just fine. I haven't tried basswood, have seen discussion and references around about it doing so, but I could believe basswood is starting to get to the limits. Matte board I would also expect to maybe be at the limits, because it's generally pretty dense and takes effort to cut.

 

[Long_Gone]

Looks like you have it figured out. Have fun, stay safe.

 

[mjennings]

I have a Cricut Maker and have used it to cut balsa for a couple low power rockets. I did not have any problem whatsoever with that. Took a couple passes, but not an excessive amount of time by any means and the results were all very crisp. I would use it a lot more for that purpose except the software is so clunky. I believe the Cameo 4 can exert more pressure than the Maker, so I'd expect it to be able to cut balsa just fine. I haven't tried basswood, have seen discussion and references around about it doing so, but I could believe basswood is starting to get to the limits. Matte board I would also expect to maybe be at the limits, because it's generally pretty dense and takes effort to cut.

Cool I l will give it a shot once we pick up a heave blade and mat.

 

[BigMacDaddy]

I went ahead and purchased a Sainsmart Genmitsu 3018-Pro w/ offline controller for $180 (Amazon) and upgraded to 3040 (Sainsmart direct) for another $50 (plus a bunch of bits for a bunch more money -- I guess bits are my new filament). Seems like a nice size work area and will be easy to mount my 300x200x2mm plywood.

Got everything built over last couple of days. The mechanism seems to grind some moving backwards along Y-axis (seems to be the anti-backlash nut, put a bit of electrical tape around it so it would bounce around less and that was better). Otherwise everything seems to work pretty well. I'd like to add some limit switches to this setup (I have a bunch I bought for another project) but have not looked into how to do this yet. I am sure that I will need to do more upgrades once I get to really using this. Made some spoilboards with 1/2" MDF (I just made these with my chop saw since they do not seem to need much precision, at least not for what I am planning). Next step will likely be an enclosure and dust boot / vacuum setup.

I decided to use Easel (for design) and UGS (for uploading G-code) based on some tutorials I watched (and based on complementary educational use for pro version of Easel). Very easy to use although I need to play with streamlining the process to get my design files transferred around as easily as possible -- goal is to get CNC milled fins and 3D printed parts to all perfectly fit together.

I just did my first cut (just a simple outline of an SVG file in a junk piece of MDF using the standard 20 degree v-bits that came with it). Worked fine -- very loud (I don't think these are the correct bits for MDF) but mess was less than I was expecting for this quick test. Feeling more confident about trying to cut some fins (got some 2mm downcut bits for that purpose).

I will post results of my 1st fin project.

 

[mtnmanak]

The Sainsmart is a great entry level machine. Perfect for learning CNC and cutting lightweight materials.

When you are ready to move up to the next level, I purchased a Shapeoko 3 (current version is the 4) last year and have to say it has been amazing. I will probably upgrade eventually to a larger/more powerful machine, but, for now, it is awesome. Slices through any wood I can fit on the table (I have easily cut 1 inch thick wood and acrylic) and carves up aluminum and fiberglass easily (I have cut up to 1/4" on both materials). Excellent machine if you outgrow the Sainsmart. The free software that comes with the Shapeoko is great for most jobs, but the next step in that arena is learning Fusion 360 in order to incorporate ramped plunges, adaptive cutting, etc.

 

[BigMacDaddy]

The Sainsmart is a great entry level machine. Perfect for learning CNC and cutting lightweight materials.

When you are ready to move up to the next level, I purchased a Shapeoko 3 (current version is the 4) last year and have to say it has been amazing. I will probably upgrade eventually to a larger/more powerful machine, but, for now, it is awesome. Slices through any wood I can fit on the table (I have easily cut 1 inch thick wood and acrylic) and carves up aluminum and fiberglass easily (I have cut up to 1/4" on both materials). Excellent machine if you outgrow the Sainsmart. The free software that comes with the Shapeoko is great for most jobs, but the next step in that arena is learning Fusion 360 in order to incorporate ramped plunges, adaptive cutting, etc.

View attachment 491622
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Cool thanks -- It does look like all these technologies can get a bit addictive w/ constant upgrade paths. I loaded Fusion 360 but it was a bit complex... might need to leave that to my kids to learn / use...

 

[BigMacDaddy]

Pushing ahead... Did my first fin cut-outs. Big Daddy Clone on the way...

EDIT: I will pay more attention to fin orientation in the future, the plywood I have does not have as much of a grain issue as balsa but it has a bit less flex in one direction than another.


CNC was much quieter with the correct bit for the material (2mm downcut blade).
View attachment 20211126_124341.mp4

 

[Sandy H.]

Very cool! Glad you jumped in. One thing I enjoyed with my first CNC experience was using the machine to make upgrade parts for itself. I'm not sure what could be useful on your machine, but you'll probably find a time or two that you can make pretty functional parts by laminating pieces of material together to build thicker structures than you could comfortably cut with the machine. Also, using location holes cut at the same time and using dowels to glue up sub-assemblies is a great technique.

Enjoy the ride!!!

Sandy.

 

[BigMacDaddy]

Very cool! Glad you jumped in. One thing I enjoyed with my first CNC experience was using the machine to make upgrade parts for itself. I'm not sure what could be useful on your machine, but you'll probably find a time or two that you can make pretty functional parts by laminating pieces of material together to build thicker structures than you could comfortably cut with the machine. Also, using location holes cut at the same time and using dowels to glue up sub-assemblies is a great technique.

Enjoy the ride!!!

Sandy.

Thanks -- some really interesting ideas...

I have been learning to use the 3D printer for the last couple of years so learning to use CNC is the next tool set (and then a laser cutter will hopefully follow soon behind this). Seems like between the 3D printer and the CNC/laser cutting there are so many things that I can try to make!

I'd like to make an all CNC-milled/laser-cut rocket just as an experiment. Something like: https://www.rocketarium.com/Rockets/Rebel-John

I am also curious about milling foam to make complex shapes like an F-117 body (although I think I need to make my enclosure before I fill my house with foam dust).

 

[RCBrust]

I am also curious about milling foam to make complex shapes like an F-117 body (although I think I need to make my enclosure before I fill my house with foam dust).

I was also curious about this so I tried milling some 1/4" foamboard to see how it would work. I was pretty happy with the results. I used a compression bit so that I wouldn't get tear out on either side.

Randy