Cutting foam sheets... with a needle!

[jhitesma]

Air Assist is definitely on my To-Do list. 5 Passes isn't a horrible number. I don't know squat about laser theory. So if you can do 1/8" in 5 passes with a 3W laser, shouldn't you be able to reduce the number of passes by (aprox) 50% if you increase the power by 50%?

That was already at the max power of my laser. At least as high as I'm willing to go with it (you can push them higher but you significantly shorten their life.) Cutting a motor mount for my FT Explorer took almost an hour doing 5 passes (I forgot to mention that the feed rate had to be VERY slow as well.)

After reading your post, I checked the specs on the JTech 3.8 and 7w laser kits. Spot Size = 0.011 on both. 6mm spot size? Death Laser?
I don't see myself needing a CO2 laser anytime soon.

Jtech has good stuff...but man are they pricey. That 7w laser is more than twice what I paid for my 40w CO2 machine...and that's a full machine not just a laser. Yeah, I had to do quite a bit of upgrades to the machine and I stepped up with a smoothie board - but if you're really just interested in cutting then you could go with a RAMPS for over $100 less and have an equally useful machine.

I also note that jtech doesn't list a max spot size and show a typical spot size larger than the quoted smallest...so...not sure just how accurate that info is. Note also that by their nature diode lasers tend to have an elliptical spot rather than a round spot which again results in slightly less efficient power delivery to the work.

They do note that the spot is rectangular and the size quoted is the longer dimension. They also note that actually running it at 7w output will significantly shorten it's life. So selling it was a 7w module is to me a bit misleading.

Also, from what I've read on Banggood https://www.banggood.com/EleksMaker...-p-1127310.html?rmmds=search&cur_warehouse=CN and elsewhere, 7W laser can even mark stainless and aluminum. That would be plenty enough for me. But I'm very nervous about Banggood at $300 and choking on JTech at $625.

I've actually had success "marking" aluminum with my 3w. Even a 40w (or 60w) CO2 can't actually "mark" aluminum though - what's actually happening is you can etch the anodizing. If you have clear anodizing then it looks like marking but the aluminum itself isn't actually being marked. And the quality of the anodizing can vary wildly. Surprisingly the anodizing on my cheap HobbyKing Charger is REALLY tough stuff as despite being black I can barely etch it at all even at high power and low speeds with my 3w...but most other anodized things I've tried have etched very easily at higher speeds and lower powers.

The big price difference between jtech and the Chinese sellers is in the support Jtech provides and the provisions on their drivers to meet US safety regulations (keylocks and dual interlocks). Most of the actual laser diodes in the modules that jtech sells you can get direct at much lower cost - but you have to source your own parts to assemble it into a working solution. My laser used the same diode that was in jtech's kits at the time but I spent about half what they were charging to put mine together. I had to order parts from multiple sources to pull that off...but the cost savings was worth it to me and the safety locks weren't as important to me since my machine is in a locked building that only I have access to. If it was in my house where my daughter could get to it (like the CO2 laser is) safety interlocks would be far more important (and that's why I added them to my CO2 laser!)

I love my diode laser - don't get me wrong. It's VERY useful and I'm glad I have it. But I'm also glad I didn't spend much over $100 putting it together and am even more glad that I now have a CO2 laser as well for real cutting. Even so I'll be keeping my 3w laser because it has a MUCH larger working area even if it isn't nearly as powerful.

 

[dkj4linux]

All,

Earlier in this thread -- here -- I started messing with air-assist. Dave "GremlinRC" and I were both playing with Banggood 3.5 watt lasers at the time and he finally convinced me -- with pictures -- it was worth the effort. So, I documented the process I followed to successfully cut some 4.7mm luan plywood in 4 passes... that I had also cut in 5 passes, without air-assist, with both a 2.7 watt laser and the Banggood 3.5 watt unit.

That said, that particular 4.7mm luan plywood was apparently the odd piece. I've never found ply of that thickness that cut as nicely, even of the same brand, bought at the same store. So, I'll simply say that I don't think all plywoods, even of the same thickness, are created -- and laser cut -- equally... I think it's the glue used in its construction. But it was a great test and we/I learned alot.

First, a fan and shroud, even without air-assist, are IMO a necessity... for flame suppression, clearing smoke, and reducing staining. Then power and feed -- although for cutting, I usually just set it for full-power... so feed rate is about the only thing you can vary. And, MOST CRUCIAL -- absolute best FOCUS need to be achieved to get best results... I use the fool out of Ryan Zellar's laser focus script any time I change material and/or thickness. Finally, strong air-assist will help greatly... I saw a 20% reduction in the number of passes needed in the thicker ply, from 5 passes to 4.

IMO half a dozen passes aren't too big a deal if it yields a good part. I also think hobby-grade plywood probably laser cuts better than your typical construction-grade stuff... I don't think you should have too much difficulty with 1/8", and thinner, hobby grade stuff. Finally, I found the additional noise from a compressor negated the reduction in the number of passes for me, so I've usually cut without air-assist... at least, until I found and printed Pawpawpaw85's air-assist shroud for diode lasers (https://www.thingiverse.com/thing:2832127). I can't say I see the dramatic improvement that I did with the compressor but I do think it helps.

-- David

 

[IsmaelPR77]

Hi everyone! I have tried to keep up with this thread but oh my. My main question, is there a needle cutter that has been refined and updated to work well? I see different versions on Thingiverse. I am about to start putting my needle mount together and I am curious to know if I have the "best" needle mount setup. I have printed this version https://www.thingiverse.com/thing:2450613

 

[dkj4linux]

Welcome to the party!

Jason (jhitesma) Hitesman's needle cutter, the one you've identified, is one of the more popular out there and that particular one is specifically designed for the MPCNC tool mount... and it works well. You didn't say what CNC machine you are planning so it may, or may not, be a drop-in cutter for your need. Not a problem, however, as there are numerous ways to modify it to fit your machine. The reason there are so many different versions out there is that there are myriad machines it's been mounted/adapted to... and all the needle cutter development over the years has been pretty much out in the open (public) and reflects its evolution over several years.

Please tell us more about your plans for its use. We're here to help!

-- David

 

[IsmaelPR77]

Welcome to the party!

Jason (jhitesma) Hitesman's needle cutter, the one you've identified, is one of the more popular out there and that particular one is specifically designed for the MPCNC tool mount... and it works well. You didn't say what CNC machine you are planning so it may, or may not, be a drop-in cutter for your need. Not a problem, however, as there are numerous ways to modify it to fit your machine. The reason there are so many different versions out there is that there are myriad machines it's been mounted/adapted to... and all the needle cutter development over the years has been pretty much out in the open (public) and reflects its evolution over several years.

Please tell us more about your plans for its use. We're here to help!

-- David

Thanks for the info David! I am building an MPCNC which needs the wiring and belts but I am knew to the whole MPCNC scene.

 

[dkj4linux]

You should get plenty of help... both here and over in the V1Engineering forum, home of the MPCNC. Keep us up to speed on how you are progressing... and don't beat your head against the wall (at least, not for too long...) before asking for help. Good folks... both places

-- David

 

[bperc]

Hi everyone! I have tried to keep up with this thread but oh my. My main question, is there a needle cutter that has been refined and updated to work well? I see different versions on Thingiverse. I am about to start putting my needle mount together and I am curious to know if I have the "best" needle mount setup. I have printed this version https://www.thingiverse.com/thing:2450613

I upgraded to that version of needle cutter and it has been working great for me.
https://forum.flitetest.com/index.php?threads/cutting-foam-sheets-with-a-needle.24251/page-104

 

[Headbang]

Just a thank you to all here! Esspecially Jason! Still refining my needle cutter, but I would not have things cutting planes right now if it were not for all the valuable information here.

 

[x33]

Hello to all (especially to David ),

I'm back again after beeing off for a longer time...had to do some work on a house we bought...and when I had some free time, I was flying with my DLGs as often as possible. In my club, there are some members with halfe the age of me. I try to gain a little more height in throwing than this guys...this kind of "competition" may sound a little weird...but for me it is fun to see that more practise on throwing equals the higher power.
So there was not much time left for "playing" with my cnc...did some minor improvements with the wires and cables...looks now a little more professional. ;-)

I also bought an older router from a guy who stopped working with this machine (because of age and health problems)
This router is from a company named "Haase" model is "cut2000"
The condition is fine...only the build in electronic (stepper driver) is outdatet and will be changed to up-to-date arduino-board.
The cables/wires are mostly unschielded...could be that I will fix this too!?

After that, I have to do some test runs to find out which machine is better for me (comparerd to my DIY with belt-drive and supported rails)

Greetings from Germany
Joachim

 

[dkj4linux]

Joachim! I'm so thrilled to hear from you again!

Now, 72 years old and feeling every bit of it, I've slowed down greatly of late. I've built a few simple CNC machines -- mostly laser -- since we last talked but, after losing my 2 best buddies in a 9 month span this past year, I've devoted more of my time to [poor] golf and trying [feebly] to setup/organize my more manual/traditional/messy workshop/shed than CNC. But I think back often -- and it's documented in this thread! -- to the times when you and I and "Dublin Dave", especially, were actively kicking around ideas for improved needle cutter operation and our home-built CNC machines. Those were good times and it was really fun to collaborate with you guys and get the creative juices flowing like that...

I'll confess I had to google that DLG flying stuff you mention. My, if I rapidly spun around a couple of times like that launching the plane... no way would I be able to get up off the ground, with my head spinning, and find and focus enough to actually fly the plane. I think I'll leave that to you younger fellows

That looks to be a pretty solid-looking CNC machine mechanically... I know you'll have it humming along nicely, with updated electronics, quite soon. Keep us updated with your progress and plans for it...

And please fill us in on what you're still doing [hopefully] with your needle-cutter... and some of those light-weight indoor planes (and DLGs?) you used to cut with your wooden prototype needle-cutter, strapped to your buddy's over-powered, over-weight, industrial-grade CNC machine

Take care, my friend. Again, it's so good to hear from you. -- David

 

[x33]

-->1< Now, 72 years old and feeling every bit of it........ I think I'll leave that to you younger fellows

-->2< That looks to be a pretty solid-looking CNC machine mechanically... ...Keep us updated with your progress and plans for it...

-->3< And please fill us in on what you're still doing [hopefully] with your needle-cutter... and some of those light-weight indoor planes

Hi David,
>>>1<<< this joke is real funny...'cause end of December will be my 71th birthday
This dlg-spinning_around_moves are not as complicatet as it looks at the first glance...the footwork is a little like dancing.
The only drawbacks are the cost for the plane...it has to be very lightweightet and also very strong (professional made from carbonfiber, flight-weight is under 250g with a span of 150cm) Look at > Snipe by Vladimir < Nothing for a DIY-project
The contest-guys are throwing to 70 (may be 80) meters...my personal record ist 50m...normally 30 to 40 meters is high enough to find some thermals under good conditions
>>>2<<< this "cut 2000" router looks good ...with double driving screws on the main axis...I'm a little anxious about the rails -> they are not supported...may be there will be some vibrations.?!
>>>3<<< the needle-cutter is working fine on my diy-router...made a few of the small indoor-shockflyers for club members....did some minor improvements with the time.
I would like to send you the cad-file (if you like)....but sadly the last month one of my harddisks crashed (doing strange noises ) and the backups are not on the newest/last level

Greetings from cold and wet Germany
Joachim

 

[dkj4linux]

Hi David,
>>>1<<< this joke is real funny...'cause end of December will be my 71th birthday
This dlg-spinning_around_moves are not as complicatet as it looks at the first glance...the footwork is a little like dancing.
The only drawbacks are the cost for the plane...it has to be very lightweightet and also very strong (professional made from carbonfiber, flight-weight is under 250g with a span of 150cm) Look at > Snipe by Vladimir < Nothing for a DIY-project
The contest-guys are throwing to 70 (may be 80) meters...my personal record ist 50m...normally 30 to 40 meters is high enough to find some thermals under good conditions
>>>2<<< this "cut 2000" router looks good ...with double driving screws on the main axis...I'm a little anxious about the rails -> they are not supported...may be there will be some vibrations.?!
>>>3<<< the needle-cutter is working fine on my diy-router...made a few of the small indoor-shockflyers for club members....did some minor improvements with the time.
I would like to send you the cad-file (if you like)....but sadly the last month one of my harddisks crashed (doing strange noises ) and the backups are not on the newest/last level

Greetings from cold and wet Germany
Joachim

Hahahaha... with your birthday coming up soon, just let me say, "Happy birthday, Joachim!" A golfing buddy of mine is 4 days older than I am... I'm "youngster" and he's "old man"

If it's like dancing, no way I could launch those planes.... plus both my shoulders are messed up It's a shame those planes are not really DIY... they would be a real challenge to build so strong and light.

Vibration could be a problem... depends on what you are cutting. But Haase is a reputable brand and I'll bet it's engineered perfectly for what it was designed to cut

I've got a golf outing this morning. Gotta run!

Later. -- David

 

[x33]

Needle Cutter -- (No) Improvements

My cutter is still the same (since Mar 217) and is working fine...
===> see post: https://forum.flitetest.com/index.php?threads/cutting-foam-sheets-with-a-needle.24251/post-332319
I did not made any changes and could'nt see any reasons for imrovements...the first needle is still "alive"
The long wooden needle-guides are storing some grease/oil and the needle has nearly no room for bending or vibration.
An important point is to balance the flywheel for minimum virbrations at working-rpm...this takes a little time, because you have to do the fine tuning under working conditions (not only static).
>> For a friend, I machinend a flywheel out of brass (not Alu)...this is much heavier and runs smoother
Also a good point is to choose the motor a little bigger then necessary (heavier and better ballbearings) ...this minimizes vibrations and will expand the lifetime.

Greetings from Germany
Joachim

 

[x33]

--> Laser <---

refering to post -> https://forum.flitetest.com/index.php?threads/cutting-foam-sheets-with-a-needle.24251/post-436531

An addition to the needle-cutter I'm using a 3W laser-modul from Banggood. When this modul is out of focus, the laser-dot is shown as nearly quadratic. With this, I can focus a very small burning-dot (may be 0,2mm). By using an air nozzle, I can cut 5mm Balsa and normal Plywood running several passes.... but I have problems in cutting of this special, hard plywood (2 or 3mm with 5 layers - use for building airplanes)

For a few month now, I'm looking for a more powerfull Laser-Modul.
There are several 5w+7W Moduls on the market...but if I'm looking closer to the specs, the unfocused dot has a rectangular shape (two diodes in parallel???) and the focused burning-point is greater.
I do not belive, that this will give me more power for cutting...may be it works a little better for engarving, doing line-by line?

Greetings...Joachim

P.S. Does anyone have made some tests with this laser-etching-sprays???
https://www.trotec-materials.com/news/laser-marking-products
https://www.gravierbedarf.de/epages...bjectPath=/Shops/63201300/Categories/Thermark
the price is VERY high!!! ( 95.00 € and higher )

I tried this...with nearly no result ---> https://community.glowforge.com/t/b...tch-stainless-perfectly-see-ya-ceramark/17699 ...may be this wil work with more power

 

[ironkane]

JTechPhotonics has an article about using Powder Coat. https://jtechphotonics.com/?p=5582

1. Spray the work piece with powder coating.
2. Laser at low power where you want text.
3. Wash and lightly scrub the panels to remove the excess powder coating.
4. Place in the oven for the final bake.

Would be cool if this works well. Because you can use multiple colors on a single project.

 

[x33]

Christmas Decoration made from DEPRON using the needle cutter.

As some kind of late christmas-gift , I'm posting a picture of a decoration, made with the needle Cutter.
The size is 400mm by 450mm - cutting time 1/2 hour.

Greetings from Germany...Joachim

 

[dkj4linux]

Well done, Joachim! It still lives... and is as impressive as ever!

Happy Holidays to everybody!

-- David

 

[mayan]

@dkj4linux thanks for the very detailed post will be following this thread.

 

[IsmaelPR77]

I need some advice. I am getting some great cuts with my setup. But the bottom side of the foam board isn't as clean cut and the top is this normal or to be expected? Or should I take a look at something that may be off and causing this issue? I have tried varying the speeds, etc. But nothing minimizes it.

 

[x33]

I .... the bottom side of the foam board isn't as clean cut and the top is this normal ...

Hi, please post a photo of the setup and the cuttings.
When cutting "FoamBoard"(sandwich paper-foam-paper???), you have to take care of a good, long needle guide to minimize the movement to the sides...the needle is suppost to punch "straight"
https://ftforumx2.s3.amazonaws.com/2017/03/146231_b3ea7f5395a11b45e564b938e2f1940a_thumb.jpg

Also important ist the material of the "spoilboard" .... You will have no clean cuts on the "cutting-threw-side" if this spoilboard is to soft.

Greeting from Germany
Joachim