CNC laser versus milling machine - A newbie's quest

Hi all,

I'm a total newbie to the world of home cockpit building but I have been totally inspired by the absolutely stunning cockpit examples coupled the community spirit of this forum, to start my own project.

I've been reading the forums for a number of weeks and have come to the conclusion that a CNC machine for building panels is a must (especially given my skill with hand tools!).

Due to my limited budget, I would be looking at a Chinese eBay type machine but I cannot decide between a CO2 Laser engraving / cutting machine, which I've seen great results on Gadroc's and Agrasyuk build pages and a CNC milling machine such as the CNC3040.

The CNC milling machine feels like a more flexible option as it can mill lightweight metal parts but I'm not sure how good the engraving results are.

I would really value the input of the community in my discussion making process.

It would also be fantastic to get some photos of panels created with a laser and milling machine for comparison and the types / models of the machines used.

Thanks in advance and happy new year to one and all

I have both machines, a cnc router and a laser.

There is overlap with what each can do so while I might have a job that the router is capable of I may still use the laser instead or vice versa.

There isn't much the laser can do that the router cannot do but the difference is in the quality - specifically when it comes to engraving and the speed of it.

IF I had to have only one machine and it was to make cockpit panels then I would take the laser over the router.

This is because it can cut the material, it can engrave it giving a professional look that the router cannot and it can do it a lot more quickly. Parts can be cut quickly without as much waste and you can cut inside corners squarely which can't be done with the router.

You dont have to clamp your work on to the table. This is more important than you would first think. It saves a bunch of time and often material as well.

The only downside is you cannot mill a panel from solid material, you need to cut layers of a panel from sheet (usually acrylic) and assemble them. No real problem with this method though.

So, strickly for panel building - I would go with the laser.

Also, my machines are much bigger than the ones you are looking at. Mine were more plug and play. When you look at the forums you will see a lot of mods made to the basic lasers that increased the cost a lot to make them more functional.

Gadroc has documented his changes in his thread. It sounds like he has a good laser out of it.

While in theory possible to do aluminum on a small router I would want to see youtube, examples of a small machine you would get doing it. CNC routers can do it, mine rips through it but it weighs a couple of tonnes and has a 6 HP spindle to do the work.

The smaller desktop machines will give you vastly different results that may not really make you put a +1 in the 'pro' column.

IF I had to have only one machine and it was to make cockpit panels then I would take the laser over the router.

agreed, but the key word has to be panel making and pit building. generally i feel router is more suited for general hobby use. and sooner or later i will complete that cnc router build too

OP, hi and welcome to our forum.

from my experience the cheap Chinese laser of K40 veriety is near useless when stock. it will need a better controller (+ stepper drivers) to handle normal drawings. and engraving on painted surfaces requires air assist, it burns quite bright in there under the lid otherwise :shocking: :)

if i to start over i would not go for the small machine again. while we generally don't make large parts the ability to handle the entire sheet would be awesome. would have saved time and material (but that situation is soon to be fixed). if room is at premium then of course the small one will have to do.

fume exhaust - major MAJOR consideration. engraving is not a problem but during longish cutting sessions it is quite something. aside of improved exhaust (stock is worthless) from the table i'm running a huge fan that blows air out of open garage doors (so id doesn't bleed into house). on less then moderately windy day i can smell the thing from across the street. in that respect router has the upper hand

Thanks for the advice gents, it is appreciated.

Looks like a laser is the way forward, space is a problem so unfortunately it will have to be one of the smaller machines but I will see if there are any slightly larger machines that will fit my work space and budget requirements.

I hadn't considered fume exhaust which could be a major head ache as my "workshop" is a garage which is integrated in to the house. Filling the house with fumes is a sure way to push my long suffering wife over the top...

I will do some more research in to the modifications (and cost) that are needed to the cheap ebay machines, I did find an interesting open source replacement laser driver board project to replace the existing Chinese control boards (http://www.laoslaser.org/) for about ~£150 which could be a way forward.

All great adivce that I agree with already. I will advise caution on the open source or Mach 3/Linux cnc path for a laser. My general advice is I go that way if your interested in teaking the machine or writing your own laser control code. But if you just want to engrave and make panels get a light object dsp. It works perfect every time and you'll focus on tweaking your part design instead of your machine.

Marco has put together a great little guide to make a K40 a serviceable machine. Read it and if you don't feel up to that level of DIY then save up and get the next level up of machine which includes a DSP type controller. That will put you into the $3000 plus range. Up converting a K40 will be a total of $1500 to $2000 range depending on your luck with the quality of the power supplies that come with the K40 you get.

Thanks Gadroc, the guide is extremely useful.

Given my very limited coding knowledge, I'll take your advice and stay away from the open source option.

I just need to weigh up the costs of upgrading (fixing) a D40 compared to buying the next model up. A quick, ill-researched calculation based on the Lightobjects.com's D40 upgrade kit, ebay pricing and UK import duty:

Desktop machine (D40):

· Machine purchase cost, delivered:~£500.00

· Upgrade kit with delivery and import tax: ~£560.00

· Air pump and 10% for unforeseen costs: ~£120.00

Total cost: ~£1180.00

Next Chinese model up with DSP, air assist and larger working area:

Total cost delivered: ~£1760.00

There seems to be a fair amount of extra features with the higher priced model, I'm just uncertain of the quality. With the upgraded desktop laser option, I know the machine has been fixed and I should not incur extra costs (bar a tube replacement).

I really need to find a solution to venting the fumes to ensure I'm not smoking the house out each time I use it..

More research needed.

FYI the machines I'm looking at are:

Desktop model:

http://www.ebay.co.uk/itm/PRECISE-CO2-LASER-ENGRAVING-CUTTING-MACHINE-ENGRAVER-NEW-USB-PORT-/290838270084?pt=LH_DefaultDomain_3&hash=item43b74fd084

and

DSP model:

http://www.ebay.co.uk/itm/NEW-50W-PRO-CO2-LASER-ENGRAVING-CUTTING-MACHINE-ENGRAVER-/121045891202?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D4575485876917361242%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D121045891202%26

Dont do it. I wouldnt pay that kind of $$ for a small chinese one like that.

You are in the same $$ territory as this http://www.wklaser.com/product/11_190.html which is from a well know chinese maker whom I got mine and I know a number of other people have.

Thanks for the warning metalnwood, I'll investigate pricing.

UK import tax (20% + extortionate handling fees) and delivery could be an issue with systems sourced from overseas (the Chinese ones are located in the UK) but I fully appreciate the benefits of buying a 100% working machine from a reputable supplier.

The price of my pit build is escalating even before I have started!

I asked for a price for it and the smaller 3040 http://www.wklaser.com/product/11_186.html

I only just noticed that it is already in the UK so it includes your VAT already (I think?)

From memory the one I first posted is around $2500usd, but more when VAT is applied.

I am just suspicious of those very generic ones on ebay, no matter what the price.

This one would be cheaper http://www.wklaser.com/product/11_191.html

Out of the factory they are ready for good fume extraction. Mine has a 8" outlet and the blower clears the machine nicely, these would have similar. I think the one you listed from ebay will require modding to get it done well.

sorry, value in BP doesn't tell me much, but it indeed seems somewhat overpriced. try to look at as much as you can, i noticed prices tend to vary within a hundred or so even with same seller.

the small one is what i and Gardoc started with. after controller upgrade my biggest beef with it is the work size that causes waste of material. it can be enlarged somewhat by couple mods but not significantly. note, you will need to do something about absence of normal cutting table. after i finish cutting the first batch of panels i crave major overhaul will happen, .

you forgot to allocate for dust collector fan (or some other high powered fan for fume extraction. perhaps you already have one)

the bigger one does look better to me. not because of included controller or better laser routing assemblies but due to larger work area without that much more footprint on the floor. they also seem to offer lift table that will care of any focusing issues. fan on the back does not look up to a task of evacuating cutting fumes . and i'm not sure how the supposed increase of power affects the thing.

but as metalnwood said you getting into price range of better machines

(he probably wanted to link this one: http://www.wklaser.com/product/11_186.html )

but overall if small one is all you can afford it is better then nothing at all.

It is just better to find the local CNC builders in your area and work with them to cut your pieces. Have them fork out the cash required to get a $2500 laser engraver or a $7500 router table. Only thing you really need to know is how to CAD up DXF vector art files to give to them. Have them endure the consumables, calibration and maintenance on the machines. I have a manufacturing engineering degree and I don't even want to mess with maintaining machines like that. I think it's much more important to be good with SolidWorks and Draftsight and know people with machines, than to have them yourself.

It is just better to find the local CNC builders in your area and work with them to cut your pieces.

That is true too, if you can find a local company that will cooperate with you. Some may and some may not. Paying commercial rates can cost you a lot to do the panels, especially with some trial and error.

Finding some kind business who will help you out without charging you for every minute will be hard when you keep coming back for each panel.

If you can find it then that's good but through many forums I know many people can't. BHawthornes advice is gopod and some research should be done on that front.

Also, this is one company that has had a bit of marketing done on websites so the name is familiar, I dont know if their pricing is good or bad but it wouldnt hurt to put a panel in to their cost estimator and see what it tells you. If you can get 20x as many panels made for the cost of a reasonable laser then...

http://www.ponoko.com

A lot of machine shops will charge you for setup, so you might ask up front how much is setup cost and how much is just IPM charge. It might make the most sense just to setup a whole nested layout and cut all you can from whatever the maximum cutting area is on the machine. Stuff like that you can't really know beforehand though and is going to be different everyplace you look into.

Personally, if I could find someplace locally with a decent sized cutting area for laser and a decent sized router table I'd be set for whatever is needed. I've not dug around locally much though. I've found a few router tables but no laser in a few "mom and pop" machine shops locally. One has a high speed 5x10 foot router table capable of both wood and metal.

Another option is to take a few machine shop courses at a local community college. Having the run of their machine shop for the cost of a 3 hour course can more than pay for itself. Both of the major community/technical colleges in my area have engineering departments and their students do personal projects all the time in machine shops that are excellently equipped with multiple 3-axis CNC, waterjet, CNC lathes, etc...

The online idea is not such a good one when I think about engraving etc. Ponoko for example have all the plastics but you can't paint them and then laser engrave away the writing.

They dont have the lasermax type material to do it properly.. so it's a bit of a tough one to use an online shop, now I think more about it.

If you adopt a process that requires cutting then you taking away the parts for painting then taking them back for engraving the costs will go up a lot as well.

Anyway, check to see how much you can get done for what cost. Be realistic with them about how the process may go. I.e. dont lead them to believe it will be simple if you think they will have to do it piece meal while you paint or do things in between.

Worst case doing that you may invest hundreds and then they tell you they are fed up and you have to find some way to finish it..

You get the jist...

Another option is to take a few machine shop courses at a local community college. Having the run of their machine shop for the cost of a 3 hour course can more than pay for itself. Both of the major community/technical colleges in my area have engineering departments and their students do personal projects all the time in machine shops that are excellently equipped with multiple 3-axis CNC, waterjet, CNC lathes, etc...

Similarly, a lot of places have makerspace, a place where you can go and usually pay a small monthly and then a small amount per minute for using a variety of machines.

I believe Gadroc uses a place like that for his CNC needs, in fact.. just checking his website he uses this place. http://columbusideafoundry.com

There is sure to be something within reach of you that is similar.

Wish there was a place like that in Wichita, KS. We're heavy aerospace manufacturing, but I donno of any maker co-ops around here. Wonder if I did a crowd source for a laser and a table if anyone would bite for around the Wichita area? We could put it in the restoration building at the Kansas Aviation Museum.

Thanks for the advice gents, it's a far point regarding the outsourcing of panel cutting and I had never considered a using a collage or a makerspace type service.

I'm not sure it those options are available where I live, but I can see the added benefit of having experienced people to hand that I assume comes with using a collage or a makerspace service.

I have to admit that owning my laser does bring out my inner James Bond villain and I would use it for other projects asides pit building but I'm not made of money and I need to consider all options.

Do the math as well... I have a great maker space available to me and at $35 per hour it's dirt cheap. If you have perfect plans and just need to cut once its great. But you do need to figure in time to experiment and learn how you want to do panels. I still opted to get my own as I break even in less than 100 hours of cut time. With engraving you can easily be an hour per panel. Not to mention the fun factor of having one. In my case the K-40 was always a stepping stone. For me it was the same price as buying a tube and powesupply. I used it till I was able to spent the rest to build the larger machine. Building my own has been great. I've learned way more about CNC and how a laser engraver works. Aligning and other maintenance activities are much easier now. In addition I have a 40w machine with a 12x24 cutting area for a great price. This path is not for everyone and you have to be willing to put in the mechanical elbow grease to get it tuned up.

Another possible approach is find a trophy / plaque / awards store that has a laser engraver. You may find someone who is will to work with plastic and files you provide. You cut and paint the panels then pay the store to engrave using your file. You'll probably have to supply several test pieces to determine the proper settings for the particular machine, but once you know that, and develope a working relationship with the store owner you should be able to make whatever panel you need.

Still, there's a lot to be said for Gadroc's approach. Building the tools teaches you a lot and it can be very satisfying. I'm taking that approach now with a small CNC router.

i'd say go for it :) . the cost is not trivial but bearable. going out might have made more financial cense, but I'm really enjoying mine despite some frustrating moments. immidiate availability is awesome, and perhaps you will get a use of it in other hobbies. I already did some cardboard work for daycare my kid goes to. he was all excited to watch "there is a little laser fire that goes PSSS" (and it moves faster then with plexi), intrigued by the fact he could draw things and then actually touch the shapes, teachers were happy with materials . end result - cool crafty thing he brought home.

can you tell i'm super excited owner? :D

While we are talking about other peoples money - yeah, do it if you can swing it. :)

Building a cockpit can take a bit of time, you play around with processes for example getting proper buttons done has taken a few iterations until I was happy with the results. You can only do it when you have the time, an hour here or there. Having a machine at your disposal makes all the difference for me.

If you had it, trust me, it would get used for all sorts of things - stupid things like fancy business cards for yourself, other hobbies, things for the kids. I also have made stuff for my boys preschool.

If you have never built panels before I am not sure you would get the quality you want by using someone else, at least not without them doing them a number of times for you until you get the procedure correct.

I don't know. What lasers go for in your area but you could even get 60 percent or more back if you don't want it when the project is finished. I know over here I could get 100 percent back on it.

FYI, the 3040 I posted on the other page is 1800 usd delivered to your local port. That includes an air assist ump, a large extraction fan, honey comb table, water cooling. Plus more accessories if you wanted.. Pm me your email and I will forward the price list I just got, if interested you should talk to them directly. I am very happy with the laser i got from them.

 

Still, there's a lot to be said for Gadroc's approach. Building the tools teaches you a lot and it can be very satisfying. I'm taking that approach now with a small CNC router.

Good luck Mike, I am sure you won't be to far away from having a machine. You are lucky being in the states, you can get all the supplies so cheap. I made a joes 4x4 but the prices for the bits so so expensive to get locally or bring over that I ended up making a highly modified all aluminium one with proper linear rail and a water cooled spindle. It was a great machine until I decided I couldn't live with a half sheet size and had to go bigger :smilewink: