Saturday, January 23, 2016

Low Power CO2 Lasers

I used to stay away from lasers, considering them to be over-priced voodoo and best left to be outsourced to someone else.

However I found myself in need of a 40 watt CO2 laser, so I bought one.  It still hasn't arrived yet, however I spent all afternoon yesterday researching on how to set one up and run it.

I need this laser to build the machine shop seed project.  Outsourcing the laser cutting will result in $10 per machine cost and depending on someone else to do the job.  That someone or several someone's also do other jobs, so my orders may or may not be done in a timely manner.

My assumption as to the difficulty to build and operate a laser was sadly over-estimated.

Lately I keep getting the feeling like I started out doing the difficult first.  

When I started 3D printing, I built my own machine from ground up with my own design.  That machine is at present humming away in the lab making some cable clips btw. It was a serious pain in the ass.  Months and months spent trying to get it right.  My education to learn this was quite expensive.

Since then I built a mach3 controlled machine and found that it was much easier to set up than a Arduino controlled machine (although Arduino is easy of you got the right instruction guide)

I set up a Raspberry Pi CNC controller with a touch screen, and learned how to set up GRBL controllers.

So my first laser engraver has arrived (a whopping half watt) and despite it having a defective diode, I studied it and figured out a bunch of stuff how to duplicate it.  

It just keeps getting easier and easier to build these things.

When the new laser arrives, I already got a bunch of projects to make with it.  I will be building a cheap laser engraver.  Something solid state, 2 watts, about a 18x18 inch working area and selling on the local market for about $300 to the sign makers. China price for this size and power is around $300 on eBay, so accounting for shipping, and tax I can handily beat the Chinese at their own game.

I have a large batch of machine shop seed printer kit orders to fill so it looks like the new laser cutter will be busy and possibly will need a second and third Co2 laser if things work.  

Now if only I can find another guy or 3 like the one I just hired to keep up with orders.  Saw some larger shop space near the new office the other day came open.  May have to rent that soon too.

Friday, January 22, 2016

CNC Plasma Machine

Got it installed, just need to tidy up the wires, add in the slats and the torch height controller.  

Runs a lot faster than my Torchmate.

Next machine of this type is 4x8 feet with rack and pinion drive.  

Here a few more pics from yesterday.

Shop makes grain handling equipment.  Elevators, mills, conveyors etc.

Wednesday, January 20, 2016

3D Printer Bed Adhesive Sheet

One of the biggest issues with 3D printing using the FDM method is that the molten plastic when laid down often times does not stick to the bed. 

Various techneques are used to make the material stick.  PLA glue, ABS plastic dissolved in acetone, hair spray, blue painters tape are the most common materials.

However there are other methods that have started to percolate thru the industry. 

One method is by using a proprietary material that is then adhered to the glass bed, one is able to skip entirely the glue/tape process. Basically print on this material.

I have been watching others experiment and seeing several new types of coatings being offered.  However I decided to experiment with various materials and coatings myself. 

At long last I have had my 'eureka!' moment.  I finally cracked the materials science behind the coating.

So in about a month once the store is fully stocked and running, I will be offering my own bed adhesion material.

I still have not finalized a name for it yet however.

I am testing it with both PLA and ABS, and so far on unheated print beds I am able to successfully print without the bottom of the print warping.  It does take a little effort to remove which is a good thing.

The same print surface so far has endured many repeated uses in the same spot to determine if this is a viable material.  So far early indicators are that yes it is good.

More testing will be conducted over the course of the next month and if successful I will have another item to add to the product line.

So far I make 3D printers, CNC routers, CNC mini mills, 3D printer parts and coming very soon a new super low cost laser engraver.

Things finally getting traction as the last few years of effort is showing fruit. 

The new CO2 laser will be arriving soon, and the solid state laser will be upgraded to a higher power laser.

Fused deposition modeling - Wikipedia, the free encyclopedia
It is one of the techniques used for 3D printing. FDM works on an "additive" principle by laying down material in layers; a plastic filament or metal wire is ...

Monday, January 18, 2016

Shop News

I bought a 40 watt co2 laser today.  The frames for the first batch of the tiny printers will cover 1/3 of the cost of the machine purchase alone.  That is 19 frames and the $10 machine time per machine if I hire it out.

Me and my partner was debating the most cost effective use for investment money. I basically ran thru the options and we worked out which would bring in income first.  So a new mill got bumped down one notch in priority.

With the new lower cost of the co2 lasers, it makes sense to re-visit that option.  I only wish that a lot of these tools and machines were this low cost when I started this venture 4 years ago.  

Lasers went from $2500 to $500 and CNC mills are now down to $185 for the cheapest models.  $1000 will get a fairly strong model for production work.

Small machines like these used to be viewed (and still are by many) as hobbyist toys. But somewhere along the way the hobbyists discovered that real work can be done with the cheap 'toys'.

Got the very first 3D printer I made 2 years ago back into service with a new print head.   Some of the printed parts on it are starting to deteriorate.  Making new ones.  The machine makes beautiful prints and is really fast.  I stopped using it mainly because the E3D extruder on it was total junk.  Paid $90 for that part 2 years ago.  The cheap china replacement that is reliable is $10

The other laser I bought arrived with a defective diode. Awaiting word about replacement part.  See the review in previous post.

I have however gained a ton of useful info from it in spite of the laser not working. I will be taking a calipers to it and duplicating it for the local market with a 2 watt laser. 

The software and manuals with it are very good.  All open source free stuff.  Ironic huh?  Americans copying Chinese goods and beating them at their own low price game.

Putting one of the big red industrial printers into service this week after make a couple new parts.  I came up with a improvement to the bed level mechanism.  One problem when going big is that the methods that work for small machines do not work on large machines.  

The small printers use what is basically a spring loaded bolt.  The bed is held up on a spring.  Because the bed is so big, I use engine valve springs to hold it tight.  But it's a pain in the ass to assemble cause it takes 2 people to put it together.  One to hold the spring compressed and one to fasten the nut.

However that can introduce resonance in the machine as tiny vibrations are amplified due to the design and those vibrations can be seen in the surface finish of the part being printed because the spring can vibrate.  I really beefed up the Z axis and print bed from the initial prototypes to overcome these issues.  The bed now consists of lasered and bent aluminum with lasered steel reinforcement.  

The up and down motion is handled by a industrial grade linear guide mechanism.

So I ditched the entire spring loaded design, and came up with a new design that exerts a positive control over the bed height.  As a bonus it saves me a couple dollars.

That pretty much does me in for new machines until I can get more control boards, driver chips, pulleys and extruders.  Placing order for more parts hopefully this week.

New guy is working out well.  He loves to use the CNC mill. Fascinated by it.  Put him on a few machine building tasks and he needed very minimal instruction.  He just grabbed the proper tools and went to work.  End of the day the machine was put back together and aligned.

It is amazing watching the next manufacturing revolution coming together.  My partner has been in the manufacturing and fabrication business for all of his career, and today he looks out at his factory, shakes his head and says anyone today can build a modern high tech factory with only a little amount of money.  

Just think that even a mere 5 years ago the desktop manufacturing revolution was just getting started.  

This week I was on the Ali Express website looking for ideas, when I came across a large number of products made from 3D printed parts.

Americans really need to pull collective head from rear when it comes to this stuff cuz the Chinese are eating their lunch.

Even in Africa this stuff is taking off.  I got a African student engineer I regularly correspond with, building his own high tech shop from what essentially started out as a 3D printer kit as the seed.  

CNC Low Power Laser Review

So I got my hands on my new CNC laser engraver Saturday after a meeting discussing the machine shop seed project logistics and reviewing the parts that arrived from China vendors.

Ok first the good news.

It arrived with a GRBL board.  Open source, and lots of documentation.  The CD had a version of Inkscape pre-configured for the laser and the GRBL flavor of gcode it takes.  

Basically the machine runs on standard code 2 axis with spindle on and off commands.

So I hooked it up, got the drivers working.  Tried the spindle on command and jogged the machine leaving a nice deep satisfying engraving in the piece of plywood I was using.

It is only half a watt laser but boy it does engrave nice if a bit slow.

It arrived with the x and y axis motor plugs reversed which was obvious when the jog controls were reversed in the included GRBL control software.  GRBL btw is free open source and good stuff.

So I ran a test file made in Inkscape, saved the gcode, imported it to GRBL controller and ran it.

3 min later the laser diode died.

Notes on the machine.  The power supply is 2 amps, and the frame is made from a cheap version of Bosch 20x40mm extrusion except the grooves are 6.35 mm (1/4 inch) instead of the standard 6mm Bosch stuff.

The roller bearings are 6mm wide so there is a considerable amount of slop in the thing although, it did not seem to affect output quality as the low power 

The laser takes a very slow speed.  Frankly one could have powered it with threaded rod instead of belts for a better effect.

The software was well configured but they could have benefitted from someone who spoke English better to do the manual.

As a 3d printer frame it is not acceptable.  Too sloppy at the high speeds a printer needs.

Meanwhile I bought a professional grade 40 watt co2 laser to do jobs around the shop.

My new employee is working out well.  By far the most enthusiastic about what I make and do.  He offered to come in today on his own time just to learn the machinery.

Tomorrow is yet another attempt at delivering the CNC plasma.  Lack of a big enough truck is hampering efforts on that front.

I put one of my old 3D printers back into service yesterday.  It had broke and was in need of a few parts which I replaced.  I then used it to print a better X axis for itself as the one I have on it is held together with super glue

Pics to follow.