Working with a Free CAD
Most readers here know CAD is the acronym for Computer Aided Design. I think it is fair to say that the computer has totally replaced the pencil and paper (drafting) of the not so distant past. I was taught drafting or mechanical drawing back in the 1960’s. (Maybe that was a long time ago…)
Well, CAD is all that I use today. Pencil only meets paper when I am doing some preliminary sketches or idea doodling. I also get preliminary dimensions and add to my pencil sketches. Paper and pencil are not totally absent, but present and necessary only in the very initial idea stage.
I own and use several types of CAD systems in the jewelry, machine tools, and 3D printing that I enjoy. I am not going to promote one from the other, but each version or type that I own have their own special features that help me. Every designer needs to find the CAD systems that works best for their own skills and needs.
As a hobbyist user, I consider myself a semi-pro. I use the big-name software, but not to the design extent of a major commercial manufacturing industry. I am not designing a new 60,000 seat sports stadium with a free-span roofing system. What I create I can hold in one hand.
One of the major big names in CAD is AutoDesk. Makers of AutoCAD, Inventor, Fusion 360 and others. But there are other very serious and big-name CAD software systems. There is a free CAD product actually named FreeCAD. (I have it.)
I mention AutoDesk as I started using one of their 2D (two dimensional) AutoCAD packages when I first started working in the construction industry. Today I use a new 3D system they offer called FUSION 360.
AutoDesk software has always been very professional and therefore very high priced for a hobbyist. They had a 2D (two dimensional) AutoCAD Lite version at a reasonable price, but not free. I used that for many years.
But FUSION 360 broke new ground for AutoDesk when they offered it free to hobbyists and start-up business. They have recently (this year) modified that “for free” offer. The Start-up/Hobbyist has been separated into Start-up (Commercial) and Personal (Not for Commercial Use) Both are free but there are some limitations for free Personal. I then became unsure in which group I belonged.
I first registered Fusion 360 for KautzCraft Studio and thus qualified as a Start-up business, as I sell a few of the small jewelry and 3D printed items I design in CAD. My other (purchased) 3D CAD software systems (mostly Rhinoceros and Vectric Aspire) I pay high dollar to own and have no qualms about income derived from using them. They are the CAD I use for jewelry design. Fusion 360 is my primary 3D print CAD. I sell very little of my plastic 3D printed Junque. I mostly give it away.
I am not really a Start-up Commercial business by its true industry definition. I am a hobbyist making some minor profit from selling some of my hobby-made items. I recently changed my FUSION 360 Start-up to the Personal (free) subscription after AutoDesk (at last) clearly defined a hobby revenue amount. I never intend to grow into a $100K business.
Buying the regular subscription is what AutoDesk really wants the Start-up to do. At least grow into a need for a purchased subscription. The promotion subscription price (about $25/month) is in-line for what I pay for my other CAD, but I really don’t need to pay for a third (actually 4th) CAD system. I like F360 well enough, but not enough to add it to my overhead costs. I am a small hobbyist, earning enough (in my old-age retirement) to pay for the materials and tools of my hobbies. If I don’t need a tool, I won’t buy it.
I now know my limited personal hobby revenue qualifies for the amount AutoDesk defines as personal use. They state (in writing) less than $1000 revenue from hobby sales qualifies for personal use. Total KautzCraft Studio revenue including jewelry is not even close to that annual figure. $1K revenue is not very much these days. But it is a mark in the sand. I have no need to worry where my hobby business fits.
If I were manufacturing and making a sustainable living from the use of their software in a commercial business, I would be happy to be paying my share to support THEIR business. Plain and simple. If THEY offer free use to me as a hobbyist, then I accept their generous offer.
The personal (not for commercial use) version eliminates the collaboration feature, data management and generative design. Also, phone and email support are not available. There are limitations from importing commercial file formats. Nothing I need at this point.
If someday I become NOT qualified for free use, I will let AutoDesk know. In my heart, I would know when I am not, and would do what is necessary. Free use is a privilege and not a right. Some folks may fail to understand a free privilege does not mean unlimited.
I could live (enjoy my hobby) without FUSION 360. That’s my second determining indicator. But I will admit I have gotten comfortable using FUSION 360. It does have some quirks and limitations, that’s why I am keeping my other CAD packages updated. If FUSION 360 goes away because of qualification abuse, I will miss it. But I have several options for continuing with my other tools.
There may come a time when all I need is FUSION 360. I’ll probably make that decision when or if I must choose to renew the other subscriptions I have. I think Vectric Aspire is one of my keepers for sure. But I need more than just that CAD/CNC system alone.
If You Have One Head, It Lasts All Day...
"Bit-O-Honey goes a long, long way..."
Three dimensional printing has been a love/dislike experience for me. I love the technical and specialized skills required to be proficient. I dislike the fact that I am making nearly worthless plastic Junque.
Recently I realized, doing the 3D printing process was my enjoyment and the cheap Junque was OK if it looked good.
I ventured into multi (2-color) printing to see what that could do. I bought a Geeetech A20M, single nozzle, two filament printer. The previous posts shows what it can produce.
Been doing a lot of study on multi color printing. When I started with the A20M, I wasn't sure where I was going with it. It's got me hooked for the "artsy" printing. One color has become boring except for purely functional item printing.
I have determined the blending two or three feeds into one nozzle is the most versatile and interesting method for me because of the color blending that is possible.
The IDEX (two independent print heads) and single head dual nozzles are the best choice for soluble support and are well supported by present slicers.
IDEX is also the only way to do large dual prints if that is a desire. Dual print size is not limited by fixed nozzle separation
Multiple fixed nozzles bring their own host of challenges with alinement, nozzle drag, and oozing. Also cook-off if a nozzle sets unused at print temp for too long.
Nothing is perfect with either multiple or single nozzle multiple color FDM. There are coding and tricks to mitigate most of the known issues. That's what I have been looking at.
Wiping and proper parking of the idle print head is a must with IDEX. Except for possible print alinement issues of two independent moving heads, I like it better than two nozzles in the same head. That's only a "like", not a tested experience. Mainly because it gets the oozing nozzle away from the print area.
But... The color blending single nozzle is a huge feature for me. Nozzle purge is actually required by all types of these printers. That alone is not deal breaker. Just part of the process.
I am putting the IDEX and other dual nozzle printers in the "serious prototype" category. They are the best (only) way to do special and complex supports. Shut down one nozzle and you have a great single color printer. Another color is ready to go.
The blending single nozzle is the "artistic" system. Color blending is far from perfect as I have discovered, but it is "artsy" and the non-predictability of color blending is a feature.
I just saw the three color version of the A20M. It is the A20T (T for Three or triple color.) (See picture.) I can imagine how three colors will behave.
Push button set-up and printing is NOT yet available for triple feeds. 3 colors single nozzle are well ahead of the curve for automation. But it is entirely feasible and possible process with all major slicers. S3D, Cura and Repetier-Host can slice and run 3 nozzles. The user has to know how.
I presently have working examples of all three slicers. They will need some additional tweaking for sure. The operator person is not D.I.W. for slicers for the A20T.
Three color printing is definitely NOT for the newbie. A guy I watched on Youtube doing crappy fast printing on a A20T made me sick. He just wanted to be first with a video. No finesse or technique. It did show me that ANY schmuck can operate the printer.
Well, I guess I am sold on an A20T. Just need to fall off the edge of this cliff in front of me. It's so far down, I can't see the bottom. Maybe I'll fall forever??
What? Yet another printer???...
2020 Show and Tell
This is my latest design/build project. First for the new 2020 year and new decade.
The CAD used is Fusion 360. Not bragging-up F360, but it got the job done. Since I am using a free “Startup” version, I can’t complain too much. It does have quite a few weaknesses and this project crashed several times while refining the lofting. I like the F360 workflow and the price (free). So, it’s not a perfect CAD, but (again) gets the job done.
Enough about the CAD. This is about the project.
My printer is a 2 color Geeetech A20M. Single nozzle color blender type extruder. This allows me to blend two filament colors while printing. A free software application called (Duh?) Colormixer is available from Geeetech. I can control the mix between 2 (or 3 if I had them) colors as the filaments flow through the single extruder. (Single nozzle extruders only!)
I used Simplify 3D for the slicing. The project STL is sliced as if using a single color, then the gcode file is passed through the Colormixer app where the color variations are added to the gcode. The end results are what is seen here.
I enjoy the color control and as shown, adds a lot of pizazz to a 3D printed item. The two colors are dark green and a dark (fire engine) red. Christmas colors. The blending moves from solid (100%) of green to solid (100%) of the red. The between color is a fabulous brown shade.
The small bowls (candle holders) are 50% reduction of the large (original size) bowl. Remember, a 50% 3D reduction decreases volume by eight (8).
The candles were designed (F360) to fit the small bowls and hold the tea lights. The white candles are printed on my “MamaCetus” Tiertime Cetus mini printer. The color candle on (of course) the A20M.
|Two version of the small holder||Muliti color candle version|
|Large base on A20M. Starting at solid green.|
UPS for 3D Printing
The three-dimensional printers see a lot of run time here at KautzCraft Studio. The larger prints run for twelve hours or longer. A lot can happen in that time span. Here in Texas and I am sure everywhere else, the weather can change for the worse.
That can lead to power interruptions which can kill a print job in the eleventh hour. It has happened often enough that it became a high priority to find a solution.
Many of the newer three-dimensional printers now offer power interruption protection and can be restarted where they are stopped mid-print and resume the print. That’s not always a perfect solution as the printhead is not parked in a “safe” area above the print and can actually “glue” itself to the print as the heat goes away.
The “pause and resume” works well, but when the power is instantly gone as in a power outage, the pause move (to a safe location) cannot be executed.
The obvious solution is a device called an Uninterruptable Power Supply or UPS. The link will lead to additional information. Often called a battery back-up. Used with any electrical device (like computer equipment) that must continue to operate when normal power is interrupted.
The UPS is a power line (usually 120 volt) battery backup system. A relatively large capacity low voltage rechargeable battery is maintained in a charged condition and is connected to a converter (inverter) that produces 120 volts alternating current.
The converter (inverter) is instantaneously energized and switched to carry the load when the normal power fails as during an electrical storm or other reasons.
A UPS is a perfect solution for saving 3D prints that have a lot of time and material required in their creation.
There are many sizes, brands an features available when selecting the UPS for this task. The choice was a given for me as the brand is owned by my last employer, Schneider Electric -- owners of the APC brand. We used them exclusively as back-up in our energy management control systems.
The proper sizing is the important decision. The UPS is generally intended as instant replacement of power when the normal source in interrupted. Its action is “instant on” invisible and instantaneous supply of the (usual) 120-volt power. The load never “sees” the power loss.
The UPS is NOT generally intended a replacement for back-up mechanical power generators. It is the “gap filler” between a power failure and the startup time for a motor-generator or other long-term power supply.
That reduces the cost and maintenance of needing a high capacity UPS. Batteries are maintenance items and need replacement. But the purchaser is free to choose the capacity and run time they need for the application.
My choice with 3D printing is a UPS run time of not more than one hour. Thirty or as low as fifteen minutes would be adequate. My desire is to ride through the usual one or two second “blink out” that we usually suffer in a weather event. Long term outage is rare and a risk I will accept for a print loss.
It’s the frustration of those few second outages killing a long print that the UPS is intended to relieve. Starting a print in the morning and hearing thunder in the afternoon is not comfortable and cause anguish.
We have two printers connected to the UPS shown. Each will draw 250 watts when the print bed is being heated. Normal run wattage is about 50 for one printer and 100 watts for the other (part of the 250 total load). Not sure why the difference. The nozzle heater may be larger on the 2 color printer. Stand-by is 7 to 10 watts (steppers and fans off). Except for start-up the high wattage print beds cycles with about a 10% duty factor.
Peak load is about 500 watts, but it is not likely the UPS would be used when first warming the print bed. Average run load (per printer) is 50 to 100 watts. 150 watts with both printers running.
I selected a 900 watt APC UPS. The pure sinewave some units feature is not critical. The UPS unit wattage needs to be adequate for the full wattage it is intended to support when it assumes the load. It is also an indicator of how long it will operate under the load. The price class for the UPS shown here is ~$170.00
The Schneider APC has intelligent controls that display the power (wattage) being drawn. It then computes the run time for the present charge of the battery. (Other brands may operate differently) With one printer operating the indication is the UPS can carry the load for one hour on the battery. That more than meets my goals. Two printers would probably run for thirty minutes.
I have produced a video that demonstrates the action of the UPS in a simulated power failure. There is absolutely no hesitation in switching to the UPS when power is interrupted. The same when going back to normal power.
The UPS fully satisfies my needs and peace of mind about running long prints. I must point out my computers are NOT using the UPS so long prints are always run from files loaded by SD memory. There is no particular reason the computer could not also share the UPS but in my case, the printers are not close to the computers.