DESIGN - "I Can't get you outta my head...!"
This build has undergone several iterative changes along the way - for the most part the plans are solely in my head until it is finished, due to minor and/or major changes for whatever reason. For instance this image below - was a bracket printed to hold a 10mm Bearing for the X and Y axis shaft.
However after printing 8 of these realising that mounting them would be a struggle without losing precious build volume.
So the design was tweaked in favour of the following - which is effectively 2 of the same piece as above joined together solidly between, then each of these abut either side of the framework.
The original plan was to build something bigger than the Anet A8 I have - which although it has some great upgrades, such as MKS 1.5 RAMPS, duel extrusion, etc. the build volume is still not quite sufficient for some work I wanted to achieve.
WHAT DO I NEED?
Something which probably wasn't a big issue, but maybe some of the changes I made caused it to be with the A8 - The vertical orientation of the X carriage shafts and the cantilevering weight of the tool itself causes the slightest of twists to the shafts, which causes a slight difference in Z position from the edges of the build area to the centre (when I say slightly - it might only be 1mm - but when you are printing 0.2mm layer height - that is a full 5 layers!) . Moving to Bowden extruders fixed this by reducing the cantilevered weight, but the secondary problem is the jumping nature because there is still play in that design, and when just a small amount of poor extrusion on one pass, will cause the nozzle to catch due to the play, and can be awfully noisy as well as sometimes missing X or Y steps as a result.
Hence why quite a few more successful designs use the two X shafts in a horizontal position with the, most of them with the tool placed in between both. This design is fine where the X carriage only stays on the X plane, as there is no real loss of print volume.
Ideally however - Extra print volume is what I am after, so the ideas of CoreXY/H-bot and X/Y mobile carriage are where my attention lead.
The first problem I have 99% of the time, is the timing for getting parts. My mind races a lot of the time and it is frustrating when at 1 am in the morning you get an idea of something you want to add/modify and there is no-where open to get it, or it might be late Friday and you know that even if you ordered something on Ebay, unless they are local, allow pickup are open on weekends or after hours - then the idea is Doomed to fester...(Big shout out to silvers-123 on ebay - they run CNCShop where so far most of my purchased parts have come from - great prices, good quality items, and happily allowed me to pickup locally.)
I come from a long line of engineers, and have been tinkering for at least 40 years (since I was 3,) so getting around technology and manufacturing, regardless of any formal training, is pretty much second nature to me. But still, this is my first 3D build, other than having to put together my Anet A8 when I bought it only 6 months ago, and that was prefabricated.
So when you are a little restricted for space - where do you build a New printer, when you also need to print parts for it with your old printer...
Solution: put the frame together and put the original 3D printer inside it...
Probably the biggest problem you are going to have during any Build is getting the "right" answer from forums, google and so on. For the most part the reason for this is, there is no single Right answer, especially as everyone has different build skills and experiences and more than likely a different purpose or outlook on how things might look or operate.
For instance initially with my build I wanted to completely enclose the whole unit which would mean clean edges for the framework so I could easily place perspex around the whole unit - but when my need to have the Bearings I purchased sitting a bit further back on the framework - they now jut out a bit so I will need to change my enclosing design, however to me it actually looks quite good as it is, almost as though it is Designed that way...haha, so will try and enclose it but keep them sticking out as a Design element. Some might not like this and completely disagree - so will say "Well you should have done it this way..." - whatever you do, listen to Advice, not criticism.
To Print...or Not to Print
So how much of your build Can, Should and Will you print?
My build as previously mentioned has and is continually going through phases to suit both requirements, improvements and new ideas, for instance looking to use this build to also incorporate a 3D Scanner functionality has me thinking of a Rotating table attachment - Simples!
Besides one part which was printing on the Anet A8 at the time of this image, the below image shows a whole lot of parts I have printed (excluding 3 parts not showing here also as they are the Mounting blocks for the Heatbed to the ACME screw and Vertical supports.)
The 10mm Timing chain(s) 10mm timing chain Al gear, 10mm Linear bearings, 10mm Radial bearing, 8mm steal shaft were all from silvers-123 on ebay. The 10mm shafts on the right?? - Bunnings 10mm Galvanised steel shaft - More about these later on.
There are also some 8mm Linear bearings there - these came out of the Anet A8 when I replaced them with Plastic bearings to reduce noise in that particular printer.
Apart from this you can see the various printed parts.
4 x Clear10mm x 16t T5 gear.
4 x Green 10mm x 24t T5 gear.
2 x Green/Black X or Y Carriage sled (the opposite axis sleds were still printing - the reason I list them as X or Y - is it really doesn't matter which way around they go, but by the time I am finished there may be more reason to have them the other way around...You will see why lower down.) ** Addendum - Will be replacing the 2 x shaft units with wider ones now due to placing Tool between them, not off-set (more on this later.)
4 x Green & Black Bearing brackets - one already mounted in top right corner of the frame.
1 x Green/Black X/Y Tool Carriage - this is the central Tool carriage, it may undergo some more iterations as we go to accommodate the need for attaching more hardware to it, or changing the orientation of Pre-designed holes, etc. I have already found it works well just as a base with it's pre-designed 4 holes to simply attach a Tool plate to the bottom of.
As seen here with a Diamond Head bracket I designed for the Anet A8 easily attached to it. (This thing is coming together like the ISS...! Making adaptors for adaptors...haha)
In terms of deciding to print any/many of these parts - It comes down to the application itself, and also in this respect the method you then use to print, i.e infill at 10% for parts with less stresses on them, and maybe 25% or higher with those with higher stresses. I have tested the impact strength of my PLA parts for instance when creating a 100% infill Golf ball - I hit it with a Driver at full swing - if Golf physics is to be believed, this exerted a force of anywhere between 1000 and 4000 pounds of force. the only damage visible afterwards was decontamination of about 20 layers at the point of impact.
So you can see why some people are making Working Planetary gears systems out of 3D printed parts.
Most of the parts for this printer as seen above are printed at between 10% and 15% - for prototyping purposes. By the time I finalise a design I bump the in-fill up a bit and also decrease the print speed slightly (for instance for Gears where precision is key.) - the Sleds for the X/Y shafts for instance can be printed faster and at only 10%-15% as their aesthetics are not key, so a few little imperfections here and there are not a problem, and the Forces on them are very minimal.
The Diamond head Venturi however - due to the proximity to the Print head - needs to be done in ABS, but for me so far that has presented it's own challenges, as yet I do not have an appropriate Build surface to get ABS to stay Stuck to it, the Venturi and bracket I did print are probably my best ABS attempts with the A8, and not too bad...do the point where I installed the Diamond Head on the A8 last night and ran a calibration cube test - it ran flawlessly!
Within this weekend just gone - after printing off the custom bracket to hold the Tool to the X/Y Carriage and moving it to the extremes I have noticed a significant reduction in expected build volume with all the timing belt pulleys, and whole gantry system in place.
Namely it went from the volume of around 500mm x 500mm that I initially had envisioned, to a mere 330x330mm - So I was losing almost half my space due to the Tool placement being off-set due to having both X and Y rods.
Luckily the fact I was able to increase the height in one iteration meant I can now leverage this to get more Overall volume, by sacrificing some height instead, thereby placing the tool(s) directly under the X/Y Carriage - so although I haven't yet calculated total height, it increased X / Y back to about 450mm x 450mm, and I dare say height will be somewhere around 450mm too.
With this being said - the parts I have been printing even in the current iteration, and overall design has a secondary advantage - from a Scale perspective it is not necessarily limited to this. In other words all I need to do is increase the length of the Timing belts, carriage rails, acme screws, frame, and all the existing printed parts can slot straight in without re-design.
Back to my initial Gantry design, although in the marketplace it has some solid maturity in big names, this is a problem you will face when having both X and Y moving gantry, and something which should be considered regardless of design. In that if the design of one element causes you to bend the rules in other areas it needs to potentially be reconsidered.
For instance using X-Y moving gantry means you have maybe 4 options to mount your tool.
1. Off-set the tool to the corner of the gantry - depending on the weight this will add torque in that corner of the gantry and also as I have experienced - massively reduce print volume in both X and Y axis.
2. Place the tool underneath the X-Y gantry - depending on how big your tool is - this could massively decrease your Z axis height. Maybe not so bad for Laser or Milling, but for 3D it isn't ideal.
3. Increase the distance between X guide rods or offset Y guide rod and centralise the tool on one axis - will give the same result of either reduced X or Y axis.
4. Use a design which is More efficient with the space - such as changing from X/Y cartesian to H bot.
5. Increase distance between X and Y axis guide rods, and distance between both X axis rods place tool securely between both X rods with Y rod over the top of the tool.
For me option 5 is only minutes old...and might just enable me to recycle the Single Bearing brackets I made earlier, I can mount them Above the current frame-work which gives around 100mm extra height. I measured
I am looking at the secondary possibility of revising this into a H bot design - which removes the need to have the Y rod over the top, thus meaning I can have the tool sit in between two X slides. I just don't like the Excess use of timing belts in the traditional H bot, so will look at re-inventing the wheel if and when I need to...haha.
**I Will be adding a lot more images as I go as well as the source files for Final printed pieces.
As mentioned timing is often my enemy, so instead of waiting for T slot extrusion to be available and/or shipped I went for a close alternative, it's called Connect-IT and is available from Bunnings here in Australia, they always have tons of it, in varying sizes. In particular they have standard metric sizes of 450mm, 600mm, 900mm and longer.
They also have all the connectors to join them together (mind you for one lot of the connectors I had to store hop due to incorrect stock values - looks like people have a habit of mixing up the pieces in the small bins they sit in, and since Bunnings now do self-checkout, these small items easily go walk-abouts.)
So - after picking up 16 x 600mm aluminium extrusions 8 corner pieces and 4 x 4 way connectors, and cutting up a couple of pieces I already had to make some shorter 150mm pieces. It took me no longer than 10 minutes to soft mallet the frame together.
Next as far as the Frame goes - was the 25mm x 50mm Aluminium tubing used as supports for the Z axis stepper motors - these have undergone a further change to get the motors Underneath the tubing - and also changed to 3 steppers rather than 4.
BUILD PLATFORM (not build plate - just the Platform which forms the Z axis - which will then have a "Build Plate" on top of it.)
Here I found conflicting or rather lack of hard argument as to why I should use 3 over 4 motors, but after a bit of thinking and quick plane vector mathematics:
I decided 3 was more optimal - because even though it is a Square, it acts in 3 dimensions, X, Y, Z. With 3 motors to adjust Z heights you only need to move one motor at at time to act on each plane (prodominately Z.) If you had 4 motors, you would need to move either 2 at a time or 3. If you only moved 1 - at least two other points act as an anchor and prevent the movement, thereby twisting the plane.
BEARINGS, RAILS, SCREWS (Platform cont.d)
I have seen several people reference possible needing to have bearings for their lead screw attachment to the build plate, or on their Z guide rails when using similar moving z axis plates. With my leadscrews and lead Screw nuts - there is enough play between the nut and Screw to allow for the slight twist, where in testing I have had the build platform upwards of 50mm difference in height without causing too much torque on each of the other screws - the worst would be having them move to a point where they jammed - I figure if you have to adjust the build plate more then 50mm in height anywhere, you would probably be best getting rid of the cooking wok build plate you are trying to build on!
The Stability of the plate itself is handled by the vertical shafts situated along side the lead screws
(Image here showing Build plate Mounting block for Lead Screw nut and 10mm Linear bearing for Z axis stabilising shaft.)
Again using the concept of a well known brand - referenced by Keith Davis in his design - I was able to closely resemble his setup half through seeing his design on the basis really of evolutionary theory. Namely that given a certain number of conditions, no matter where and what life and technology will evolve similarly through requirement.
For instance if the Wheel was not invented by whom-so-ever it was, eventually it would have been by someone else, we often use the term "You wouldn't reinvent the wheel" - because for all intense of purposes, it is what it is and although styles and aspects of it might change to suit purpose, it won't really change from being "round" in nature (I say "round" in case anyone wants to argue the use of Spherical wheels) - and this is because regardless of individual design, tread, style, etc. anything circular/spherical will be 100% the most proficient design for said wheel.
** I will be updating the Build, including images and SCAD, SKP and STL files probably this weekend - design files will include Some versions of files too - simply because - feel free to take anything away from this and integrate into your own requirements or ideas. Also - happy to CAD any alterations to any of my existing files if anyone wants any minor changes.
*Example of one file uploaded: XYCarriage-CentreAxis-doubleX-2.skp - this contains 3 Components. 1 is the Gantry carriage, it's Underslung tool sled, and the Anet A8 Diamond Head adaptor, just export each as separate STLs from sketchup to print individually.
As this CNC Build RAMPS up - ok bad pun...live with it... I will be using a Modified RAMPS setup, namely an ATMega256, RAMPS 1.4.2 main board as well as a CNC V3 shield for arduino. along with marlin firmware (I don't need any more than the 5 extruders Marlin handles - even if I go full colour - CMYK.) I can practically drop my existing config for the A8 with MKS1.5 straight in with a few tweaks.
However I intend once this is all working and in place to replace the electronics with something a bit more purpose built. Space is not really a problem with the electronics, so I know I can set the expansion board for Steppers side by side if need be, and moreover re-design a combination board to be effectively a Ramps 1.4 and CNC shield all in one - giving up to 9 steppers, 6 temp sensors, 6 heaters, etc. I initially thought to Drive that it will then just be a Due 32 bit device running at 96Mhz. But I would instead have to re-develop the RAMPS-FD for DUE compatibility, which is a little more complex, and inclusive of SMD - which I am currently not equipped to handle.
As with my current setup it would all still be driven from a Raspberry Pi running Octopi for 3D printing, and maybe other software for other purposes - since for the most part as long as the software knows how to communicate in GCODE it is very universal in this respect.
Ultimately - the design concept is based on a highly regarded name brand unit, for which a regular size costs in the thousands, and one of this size would be edging into the 10's of thousands. It is a X/Y Cartesian printer with Raising/Lowering Z axis (Hotbed.) - Overall size is 610mm x 610mm x 750mm - with build volume of around 450mmx450mmx450mm - and will also have the ability to change work tools - such as for CNC Routing, Lazer etching, 3d Scanning, etc.
- Build License:
- CC - Attribution - CC BY
Reason for this BuildNeeding versatility in a single machine as well as increased build volume. Not to mention the challenge and satisfaction that can be achieved by bringing something to life out of your imagination and into the Physical world, it is a sweet irony that this revolves around 3D printing, and on top of this a 3D printer is used to print a lot of the working parts for the Unit itself.
Qty Part Name Part Link Comments 2 T5-10mm, 5mm Bore Timing Belt Pulley http://www.ebay.com.au/itm/T5-10mm-WIDE-BELT-12T-5mm-BORE... Link 17 Connect-it 25.4 x 25.4 x 1.2mm 0.6m Anodised Alumi https://www.bunnings.com.au/connect-it-25-4-x-25-4-x-1-2m... Link 1 used to Cut into 4 pieces as Extension for Lower section/compartment 8 Connect-it 3 Way Corner Joiner https://www.bunnings.com.au/connect-it-3-way-corner-joine... Link Corner connectors for Framework 4 Connect-it 4 Way Corner Joiner https://www.bunnings.com.au/connect-it-4-way-corner-joine... Link For connecting extensions for Lower Section/Compartment 10 T5 10mm WIDE OPEN PU TIMING BELT per meter https://www.ebay.com.au/itm/T5-10mm-WIDE-OPEN-PU-TIMING-B... Link Cut to length and Secure with clamps and on Sleds, etc. 2 T5 - 10mm WIDE 200mm LONG TIMING BELT https://www.ebay.com.au/itm/T5-10mm-WIDE-200mm-LONG-TIMIN... Link To Run from Drive Stepper to X/Y Shafts 0 6200 2RS 10mm X 30mm X 9mm DEEP GRV BALL Bearing https://www.ebay.com.au/itm/6200-2RS-BEARING-10mm-X-30mm-... Link 3 SF8-600mm 8mm HARDENED ROUND SHAFT - LINEAR RAIL https://www.ebay.com.au/itm/SF8-600mm-8mm-HARDENED-ROUND-... Link X / Y Carriage rails 2 Metal Mate 10mm x 3m Galvanised Steel Round Solid https://www.bunnings.com.au/metal-mate-10mm-x-3m-galvanis... Link Spin the rods in-store to find the Straightest 1 RAMPS 1.4 Kit https://www.ebay.com.au/itm/3D-Printer-Kit-Arduino-Reprap... Link Obviously these kits are everywhere...so pick one that suits price/availability/etc/ 1 3 IN 1 OUT Multi Nozzle Brass Diamond Extruder Rep https://www.ebay.com.au/itm/3-IN-1-OUT-Multi-Nozzle-Brass... Link 3-n-1 Diamond Head for Multi-colour mixing. 1 CNC Shield +A4988 Stepper Motor Driver+Heatsink V3 https://www.ebay.com.au/itm/CNC-Shield-Board-A4988-Steppe... Link Used to expand Steppers on Ramps to total of 9 Steppers, More heaters & fans, etc. 0 Link