Design Review! Looking for comments / critiques and ideas for my new printer build. I think this is going to be quite a lengthy post so please bear with it! I’ve been working on this design for a printer for a couple of months now and I think I’m almost finished (famous last words) and ready to start ordering parts and building! What I’m looking for some thoughts on the designs and any ideas you can think of to improve the design before I build prototype one! The basic spec for the machine is to be a high quality (but reasonable cost) PLA, single material printer, with a 200 x 200 mm print area (220 x 220 mm build plate). Secondary targets are that it is reliable and easy to use (auto-level), low noise and reasonably compact. I have opted to use linear rails across all axis for the rigidity and smooth motion. I plan for this to be open source once I have created the first prototype. [b]Here is the general design: ([url=https://imgur.com/a/DXAob3c]Image[/url])[/b] [list] [*] Core XY – lightweight printhead for quick printing (still not added the AB Drive mounts) [*] 3030 frame – very rigid [*] Enclosed electronics [/list] So here is the spec, specific design and thoughts. [b]Print head: ([url=https://imgur.com/a/nKOnQn3]Image[/url])[/b] – Still a work in progress, need to add the BLTouch and more effective exhaust vents [list] [*] E3D V6 with Bowden, with titanium heat-break, silicone sock. – Titanium gives a sharper definition between hot and cold and strengthens the hotend. [*] BMG extruder – dual driving gears for ultimate grip and gear reduction for more precise filament movement. [*] Two 4010 blowers for part cooling [*] One 3010 cooling fan for the V6. [*] BLTouch – mechanical auto levelling so any print surface can be used and minimal inaccuracy. [/list] [b]X Axis: ([url=https://imgur.com/a/eiCj5H0]Image[/url])[/b] [list] [*] MGN9 rail running across 5mm plywood beam – Hopefully very rigid. My main concern with the current design is twisting in this axis - any thoughts? [/list] [b]Y Axis: ([url=https://imgur.com/a/JXxuaDo]Image[/url] - Upside-down)[/b] [list] [*] Dual MGN 12 rails bolted to frame [/list] [b]E Axis: ([url=https://imgur.com/a/c1pE9l9]Image[/url])[/b] [list] [*] Tensioner built into the head mount allows for individual tensioning so you can square up the X perfectly. [/list] [b]Z Axis: ([url=https://imgur.com/a/8kI5gKr]Image[/url])[/b] [list] [*] 4 MGN12 linear rails mounted to the frame [*] 3 lead screws in a triangle – fully defines the bed plane [*] Belted Z screws – all three screws belted together to prevent misalignment of the Z platform. - A touch concerned about tooth engagement on some of the pulleys but its apparently within spec. [*] Tensioner to be designed. [*] Single motor drive – no worry about motors running out of sync [*] Antibacklash Nuts (mounted side down) to seat the bed perfectly at all times. [/list] [b]Bed: ([url=https://imgur.com/a/Ta4CJRz]Image[/url])[/b] [list] [*] Mk3a PCB heated bed – Reliable non-mains heating. [*] ULTRABASE glass tile clipped on top – Gives great adhesion and good flatness - (I may opt to use a silicone heater bonded directly to the Glass tile) [*] 2020 frame for mounting the bed [/list] I may look at seating the bed on a kinematic coupling to allow thermal expansion without over-constraining however the glass has extremely small thermal expansion and any expansion can be compensated for with Z probing. [b]Frame: ([url=https://imgur.com/a/xkbwPFy]Image[/url])[/b] [list] [*] 3030 Frame – very rigid [*] Corner plates – keeps frame square and rigid. [*] Blind joints – bolting directly into the end of each extrusion to give good metal on metal connection. [*] Printed Feet (PLA to start, TPU one day) – A little vibration insulation and less scratchy on the table than bare extrusion! [/list] [b]Electronics:[/b] [list] [*] 24V System [*] Duet wifi controller with TMC 2660 drivers (I know you're here somewhere DC42 - I cant get enough of the duet, its great) [*] Sonoff Smart switch for remote mains control and auto power off after longer prints. [*] RGB skirt and part lighting to indicate printer mode (Red = Heating, Blue = Printing / idle etc) [/list] I’m really interested to hear what you think of the design and any comments / suggestions you have. I also don’t have a good name for this thing yet (thus PRINTER). If you have any name suggestions, I’d love to hear them! ([url=https://imgur.com/a/ff3wI4P]If youre interested you can see how the design has developed here[/url]) https://reprap.org/forum/read.php?1,839559,839559#msg-839559 Mon, 08 Jun 2026 11:01:10 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?1,839559,848085#msg-848085 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,848085#msg-848085
The evidences you provided are everything but evident and challenged by a few here, not just me.
To demonstrate it on your machine, that would be an evidence. The rest is just opinions.

Strange but all great designs that just start as a computer rendering never complete ???? Reality is such a bitch !]]> MKSA General Wed, 27 Feb 2019 05:40:21 -0500 https://reprap.org/forum/read.php?1,839559,848018#msg-848018 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,848018#msg-848018
I have been working on this slowly but due to some personal things its had to take a back burner for a short while.

Its had some major (and some minor) changes and is what I would say is nearly ready to build with the potential to be a very nice printer. A specific 'system' has been taking up a lot of my time (more than expected) but results are extremely promising from the test machines Ive had it run on so that is relatively exciting.

Im not sure how you want me to prove the benefits of spring based tensioners - the evidence is already out there and we discussed it before, even in that post you linked. I'm not really interested in taking this discussion further (here or elsewhere) because I see no benefit to it - I have already outlined the key points which you seem to fail to acknowledge, find some pedantic argument around, or completely dismiss for your superior knowledge.

And yes I agree it should be moved to the CoreXY Section but like I said before I dont know how to do that so repeating yourself doesn't really help.

It is unlikely I will be posting any further updates to this project on this site - It seems that unfortunately the userbase interested in constructive discussion is very small and outnumbered by those intent on derailing and discouraging. (I am of course not referring to this thread exclusively)]]> Ed3D General Tue, 26 Feb 2019 14:04:16 -0500 https://reprap.org/forum/read.php?1,839559,847958#msg-847958 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,847958#msg-847958
Just curious. Indeed I would have liked you back up your claim about the benefits of belt spring tensionners on it.
ref: [reprap.org]

This thread should be moved to the Corexy section for easy follow up.]]> MKSA General Tue, 26 Feb 2019 02:32:37 -0500 https://reprap.org/forum/read.php?1,839559,841202#msg-841202 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,841202#msg-841202
Im not sure I follow what you mean about fusions sketching. My experience is mostly in Solidworks but I use NX a lot as well. I dont think part modelling is actually too bad in fusion but I make a lot of use of the gestures in Solidworks and the ribbon toolbar is excellent for quick access to tools.]]> Ed3D General Wed, 12 Dec 2018 17:13:31 -0500 https://reprap.org/forum/read.php?1,839559,841194#msg-841194 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,841194#msg-841194
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Ed3D
In terms of print speeds I'm not looking for anything super fast but something reasonable would be good. Obviously its a bit of a sliding scale where increasing print speed typically decreases print quality but if I can get something good at around 75 - 80 mm/s that would be great.

That isn't that fast in relative terms, I would just stick with a 2020 aluminum extrusion for the X, as your carriage is likely to be quite sturdy (i.e. no round rods). Maybe others can chime in here.

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Ed3D
I've never got on with Fusion 360 for modelling but use it semi regularly for CNC tool-paths (less so now that I no longer have my CNC though). I find fusion struggles with larger assemblies, especially when it comes to making changes, and the UI is quite slow compared to what I'm used to.

I find part modeling in Fusion 360 much better than Solidworks now (long time user of Solidworks too), mainly due to how the sketch just adds features to the face, that can then be independently selected for extrudes.

I agree on the assemblies though, changes aren't as easy to make, and it can go sideways quickly. If I deviate too far from the original intent, I just start a new clean assembly.]]> gmedlicott General Wed, 12 Dec 2018 15:50:43 -0500 https://reprap.org/forum/read.php?1,839559,841170#msg-841170 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,841170#msg-841170
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gmedlicott
The outer Z bracket dimensions also look good, enough to compensate for slight rail miss-alignment but still stiff enough.

The brackets are going to be designed to slide in and out to compensate for rail spacing and also potentially allow the carriage to rotate +/- 2 deg or so to allow for rail alignment. On the design with the central Z rails the whole aluminium extrusion of the bed frame would slide in and out being held in with corner brackets (not pictured). So either way the rail alignment was compensated for! My only concern is the massive amount of space those brackets fill but I think that's because it reminds me of cantilevered beds, which this wouldn't be.



In terms of print speeds I'm not looking for anything super fast but something reasonable would be good. Obviously its a bit of a sliding scale where increasing print speed typically decreases print quality but if I can get something good at around 75 - 80 mm/s that would be great.

For this project I'm using Solidworks for the CAD. The images are taken from the PhotoView 360 add in which I believe is being made obsolete this year in favour of their new rendering solution. I am by no means the best at rendering but the defaults seem to give semi decent results! I've never got on with Fusion 360 for modelling but use it semi regularly for CNC tool-paths (less so now that I no longer have my CNC though). I find fusion struggles with larger assemblies, especially when it comes to making changes, and the UI is quite slow compared to what I'm used to.
]]> Ed3D General Wed, 12 Dec 2018 12:30:11 -0500 https://reprap.org/forum/read.php?1,839559,841096#msg-841096 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,841096#msg-841096 gmedlicott General Tue, 11 Dec 2018 17:13:22 -0500 https://reprap.org/forum/read.php?1,839559,841090#msg-841090 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,841090#msg-841090
What print speeds are you aiming for? If it isn't super fast, the moving mass of the XY is more of a red hearing if your linear guides are stiff enough.]]> gmedlicott General Tue, 11 Dec 2018 16:23:33 -0500 https://reprap.org/forum/read.php?1,839559,841083#msg-841083 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,841083#msg-841083


I'm playing around with the idea of moving the two rails to the rear frame members to allow me to mount the Y rails on the underside of the extrusion. The benefit being I can run the belts under the extrusion which will drop the overall printer size and then use a system similar to the blackbox printer. The two rails at the back will prevent C rotation and XY translation the other degrees of freedom being handled by the 3 screws. Having the screws along one edge like that gives a need for a slightly more rigid bed frame but it should be ok. It's not quite cantilevered due to the two screws at the front. Idea like so: (excuse the terrible block brackets)



Thoughts?

I'd quite like to explore the carbon fibre square tube for the X axis that the blackbox uses.
]]> Ed3D General Tue, 11 Dec 2018 15:35:35 -0500 https://reprap.org/forum/read.php?1,839559,840520#msg-840520 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840520#msg-840520
Any drawing, prototype ?]]> MKSA General Thu, 06 Dec 2018 02:25:43 -0500 https://reprap.org/forum/read.php?1,839559,840499#msg-840499 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840499#msg-840499
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gmedlicott
I like the maglev 2020 X axis!

Me too - Design is so much easier when all the parts are maglev. The current plan is to print a bracket thing that holds the 2020 and the idlers.

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gmedlicott
A note on the frame extrusions, 3030 is obviously stiffer than 2020, but compression or torsion is not the main concern here (for the cubic outer frame), racking is. 2020 extrusion with a diagonal brace on the face is orders magnitudes stiffer than 3030 with no brace. Think triangles instead of squares that can collapse.

Oh absolutely a triangle is miles better. I'm not sure how I'd get them in though because its a bit of a tolerance stack-up issue and its pretty hard to cut the V shape you would need on the end. Perhaps there's a way to make them work though - I'll have a think about it. Even If I can put one across the back it would help a load, the vertical pillars will get in the way of the sides.]]> Ed3D General Wed, 05 Dec 2018 17:07:59 -0500 https://reprap.org/forum/read.php?1,839559,840487#msg-840487 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840487#msg-840487
The 2 rail, 3 lead-screw Z axis is a popular arrangement that seams to work well (still over-constrained in multiple directions, but the Z should travel and build plate should always be perpendicular, so less of a concern).

I like the maglev 2020 X axis! When you do mount it to the rails, use plastic (3d printed or machined) to take up the slight possible Y axes out of parallel.

A note on the frame extrusions, 3030 is obviously stiffer than 2020, but compression or torsion is not the main concern here (for the cubic outer frame), racking is. 2020 extrusion with a diagonal brace on the face is orders magnitudes stiffer than 3030 with no brace. Think triangles instead of squares that can collapse.]]> gmedlicott General Wed, 05 Dec 2018 15:22:11 -0500 https://reprap.org/forum/read.php?1,839559,840477#msg-840477 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840477#msg-840477
Seems that you still have a lot of parts to make though so good luck!]]> Forum-Layman General Wed, 05 Dec 2018 12:35:29 -0500 https://reprap.org/forum/read.php?1,839559,840355#msg-840355 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840355#msg-840355


The main changes are:

  • Removed frame brackets
  • Changed to curved extrusion - because they look nice :P
  • X Axis now uses a 2020 profile as a backing
  • 2 Z Rails, 3 Leadscrews
  • Considering using piezo instead of BLTouch (for packaging mainly)
  • Considering switching to the threaded V6 instead of groove mount for easier mounting
  • 3 Point bed levelling

Things still to work out:

  • Belt tensioner
  • Access to electronics
  • A B Drives
  • Most brackets
  • Better belt solution in the basement
  • ABL sensor integration
  • Cable routing
  • much much more

]]> Ed3D General Mon, 03 Dec 2018 16:59:19 -0500 https://reprap.org/forum/read.php?1,839559,840185#msg-840185 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840185#msg-840185
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MKSA
Is the acceleration in the Z direction ? Etc...

ah - I see the confusion, I've mixed up my axis as I typed up my response. Weight acts down in Z as does gravity, acceleration in Y. The CAE package I use uses Y as the vertical axis so when typing up I forgot to convert back to sensible axis.

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MKSA
Anyway, at least you seem to give up on the cut wood/plastic sheet to reinforce the linear rail.

The plywood / plastic was never intended to reinforce the linear rail - I'm not really sure where you got this idea. It was simply a neat way of mounting one rail to the Y axis blocks - in terms of deflection there is no difference between the rail on plastic / wood and the rail on its own except the rail on a backing has the extra holes for mounting it a bit easier]]> Ed3D General Sun, 02 Dec 2018 10:13:13 -0500 https://reprap.org/forum/read.php?1,839559,840178#msg-840178 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840178#msg-840178 is the 300g weight for carriage (hot end included ?) the 3N in Y direction ?, NOT "Is the hot end included ?" () are there for a purpose.
Is the acceleration in the Z direction ? Etc...

Fact is, you are not clear as to the mass, force, accel per axis.

Anyway, at least you seem to give up on the cut wood/plastic sheet to reinforce the linear rail.

" I pulled that number right out my arse ... " Computer Arse Design. Interesting approach, strange results though. Note the 24V and the Duet are good choices. Different diet ? :)

I am done.]]> MKSA General Sun, 02 Dec 2018 09:03:02 -0500 https://reprap.org/forum/read.php?1,839559,840165#msg-840165 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840165#msg-840165 
I beam:           91.42 grams.       2.81 microns max deflection.
Box Beam:         116.64 grams.      1.33 microns max deflection.
2020:             136.12 grams.      1.50 microns max deflection.

So from worst to best, I beam, 2020, Box beam like you suspected!




Edit for MKSA's questions:
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MKSA
May be, just some clarification please.

Why is the 300g weight for carriage (hot end included ?)

Because I pulled that number right out my arse based on what I guessed the weight would be. 110g V6 (inc wires), 80g per fan (2 of) and some plastic (30g). Its kind of irrelevant though when comparing options as you're looking at the difference but if you have a better suggestion for weights and accel I'm happy to re run the analysis.

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MKSA
the 3N in Y , the 3m/s² requires indeed 0.9N but why added to gravity in Z ?

Because my printer will be operating on earth not the ISS (budget constraints).

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MKSA
How is the total deflection computed ? And where ?

Total deflection is URES calculated at the most extreme point - not wholly representative but a good representation.
]]> Ed3D General Sun, 02 Dec 2018 06:18:27 -0500 https://reprap.org/forum/read.php?1,839559,840164#msg-840164 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840164#msg-840164
May be, just some clarification please.

For ex. Why is the 300g weight for carriage (hot end included ?) the 3N in Y , the 3m/s² requires indeed 0.9N but why added to gravity in Z ? ... How is the total deflection computed ? And where ?

At least, some progress compared to the cut wood or plastic sheet as rail "stiffener"]]> MKSA General Sun, 02 Dec 2018 06:12:18 -0500 https://reprap.org/forum/read.php?1,839559,840160#msg-840160 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840160#msg-840160
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mcdanlj
My chiwin rails ran better (smoother, less resistance, more consistent) after I attached them to 2020 (using a very tight jig to make sure they were parallel all along the length) than they did unsupported, for what it's worth.

That's useful to know, i guess there isn't much room in the carriages to account for deflection.

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mcdanlj
Hardware store aluminum in my experience is usually pretty soft. Around here, 6061 is the most widely available strong alloy.

Plenty soft but I think my issue will be squareness and location - i dont have a pillar drill currently which would be ideal, so hand tools it is....

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o_lampe
Interesting numbers!
But torsional forces are not neglectible, when you mount the extruder to one side of the Y-beam/rail.
I guess, in that discipline the square tube finishes second compared to T-slot and the I-beam is third?

Yeah - not any easy back-of-the napkin maths for including torsion though. I'll look at running another FE study later on but I'm not sure what the result will be because you have to consider beam weight as well as carriage weight and beam shape.]]> Ed3D General Sun, 02 Dec 2018 05:24:52 -0500 https://reprap.org/forum/read.php?1,839559,840152#msg-840152 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840152#msg-840152 But torsional forces are not neglectible, when you mount the extruder to one side of the Y-beam/rail.
I guess, in that discipline the square tube finishes second compared to T-slot and the I-beam is third?

Unfortunately the filament path usually doesn't allow us to mount the extruder below the beam...

[OT] Just got inspired to make T-slot extrusions from prepreg-carbon, but that's just a dream]]> o_lampe General Sun, 02 Dec 2018 03:01:21 -0500 https://reprap.org/forum/read.php?1,839559,840143#msg-840143 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840143#msg-840143
Hardware store aluminum in my experience is usually pretty soft. Around here, 6061 is the most widely available strong alloy.]]> mcdanlj General Sat, 01 Dec 2018 19:43:30 -0500 https://reprap.org/forum/read.php?1,839559,840135#msg-840135 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840135#msg-840135
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the_digital_dentist
I'm not sure what numbers it would take to prove it, but I suspect that square tubing is both lighter and stiffer than an equivalent size t-slot, and you can pick it up at your local hardware store.

You can quite quickly compare stiffness of beams of similar material by comparing second moment of inertia. From the 8020 website (because im not working it out manually for that profile) the 2020 beam second moment of inertia is 6826 mm^4 and from this calculator and for this square tube the tube section has a second moment of inertia of 7872 mm^4 so around a 15% improvement in stiffness.

An I beam is likely the optimal solution. If you put it on its side that gives 7189 mm^4 along the Y axis so pretty comparable to the box section but with a large reduction in weight (around 1/4).

I guess the key question is how much is enough though? The hardened steel rail should be plenty stiff on its own and a quick FE simulation with a carriage weight of 300g and 3000 mm/s^2 acceleration (so 0.9 N of force in the Y direction and 3 N of force + gravity effects in the Z direction) you'll see about 13 microns of sag across the rail (acceptable) and when accelerating/decelerating about 1.57 microns of deflection (also acceptable). That gives 13.2 microns of total deflection. I havent considered torsional effects in that though so that may play a bigger part. You'll likely only notice 13 microns of deflection on the corners of parts (and probably only with a microscope) so the question is - do I put a cross beam in, is 13 microns an acceptable deflection?

Id probably opt to use 2020 extrusion just for simplicity if I do go for one. I would likely struggle to put holes into aluminium I beam with the tools I have. Time to have a think.]]> Ed3D General Sat, 01 Dec 2018 14:24:05 -0500 https://reprap.org/forum/read.php?1,839559,840111#msg-840111 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840111#msg-840111 a function of the relative belt tensions. If you're concerned about the guide flexing, mount it on an aluminum tube. That will increase rigidity without adding a lot of weight.



I'm not sure what numbers it would take to prove it, but I suspect that square tubing is both lighter and stiffer than an equivalent size t-slot, and you can pick it up at your local hardware store.
]]> the_digital_dentist General Sat, 01 Dec 2018 08:30:29 -0500 https://reprap.org/forum/read.php?1,839559,840106#msg-840106 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840106#msg-840106
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MKSA
Would it be possible also to move this in the correct topic, CoreXY, eventually in a sub category "in progress" for follow up.
So many similar projects that get buried in the "general" discussion.

I have no objection to that - but also no idea how to do it.

I've made some changes to the design to incorporate what people have been saying. Will post renders when I finish up some bits.

I'm still working on the X axis though. What do people think about using an unsupported MGN12 rail between the two sides as opposed to either a 2020 beam backing the rail or a wooden/plastic laser cut sheet? Id obviously like the weight benefit of not having a supporting piece behind it but I'm concerned about the deflection and ability for it to stay square to the Y axis.]]> Ed3D General Sat, 01 Dec 2018 07:24:09 -0500 https://reprap.org/forum/read.php?1,839559,840087#msg-840087 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840087#msg-840087
Would it be possible also to move this in the correct topic, CoreXY, eventually in a sub category "in progress" for follow up.
So many similar projects that get buried in the "general" discussion.]]> MKSA General Sat, 01 Dec 2018 00:11:17 -0500 https://reprap.org/forum/read.php?1,839559,840002#msg-840002 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840002#msg-840002
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Ed3D
Does it have to have any advantages? If I wanted a printer I'd just go out and buy one. If I wanted to build something than I'd have posted asking for printer kit recommendations. This for me is about designing something, understanding the mechanics of it and making something that's my own design. It doesn't have to be innovative. You say I should copy other designs that I know work... well that's exactly what I've done - I didn't invent CoreXY, using three lead screws, linear rails on axis, etc etc. A new design doesn't have to break new ground, it can simply be an assimilation of things I like from other designs. This is off topic for this thread though so can we get back to the focus?
I kind of thought that asking about that was a comment on the design, which is what you're asking for.

Unless what you're really asking for is just compliments on the design, which is a different matter. (If I thought that this was it, I wouldn't bother saying anything at all.)

No, you don't have to have advantages to your design, but if there really aren't any, then the comment simply becomes "similar, but inferior to X."

You do, however comment on your choice of materials. okay, aluminum braces will have the same CE to the extrusion. That's a point. You also talk about an available choice of materials. Hey, that's why I did things the way I did, too, it made best use of what I had available to me. You also answer what you see are advantages to the 3030 frame that I did not inherently see. These are answers that I was looking for, which give me a better idea of things that you were looking for. This in turn gives me a better idea of what points in the design I might take a close look at.]]> SupraGuy General Thu, 29 Nov 2018 17:02:59 -0500 https://reprap.org/forum/read.php?1,839559,840000#msg-840000 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,840000#msg-840000
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SupraGuy
In any case, I was asking what ADVANTAGES, not what differences.

I understand well the appeal of designing something different. Other design features were copied and emulated as closely as I was able from known good and working designs, as I felt no need to re-invent parts of the design which already existed and were perfectly adequate.

Does it have to have any advantages? If I wanted a printer I'd just go out and buy one. If I wanted to build something than I'd have posted asking for printer kit recommendations. This for me is about designing something, understanding the mechanics of it and making something that's my own design. It doesn't have to be innovative. You say I should copy other designs that I know work... well that's exactly what I've done - I didn't invent CoreXY, using three lead screws, linear rails on axis, etc etc. A new design doesn't have to break new ground, it can simply be an assimilation of things I like from other designs. This is off topic for this thread though so can we get back to the focus?

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SupraGuy
I'm unsure that the thicker extrusion offers much advantage. I don't think that the 2020 extrusion flexes under the kinds of loads that the printer puts on it. Any flex comes from corner joints. You have addressed that, but then so do many other designs, and I didn't see any innovative deviation there. If anything,I'd bet that the full sheet approach that the Railcore took is ultimately a superior solution in terms of frame squareness and rigidity, and does not have a lot of extra cost to it.


Ive seen quite some flex in 2020 frames but like you say it usually comes from corner joints. I think blind joints go a long way to resolving that. I'm not sure about using 3030 over 2020 but I feel like more cant be a problem - its better to overspec than underspec ( I also quite like how it looks but thats besides the point ). The benefit to 3030 over 2020 that I see is mainly in the better torsional rigidity it gives the frame by giving you a larger contact face and bigger thread allowing you to give it more compression on the joints. This is one of the reasons E3D is using the double width extrusions and switching from 2020 to 3030 is very noticeable on a 300x300 machine.

The issue I have with the full sheet solution is that due to the equipment available to me it would have to be plastic sheets. Thats a problem because of the two materials having different thermal expansion. So either you're stressing the plastic meaning it wont help location and squareness beyond initial setup or your plastic moves in relation to the frame in which case its just an enclosure and not a locating feature. The second issue is that I mainly print PLA so having the open sides for airflow is excellent which obviously the panels block. I think ill probably lose the brackets from the design - its a lot of printing time and plastic for not much (if any) gain.]]> Ed3D General Thu, 29 Nov 2018 16:15:01 -0500 https://reprap.org/forum/read.php?1,839559,839926#msg-839926 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,839926#msg-839926
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Ed3D
So theres a few differences to the railcore - but it did provide a fair bit of inspiration. I think the main differences are the different rail arrangement, the frame thickness, and the 3x lead screw setup

Like dc42 said, the Railcore offers 3X leadscrew motors with individual control for auto-levelling.

In any case, I was asking what ADVANTAGES, not what differences.

I understand well the appeal of designing something different. After all, that's what I did, too. It's based very loosely on the I3 for kinematics, but I was looking for specific advantages over what I had before. In this case, it was more precise control of the print head position, which the leadscrew based movement offered, as well as frame rigidity and enforced squareness. Other design features were copied and emulated as closely as I was able from known good and working designs, as I felt no need to re-invent parts of the design which already existed and were perfectly adequate.

I'm unsure that the thicker extrusion offers much advantage. I don't think that the 2020 extrusion flexes under the kinds of loads that the printer puts on it. Any flex comes from corner joints. You have addressed that, but then so do many other designs, and I didn't see any innovative deviation there. If anything,I'd bet that the full sheet approach that the Railcore took is ultimately a superior solution in terms of frame squareness and rigidity, and does not have a lot of extra cost to it.

You've noted a couple of disadvantages, such as the "no true square" L profile, so what advantages were you aiming for? Did you achieve them?]]> SupraGuy General Wed, 28 Nov 2018 17:31:35 -0500 https://reprap.org/forum/read.php?1,839559,839808#msg-839808 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,839808#msg-839808
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So theres a few differences to the railcore - but it did provide a fair bit of inspiration. I think the main differences are the different rail arrangement, the frame thickness, and the 3x lead screw setup.

Unless I am mistaken, Railcore uses 3 leadscrews too, with a choice of driving them all from a single motor or driving them independently to do auto bed levelling (not to be confused with auto bed compensation, which compensates for the bed being out-of-level amongst other things).

I appreciate that you want the fun of building your own design, but if you start from an existing debugged design instead then you will be able to design truly innovative modifications sooner, instead of fixing issues that have already been fixed.]]> dc42 General Tue, 27 Nov 2018 17:54:15 -0500 https://reprap.org/forum/read.php?1,839559,839758#msg-839758 Re: Design Review! Looking for comments / critiques and ideas for my new printer build. https://reprap.org/forum/read.php?1,839559,839758#msg-839758
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Ed3D
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MKSA
Seeing this, I experience "deja vu" :)
Indeed, in the coreXY thread (and others regarding the misuse of linear rails), plenty of similar request for reviews with pretty much the same design errors.
SO why not first study the couple of machines that have been built and really work well then try to improve eventually on their design or as good but cheaper, easier ....
I know the saying: "we learn more from our mistakes than success". Yet I think we can save time by learning from other's mistakes.

Thanks - very helpful.

You welcome.

[reprap.org]]]> MKSA General Tue, 27 Nov 2018 05:45:04 -0500