RepRap HELIOS is a highly printable SCARA 3D printer. It has an outrageous print area and can print on almost any flat surface.

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Current 3D printing practices never seemed quite right to me. Our tech world is full of amazing robots with amazing capabilities while our 3D printers are usually stuck in a box. I am hoping to do my part to peel that box back a bit and show off some possibilities.

RepRap HELIOS is a 3D printer that uses a SCARA arm while at the same time has no moving steppers. It is tiny, light, quick, accurate, and has a massive print area.

The design is parametric so all of the details can be modified.

Build Area: 5 times bigger than a 200x200mm printer.

Build Height: 100mm

Speed: Prints well at 30mm/s but have printed at 90mm/s with acceptable results. More testing is needed.

Accuracy: Calibration cubes have been shown to be square in all dimensions and dimensionally accurate +/-0.4mm

Precision: It is a SCARA so hard to say and microstepping helps but can't be fully trusted. Let's just say at full steps it is good enough and in practice it is awesome.

Auto Bed Leveling: Yes

Endstops: No. I use a magic accelerometer to fully characterize the machine.

LCD Panel: Yes. Why have I never used one before? They are awesome for standalone printing.

Controller: Smoothieware compatable

Firmware: Heavily modified custom Smoothieware

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  • Brain Fart

    Nicholas Seward05/01/2017 at 20:14 16 comments

    I have been furiously working to get out v0.2 that fixes many of the issues I found in v0.1 (the first prototype). I did a fair bit of design work in Autodesk Inventor because I am most comfortable with it. Once I felt good about the design, I moved over to Onshape and started remodeling the design but this time I made it highly parametric. The idea is that you can change a few parameters to make the parts suit your on hand components and personal goals. Everything was going well until I took a break to work on the kinematics of the new layout. I immediately found a core flaw that caused the whole redesign to fall apart like dominoes.


    Can you see it? The bottom belt can't do anything. I swear I thought about this being a problem and then figured a solution around it but here it is. I have a solution for this but I have to start from the ground up again. This design is very interdependent and all the parts have to work in concert. I actually like the new direction better but it has delayed me a week.

    I am obviously still working on the design and am not ready to publish step by step instructions for this project. However, in a show of good faith, I have uploaded my working prototype files and firmware. I can't stress enough that no one should build it directly. There are some easy things that could be fixed. (belt tensioners, fixed arm lengths, increased mechanical advantage, plastic reduction)

    Prototype Files

    Warning: I provide the files as is. Please don't build this version. If anyone decides to build a HELIOS from these files, they will be on their own. I am working furiously (with precious little free time) to finish v0.2. I will gladly provide support for v0.2 builders. Any time that I have to spend supporting a v0.1 build will take away the time I have to devote to v0.2.

  • Adventures in Firmware

    Nicholas Seward04/24/2017 at 03:56 2 comments

    Alright. Lot's to cover here so let's dive in.

    This printer requires quite a special firmware package. I have been modifying Smoothieware but there are a lot of bells and whistles I had to add. Here is a short list.

    • Lazy arm mode switching (when you get to a place where the current arm mode can't go...switch but don't switch back until you are forced to.)
    • Machine coordinate moves when rapidly moving. (Say you move from one side of the build platform to the other. The quickest way is to swing the arm in an arc instead of going in a straight line.)
    • Codes for setting machine coordinates
    • Homing with a common end stop (accelerometer)
    • Incremental bed leveling (The bed is 5 times bigger than a normal 3D printer and you can reach most of it in 2 arm modes so the probing required is 10 more than typical. To combat that I have come up with a way to probe as you need where ever you need.)

    As of now, all of these items have been prototyped and put into firmware with the exception of the accelerometer probing. I have only done an offline proof of concept of the accelerometer probing but I am convinced it will work. Check out these videos for more details.

    It has been a wild quick ride. I will leave firmware for awhile to help let my brain recouperate. I am now on finalizing RepRap HELIOS v0.2. I hope to order parts tomorrow and have it working by the following week.

  • Background

    Nicholas Seward04/22/2017 at 05:16 0 comments

    I put pen to paper just 19 days ago. It has progressed faster than I would have ever dreamed. I would have posted more here but I didn't even know about this until a few days ago.

    I teach at a residential high school in Arkansas for gifted students. I had one of my students work on a 1-arm SCARA mockup that has been bouncing around in my brain since the first time I saw a RepRap Morgan.

    The results where more than promising. We quickly started making plans to turn it into a 3D printer. My intention was to bring my student along on the design journey but I was a dog with a bone and I could now see what this could be. I cranked up AutoDesk Inventor and quickly cranked out this.

    I ordered all the vitamins and started printing all parts. I quickly got a functional arm together.

    I then set to work on making the firmware take care of the kinematics. Shortly thereafter, printing!

    I have taken it so much further than this but I think this is a good place to wrap up the first post.

View all 3 project logs

Enjoy this project?



marty.swartz wrote 15 hours ago point

So, you know how happy your dog is to see you when you've been away for a while? It's because they were worried that you were eaten by a larger animal.  

I fear that Nicholas has been Borged by Makerbot. 

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sander wrote 2 days ago point

Hi Nicholas, i hope all is well with you?

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Nocturnal wrote 2 days ago point

So any chance of a quick update Nicholas? Even if it's just to let us know you are indeed still among the living.

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Luke C. Ruppersburg, Jr. wrote 05/30/2017 at 08:04 point

I was quite a fan of the Simpson printers, and now that I'm considering building a printer (partly as a learning experience, partly to get a better understanding of 3d printers, partly because I want a very large build volume printer for cosplay and other stuff) I decided to see if any advancements had been made on the simpson printers. I check your youtube channel and see this thing and wonder if it's yours... yep, it is. Yep, it's amazing.

When files are available I'll definitely build one just to see how it is. Until then, I'll have to research core XY designs and maybe try and set up a small simpson printer. 

What sort of costs are you expecting for this printer? Is it going to be as low vitamin as the simpson?

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marty.swartz wrote 06/05/2017 at 15:46 point

Watch all of the project videos. Indeed there are very few vitamins. I recall in some previous comments that Nicholas was predicting a built cost of $600. We shall see.

HEY NICHOLAS!   It's June now, time to let her rip!

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marty.swartz wrote 05/26/2017 at 00:59 point

*crickets*   ....very -WATCHFUL AND EAGER- crickets out here waiting with their bated cricket breath.

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Peter Stojcsics wrote 05/25/2017 at 16:15 point

Can't wait for the 0.2!

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Robert Chave wrote 05/19/2017 at 22:55 point

Nicely done. A portion of this may work well for a colleagues need for a small, low cost, limited life, pick and place robot.  

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Klaverentwee wrote 05/19/2017 at 18:15 point

I just love this idea and will definitely build one. I especially love the high level of RepRap DNA and low level of vitamins. Have already started to source some parts I don't see changing. 

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alkarpinsky wrote 05/18/2017 at 19:12 point

hope you've seen this:

Relevant due to the 3d printing attachment.

I personally think HELIOS is a better design in everyday but I DO like the Z axis movement on this Evezor

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Nocturnal wrote 05/18/2017 at 09:18 point

I can't wait for this... seriously I can't wait... Hurry up! :-P Welcome to the instant gratification era.

I've been doing a little shopping for suitable parts during the last two weeks, and I notice you haven't listed the accelerometer that you are using. Is that because your still not 100% on using it?

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marty.swartz wrote 05/15/2017 at 01:27 point

I'm looking at this device, and thinking that it has the highest RepRap "self-reproducibility" factor I've seen yet. There are SOME vitamins we can't escape - steppers, processor, pusher, hot end, power supply. Helios seems to need very few manufactured parts beyond that. Belts, stepper hubs, just TWO smooth rods, bushings, flex wiring, and a bolt. (Oh, add the accelerometer, but lose all end stop switches - a worthy tradeoff.) Very impressive! Can't wait to see v0.2!

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Ninjalicious wrote 05/12/2017 at 00:22 point

Hey Nicholas, can you post STEP files in your next part file update? I'd love to a crack at the design in SolidWorks. Love the progress and the project mate!

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alkarpinsky wrote 05/10/2017 at 18:38 point

I've been following this for a few weeks now and CONGRATS on the lackaday prize nomination!

Hope this keeps moving along! I'm keen to build!

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zacldoyle wrote 05/08/2017 at 01:25 point

Firstly, great project. Secondly, I wanted to ask if you had explored other ideas for the Z-axis? Most machines of this nature incorporate the Z-axis at the head of the unit. However, your machine happens to be rather unique in allowing many other z-axis solutions. 

Personally, I'd suggest trying a scissor lift stage mechanism such as this:

Maybe this project would be too heavy for this mechanism to be created out of the plastic being extruded but I think it may be worth a shot since this could significantly increase your Z-axis.

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Nicholas Seward wrote 05/08/2017 at 01:28 point

I am really looking forward to people's modifications to this design.  I want to give a hackable framework that is easy to jump off of.

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zacldoyle wrote 05/08/2017 at 01:30 point

Fair enough. Thank you for your contribution to a better society!

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alkarpinsky wrote 05/10/2017 at 18:12 point

I was thinking of something similar for raising the 'arm' off the home mount to increase Z height of the entire arm (this would increase the build envelope), and then use the current Z height setup for fine tuning/ layer height for printing. 

I checked out your link and this looks like a good solution. Maybe not for this application, but I think it's still good solution for many problems found in 3d printers with Z wobble / multiple lead screws and syncronisation. I wonder why it hasn't been used before? I know for certain there is a thingiverse file for a similar scissor lift

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theodonkulus wrote 05/03/2017 at 17:59 point

NIce work dude! I may build this using the dead Ormerod 2  I have laying around in parts  now :P. Think this firmware can be run on a DuetBoard?

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Nicholas Seward wrote 05/04/2017 at 15:20 point

This firmware won't run directly on a Duet but I am working with the main contributors for the RepRapFirmware.  They have plans to add support for it among other non-Cartesian printers.

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sander wrote 05/01/2017 at 19:09 point

Oh men, can't wait. Nice nice Work
Would it be too impatient to ask for a small list of -vitamins- so we could already start raking/sourcing those ball-bearings, belts, and bolts?

Probably :)

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Nicholas Seward wrote 05/01/2017 at 20:28 point

The BOM has been changing internally on an hourly basis.  I really wish I could have it nailed down at this point but it is still highly in flux.  Just to give you and others a basic idea of what the problem is here are thoughts on specifics.

Belts: I am playing with mechanical ratios and belt tensioning schemes all of which invalidate any belt choices.  I will also give you the choice of the exact tooth counts for the pulleys which will make your belts unique from others.  The cool thing is by adjusting some lengths and tooth counts you can make a belt you have work.

Steppers: My goal is to make it work with any normal sized NEMA17 but depending on the mechanical advantage the steppers may need to be 0.9deg/step.  If you want to get steppers that are sure to work get 34mm-40mm 0.9deg/step NEMA17 steppers.  That said...I fully expect this design to work with generic $6 steppers and still have a better resolution that my prototype has with the fancier $12 steppers.

Bolts: Your choice of steppers drive many bolt lengths.

Rods: If you have 8mm rods in the 170mm-200mm range then you are golden.  The bearings will be two LM8LUUs.

The electronics and hot end are listed above.

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VuiMuich wrote 04/28/2017 at 21:03 point

Very nice and looks so clean and versatile.

Might be actually be some nice base for a laser engraver/cutter as well, especially when already using the Cohesion Mini..

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Nicholas Seward wrote 04/28/2017 at 23:49 point

I can't wait to use a laser on it.  

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Hamtastic wrote 04/28/2017 at 10:26 point

This is awesome, I toyed with a similar idea a while back but couldn't get my head around the maths required, and didn't want to splash out on the Smoothieboard without being sure I'd get it right.

I'll definately build one of these when you release the files, currently toying with the idea of mounting it on a glass table with some sort of heater underneath for a huge heated bed :)

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Morning.Star wrote 04/27/2017 at 17:03 point

"Outrageous print area" :-D 

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cozmicray wrote 04/27/2017 at 15:45 point

Conceptforge would be much better environment for project

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Nicholas Seward wrote 04/27/2017 at 16:39 point

ConceptForge is no more.

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