Awesome!!! Yeah...I think the right two are defining parallel planes. I would suggest https://youtu.be/Q6_u6FMpCSE but with the carriages on different sides of the rail like you have so you don't get collisions.by nicholas.seward - Look what I made!
2022 is soon. Patents don't prevent your own building adventures. You can also document your work as long as you aren't monetizing it. I think a disclaimer is more than enough in the name of the law. They wont sue anyone unless they actually sale a tripteron.by nicholas.seward - Look what I made!
They might be amenable to a free noncommercial creative commons license. At least they should be. It preserves the ability for them to dual license it for money and it makes them look good. That said it is easy for them to say no because it would require lawyers to do work and it is not risk free. If you have some contacts, I can get the inventor to put pressure on the licensing department toby nicholas.seward - Look what I made!
Arm length needs to be just long enough to reach across the work volume. A smaller angle will allow the arms to be shorter. The flex of the arms is proportional to length^3 so you definitely want to minimize it.by nicholas.seward - Look what I made!
You are correct but I would just use 1 for both and then use the steps/mm to calibrate. The ratio between the two is the real important number and yours is 1:1.by nicholas.seward - Developers
Yes! There are now a few 32 bit solutions that can run 7 dof. I am now really just waiting on some free cycles. This is an eas build but will require custom firmware and a brand new slicer.by nicholas.seward - Delta Machines
There has been an order of magnitude more feed back coming from Google+ so I will not be posting here except to answer peoples question. Google+ Collection This is a link of all the work I have done so far.by nicholas.seward - Polar Machines, SCARA, Robot Arms
Quotecozmicray Where is the design / build home forum for Helios? A place on Concept forge? Please post URL? Hold your horses there little doggie. I put pen to paper 19 days ago. You of all people should know I shouldn't jump the gun on publishing until I have a proven design with great documentation. I am pushing hard on getting the second prototype done that fixes all the problems fromby nicholas.seward - Polar Machines, SCARA, Robot Arms
FIRST PRINT!!!!!!!!!! Here is my second print.by nicholas.seward - Polar Machines, SCARA, Robot Arms
On my current prototype all belts are gt2 6mm 250 teeth. They are fairly easy to find.by nicholas.seward - Polar Machines, SCARA, Robot Arms
Now that I have a my prototype moving, I am making a laundry list of things that should be fixed before release. One huge change is slimming down the arms while making them more rigid. I am still playing with the layout but I thought this picture would help people see how the 4 static steppers can get the job done. For those that are interested, here are some of the improvements I am doing.by nicholas.seward - Polar Machines, SCARA, Robot Arms
Got the arm together. All is smooth and backlash free. I have two more big parts to print and am waiting on belts from China. I should have test prints by the end of this month if all goes well.by nicholas.seward - Polar Machines, SCARA, Robot Arms
@cozmicray You got all of the belt paths right. This image should show you where all the steppers are. The firmware, as mentioned above, is going to be a modified RepRap Morgan firmware which is really just smoothieware.by nicholas.seward - Polar Machines, SCARA, Robot Arms
@Cozmicray: Nice! The colors really help see what is going on. I have a few designs running in parallel. The one I will build first will be the pure belt version. I have ordered the parts for the screw version but there are quite a few reasons that I don't like that solution as much. To drive the hub screw I would still need a large pulley so I opted to keep the super compact quadruple stepby nicholas.seward - Polar Machines, SCARA, Robot Arms
Quotegrean2007 It is interesting to look at the cuts along the axes of the gears, how are they fixed? There are some things missing but here is that cut. I don't know if it makes things super obvious but combining that with the youtube video should get you a full understanding of the layout.by nicholas.seward - Polar Machines, SCARA, Robot Arms
@comicray I actually am using a 6mm rail to save weight. I tried to get a 6mm or 1/4 inch screw but it was an order of magnitude harder to source. The linear rails are nice but you take a hit on weight, compactness, and cost. At this point I think it is just as valid as a design choice but I already have the hardware pictured. Motor spacing works. It is super tight by design. RE Wally: I amby nicholas.seward - Polar Machines, SCARA, Robot Arms
I am also looking at a screw for the Z. I have parts for both ways. I think this way is a bit more compact and simpler design-wise. I am not sure I can get by with only one smooth rod. I have room and for a second if needed.by nicholas.seward - Polar Machines, SCARA, Robot Arms
Can you clarify what you mean by axis of effector?by nicholas.seward - Delta Machines
Quotegrean2007 Interesting design! What firmware is used? I will use the RepRap Morgan firmware with very small modifications to get started. In the end I need the firmware to do lazy automagic arm mode flipping during a print. That will require a trick or two.by nicholas.seward - Polar Machines, SCARA, Robot Arms
I really don't have time to be working on this but my mind is going crazy with this design so I had to pencil to paper. There are a few neat innovations. (I can't say that they are original but it is a beautiful culmination.) It is highly printable.153mm arms similar to RepRap MorganGear reduction similar to RepRap MorganSame kinematics as RepRap Morgan (Well...this can change arm modes butby nicholas.seward - Polar Machines, SCARA, Robot Arms
I am saying that the arm geometry is inherently less rigid than other column deltas. There is very little we can do about that. One solution is to have two screw on each axis with two or three spinning nuts. This will allow you to use the standard 6 arms. However, that is just a more complicated way to do the original.by nicholas.seward - Delta Machines
I don't see how you can use only 3 bearings. To kill wiggle in the z direction I think you would need 6 bearings at least. That said...I found many large enough bearings that can go around the screw for less than $5 which keeps the total bearing cost to $30 which is nothing. Agreed that the rotation of the nut is low inertia but now the carriages have larger inertia. I don't think this will bby nicholas.seward - Delta Machines
QuotePascal68 Hello, If the problem of precision is due to the rotating screws, why not turn the carriage nuts, each equipped with a PAP motor. It allows to have screws of very big section, and more rigidity. I thought about using something like this. The main problem is the screw wobble so this is a great solution. The secondary problem of having horrendous kinematics isn't really an issue tby nicholas.seward - Delta Machines
QuoteApsu Hrm. Not sure how I want to proceed from here, short of machining. Hmm. Now that you have tested a few different directions, figure out the fun gradient and apply a hill climbing algorithm. :-Pby nicholas.seward - Look what I made!
QuoteApsu Alright, round two complete. YouTube Link Small amount of backlash/bounce present still, it's really hard to do this successfully with printed joints. Will have to think about the material design a lot harder. But it's an improvement! With a low enough jerk and acceleration setting, this could make amazing prints. I think you just have to bite the bullet and go with wide joints. Iby nicholas.seward - Look what I made!
Quoteleprud Hello! I'm also trying to buid tripteron. At first i wanted it to be without any linear slides, only trapezoidal screws, but failed to mount arm on nuts, that it won't move, so i had a "leaning" sideways arm, as nuts "tickle" on screw. Of course used two nuts, different rubbers, screws, elongations, etc. Nothing helped.. So i ordered linear slides and this is what i've done today.by nicholas.seward - Look what I made!
Awesome work! Side thought: All of those joints have pretty low angular velocity. A pin joint could perform very well here.by nicholas.seward - Look what I made!
@rsenas: I haven't changed much. I have switch two of my machines from a geared extruder to a direct extruder. Other than that, it works great. The biggest negative of this printer is the resonance that happens when you turn corners due to all the stretch in the string. This could be solved with higher test string. For me, the problem is only cosmetic at higher speeds so I have no motivationby nicholas.seward - Developers