New aluminum profile for delta like printers, reducing nb of parts

Hello all,
I wanted to build a delta and I found that the v-slot and maker slide were not really designed for delta. We need a lot of extra parts including printed parts. So I start designing a special profil for delta printers based on the same technology than maker slide or v-slot but that will allow to:
-mount the linking profiles with no parts
-mount the pulley with just a t-nut and a shouldered shaft
-mount the switch with no plates : just screws and tnuts
-able adjusting the position of switches
-differenciate mechanical stop from switches as we do in robotic industry : first the limit switch triggers and then if it still not stops it will stops later with the mechanical stop : the limit switch is not a mechanical stop.
-mount mechanical stop
-able adjusting the position of mechanical stops
-precisely have the right length between the vertical profiles

I call that profile a "Delta slide".
as you can see on the pictures below, the swith will not be touched by the v-wheels of the carriage even if it goes to the mechanical stop. (green is when it is not touched, red is the trigger but the lever can be pushed completely against the switch)

I also joined zipped IGES of the model.


So the only required parts would be the motor plate (than be also produced for quite nothing by laser cutting) and the part to link the belt with the carriage : it should considerably reduce the price, put it stronger and even easier to build.

I would like to setup an indiegogo or kickstarter on that if enough people interested. So what I would like to know from you is :
-what do you think of it ?
-is the "step" see on pictures a good idea or not (because if there was no step it would be easy to make it bigger with longer linking profiles).
-doest it worth it ?

Thank you all for your feed back.









DeltaProfileAssembly.zip

My $0.02 is that the economy of scale will not support mass production at a reasonable price point of an extrusion that is only useful for a DIY delta printer. If it could be used for CNC machines, making cabinets, and store display or office cubicle walls, it would be a different story.

The biggest eyesore to me is that you made no effort to cap the ends of the rectangular cross bars where they meet your custom extrusion. Plus, it appears to me that the only way to tighten the T-nuts joining the side and angled extrusions requires drilling precision holes in the side extrusions to slip an allen wrench through.

At then end of the day, I don't see how the manufacturing costs of a custom extrusion by a specialty foundry could ever be cheaper than paying a local "job shop" metal fabricator (or typical high school metal shop!) to punch out a dozen 30-degree sheet metal inside corner braces to hold commonly available rectangular extrusions in the exact same geometry as your custom extrusion. I bet that they could even punch out 60-degree caps to conceal the corners and you'd still be saving significant money.

Just my opinion.....

Thank you very much vreihen for your post.

I agree with you: it's a "niche market" as some business men would say. Delta architecture could also adress CNC : delta CNC heads exist and can be mounted on traditional milling machine to give them additionnal degrees of freedom and digital abilities : that is still a niche market.

To cap the end is an interesting question :
What do all of you say about that : is it required ? some 3D printer have, some haven't.
If it is required it could be adressed either with a larger "step" (compare with initial pictures) to the size of the profiles or with additionnal printed parts that I would like to remove...
Larger step :


For the top of the delta slide, my idea is to put a laser cuted plate over the whole printer
About the price I am asking a local foundry, so I should have an answer shortly. They already told me that the minimum order would be 250kg. So using 700mm length profiles (0.9kg), as we need 3 profiles for a printer, it corresponds to "only" 278 printers.
For the T nuts joining this could be solved either with the larger step as said above because misumi sells HBLBS5 to link profiles. In the other hand Misumi can sell profiles with drills already made for 2.4€ each hole : it would cost something like under 57€ for the whole printer compared to the 48€ for HLHS5.
Finally it may not be so hard to do manually : just have to drill a hole with a vertical driller and a mechanical stop to keep the same position for all of the profiles. Then counter drill for the screw head.
What do all of you would prefer ?

Thank you again vreihen for your comments

I waited patiently to see if anyone else had an opinion, and suspect that the silence speaks volumes about the lack of interest in yet another custom extrusion system that has no use outside of a delta printer/CNC/robot. 80/20 already makes a 60-degree extrusion, and I am wondering if it would be cheaper in the long run to buy that and blind rivet some OpenRail to the inside edge of that for the carriages to ride on since you'll have to drill anyway?

I haven't been part of this community long, but I have the impression that the spirit of RepRap involves designing printers that can be built in even the most remote parts of the world using whatever materials are available in that region. Desktop manufacturing versus mass production. As an example, RichRap built a 3DR using bamboo posts for the supports, to show that it could be done. Having a single-source component seems to be exactly opposite that philosophy, and the fact that it requires mass production may also explain the silence.

My own preference is to make a printer in my garage...that doesn't look like it was made in my garage out of a pile of threaded rods like a Prusa/Mendel. If you take a look at the Cherry-Pi or a few other delta-based printers based on extrusions as crossmembers, it looks like a finished product. It also has some aesthetic value (pleasing to the eye), in that it could be set up in a living room and not look out of place next to a couch and coffee table. This is why I have a pet peeve with unfinished ends and uncapped extrusions.

Anyway, I'm curious to see if anyone else has an opinion to share one way or the other, but I'd say that selling enough to make "only" 278 printers is probably not feasible given the underwhelming response so far.....

May be I posted in the wrong topic to gain wider interest?

@vreihen:your point is interesting. Then why people managed to setup makerslide and v-slot ? They could have done the same result using available guidings. Is it because the price went down ?
If so, with a new "delta profile" there would be even less parts so it should work : why nobody is then interested ?

About making on our own lacking parts vs mass production. I would say that printing parts cost money and takes time. The printed parts to have a delta may be somewhere close to 1kg of plastic ~35€ to be compared to the added cost, if any, of a "delta profile". Not counting advantages of higher rigidity & perfect geometry. The enlarged geometry above doesnt require drilling. Mounting can be achieved with angle brackets at about 2€ each : so 24€... or drilling : 0€ and a gain of 35€.
May be the ratio quality/gain is to low?
Please readers, give us your opinion !
Thank you all !

Quote
erylon
May be I posted in the wrong topic to gain wider interest?

@vreihen:your point is interesting. Then why people managed to setup makerslide and v-slot ? They could have done the same result using available guidings. Is it because the price went down ?
If so, with a new "delta profile" there would be even less parts so it should work : why nobody is then interested ?

About making on our own lacking parts vs mass production. I would say that printing parts cost money and takes time. The printed parts to have a delta may be somewhere close to 1kg of plastic ~35€ to be compared to the added cost, if any, of a "delta profile". Not counting advantages of higher rigidity & perfect geometry. The enlarged geometry above doesnt require drilling. Mounting can be achieved with angle brackets at about 2€ each : so 24€... or drilling : 0€ and a gain of 35€.
May be the ratio quality/gain is to low?
Please readers, give us your opinion !
Thank you all !

Makerslide and v-slot are successful because they can be applied to other applications.

Also, I think making someone drill a hole in an extrusion that is specifically made for an application so that they can use it in that application is asking too much. You might think, "But it's only a hole!" True, it is. But people are lazy, especially consumers.

Lastly, printed parts for a delta do not take a whole KG. Maybe half at most, but that is only a few build like the 3DR.

While I think it is a neat concept, I don't see the advantage of using this over 60 degree extrusions already on the market.

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Hi.
I think your profile will be expencive, and quite difficulte to extrude. If you look at the basic rules of aluminium extrusions construction, you would see that you should aim for even wall thickness, and as few closed openings as possible. At the moment, I think it this profile will be really hard to extrude within the tollerances we need....

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Quote
angelo
[www.item24.de]

This could also replace the dual-top extrusions on the mendelmax I think.