Custom Brackets

[JavaRN]

I finally came to my final mod for the RN before I start programming it again. This time I want to make arms 5 DOF. But to be able to do this I want to design two custom brackets so that I can fit two servos together. But I'm finding it very difficult to do so. Today I've spent more that three hours to be able to do one (and I need another )

The way I did it was to design it on my computer as a diagram, then I printed the template and placed it on the aluminum sheet and then I cut the brackets. All works fine until I need to do the holes for screws, some of them don't match exactly even though on paper they are perfectly aligned and to measure.

Anyway, what I would like to know is how you do it, so may be I can do more brackets in less time

Charles

[CaptKill4Fun]

I finally came to my final mod for the RN before I start programming it again. This time I want to make arms 5 DOF. But to be able to do this I want to design two custom brackets so that I can fit two servos together. But I'm finding it very difficult to do so. Today I've spent more that three hours to be able to do one (and I need another )

The way I did it was to design it on my computer as a diagram, then I printed the template and placed it on the aluminum sheet and then I cut the brackets. All works fine until I need to do the holes for screws, some of them don't match exactly even though on paper they are perfectly aligned and to measure.

Anyway, what I would like to know is how you do it, so may be I can do more brackets in less time

Charles

Hi,

Is something like this what you're looking for?



This bracket allows the user to put two RoboNova-1 servos back-2-back ... one bracket on each side of the servo ...

Even though it's arcylic plastic, they're pretty strong using the servo as an integral structural piece of the system.

I figure to sell these about $5/pair + S&H ...

[JavaRN]

No not exactly like this its like the standard ones that come with robonova (the rounded ones), but they have to be the shape of a triangle in the sides. I managed to do two yesterday and I will post a photo of them later on today or tomorrow

[DirtyRoboto]

Is your drillbit slipping on the metal? This may cause the problem you are talking about.

Use a centre punch to mark the holes. drill slow and precise.

[Humanoido]

The first thing that comes to mind when working with printed templates on paper and transferring to metal, especially when I was bending metal, is lining up the holes requires bend compensations for the thickness of the metal in the bend.

humanoido

[JavaRN]

The first thing that comes to mind when working with printed templates on paper and transferring to metal, especially when I was bending metal, is lining up the holes requires bend compensations for the thickness of the metal in the bend.

That was actually the problem. In the template I designed the holes were perfectly aligned but when I bend the bracket they are no longer aligned. So what i did was to first bend the metal then do the holes - this makes drilling more awkward and time consuming, but it worked!

[NovaOne]

I find the best way to design a bracket is to use a package like Autodesk Inventor, to make a 3D model. Then let the software package do the work of "virtually unfolding" the part and to generate a template, that I glue onto the metal plate.

I prefer using a metal hole punch to drilling eg:
http://www.mutr.co.uk/catalog/product_info.php?products_id=452

Also I like to use guillotine and manual nibblers (like part number 86-2150 from:
http://www.rapidonline.com/) in preference to a saw.

[CaptKill4Fun]

No not exactly like this its like the standard ones that come with robonova (the rounded ones), but they have to be the shape of a triangle in the sides. I managed to do two yesterday and I will post a photo of them later on today or tomorrow

Hi,

These brackes are designed to use the alternative end-caps on the HiTec servos so instead of working with the servo horn and triangle attachment points these brackets connect two HiTec servos end-to-end with the servo horns sticking out above the bracket.

Basically, think of the two servo horns sticking out from the big 12mm holes and the 4-mounting body screws of the servo going through this bracket on each servo ...

I find this easier than trying to cut, bend and drill soft aluminum and I think these provide a stronger connection too.


In your RoboNova-1 kit some servos are built with the triangle mount and a fat 5mm hollowed-out servo horn while others have a more traditional style servo horn and a flat end-case ... you can get the kits from HiTec to shift from one configuration to another and when you buy a HSR-8498HB servo the two types of servo horns and end-caps come with the servo.

I don't know how much HiTec charges for end-cap kits, but I'd be very suprised if you couldn't get them from HiTec or a hobby shop.

[Humanoido]

Quick question - NovaOne, did you have a photo post and info about those unique looking grippers?

humanoido

[NovaOne]

Yes.

http://robosavvy.com/forum/viewtopic.php?t=1540

Their advantages are cheapness and the fact that all the stock RN moves still work without being modified.

Chris