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Ermm to me by arranging the profiles at the top of the 160 side pieces your wasting 80mm of height that could be used to lower the gantry height and increase stiffness or keep as it is and gain clearance.
The gain in having the motors under the bench isn't worth wasting stiffness, also moving the motors to the outside will shorten the belt length.
Also, the slightly elevated sides put the rails up higher and stop debris from hitting them directly and building up against the rail.
Those are some extremely good points..Quote:
Originally Posted by JAZZCNC
By moving the motors to the outside of 160x80 profiles, the belt lengths will be shorter and I will be able to move the 80x80 profiles down 80mm. This in turn will decrease the needed height of my gantry sides by 80mm while also protecting the Y-axis rails.
There is no doubt, I will make those changes. Maybe I could even change the sides to 200x80 and be able to make the gantry sides even lower! Now it starts to turn into a raised gantry design. The drawback will be that it becomes more difficult so access the machine table from the side, when e.g. fastening the workpiece.
Thanks JAZZ!
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Yep there's always going to be some trade off with design like this, you just have to decide which is most important to you.!Quote:
Originally Posted by NordicCnc
Yes.Quote:
Originally Posted by JAZZCNC
If I think about it, side loading would not be too complicated with only 200mm raised gantry sides. You can still reach for all the clamps quite well and large wooden sheets can be loaded from the front.
The purpose of the high gantry sides was exactly for that reason, to simplify side loading. But now when analysing the problem closer, this will probably not have any impact to me at least.
Time to modify the design... again!
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Hello, I like the way you're showing how your design is evolving, it's great for other people to learn from.
I notice your servo mounts for the x axis (long axis) are separate pieces. Could they be combined into the aluminium end plate you're using to hold the profiles into a 90degree corner?
Regards
Bob
Hello,Quote:
Originally Posted by BobTSkutter
Thanks for your feedback! I am glad that you appreciate it.
About the servo motor mounts (the long axis is the Y-axis in my case). The servo motor mounts and the BK15/BF15 bearing spacers are exactly the same as the ones used in the X-axis (gantry). The goal here is to have as few different parts as possible (commonality and re-usability).
Yes, it would surely be possible to have the motor mounts integrated into the end plates. The design of the BK15 bearing plate would perhaps need to look a bit different and. The servo motor axis length and the end plate thickness are the constraints. Machining is needed in the servo motor mounts in order for the motor axis to align with the ball screw (the F-length can be machined longer but the motor axis length can't be changed) and also allow for timing pulley mounting. Too thick end plates or too shallow motor mount machining, will make the motor axis length to short for mounting any kind of pulley. I also like to have the motor mount bracket separated from the machine. This way I can design new brackets later if I want to change the servo motors for some reason, without tearing down the machine itself and then having to realign the axis/ball screw.
Good point anyway and I like your idea. I will have to check the feasibility of this!
If you are bolting into the 80x80 ends through the 160 sides then I wouldn't waste the aluminum on those endplates because they offer very little to the stiffness, There are no forces involved in those areas so they are more cosmetic than structural.!
Quick update based last feedback collection. Many thanks to everyone contributing with their opinions!
- Raised gantry design with 200x80 item profiles. This allows for significantly lower gantry sides and will increase stiffness. It will also protect the Y-axis rails when they are further away from debris.
- 120x80 item profiles as table bracing, bolted through the 200x80 using counter bored holes. Alternatively I will use some item equivalent connectors, but I think bolting through is better in terms of rigidity.
- Motors on the outside, to allow for shorter belts and also lowering the table bracing to the bottom plane.
- End plates replaced with end caps from Item. These are only for aesthetics.
Attachment 27649 Attachment 27650 Attachment 27651 Attachment 27652 Attachment 27653
Next up will be figuring out cable routing and placement of proximity sensors. Is there any significant difference in terms of tolerances when comparing mechanical and optical sensors?
Its coming along very nicely Nordic.
What software are you using?
Thanks Sterob! I am using Siemens NX for CAD. I would probably use Fusion but I am lucky to have a work computer with a NX license. In the future I plan to move to Fusion, to ensure that whatever happens with work, I will still have CAD access, lol.Quote:
Originally Posted by Sterob
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