This is the project log for my next machine.
This next machine will be built with the lessons of previous mistakes in mind.
While my first machine is/was successful there are a few annoyances that I wish to illiminate in the second machine.
- The first machine does not take a standard sized sheet of MDF
- It has rails on the sides that make putting the work onto the table a bit awkward. I want a table where I can slide a sheet on.
- It does not have limits switches or zeroing swithches.
- The X axis is belt driven from one side only. I plan to have a drive shaft through the gantry and drive it from both sides.
- The gearing down is not enough to get maximum torque out of the servos. Even though the machine works fine the motors are only running at 20%. Instead of 3:1 ratio I will be trying double reduction to get 9:1. I figure this will give the machine greater torque and also greater control over the gantry movement at higher speed. At higher speed I noticed partial overrun of the gantry.
- The visual appearance is poor.I am thinking of ways to hide as much of the working components as possible. If I can make it look like a block then this will be good. ( The volvo look )
- It does not have a good hold down system. I plan to incorperate a vacuum hold down system. I have come up with an idea that will allow solid hold down no matter what the shape.
- The spindle is not controlled by the computer. It was manually turned on and off.
- There is not dust collection setup
If you are like me, you dive in and make many mistakes, disregarding much advice that others give, only to find that you may have a few regrets down the track. On the other hand, I hope this thread will assist future builders with their designs. From reading this post so far you might be thinking my first machine was a total failure, in actual fact I am quite pleased with it and make a living from its work. I just want to improve on its features and usability.
I took a few contraversial chances with my first design that I have proven to myself to be quite acceptable, and will be keeping with the new design.
- Using timing belt and pulleys for movement, instead of ball screws.
- Using V bearings on the edge of angle iron, instead of traditional THK rail or linear bearings.
- Using allthread for my Z axis
All of these comprimises have worked well and have saved me a lot of money.
I will continue to use these methods.
I expect this next machine will take me 1 month to complete. I will post lots of pictures along the way.
This will be my mentor machine along with a few of my own modifications.
http://cnczone.com/gallery/data/500/...uter_Table.jpg
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