Handibot modifications

I bought my Handibot for a specific application. I need a cut area of about 12" x 24". I do not want to have to move the machine to different panes. I would like to modify the Handibot to cover the area needed. Where can I purchase longer lead screws and rails?

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In theory this might be possible. In practice, well, let's just say a lot could go wrong. The first problem is that longer rails of the same sectional dimension will sag more over the longer unsupported spans. Or not be damped enough. Or else the motors would prove painfully slow in the larger work area. CNC machines are all trade-offs between various design goals and price, the HandiBot included.

I don't understand your statement about unsupported longer rails. The rails are attached every few inches and continuously supported. Are you referring to the lead screws being unsupported?

The jog speed of the Handibot if perfectly adequate for a somewhat larger cutting area.

Hi 648,

The primary issue with extending the travel area is the Y axis off-center drive. Where the layout of the X axis allows for longer travel in principle, the off-center Y axis drive has limits beyond which racking becomes a concern. Further, to accomodate longer rails and lead screws a modified exoframe would need to be designed.

We think the best approach is indexing at the moment. We've talked about eventually offering a larger Handibot if enough demand is there.

David

I consider this a prototype for a larger Handibot. The bulk and weight of the larger capacity will make this less "Handi" however.

The racking problem in the Y axis does seem to be a problem. Another motor would have to be added to the other side. I understand the control board can take a fourth drive. Can software parallel the two Y drives or would the step and direction have to be hardwired on the control board? Seems like hard wire is the way to go since that is the way my PRT is configured and would guarantee the drives are synchronized.

The original post was looking for suppliers.

To 648

Just a quick additional comment. You can define the extra axis (channel 5) to work exactly like the Y in the software. I don't think there would be any issues with that. (With a little soldering, you could also hardwire it to the number 2 channel ... which would make it identical ... but not really necessary.) If there is enough interest in it for accessories, we will bring out all 6 channels in a header on future boards.

Ted Hall, ShopBot