'Otter'. Build log.

**Blazing Black Beard** · 23-10-2018

I know this is not something I should really be considering to buy so early on in the design stage but I could not help but take a look around at spindles. There's a mind boggling amount available out there and one that especially caught my eye was this:

https://youtu.be/pWNeW-lH9RA

Any comments regarding suitability or alternatives would be appreciated.

**Blazing Black Beard** · 24-10-2018

Some NEMA 23 stepper motors came today

**mekanik** · 24-10-2018

Most people just use the standard box section, if you are welding there will be distortion you can reduce this somewhat by just stitch welding it, doesn't have to be full weld. the distortion in the base (X) axis is is eliminated with epoxy grout levelling.
Regards
Mike

**Blazing Black Beard** · 24-10-2018

Originally Posted by mekanik

Most people just use the standard box section, if you are welding there will be distortion you can reduce this somewhat by just stitch welding it, doesn't have to be full weld. the distortion in the base (X) axis is is eliminated with epoxy grout levelling.
Regards
Mike

How can the face on the side of the box section be used to keep the rails parallel though? These can't be poured with epoxy as it would just run down and onto the floor.

If you look at RoboCNC you'll see he just uses the straight vertical face on the side of the aluminium to keep his linear rails parallel and straight.https://youtu.be/YOVHtjXi07Q?t=2m02s

**mekanik** · 24-10-2018

The epoxy goes on the rail mounting surface, the guy in the video is using the ally profile as a reference, dont like this unless it's been machined to be flat, you should be using a precision straight edge to set the rails.
Regards
Mike

**Blazing Black Beard** · 24-10-2018

Originally Posted by mekanik

The epoxy goes on the rail mounting surface, the guy in the video is using the ally profile as a reference, dont like this unless it's been machined to be flat, you should be using a precision straight edge to set the rails.
Regards
Mike

Yes, that's what I thought. I need to find a precision straight edge then. Any suggestions?

As for the stepper motors I received earlier, they do not have the D shaped shafts. A friend of mine said it was a shame but they look like quality motors. I'm going to take an educated guess that round shafts aren't as good for this particular application, is this the case? Can anyone see any issues with them being round shafts as opposed to D shafts?