Game on!

[Voicecoil]

Having found it very difficult (or very expensive) to get anything done on a reasonable timescale by the local anodisers, in desperation I thought I'd have a go myself. £50 worth of chems and some plant troughs later I managed to get the gantry box done this evening, took a bit of fiddling with the process but not too shabby in the end.

[Gav74]

looking good

[Voicecoil]

With all the beams now anodised I thought it was time to indulge in a bit of damping, as handling the box sections in particular showed that they were ringing a lot at mid-audio frequencies (which match up nicely with the stimulation given by typical spindle speed/cutter flutes). I thought I'd try my old fave Tecsound, but wasn't overly confident of it working as I've never used it on anything thicker than 2mm thick metal sheet before, and the box sections I've used for the side beams and gantry are 7 & 10mm thick wall. However in reality it seems to work pretty well, hanging an untreated section up on a piece of wire and giving a gentle tap with a hammer gives something not unlike a tubular bell, whereas a damped section is just a bit of a thunk. Here's some sound files from the tapping to illustrate the difference
Side beam undamped.mp3
Side beam damped.mp3
Looking at the decay time in an audio editor, the damping has been increased by something like 6X - a useful improvement I think - now to do some of the other parts!

[Voicecoil]

Thought I'd better check fit on the Z-axis before assembling the gantry as the X carriage is integral to it: all fitted suprisingly well once I'd clocked that the Z slide extrusion was supplied under-width and was causing the assembly to sieze at the end of travel

[Voicecoil]

So, the last few days I've found time to build up the chassis/Y axis. Getting the side rail assemblies properly aligned was a bit of a faff, but it's done now!!

[Lee Roberts]

Looking good, nice to see something diff to the norm

[Voicecoil]

Looking good, nice to see something diff to the norm

Cheers Lee - I thought it was worth going back to basic principles and trying a few slightly different approaches to see if was possible to make an aluminium machine that was a bit more rigid than normal. I've learned a lot as I've gone along and come up with some improved ideas which will be incorporated into this build once I've got it cutting metal and can make more accurate and complicated parts - those ideas will also go into the big machine which is the long term goal.

[kingcreaky]

as lee says its great to see new methods. thanks for posting, keep it coming,

[routercnc]

Somehow I managed to miss this thread and have just caught up. Great work Voicecoil and I heartily approve of the twin Z ballscrews. Glad the stiffness spreadsheet is still helping people out.
Let the over build commence - great machine !

[Voicecoil]

Somehow I managed to miss this thread and have just caught up. Great work Voicecoil and I heartily approve of the twin Z ballscrews. Glad the stiffness spreadsheet is still helping people out.
Let the over build commence - great machine !

The twin ballscrew thing kind of evolved, it came from trying to minimise twisting moments on the gantry - I'll be finding out in about a month's time how well it works I guess! Meanwhile lots of wiring and screwing together to be done :-)