El Beast - Initial design phase, comments and critique welcomed!

[Zeeflyboy]

Indeed, it doesn't guarantee alignment to the bed, but to the rail/carriages... which are aligned separately to the bed. If the plate was at an angle to the rail/carriages the readings would change as it moves past - I can actually demonstrate that by inducing an angle.

If measuring to the bed then yes, it needs another point of reference... but moving the indicator is enough to induce a small change just when it comes down into contact with a different part of the plate so that's not quite so easily done. I figure it's easiest for me to align the rails to the bed, then align the side mounts to the rails.

[routercnc]

Indeed, it doesn't guarantee alignment to the bed, but to the rail/carriages... which are aligned separately to the bed. If the plate was at an angle to the rail/carriages the readings would change as it moves past - I can actually demonstrate that by inducing an angle.

If measuring to the bed then yes, it needs another point of reference... but moving the indicator is enough to induce a small change just when it comes down into contact with a different part of the plate so that's not quite so easily done. I figure it's easiest for me to align the rails to the bed, then align the side mounts to the rails.

Understood -carry on !

[Zeeflyboy]

Just interested in some thoughts of this slightly different approach to mounting the rails in reference to the eco-cast bed. One of the rails in particular has a very slight bend it seems (not unusual apparently from my research), and the method I used of clamping the carriage with a spacer isn't working quite as well as hoped due to what I assume is the steel rail bending down the 20mm bed surface rather than being pulled up during the clamping.

I designed this little spacer which would be screwed into the extrusion and has some up/down movement on the screw slots and are slim enough to pass under the carriage. The idea would be to drill the extrusion to take 6 of these along the length of the Y-axis. they could be butted up against the bed plate and then screwed down into place, then the rail can be clamped against them while fastening. Basically ending up similar to having a machined lip for the rail to butt up against.



The plan for making these would be to align them on the machine in such a way that the important dimension (height) would all be cut on the same part of the ballscrew to minimise any potential variation.

[Zeeflyboy]

I'm waiting for some new end mills and some motivation to re-cut the front plate after my motor mount boo boo, but in the mean time I made a start on a low profile machine vice I designed. Haven't been very happy with the low profile vice I already have and want something much stronger and hopefully more accurate.

This is the overall design, today I made the fixed end:



Basically it uses a bolt pattern on the bed for alignment dowels and bolting down, but gives access right down to bed level (or below with a cut out I suppose!) which will be useful when trying to machine or drill taller pieces. I have since tweaked the design slightly to allow the travelling end to be bolted down as well if required for extra rigidity.

Missed taking a photo of the first bits, but basically vertically it is made up of 2 pieces of plate as I don't have any tools long enough to cut the whole thing in one pass and it allows me a bit more flexibility in how it is made.

After machining the two pieces and bolting them together, I popped them into the machine again and faced them down by 0.2mm on each of the main faces to give a nice flat and square face.






And after a quick tickle with some 1500 grit wet and dry:






Once I invest in some anodising equipment the plan will be to give this a nice black anodised finish... assuming the thing works as expected.

[Chaz]

I'm waiting for some new end mills and some motivation to re-cut the front plate after my motor mount boo boo, but in the mean time I made a start on a low profile machine vice I designed. Haven't been very happy with the low profile vice I already have and want something much stronger and hopefully more accurate.

This is the overall design, today I made the fixed end:



Basically it uses a bolt pattern on the bed for alignment dowels and bolting down, but gives access right down to bed level (or below with a cut out I suppose!) which will be useful when trying to machine or drill taller pieces. I have since tweaked the design slightly to allow the travelling end to be bolted down as well if required for extra rigidity.

Missed taking a photo of the first bits, but basically vertically it is made up of 2 pieces of plate as I don't have any tools long enough to cut the whole thing in one pass and it allows me a bit more flexibility in how it is made.

After machining the two pieces and bolting them together, I popped them into the machine again and faced them down by 0.2mm on each of the main faces to give a nice flat and square face.






And after a quick tickle with some 1500 grit wet and dry:






Once I invest in some anodising equipment the plan will be to give this a nice black anodised finish... assuming the thing works as expected.

Nice work as always.

[Edward]

I'm looking forward to your testing the backlash (or lack thereof) in those nice TBI screws and the bearings.

The reason is that I am going to build a similar small machine to yours, albeit with two ballscrews - driven by one motor and initially I was planning to get the Chinese ones from Fred, with double nuts. But these TBI ballnuts you have are also very tempting, they ooze quality.
Edward

[Zeeflyboy]

I guess double nuts will always have the edge longer-term in maintaining their backlash free nature (although worth noting TBI do double nuts too if that's what you are after).

I wasn't able to measure any backlash in the limited testing I've tried so far, resolution of the equipment was 0.01mm - more detailed testing will have to wait until the machine is assembled I'm afraid, which could mean waiting quite a long time at this rate!