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Thanks Rick, I was originally considering the 1/4" (6.35mm) Mini V Gantry Plate but didn't think of using an extra precision shim. Something to revisit in fusion 360. Got to like the design process, it's never ending, but I kind of like the challenge.

 

Much better solution for the "outriggers" Rick. I like it. So I'm still bit confused as to whether the plate is 1/4" (6.35mm) thick as here Mini V Gantry Plate™ or 6mm in the STEP Parts Library PDF. Not to really matter as I could make up the 0.35mm difference with some Tally-Ho cardboard between the Y beam and the frame

 

No worries Rick, I think I can work around it either way, though 6mm would be the preference.

 

As the saying goes, "measure twice cut once", I think I made a mistake. The measurement from the plate to the centre line of the Standard wheel assembly on paper is: 6mm spacer + 1mm precision shim + 5mm bearing + 0.5mm (1/2 precision shim) = 12.5mm. While for the mini wheel assembly it would be: 6mm spacer + 1mm precision shim + 1mm precision shim (mini wheel one) + 4.5mm bearing + 0.5mm (1/2 precision shim) = 13mm.

So there would be a 0.5mm difference between the Standard wheel assembly and the Mini wheel assembly if you leave out or add a extra precision shim, before you take the plate thickness into consideration, by my calculations.

Still not a problem with a bit of "Tally-Ho cardboard"; might just have to double it up though

 

Ah my bad, then it would all add up, just right. Thanks Rick

 

Cheers Gray. Cutting area forward and back from centre is about 155mm from memory before it hits the bump stops so 310mm safe work area in the Y-axis and around 720mm in the X-axis. The table will hang out 155mm out the front and back at full Y-axis movement. The centre point of the spindle is about a mm or so out, which is not too bad; so the spoil board won't be totally centred. The limiting factor is the Double Gantry plate assembly hitting the frame first followed the movement in the Y-activator. Yes, you could extend the outriggers to increase the stability, the mini V wheels will clear the frame mounting plates by design. Though it is something I'm not planning on doing, as I want to keep it to standard cut lengths of V-Slot if possible.

 

David that's one of my worries too. It's an experiment. If it doesn't work then not hard to add another one later.

 

This better?

 

Cheers Mark and please feel free to.

 

Thanks gents, I'll have to work out a proper parts list and start saving my pennies as the Australian dollar is heading backward again, so might be a little while before I can make a start. Glad to be of some help in the meanwhile.

 

Oh and your right Mark, it makes sense moving the Y motors to the back as it would certainly make the wiring more straight forward.

 

A bit of an idea to add some extra strength to the C-Beam I had a while ago. The plan is to add a 40mm x 20mm milled aluminium channel with a 2mm wall thickness tied into the C-Beam with T-nuts and 8mm low profile M5 screws.
Being same size as the inside of the C-Beam some sanding of the channel would more then likely needed to fit and/or a stint in the freezer. My thought are that it would strengthen the C-Beam at its weakest points (circled in the cross section above).
Another wacky thought is to fill the four hollows with Plaster of Paris to add extra weight rigidity to this design.

Your thoughts.

 

Yeap I know. You miss nothing. I was was just playing around with fitting two of the anti backlash nuts blocks with the ajustments to the outside.

 

Sounds interesting Paul, hope it works out well. Some kind of before and after assessment would be great, how to do that I have now idea at the moment. Looks like I will need to learn about epoxy granite mixture. The reason behind thinking of using plaster for me is it is something I'm familiar with using it for sculptures and mould making plus the obvious in that it is dirt cheap. One of the interesting properties with plaster is that it expands slightly when drying, about 0.03% from memory, so might produce a slight internal pressure which might just work. Next visit to the tip shop, looks like I will be looking for some junk aluminium tubing to experiment on and find a way to share the results of my crazy experiment.

 

Great I'm going to look those links, firt hit with google for me was CNCCookbook: Epoxy Granite Fill thanks Paul it might just work out fine.

 

I think you're on a winner there Paul, there's even a cookbook, sort of..