4' x 4' x 8" Router Build

[JonnyFive]

I have now moved the spindle mount lower onto the backing plate, how does this look?:



I have done a bit more digging into why people within the Joe's community have moved away from ball screws to R&P, the reasoning appears to be about speed, ease of assembly / maintenace and price more than anything. Looking at the pricing of C7 leadscrews on BST Automation they seem to be cheaper than using the CNC routerparts rack and pinion system (although the postage costs are about as much as the screws!) - I'm confused as to which way to go, any suggestions please? Would I be looking at 2010 for the longest axis, it will be 1600mm long? This comes out around 1000RPM critical speed - is this too low?

All help gratefully received.

Cheers

[GrahamWhite]

Are you confusing lead screws and ball screws?
Joe's used to use lead screws and went to R&P ,ball screws are better than both but way more expensive!

[routercnc]

Looks ok to me with that spindle mount position. One thing I did on my Mk3 was to drill and tap a second set of holes a bit higher on the Y plate so I had the option of mounting it higher for very tall work. Of course you can only reach across that work an amount until the Y plate may hit it but it is a quick feature to add at the build stage. I also added tapped holes along one edge of the Y plate to allow me to bolt a reference strip and maintain spindle tram alignment whilst adjusting the spindle holder. Never used it of course! But worth a mention

Can’t help on the ballscrew a that long and r&p as haven’t used them.

If you search the forum that sort of thing has been asked before and Jazzcnc has given advice

[JonnyFive]

As far as I can tell Joe's Hybrid machine used lead screws, the Evo used ball screws and the EVO MKII uses R&P, just wondering why they would move away from ball screws if they are the best?

Good shout putting extra holes for spindle mounting, I'll definitely do that.

[Cadvision.fi]

Hello, I am new to this forum and I was looking for information of "pinion & rack & gear reduction with spring tension" -packs - similar to cncrouterparts version of
PRO Rack and Pinion Drive, NEMA 34.
Reasons why I decided to use rack & pinion were exactly those that JF mentioned above (+ the option to make extensions later). So if anyone can help me where can I get as ready sollution as possible I am interested to hear. Nema 34 and module probably 1.25 with straight teeth (the rack can be cut with laser).