Aluminium Profile Type Router - Initial questions

[AndyUK]

I'm trying to figure out whether 2005 or or 2010 ballscrew would be better, or 1605/1610 (which seems to be less available pre machined). I don't plan to use pulleys.

Meh, get a custom quote from Fred and he'll machine whatever you want, it'll still probably be cheaper than the pre-machined, and you'll have a quality product from a trusted vendor.

So filling out a speeds and feed calc for say hardwood @ 20,000rpm spindle I get min/max of 9-11 M/min speed. Assume this is the cutting speed and the rapid people refer to are movement between cuts.

Yep. No feeds and speeds calculator will ever give you rapid speed recommendations. Do remember that it will also depend on how many flutes your cutter has.

From forums someone gives 2010 screw @ 1348 RPM = 2.15m/min, so would the motor need to at appox 6740rpm to achieve that?

Then that someone is a tit and can't do maths. It was probably me. The 2010 means that the outside diameter of the screw is 20mm, and the pitch is 10mm. In one turn of the screw, the ballnut will move 10mm. So 1348 turns per minute equals 13480mm/min = 13.48m/min.

But also the motor Voltage driven needs to be known to get an idea of rpm which can be achieved?

Its less about the voltage, more about how much torque you have left when you get up to those RPMs, which then dictates how quickly you can accelerate and decelerate. Whilst I spent a lot of time doing the calculations, I still ended up with the same motors as everyone else with the machine size, so for starters find a decent build about the same size and steal their motor and PSU configuration :P Work forwards from that.

I also don't know the final weight of the gantry, I'd estimate say 20Kg based on extrusion weight + spindle and alum plate.

Quite machine dependent, but I'd guess you're lowballing it. A 2.2kW Spindle is approx 8kg alone. Rails + Ballscrews + Plates + Motors + Extrusion should be a good ballpark. Maybe nearer 30-40kg?

[CNCRY]

Thanks for bearing with me, now I have the whole idea in my head I'm keen to start building , but want to do it right first time so remaining patient, and re-thinking the design.
Is Fred the BST automation aliexpress store? What sort of lead time do people get with him and is there a ballpark % amount of import duty etc to be expected?
That RPM calculation was from a U.S forum in IPM, and was clearly wrong then. Thats clear now, so with the 10mm pitch I'd need to aim for 1000rpm to get 10m/s cutting speed, which should be about right for a 2 flute cutter in hardwood. While Aluminium would need to aim for 5m/s or 500rpm at the motor?
So from most similar builds I have seen everyone ends up with 3/4NM Nema 34 motors, but there is variation in how they can be driven.
Trying to pin down some aspects so I can then design around those.
You are right on gantry weight . Profile is 8kg + 8Kg spindle + perhaps 10kg rails and carriages + aluminium plate + motor - more like 35Kg.
Ryan

[Kitwn]

Is Fred the BST automation aliexpress store? What sort of lead time do people get with him.
Ryan

Ryan,
Yes, Fred is BST Automation. I fell of the sofa when my leadscrews and rails arrived in remote western Australia only 4 days after I paid for them. It often takes longer than that to get stuff from the state capitol Perth. You do pay quite a lot for delivery though and it's worth checking the different total cost for item + postage and 'free' postage for the same thing.

Don't forget that many Chinese businesses are closed at present because of the virus so delivery times at the moment are anybody's guess.

I don't know about import duties to Pommieland but make sure you know the total cost before comparing suppliers.

[guciTaums]

I would like to know what kind of forum is this? phpbb? Guci