dual drive x-axis?

[fasteddy]

At a price John, not a nice one either.... Would be cheaper to buy a tap a go visit my mate and his lathe....!

[HiltonSteve]

At a price John, not a nice one either.... Would be cheaper to buy a tap a go visit my mate and his lathe....!

If you speak to Michael nice I am sure he would knock some nuts up for you. I think he has got a 10 x 4 tap not the 16 x 4 that you are looking at but why not drop down to 10 x 4 trapezoidal screws to save a bit of money, especially if they are temporary and you are going to upgrade the screws to ballscrews later, will be speaking to him in a bit so I will give him a nudge for you.

[Tom]

Hello Fasteddy,

It sounds like your build's very similar to mine.

I don't want to badmouth Marchant Dice needlessly, and Kevin may still come through with the goods, but i'm struggling to find out what the state of my (overdue) order is.

Anyway, best of luck with your build. I'll update on the leadscrews when I hear more...

[Ross77]

I agree that you should definatly get on and build it, probably learn more in the process. good luck.

May have retract my statement about cable stretch being low...
Had a look around today and seems that 1m of 3mm dia. stainless cable will stretch 0.5mm under a 200N load (20Kg ,not much if cuting Al and a heavy gantry)....:geek:

May be start a new tread If anyone is intested in following this topic up? Im not used to designing things that move! traditional to keep structures stationary. There must be a way to get cheap and accurate control of CNC machines........

[Ross77]

Somebody is going to have some fun calculating it all up! not me though :lol:


I'm a great believer in horses for courses....Milling machines for milling routers for routing......Now engravings a different thing.....It never ends does it :(

I hear you, I wouldnt ever use anything but ballscrews. But I like a challenge and am happy to do the math.

Would the SS cable stretch the same every time? What if it was already tensioned (stretched) ? What if the antistretchyness of the cable was more than the chiploadedness?

Yes the stretch is a product of the load (hookes law not mine) The bit that i dont understand is that if the cable is pre-tensioned and then a load is apllied, is this always an additional load (and therefore more elongation) as the cable is in an elastic state or is only a factor if it is greater than the preload stress?

if its the later then problem solved, if not can you use plastic design on moving parts?.........

[Ross77]

Somebody is going to have some fun calculating it all up! not me though :lol:


I'm a great believer in horses for courses....Milling machines for milling routers for routing......Now engravings a different thing.....It never ends does it :(

I hear you, I wouldnt ever use anything but ballscrews. But I like a challenge and am happy to do the math.

Would the SS cable stretch the same every time? What if it was already tensioned (stretched) ? What if the antistretchyness of the cable was more than the chiploadedness?

Yes the stretch is a product of the load (hookes law not mine) The bit that i dont understand is that if the cable is pre-tensioned and then a load is apllied, is this always an additional load (and therefore more elongation) as the cable is in an elastic state or is only a factor if it is greater than the preload stress?