belt drive to ballscrew drive changeover advice required

[JAZZCNC]

To be honest, if it was me I'd just replace the belts and tweak what you have already because it will be a lot of work to fit ball-screws and no disrespect meant here but looking at the machine I don't think it's up to handling ball-screws. Ball-screws are not as forgiving regards alignment as belts and the power and torque they provide would tear that gantry to pieces if one of the motors stalled because the gantry was flexing and causing binding on the ball nut.

However, if you do go ahead then I'd go with Rm2020 and use 2:1 ratio. The reason for this is because it will give you the same speed as a 2010 but half the screw rotation speed so you are less likely to get whipping which is a major cause of stalling motors. With a weak machine, you cannot afford for one motor to stall while the other keeps spinning because no matter how fast you think you can reach that E-stop I guarantee you won't be fast enough to stop it before the gantry gets twisted up like a noodle.

You won't find machined ball-screws in UK at sensible prices. China is the place.

If you do go ahead with ball-screws then I'd also recommend while your buying from china you invest in some Round supported linear rail. This will give you more of a fighting chance and they won't cost a fortune.

[marbles]

Good advice thanks for that. I hear what our saying about the machine build. Ideally i'd just rebuild the the machine but no time for that. I do have a larger rack and pinion machine but I don't have time or inclination to go down that route again at the moment.

I have however got a complete set of chain, sprockets, idlers and tensioners for Y and X, which I think I bought as the original upgrade to the belt machine but never fitted. How about I replace the T5 belt with chain and keep an eye on the tension (cant quite remember what type of chain it was but prob the same stuff used on Mechmate builds. The chain will stretch but is certainly supposed to be better than belt. Any knowledge or thoughts about chain before I go down that route?

Or as your suggesting just replace the belt. I think I used 16mm T5 which has embedded reinforcing wire in it. Perhaps there is something more chunky but still belt I could look at?

[JAZZCNC]

The chain will stretch but is certainly supposed to be better than belt. Any knowledge or thoughts about chain before I go down that route?

Or as your suggesting just replace the belt. I think I used 16mm T5 which has embedded reinforcing wire in it. Perhaps there is something more chunky but still belt I could look at?

I've not used Chain on a CNC machine and never would because to me there must be more backlash in a chain. I use to be a motorcycle mechanic and I've fit enough chains of much higher quality than an industrial chain to know it's not a good choice for a CNC machine. A timing belt is a very low backlash and high efficiency so you won't get better unless you use screws.

I'd just use a wider 25mm belt and good quality. I'd also use the HTD profile.