2x 2005 C7 Ballscrew 1450mm Length with Ballnuts + FK/FF mounts and motor coupler

[Pheet]

Hi
I'm interested in the ballscrews and would appreciate some advice. I'm building a small machine approx 800mm x travel and 600 y travel. Gantry mass approx 20kg (+/- 2kg) with spindle. Would 2005's be up to the job?. i haven't got around to the calcs yet but for my machine I can just machine them to the right length.

Thanks in advance for any help / advice you may be able top offer

Cheers
Leigh

2x RM2005 C7 Ballscrew 1450mm length and SFU2005 ballnut complete with FK (including the lock nut) and FF mounts. Also includes a flexible motor coupler with 8mm dia bore to fit standard nema 23 shaft.

You can consider these new as although they were fitted to my machine its never cut anything. Ideal for a 4ft axis.

Delivery is an option but will be expensive because of the weight and length. Would prefer collection if possible.

Bargain at £60 each or £110 for the pair. You'd normally pay £200+ for these from China not to mention the chance of VAT and import duty on top of that.

Here's a sketch showing the exact dimensions



And a couple of images

[Shinobiwan]

Hi
I'm interested in the ballscrews and would appreciate some advice. I'm building a small machine approx 800mm x travel and 600 y travel. Gantry mass approx 20kg (+/- 2kg) with spindle. Would 2005's be up to the job?. i haven't got around to the calcs yet but for my machine I can just machine them to the right length.

Thanks in advance for any help / advice you may be able top offer

Cheers
Leigh

I know this is academic since they're sold - sorry but I'd be tempted to go for 2010.

I'll be honest and say that I've swapped these out on my machine for 2010 as they're just too slow for cutting wood on the end of a nema 23. These small motors only run up to about 1000rpm with reasonable torque. Spinning at that speed the most you can reliably expect is about 5m/min traverse but little torque left for cutting. This is fine if your doing a lot of metal routing where your usually around 1m/min or less but for MDF like I do its just not fast enough where you need to be cutting 4-5m/min usually.

Depends what your cutting the most really! Judging by your gantry weight its not a lot so doubt it will be for metal. If your mostly cutting wood go for 2010 or even 2020 if your using the latest digital drives and suitable motors as these have very fine resolution using realtime microstepping adjust and signal input interpolation. If its metals then 2005 or 2010 would be fine.

[JAZZCNC]

Thanks for letting me know . . mate.

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[Jonathan]

I considered buying them, for about 20 seconds.
The only thing this size ballscrew is good for is maybe a big milling machine or lathe. For other machines, like CNC routers, the forces on the ballscrews are so low that you don't need the slight increase in stiffness gained from using a RM2005 screw, hence you're much better off sticking with 16mm ballscrews and the appropriate pitch. The price was good, but to me that's not enough to counter the poor performance you'll get on a router with these, especially since it could increase the cost of the electrical parts. Presumably John S has a big machine to convert...

( That Old bastards not about any more and he's still beating me to it.!! )

Hmm really?

[JAZZCNC]

The only thing this size ballscrew is good for is maybe a big milling machine or lathe.

Or for replacing a worn ballscrew on a machine of a very similar size like mine.!!!

[Jonathan]

Or for replacing a worn ballscrew on a machine of a very similar size like mine.!!!

Perhaps, but we both know you'd me much better off getting 1610 or 2010 for a router this size. 325 USD including postage (but not customs) gets you two RM2010-1500mm, so yes a bit more but well worth the extra money if you are swapping since you can keep the same end-machining, unlike with 1610. Wearing out the ballscrew would take some doing anyway, I gather it's generally the nuts that fail first.

[Shinobiwan]

Perhaps, but we both know you'd me much better off getting 1610 or 2010 for a router this size. 325 USD including postage (but not customs) gets you two RM2010-1500mm, so yes a bit more but well worth the extra money if you are swapping since you can keep the same end-machining, unlike with 1610. Wearing out the ballscrew would take some doing anyway, I gather it's generally the nuts that fail first.

Got two RM2010 at 1450mm with end machining and ballnuts from chai for $218 including shipping. So 325 is very expensive where ever your buying those from.

[JAZZCNC]

Perhaps, but we both know you'd me much better off getting 1610 or 2010 for a router this size. 325 USD including postage (but not customs) gets you two RM2010-1500mm, so yes a bit more but well worth the extra money if you are swapping since you can keep the same end-machining, unlike with 1610. Wearing out the ballscrew would take some doing anyway, I gather it's generally the nuts that fail first.

Forgot who your talking to here Numb nuts.? . . . . What you think you know your wrong about.!!

This machine has been working fine for nearly 5 years with 2005 and the wear is very slight and possibly in the nut, could even be end bearings I haven't checked yet. Mostly it's down to the fact it's been abused and abused with no protection and run in some shity conditions.!!. . . . . 1610 or 2010 would give me nothing extra I have already that is of any use to me so why would I bother changing now.

It would just have been nice to have had the chance to buy some cheap replacement screws before being offered up to general public considering the involvement I've had with this machine.!! . . . ANT.

[Shinobiwan]

The only thing this size ballscrew is good for is maybe a big milling machine or lathe. For other machines, like CNC routers, the forces on the ballscrews are so low that you don't need the slight increase in stiffness gained from using a RM2005 screw

Its not slight when your spinning them at 1000rpm+ At 1.45m I've got a 1610 on the Y axis and it just starts to show whip at 10m/min, at 14m/min its like jelly! You won't run at these speeds of course but for cutting wood you want in the range of 4-7m/min depending on the cutter dia and flutes along with DOC. Unless of course your spinning the nut but I'd still go 2010 at those lengths anyway. The cost difference is minimal for the added peace of mind.

Presumably John S has a big machine to convert...

Or he's chopping them up into lots of little screws ;) More likely though is he'll put them in his cnc spares stash and leave them for a rainy day. The man has enough parts to set up a cnc factory.

[Jonathan]

Its not slight when your spinning them at 1000rpm+ At 1.45m I've got a 1610 on the Y axis and it just starts to show whip at 10m/min, at 14m/min its like jelly! You won't run at these speeds of course but for cutting wood you want in the range of 4-7m/min depending on the cutter dia and flutes along with DOC. Unless of course your spinning the nut but I'd still go 2010 at those lengths anyway. The cost difference is minimal for the added peace of mind.

The cutting force on a CNC router is a few tens of newtons, even when taking 'heavy' cuts in wood or aluminium. There's an additional force when acceleration so lets say 100N. The RM1610 ballscrews are rated for something like 7800N for one million revolutions, so operating at 100N they will last for a very long time. Hence you don't need a bigger screw unless critical speed is an issue, which according to your experiment and the calculation it isn't for this length (1450mm) and RM1610.

Got two RM2010 at 1450mm with end machining and ballnuts from chai for $218 including shipping. So 325 is very expensive where ever your buying those from.

I did not say that I had bought any at that, or any, price. That was the first seller I found on ali-express who has RM2010. Last time I checked Chai doesn't sell RM2010 and Jazz posted only a few days ago saying the same. So where did you get your RM2010, or are they actually RM1610?
Either way my point is valid - RM1610 or RM2010 is a much better choice for this length for the vast majority of machines built on this forum. If John S has got a use for them then good for him, since he's just got a good deal.