Advice on buying servos.

[Boyan Silyavski]

Just to chuck in my two penn'orth, I'm not so sure that the cables are so much of a problem. Having done a bit of research on my Yaskawa/Omron drives the plugs are nothing special and available from RS and the like. The manuals give all the wiring information - a bit of suitable cable, a soldering iron and you're away.

I agree, though depending on your skill it takes time to sort things out and solder. it took me a lot of time to solder my cables .

[Agathon]

I agree, though depending on your skill it takes time to sort things out and solder. it took me a lot of time to solder my cables .

Good point, well made. I'd sooner buy a proper factory made cable any day, but they are so expensive. I think if a bargain driver/motor combo turns up with short cables that shouldn't put one off.

[Boyan Silyavski]

Good point, well made. I'd sooner buy a proper factory made cable any day, but they are so expensive. I think if a bargain driver/motor combo turns up with short cables that shouldn't put one off.

Thats what i did , my beast did not like even 6m cables so i had to make 10m some of them using the TME cables, which honestly for 2euros per meter are incredible deal. They have all possible connectors too

[Agathon]

Thats what i did , my beast did not like even 6m cables so i had to make 10m some of them using the TME cables, which honestly for 2euros per meter are incredible deal. They have all possible connectors too

I'd forgotten that you mentioned tme.eu. At 2 Euro a metre they're a no-brainer.

[Robin Hewitt]

If I read it right, Gary would do me a set of three 400W motors and drivers for £1260 + tax. That doesn't sound too awful but I know nothing about servo motors. I'm not shopping, just cogitating.

[m_c]

The time component of making cables is very often overlooked.
For a hobbyist it's not normally a problem spending a few hours finding the connectors/cable/wiring diagram and physically making the cables, but when time is money, pre-made cables are cheap.

All my servos have been bought from Gary/Zapp. Certainly not the cheapest option, but he's not just a box shifter, and should you need any advise, he's only an email/phone call away.

One thing to bear in mind, is servos should be inertia matched to their load for best performance. Too big or too small a servo for any given load will not give a good tune. The spindle on my mill demonstrates that perfectly. It's a 110 frame medium inertia servo, and the best positional accuracy I can get before things go unstable is about 200 encoder counts, as it's not got enough of a load to help stabilise it. My lathe on the other hand, which has small inertia 60/80 frame servos, holds sub 20 counts without any problem, as the servo load is a good match to provide stability.

[Ger21]

I plan on making my own servo cables, mainly due to the issue of the available pre-made cable lengths.

Most come in 3, 5, or 10m lengths. When you get to just over 5m, you can end up with a lot of unused cable length. But is you're needs are close to the pre-made lengths, you won't save much at all making your own.

[Robin Hewitt]

servos should be inertia matched to their load for best performance... the best positional accuracy I can get before things go unstable is about 200 encoder counts

To a lay idiot like me, you seem to be saying that there is some complicated matching that needs to be done on each axis before purchasing a servo system to avoid it being a huge disappointment. My steppers suddenly start to seem like God's gift to His chosen few. Am I misunderstanding?