Any ideas for encoder mounting?
I was thinking of coming off the end of the motor shaft - there is an M10 threaded hole in it, then connecting the encoder to the shaft. I'm not sure if a rigid connection is a good idea though, is a coupling of some sort better here??
The other option is a 36t HTD5 pulley bored out to 35mm to fit the spindle shaft and mount this between the spindle drive pulley and the old lower vari-disk/brake disk in the head then mount the encoder out the front where the old speed control used to live using another 36t pulley. Not as cosmetic as the motor shaft idea but??
I remember when once was looking into that, that there were encoders that could count straight from the HTD pulley teeth. though there was some limit on the speed, but i think you are in. Though cant remember more for them right now
Last edited by Boyan Silyavski; 02-10-2016 at 03:55 PM.
Probably, i already have the encoder though ;)
Read the installation requirements for the encoder.
Depending on the style of encoder, there are different installation requirements.Avoiding the rubbish customer service from AluminiumWarehouse since July '13.
Thanks, was just looking for ideas - the encoder is a rugged little unit with self-supporting shaft capable of something like 15N radial loading which is pretty tight for a belt.
I'll try the motor shaft idea first as i have the bits for that, if i need pulleys i'll have to order some up.
You'll probably want some kind of flexible coupler for that style of encoder, as unless you can guarantee very accurate alignment, you'll likely kill the encoder pretty quickly.
An encoder with a separate disc/reading head would of been a better choice for mounting directly onto a shaft.Avoiding the rubbish customer service from AluminiumWarehouse since July '13.
I have seen the actual encoder body mounted on a spring plate presumably to allow for small misalignment
I will get a flex coupling in there.
Well, the motor was fitted, the pulleys wouldn't turn so something was wrong, then i discovered the rib that was cast into the top housing cover was rubbing badly on the top of the belt edge :(
Off it all comes again, rib was duly altered with a grinder ;) all back together again and nice smooth movement this time, my measurements and belt length calculations were spot-on and the adjuster slot on the motor plate was mid-way when tight. :)
Lugging a 3Hp motor up top on a Bridgeport on your own with only a pair of steps is no fun, doing it twice was pushing the limits a bit ;)
Just got to fit the VFD, wire up and we should be good.
Something that rarely gets mentioned...Power required...
I have a 3ph 2.2kW spindle motor on a vfd, 700w X servo, 700w Y servo, 400w Z servo, maybe 100w for pc and controller on this machine.
How do i calculate the supply capacity allowing for diversity - it will not be running 100% flat out all the time :)
I know i need to uprate the MCB's and supply cables as the build was originally for the small 1.5hp spindle motor.
Adding up the maximum ratings for all drives gives a figure way more than i can supply :)
Last edited by Davek0974; 05-10-2016 at 09:26 AM.
A quick mental calc, and I'd say 16A would cover you.
2200+700+700+400 = 4000.
Divide that by 220 gives 18A, or 250 gives 16A.
Power up surges of the drives are likely to give a bigger problem than too much current draw during use.Avoiding the rubbish customer service from AluminiumWarehouse since July '13.
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