'T - something and counting....'

[andy586]

Many thanks for the reply Eddy...you are a true gent.

I tried the settings, it spun for around 30 secs and cut out with a motor overload fault (OL1). Tried playing around with the current and rpm and it gave a few revs and then gave me either motor overload or inverter overload (OL2). Then I thought about what you said about my VFD settings being inadequate...from that I looked at the settings that didn't have a an exact equivalent and worked it out...

The huanyang has an arbitrary v/f curve which you define with the min, intermediate and max frequencies and voltages. The teco has 6 predefined curves (which appear to be for 50 or 60 hz motors). I had to set it to the magical 7th curve which i then defined. Instead of a frequency vs voltage curve, it was a frequency vs voltage percentage. So I put in values that should mimic the curve one ends up with huanyang. So i went for:

'minimum frequency' =1.2 hz minimum voltage percentage (8/220*100) = 3.6%

'medium frequency 1' = 2.5 hz medium voltage 1 (15/220*100) = 6.8%
(equivalent to huanyang's 'intermediate frequency)

'medium frequency 2' ((400-2.5)/2)= 198.8 hz medium voltage 2 ((220-15)/2)= 102.5 v
(huanyang settings didn't have this second point on curve so i just used midpoints between 'intermediate' and 'maximum').

hit play and it spun.

as for the lack of 'number of poles' and one of those 400hz's, i guess that gets taken care of with the motor rated speed (i.e. the vfd needs the product of two variables rather than them individually....). i've set motor rated speed to 24000 rpm. I need to calibrate the display (with the motor synchronous speed?) (think it will be the 3,000 same as on huanyang) and check what rpm count i get but i think it should be ok.

so once again...many thanks for the reply...it gave me the confidence to press 'run' and that was most of the battle. i will report back once i've had another play and got it running at full speed and reading out 24,000. I hope this was not a big no-no to just go for the midpoint between intermediate and max and use that as my 'medium 2' for frequency and voltage percentage but i'm sure i'll soon find out.

cheers

[EddyCurrent]

You sound like you know what you're on about so I'm confident you will gt there.

[andy586]

cheers for the support.

i had another play around. i kept motor rated speed at 24,000rpm, and set the line speed display to 24,000 rpm. this gives me what i would expect (10 hz = 600rpm, 20 hz = 1200 rpm, 100hz = 6,000 rpm and so on) but once it gets above 10,512 rpm, the rpm readout starts getting a bit funny (goes back to zero and starts counting up again)(although spindle itself rpm carries on increasing nicely all way up to 400hz). so quirky rpm readout aside, i think its all working properly. i am jut using the frequency readout at the minute. i have ordered a cheap laser tachometer which should arrive on monday. then i can tell if i am where i'm supposed to be with regards to rpm and frequencies.

all good fun...

[EddyCurrent]

So do you have these values entered ?

12-03 = 400
12-04 = 1

From the manual;
"The max preset line value of 12-03 is equal to the Maximum output frequency of the motor."

I don't know if you are controlling the speed via G-code S instructions but if you are the next challenge is to get that in sync. too. For example if I use instructions M3 S20000 it starts the spindle rotating at 20000 RPM and the vfd display also reads 20000 RPM +or- about 20 RPM. As you say a cheap tacho is almost a must to check the speed.

[andy586]

I've got 12-03 = 24,000

• 'The max preset line value of 12-03 is equal to the Maximum output frequency of the motor. Forinstance, given line speed 1800 is equal to display 900 when output is 30Hz while the operationfrequency is 60Hz.'
  
  

The first bit of the text is misleading and could make one think you put in the frequency there, but the 'for instance' bit, the units (rpm), the allowed range (0-65535) and the factory preset (1500) cleared it up for me. You put in the max rpm, it already knows the max frequency from elsewhere. It works out the portion of max frequency you are using and then tells you rpm accordingly.

and then i use 12-04 = 0 for hz or 12-04 = 1 for rpm. Once i get above 10,000 rpm the readout throws a wobbly in rpm mode but hz is fine. Tried changing number of decimal places (12-04 = 2, 3 or 4) but still the same.

The tacho arrived today. Well that was fun...! Got a bit of a safety lesson early doors so will definitely be investing in some kind of protective shield. I stuck a bit of cheapo pound land tape around the spindle first and then the reflective tape on top of that. They clung on until 350 hz and then took aim and shot off directly at me. Because I was still a little apprehensive about running the spindle at high speeds anyway (still at the 'sure hope this thing doesn't blow up on me' stage), it certainly made me jump! Just its way of saying hello i guess...quick flex of the muscles...letting me know who the boss is. Did it again but with the reflective tape directly on the spindle. Got the following:

50hz = 2978 rpm
100hz = 5960 rpm
150hz = 8960 rpm
200hz = 11970 rpm
250hz = 14970 rpm
300hz = 17960 rpm
350hz = 20970 rpm
400hz = 23970 rpm

I'm happy enough with that. I can either work backwards from those figures to work out specific rpm's, or get the tacho out again and see exactly what frequencies I need for certain rpms and stick them into the presets.

As for external controls, I don't think my bob will accommodate it as it stands (think its a db25-1205...came with the longs motor kit). I'll have a good read about it first and then consider the options. i think i'll revel in this little victory first for a while!! Got the potentiometer on panel working as well so selecting frequency is nice and easy.

Got a 6.35mm ball end for 3d work coming from wealden on monday or tuesday, still need to decide on something for profile and pocketing work. would you recommend sticking with router cutters or could i get away with end mills? There seems a big difference in price. I'm also not quite sure on how to know if a tool is centre cutting or not (e.g. http://www.wealdentool.com/acatalog/...p_Cut_229.html ). I'm using mesh cam which doesn't support ramping or helical, so I think I need centre cutting bits and a slow plunge rate. I will be working in hard woods like mahogany, maple, cedar, spruce. Making small decorative items to start with.

Anyway, thanks again for all the support. Systems all checked, just need cutter and we'll have take off!

[EddyCurrent]

Yes the manual is not 100% clear on 12-03 settings.
I use router cutters because wood is my material, for roughing cuts these are great, http://www.toolstation.com/shop/Powe...its/d80/sd2579 (the straight cutters)
and you can't complain about the price.
Wealden are pretty good, I just bought some V cutters from them, I'm not sure what you mean by "centre cutting", maybe you mean 'bottom cutting'; http://www.axminster.co.uk/axcaliber...tom-cut-insert I rather like the Axminster cutters too.
If the cutting edges extend below the cutter body I regard that as okay for plunging.

Some more tooling links to try out.

www.cutweltools.co.uk
http://www.advancedcarbidetooling.co.uk
http://www.titman.co.uk/
http://www.cutter-shop.com
http://www.completecnc.co.uk
http://www.suregrave.com/cutters_tc.html
http://www.tooltec.co.uk
www.routercutter.co.uk
http://www.routertooling.co.uk
http://www.gravograph.co.uk
http://www.arceurotrade.co.uk/catalo...raving-cutters
http://www.shop-apt.co.uk
http://www.cncroutershop.com/uk/