Variable Frequency Drives (VFD's) - what do they cost new over there?

[gerald_d]

Hi All

I am investigating high freqency spindles and found that new VFD's cost around $775 around here. Somehow I think that is a bit steep, and I wonder what they cost over there?

The brief spec is:
3-phase input and output
driving 380 - 400 Volt at 8.1 Amp
Capable of 400 Hz.

(Delta VFD 037 B or equivalent. Delta is not supported over here)

[rookie432]

Gerald,

I the last 1HP Siemens VFD I sold with similar specs was about $500.

Bill

[gerald_d]

Thanks Bill. The one I need is about 5HP, so $775 isn't so bad after all?

[rookie432]

Actually pretty good. Went back in my records and the last 5hp 480v vfd I sold was $1220 US.

Sounds like your getting a deal.

Bill

[harold_weber]

I've bought two Hitachi VFD's from driveswarehouse.com. Their maximum frequency is 360 HZ, but thats all I need for my Perske spindles.

The Hitachi application engineers have been very helpfull - any E-mail questions are answered promptly.

[gerald_d]

Interesting point Harold. By far the best price I can get for a 10 Amp drive is the Brazilian WEG (http://catalogo.weg.com.br/FILES/Artigos/4-101.pdf) brand at $511, but they are limited to 300Hz which will give a max spindle speed of only 18 000 RPM.....which is probably okay for non-ceramic bearings....

[dingwall]

Gerald, did I miss something? Is hell freezing over? ;)

I've had contact with driveswarehouse.com they responded quickly and were very helpful.

[richards]

I've been told that it's best to keep the speed at 18,000 or below with my Colombo 3hp spindle. My normal speed for most cuts in wood is around 12,000 - 13,000 rpm with a feed rate of around 5-6 inches per second and a 1-flute cutter. That gives a chip load of around 0.020 - 0.025 which works great for particle board and baltic birch.

If there are a lot of curves or corners, the actual feed speed will be a lot slower due to ramping, so I always check the saw 'dust' to make sure that it isn't too fine. 'Dust' about as coarse as beach sand words good for me in particle board while MDF has a better finish with a finer 'dust', and baltic birch seems to fall about half-way between particle board and MDF. Playing with the feed speeds and leaving the spindle speed alone is my preferred method. Also, I take an occasional reading with the infared themometer ($50 or so from the local Checker Auto Supply store) to verify that the spindle is running at 120 degrees or lower. If the temperature starts to climb above that, I take shallower cuts.

It may seem like I'm nurse-maiding the spindle, but it cuts sooo much better than the PC7518 that I'm willing to adjust my methods to fit the spindle.

[gerald_d]

Sheldon, it took a while to unwrap some of the tales spun around spindles - I have a 4.6 HP spindle on order from Fimec in Italy. Our routers have earned us huge orders for cutting MDF.

[Brady Watson]

Gerald...spindles are a waste of money. Everyone knows that regular old 'consumer' spec routers are better than a spindle.




Nice to see you are kickin' it up a notch!

-B

[gerald_d]

I could never justify the huge price divide between routers and spindles. When we started out in the year 2000, with a venture that may have been only a temporary gap-filler, the PRT 96 cost about $5000 and adding a spindle would have doubled it. Today, the SB price list gives a router at $365 and a spindle package at around $3500 (10 times more). The route I'm taking by shopping around is to get a spindle package for under $2000, which is under a third of a PRT price today. This is a very different picture to what I saw in the year 2000.

Having said all that, our old PRT will continue to run on routers - IMHO I don't think the gantry/carriage system is stiff enough to do justice to a pricey spindle. The Fimec will be going onto a 9' x 6' "board-cutter" that is being built in the back of the shop. Practically all boards, except marine ply, over here are 9' x 6' (2750mm x 1820mm). At the moment, our MDF supplier has to cut all the boards in half for us.

[dirk]

Hey Gerald
What kind of design for the "board cutter" are you using?
Similar to PRT or completely different?

[gerald_d]

Similar to PRT, except that I am not too concerned to get a high clearance under the gantry. I am making "modules" interchangeable with the existing PRT so that one could be robbed for spares to keep the other going. The modules are the motor assemblies, router/spindles, z-towers, y-cars, v-rollers (mine are not BWC), contol box with software.

[dirk]

Are you grinding your own rails for the V rollers?

[gerald_d]

A sub-contractor will do that for me - the same guy that fixed my current PRT's rails.

[gerald_d]

The Delta drives are branded DURAPulse over at Automationdirect (http://web5.automationdirect.com/adc/Shopping/Catalog/AC_Drives_-z-_Motors/DURApulse_-_GS3_(230_-z-_460_VAC_Sensorless_Vector_Control)/GS3-25P0) at very good prices.

Delta have just appointed a distributor for South Africa and I got a 5HP VFD037B43A out of their very first shipment at $540.

The Fimec spindle prices are $741 for the 18000rpm model (steel bearings) and $1058 for the 24000rpm ceramic bearing models - at the factory door in Italy. Totalled, even with cabling still to be purchased, this is a lot more economical than the $3800 Colombo package from Durham

[benchmark]

Hi Gerald,

Welcome back, I hope you had a great holiday...and a nice welcome back with a new spindle.

Which model did you get......The HT Spindle which can accept light plunge cutting, or the HM spindle motor with double angular contact thrust bearing at the work end or ceramic bearing.

Regards


Paul

[gerald_d]

Hi Paul

Got the ceramic bearings because we often run over 20000rpm. Also curious about the life of the ceramics, but may change bearing types later. Apparently the housing is standard and accepts different bearing packages. Talking the technical issues with the Italians is a little difficult.

From a spec sheet:


6587
These are the options I was offered:
- HM73c-140P 3.5kw 18000 rpm power curve 78 380V with terminal box, standard bottom fixing Price Euro 616,00
- HM73d-140P 3.4kw 24000 rpm power curve 79 380V with terminal box, standard bottom fixing Price Euro 879,20

And when I asked them: "Could you also tell me the technical difference (bearings?) between the models HM73d and the HM73c that you offered?", the reply was "The model HM73c runs at 18000rpm. The model HM73d runs at 24000rpm. Also the bearings are different. For the 24000rpm we mount ceramic bearings on the fromt side and double contact bearings on the rear side."

I would suspect that HT models are slightly less expensive, and probably also have a ceramic bearing option?

[harold_weber]

Gerald, could you tell us what led you to specify the DuraPulse VFD over the less expensive GS2 Series?

The DuraPulse drive allows one to run in the "sensorless vector mode". When I corresponded with the Hitachi factory support guy, he said that I would NOT want to use the "Sensorless Vector" mode on a Hitachi drive when driving a 2-pole router spindle. This was because the sensorless vector mode was not needed for a motor that did not start under load, and because the Hitachi "sensorless vector" mode was not really set up for motors that run at frequencies above 60HZ.

So given that you were shopping for price and the GS2 drive is less expensive than the DuraPulse drive, what are you looking for in the DuraPulse drive? Is the DuraPulse drive set up to drive router spindles in the "sensorless vector" mode?

[gerald_d]

Harold, what is this "GS" drive that you are speaking of? I picked the Delta drive because it seemed like a popular drive used by others on the forum, and because it was being imported here (South Africa) at the time (The link to the American supplier is for the American readers, but useless to me). When I get around to setting it up, I'll check whether I need to set a "sensorless vector mode", but this is mostly Greek to me. sensorless vector mode.

Aha, I understand Harold's question now..... I bought under the Delta name in South Africa, with their original number VFD..... You are seeing the re-branded Durapulse that they have re-numbered GS. We seem to be talking of the same thing! Prices there and prices here are world's apart.

[harold_weber]

Gerald, looking at the Automation Direct website you mentioned, they offer GS2 model drives and GS3(aka DuraPulse) drives. These seem to be two different models being offered by the same manufacturer. The Automation Direct "overview" page for the DuraPulse drive says it has additional features over those on the GS2 drive.

Maybe I should be asking if any of the spindle users are running their Delta VFDs in the sensorless vector mode and feel they are getting a benefit??

[gerald_d]

After reading a bit deaper, Automation Direct seems to have taken an unusual amount of trouble with their documentation to "hide" what I believe is the Delta origin of their DuraPulse series. The DuraPulse GS3 may in fact be a "copy" of the well-known Delta?