Lots of good advice!
Cheapest or most expensive is not always best. Ask yourself, if you did this job according to the Customers desire for cheapest but they are expecting to get the "most expensive" outcome and the results are to meet your expectations (for you), would it be wise and would you be happy using "your" product?
As others have said, agree on a price or rate and if it is not fair for you (or the Customer, but this is his choice), walk away. Remember, you also will be first contact point for when there is a problem or a failure to meet the expectations "expected or demanded" by the Customer. If what you did can't meet those expectations what are you going to do? It's your reputation after all and you have to supply some sort of warranty.
Don't sell yourself short or doubt your abilities by trying to do a good job at an unrealistic price or with inferior parts - you have to eat too and breaking even or running at a loss doesn't work for very long.
One of my Niece's partners does 4x4 add-ons and upgrades, he is in high demand because of his workmanship and reputation and is not inexpensive but he often spends much of his time fixing up 4x4 add-on botch jobs done by the lowest bidder because they stuffed it up. The moral here is that cheapest generally ends up costing more than what was "saved". A new bonnet or fender because the stuffed up one is impractical or too expensive to fix (labour costs) and needs replacing to start and do the job again but properly.
Someone always has to be your first Customer so get it right first time then they can be a happy and supportive reference.
Another Aussie $0.02 :-)
Thanks for the advice he1957 !
Well guys, just to set the record straight, the cheap Chinese motors I am considering have been tested and recommended by a reputable, experienced guy(also a member here on the zone) so, I'm on the safe side of things(as much as I can)... at ~$1200 for a 5.5KW servo bundle, I guess it's very cheap... just a little more than a Mitsubishi encoder alone....I know it's lacking some of the Mitsubishi features but, no one expects a race car at the price of an SUV.
What do you guys usually pay for a brand name 5.5KW 70Nm servo bundle ?
Thanks Very much !
Just as another side comment on this question, the systems such as Galil, Acroloop, Kmotion etc, because these systems close the loop in the controller, they are able to take advantage of simple non-intelligent (transconductance - torque mode) drives.
This means that almost any manufacturer of drive & motor can be mixed and matched such as A-M-C, Copley, Aerotech etc, often used to run any motors that are on the machine and still viable.
The PID loop is between motor and controller so very minimum tuning, if any is required by the drive.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Thanks for the replies Al !
Word of mouth... double edged sword......it takes skill & art to achieve.
Thanks for the info but, the main problem is the lack of machine documentation & the motors' condition, some of which have clearly been messed with so, I'd rather not bet my reputation on unknown 40yo electrical HW (from what I saw, I wouldn't call it electronics) +70Amp is sure to produce a very loud bang alarming everyone that you've got no idea what you're doing...which is not good as a business plan .
Thanks very much !