The best reliability programs start with precision balanced machines and machine parts. This involves choosing tolerances that are appropriate for the application, considering cost practicality, effectiveness, and having the smoothest running equipment. To make the best selection, a practical understanding of what it takes to achieve it is required. It is recommended that someone with balancing expertise and with experience balancing to both standard and precision tolerances be consulted, and not trusting the OEM’s or repair shop’s perspective. This is not to question the honesty or integrity of the OEM, but rather to acknowledge the inherent bias that comes from their experiences and business interests. Change is scary and hard to accept.
What will be described here will not fit all situations. In another article l will consider alternative approaches and business models. Once a precision tolerance is selected, the journey to getting precision results can be difficult. Most OEMs and repair shops have used ISO standards and therefore balanced to G 6.3 on most rotors. The thought of balancing to one tenth of G 6.3 sounds very difficult. The suggestion that what they have been doing for their customers for years is not good enough can be threatening and make people defensive. It is good to begin the conversation by letting them know that you are not dissatisfied and complaining about what they have done in the past, in fact, you would not be trying to work with them if you were. It’s just that your company is moving forward in your program and is looking for greater precision than the usual standard. Now you must be prepared to counter the objections.
In some cases, the first objection is that it would be too difficult to achieve such a precise balance. This usually comes from those who have not tried to go that far before. In other cases, it may be that they have tried it and were not successful due to using an uncalibrated balancing machine or bad tooling, issues that must be addressed in any case. It may be from a lack of training in how to properly operate the balancing machine or on the nuances of adding or subtracting weights. An effective response to the “it’s too difficult” position is to offer to have one of your people or a consultant come in to train their technicians. Usually there is a quick retraction of the too difficult argument. If not, it may be worth the time and expense to provide training, even though it shouldn’t be your responsibility, if this is an important provider that will be used often.
Another problem is when the supplier is willing to do it but says it will cost considerably more due to it being a special order. At this point you should know their rate per hour on the balancing machine and roughly how much longer it could take to get it within the precision tolerance. Realistically, the person representing your company in these conversations will not be a maintenance or reliability person. It could be a purchasing agent or someone taking that role. That person does not have to know how to balance but must know how to do battle for more than just the lowest price. Otherwise, he or she may give in when they are told how (from the supplier’s perspective) asking for such precision is unreasonable, not necessary, and would cost too much. Knowing what is reasonable and even generous is essential in such negotiations.
Another important element of negotiating or renegotiating relationships with your supplier is conveying the message that you are serious about these requirements and that they are non-negotiable. Often, the supplier will claim it is not possible to give you what you are asking for or that they are simply unwilling to do so. Even small to medium sized companies have some clout. No company wants to lose a customer. When meeting resistance, it must be communicated that you are willing to consider other vendors if they are unwilling to supply the precision you are requesting. You must also have a plan for an alternative source should that company hold the line.
One large paper company negotiated with some of their large suppliers. The person pushing this negotiation arrived at a meeting with a large motor manufacturer with a mill manager and the VP of purchasing from the corporate office accompanying him. What do they know about balancing? Nothing. They are not there to supply their expertise. They are there for one reason, to show that supplier that they are serious. After some deliberation the motor manufacturer understood that when they balance their motors to within G 6.3, some of them would also be within G 2.5 and some would be within G 1.0 on that same balancing run. They agreed the balance machine operator would attach a tag listing the tightest tolerance that the rotor met. They would put all motors that were within G 2.5 on shelves against one wall, all motors that were within G 1.0 on shelves against another wall, and all the rest on remaining shelves. When that paper company ordered motors, they would get those from the G 1.0 shelves. This was agreeable to both parties.
That same paper company met with a large pump manufacturer for the same type of negotiations. After discussions, the pump company said that they were willing to compromise and deliver pumps balanced to G 2.5 but would not go further. They assumed that since they had been a primary supplier of pumps for this paper company for many years that they would not simply stop buying from them because of this tolerance. They were wrong. The paper company found another supplier that was willing to balance to G 1.0 and the pump company lost millions of dollars in sales per year.
A final important element to these negotiations is to include a clause in the agreement involving inspection. This should not be considered an indication of doubting the integrity of the supplier but merely as assurance to the customer that all requirements are met. If a supplier is pushed to deliver a degree of precision but no other customer demands, they may assume that this request is unnecessary and unreasonable. Sending a machine or a part in the same condition as those they have sent to other customers in the past without problems may not seem to be a problem.
In one unusual case, a large refinery negotiating with a balancing shop stipulated that before the job is accepted that someone from their engineering department would go down to the balance shop (which was close by) to witness the final readings on the balancing machine. This would require the rotor to stay on the balancing machine while the engineer came to the balance shop, which would increase the price of that service. Yet the refinery felt but this was important. When asked if they inspected each time balancing was done for them, they said that at first, they went every time. Later on, they only came occasionally, but they would not let them know when.
Unannounced visits to repair shops to observe how procedures are done are also a good idea. A phrase comes to mind made famous by Ronald Reagan during the Cold War states “Trust but verify”. The same principle should apply to contract work. Acceptance criteria should be in any contract before delivery or there will not be any recourse. For example, if a motor is delivered it can be placed on a rubber mat on the floor, hooked up, and run solo. If the vibration at 1x RPM is above the amplitude in the contract, the motor should be returned. This can only be done if there is adequate lead time, and another motor can be delivered when needed. In the contract there should be a serious consequence for the supplier if this should happen. If only one unit is rejected, the message will have been sent.
None of these changes will happen overnight. There are many people that need to be on board within your company as well as the suppliers. This change may end up being a difficult process, but seeing improved reliability and longer life on our machines as a result of starting with precision balanced machines and parts will make the effort very worthwhile.