Conforming Hydroforming™

The

Critical 6

Questions To

ASK

ASK

When Searching For
A Hydroforming Company

Experience

Expertise

Knowledge

Know How

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A hydroforming press is a significant investment for any size company. The problem is many
companies have not previously purchased a hydroforming system and do not know what to
look for or the right questions to ask. There are a lot of companies that would be happy to
sell you a hydraulic press with a pressure intensifier and call it a hydroforming system. Just
because a particular company may sell hydroforming equipment does not mean they know
how to make it work.

Before you submit your confidential drawings and specifications for a system quotation,
review and address these simple set of questions to ensure that you get precisely what you
want in a hydroforming company without losing your investment.

1. Do you sell hydroforming systems or do you just sell equipment that
can be used for hydroforming?

The difference here is not in the wording, it is in the company’s knowledge base. A good
company that sells hydroforming systems is knowledgeable in all aspects of hydroforming
and what it takes to make the system perform to each customer’s particular requirements.

2. Do you have in-house FEA hydroforming analysis expertise?

Any qualified vendor will have in-house expertise in this area. This is such a critical element
in specifying and designing a quality system that not having this capability would make one
wonder about the level commitment the vendor has to hydroforming. The FEA is used for
two things, part feasibility and system sizing. All of the critical components of the hydroform-
ing system are sized based on analysis, the clamp tonnage, the intensifier pressure and vol-
ume and feed cylinder stroke and force. A misstep here could cost hundreds of thousands
of dollars if the press is sized incorrectly. This analysis capability also allows the system
supplier to determine whether a particular part is feasible for the hydroforming process and
provides the basis for discussions between the hydroforming system manufacturer and the
user regarding possible changes to improve the part characteristics for “hydroformability”.

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3. Do you have experience making my part with this material?

A company that has experience with your industry and your part in particular is invaluable.
This will give them a unique insight into your special needs and the know how to provide you
with a system that is customized for your application. A thorough understanding of the mate-
rial properties and how they change during hydroforming is absolutely critical.

4. Is the hydroforming servo controlled?

Servo control allows positions to be held within 0.001” and forces to 50 lbs. On small,
dimensionally sensitive parts this tight control over force and position is critical. It also
makes for a very repeatable process and thus consistent part quality.

5. Do you have an in-house die design staff?

You are going to need tooling designed for the part. What should the tool be made of? How
will it integrate with the press? Is it designed for easy removal from the press? A basic die
for forming a simple tube consists of four parts; upper and lower die cavities and left and
right plungers. The plungers are for plugging the ends of the tube to maintain pressure and
if necessary to feed the tube during forming. How do you design this plunger? How does it
seal the part? How does it feed the part? The plunger is also the portal for the forming
fluid. How is it integrated? Will the design ensure the tube won’t leak? Does the design
change if I need to feed my part? This discussion will quickly flush out the pretenders.

6. Is on-line trouble shooting provided as part of the support package?

This is particularly critical for production applications. A good PC based control system with
remote capabilities will allow for virtually instant support and assistance with process
development and on-line training of new operators. It will allow the supplier to “see” the
system on-line and to solve problems quickly. It will reduce the number of field service calls.
And if a service call is required it will help the service engineer identify the problem before
he leaves the factory.