Design Process
The custom sheave design process is relatively simple. You
tell us which are the constraining parameters - OD, bending
radius, weight, temperature, shaft diameter, etc - and we
will propose solutions. Refer to our order form under the
‘Request Quotation’ link. We must have maximum
product size and minimum bending radius (Root Diameter).
Economics
It is generally uneconomical to purchase fewer than ten identical
sheaves due to engineering and setup costs.
The
simplest sheaves (and most sheaves) require three distinct
CNC operations and each step requires programming and setup
time.
Materials are purchased to requirements. Very small orders
for one or two pieces are relatively expensive.
For less than ten sheaves, it may be more economical to modify
a stock sheave.
Prices for thirty or more identical sheaves will often be
comparable to stock sheaves of a similar size.
Materials
For custom sheaves of 22” OD or less, we prefer Gar-Dur,
the densest and most abrasion resistant UHMW-PE available
commercially. It is available in a variety of sizes and shape
from stock, generally yellow in color. This material was originally
developed for mallet faces that must stand up to continuous
pounding blows. We have been using it for 15 years and have
experienced excellent results.
Other materials we use are:
Other
UHMW-PE, especially for sheaves over 22” OD.
HDPE for lower performance and lower cost.
For less than ten sheaves, it may be more economical to modify
a stock sheave.
Cast polyamide, for special applications.
Aluminum
D2 Tool Steel
Composites
Composites such as carbon fiber are our newest development
in sheave manufacturing. We have a technical collaboration
with a leading aerospace manufacturer that promises to yield
lightweight, strong, sheaves with excellent wear characteristics.
We have seen weight savings of 50% with no compromise in expected
performance.
Due to tooling costs, these sheaves are economical only if
the ultimate requirements will be 100 or more. However, sheaves
of 30” OD and larger may be very cost competitive even
in smaller quantities. As our experience grows, we will post
some case studies on our web site to give you concrete examples
or weight and cost advantages.
Balancing
Our products can be statically or dynamically balanced to
suit your requirements. Normally balancing is not required
because precision machining of homogeneous materials produces
inherently balanced finished sheaves, requiring no dynamic
balancing for 1500 RPM and above.
OEMs
Contact us with your sheave requirements before freezing your
equipment designs. We can offer a better sheave at a lower
cost in many cases, if we are consulting early in the design
stage. Many times a modification of our standard sheaves is
the economical choice when certain design parameters preclude
use of an off-the-shelf sheave. Even fully custom sheaves
can be quite economical when the right decisions are made
on materials and designs. Put our experience to use for your
business.
Many
applications, particularly in wire & cable processing,
have design constraints that can’t be met by stock sheaves
from us or other suppliers. In recent years, Sheaves, Inc
has developed over 300 custom design sheaves to meet critical
customer parameters. We welcome the opportunity to work with
you to achieve the most economical solution for your particular
situation.
