The open riser
format keeps mass weight to a minimum, while the relatively deep span front to back creates stiffness, which is essential to an efficient and accurate system.
The difficult impeller was produced in a squeezer mold using an open riser
fed by a large overhead mass of molten metal.
With a pouring temperature of 770C (1,418F), an open riser
was used to prevent any shrinkage and air entrapment inside the casting.
* eliminating blind risers located below an open riser
with a heavy section connecting them;
In this case the open riser
will usually be thoroughly drained because it feeds, or tries to feed, a large portion of the casting plus the blind riser.
A skimmer core and open riser
used in combination were designed for sand and permanent molds for this purpose and are shown in Fig.
A skimmer core in combination with an open riser
prevents blockage of the ceramic foam filters.
The setting of the filters for these two parts are the same: the filter is located horizontally in the sprue, and each mold has four castings and one open riser
. The filter has been placed in the sprue due to limited space in the flask.
Beyond their basic function, risers also provide extra metal to compensate for shrinkage; allow mold gases to escape, in the case of open risers
; and provide extra metal pressure on the solidifying mold to reproduce mold details more exactly.
An entrance staircase with open risers
(to allow for rising and receding storm water) leads up to the main living quarters on the first floor.
and thinner pieces of metal allow for sturdiness as well as a more delicate appearance."