These blades are designed to be used with New3Acut and Neway 45° &46° cutter heads.
A form tool setting fixture is needed to set up and index blades on cutter head.
A basic seat and guide machine or a Bridgeport type mill is recommended for best
concentricity, finish and less effort, but a Neway's power drive unit can be used with good results,
and depending on hardness of seats, cutting with a "T" handle is also possible and with practice ver good results can be achieved.
To setup blades on cutter head , first set tool setting fixture on valve face, locating the point at top side of the seat angle.
The correct setting is to locate the seat at the center of valve face.
Than transfer this setting to the cutter head to set blades, here again set the point at top side of seat angle.
Make sure you use a pilot with same diameter as the valve stem, this is very important.
Observe the point is at the corner where top angle and main seat meet.
Also make sure you have the good and tight to orevent any damage to cutter head.
Donot over or under hang blades, always use correct diameter cutter head.
Avoid as much as possible to use 3 blade cutter heads, besides not cutting a concentric seat,
have a tendency to dig in, hang and damage can occur to cutter head and work, specialy when
using a seat and guide machine or a knee mill to drive cutter heads.
Slow RPMs gives best results about 45 to 60 RPMs. Use a bounce spring ans some cutting fluid,
soluble cutting oil, alcohol or Neway's cutting fluid, there are so many differrent materials used to fabricate
seats that you have to experiment what works best for you, use WD40 when touching aluminum on top or
To drive cutter, you need a 1/2" Hex socket attached to a 3/8" ID guide.
This driver has a 5/8" shank and can be held with a 5/8" chuck or a 5/8" end mill holder on a seat and guide machine or a knee mill.
The 3/8" ID on driver will support the pilot on top to eliminate some deflection on pilot while cutting.
We make a driver for seat and guide machine or a knee mill Part # HD375 available on ebay and in our website.
When encounter a severly warped seat, use first a correction 70° or 75° cutter head with serrated blades to narrow the cutting area of your final 3 angle cut, this will help to cut a more concentric seat.
On really hard seats, or when a full contact betwwen the cutter blades and the seat has been achieved(100% of the blades profile cutting) and the blades no longer cut, do the following:
1st.- pick & mark two blades opposite to each other(on a five cuter head)
2nd.- Raise them or slide out, about .015" above the rest of blades, using for tool setting fixture, it does not have to be exact but do not exceed more than .020"
What this will do is, a more aggressive cutter on the throat angle (60°), note that
the seat widthwill be narrowed, once the depth of cut has been reach or the seat is cleaned up, readjust the blades and finish the cut so will mantain the original blade profile and seat width.
Caution: Do not overdo this operation, you could end up with a sunken seat.
All blades have the same improved cutting angles, suitable for any drive cutting method,
basic seat & guide machine, Bridgeport type mill, Neway's power unit and "T" handle.
But for a more speedy operation, best concentricity and finish, we recommend a basic seat and guide machine with an air floating table. Cutting with a "T" handle it will require some practice to cut a smooth seat, use a bounce spring, a steady turning motion and a down pressure according to the hardness of seat.