|
|
 |
|
|
|
|
|
|
BAYO T-REAM |
|
|
|
|
|
|
|
Runout
Runout should be thoroughly inspected prior to reaming, as excessive runout accelerates wear, causes chipping of the leading chamfer and produces poor surface finish and cylindricity (the top of the hole is larger than the bottom).
The runout is influenced by the entire system which is comprised of the spindle, the adapter, the shank and the BAYO T-REAM head. All of the connecting elements should be thoroughly inspected during assembly.
Runout can cause an enlarged (out of tolerance) hole, especially in soft materials such as aluminum.
The special clamping design of the BAYO T-REAM ensures a runout of no more than 3 µm between the shank and the reaming head.
In order to obtain the best reaming results, we recommend to verify that the whole system runout does not exceed 5 µm.
Cutting conditions
An optimal reaming operation can be obtained by taking into consideration the runout, machine, adapter, coolant, material, allowance, etc. and then to apply the most suitable cutting conditions for the specific application and workpiece material.
Adapters
High speed reaming requires minimal runout. The adapter being used has a strong influence on the total runout of the reamer. The runout phenomenon depends on two separate factors:
• Runout between adapter and spindle
• Runout of the reamer where it attaches to the adapter
(tool clamping)
In order to reduce the runout between adapter and spindle it is advisable to use the most advanced and highly accurate clamping system which exists in the market (i.e. HSK, KM, COROMANT CAPTO®). The repeatability of the clamping is also an important issue, since if low runout is initially measured on the machine after setup, it should remain the same after tool indexing. Therefore both adapter and spindle should be maintained in clean condition and repeatability must be confirmed after each tool change.
Additionally, in order to obtain low runout between tool and adapter, it is recommended to use a high precision chucking system such as hydraulic, shrinking chuck (i.e. ISCAR/ETM SHRINKIN) or an adjustable adapter. When using spring collets, a high precision collet type should be used (i.e. ISCAR/ETM ER-AA).
Most recommended adapters for high speed reaming are the adjustable types, where it is possible to reduce the radial and angular runout to a minimum.
Since high speed reaming requires internal coolant supply, only adapters with this option should be used.
Hole Preparation
Prior to the reaming operation, it is recommended to produce a chamfer around the hole in order to help the reamer maintain an accurate centering position, obtain better surface finish during penetration and improve tool life. In addition, it is recommended to perform the drilling and the reaming operation while the workpiece is clamped in the same position.
For optimal reamer performance on cast iron and steel, the preliminary hole should be 0.2-0.3 mm smaller than the diameter to be reamed. On soft materials such as aluminum, a larger allowance of 0.3- 0.4 mm should be left.
In cases when the workpiece has been removed after drilling and then clamped again for reaming, misalignment between the reamer and the hole center lines may occur. Therefore, it is recommended to leave a larger allowance for reaming.
The BAYO T-REAM are capable of increasing hole diameter by a maximum of 0.8 mm.
In cases when an extremely precise and high surface hole quality is required, a core drill is used prior to the reaming operation.
|
|
|
|
|
|