Oversize Cutting by Tap & No Go Passing problem on Pillar type Drilling Machine using TSFL/QSFL |
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Problem Description: The tap was cutting oversize and not go is passing
Component Aluminum die casting Machine: Pillar type drilling machine Tapping size M10 x 1.5 The attachment used: Tapping attachment with radial parallel float/length compensation/safety clutch.
Solution: Many trials were taken with different cutting speeds. But there is no much change in the results. The torque setting was reduced from M10 to M8 . The No Go problem was not observed. Since the material is soft, such problem was observed. |
Tapping depth problem on Japanease make HMC at Bosch Chassis Systems Pvt. Ltd. |
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Customer : Bosch Chassis Systems Pvt. Ltd. Problem Description : A complaint was received from a customer that the tapping depth is coming undersized.
Following was the tapping data: Machine : Horizontal machining center Attachment used: Tapping attachment with axial length compensation of +/- 7.5 mm Tapping size: M 8 x 1.25 Spindle RPM: 200 RPM Material of the component: CI.
The tapping depth was coming undersized after tap re-sharpening. Such problem was not observed when the tap was new. Customer also claimed when such tap is used on rigid tapping holder on the machine having rigid tapping facility, the under size depth problem is not observed. Solution : The tapping cycle was observed carefully. It was seen that while taking the start the compression was getting pressed and the tapping was starting after full compression is compressed and that is the reason the depth was coming undersize. That means the tapping requires a rigid start, when the cutting edges are ground. Hence the with the help of setting screw the pressure on the compression is increased. This helped to start the tap immediately on touching the drilled hole. |
NO Go passing Problem - Tap Cutting in Reverse Direction |
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Over the years as service providers to the industry we have encountered several cases which we are an invaluable resource while solving problems in tapping. We present them here.
Problem: NO GO Passing
The trial of tapping attachment was carried out on a cylindrical head (Material Cast iron) with M8 Spiral point (SPPT) tapfor through tapping(Length=18mm). Trial was carried out at 200rpm. On Testing it was found that No GO Gauge was passing. Different speeds were tried but hte problem was persistent. We also tried changing the torque setting but no change was observed.
One more trial was taken. This time we did the tapping in the forward direction & then manually removed the tap manually from the bottom of of the tapped hole. We found that NO GO wasn't passing. This meant that the tap was cutting in the reverse direction.
Thus problem was basically in the tap & replacement of tap with proper geometry solved the problem.
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