A tapping machine is a long-term investment and the wrong choice can cause immense frustration while using it. Here are some key things to check before buying a tapping machine.
Spindle Speed Range
As well as knowing how to use a tapping machine for tapping, knowing what you are buying is important. Taps are used for different materials at different speeds, so ensure the spindle speed is suitable for all of the materials and tap sizes you use. Aluminium / Plastic: Higher RPM, Steel / Stainless: Lower RPM, Controlled Cutting.
Torque Limiting and Clutch Adjustment
Check the tapping machine’s clutch for fine tune-ability. The clutch should allow you to set the torque limiting of the tapping machine drive to come out of drive before the tap snaps. The amount of fine tune-ability of the clutch is important – particularly for small threads in hard materials. This is where the fine tuning of the clutch will have a large impact.
Arm Reach and Throat Depth
Work out the largest workpiece you are going to use and check the arm reach and the depth of the throat of the tapping machine against this. It is no good a tapping machine looking great in pictures if the actual physical dimensions of the machine do not allow for the largest workpiece that you are going to use on a regular basis.
Power Source
Pneumatic tapping machines are ideal for use in workshops with an air supply and provide constant torque. Electric tapping machines do not require a compressor, are generally quieter and more portable than pneumatic machines and ideal for use in confined spaces. Battery-powered tapping machines are ideal for users that travel from site to site and require a tapping machine to use on odd sized workpieces.
Chuck Runout and Quill Play
Run the tapping machine under power and check the run out of the test tap held in the chuck for any signs of run out or play in the quill.
After-Sales and Spare Parts
Check if the supplier holds UK stock of spare parts for the tapping machine you are interested in. Also, ensure that the tapping machine you are purchasing complies with your requirements for safe use of work equipment and machinery before it is delivered to your site.
A useful reference for Tapping Machines is www.cotswold-machinery-sales.co.uk/roscamat-tapping-machines/.
A few checks now will save a lot of grief later.