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Harold Hall

A Tapping Stand having Automatic Feed,

 Harold Hall

Tapping Stand, Automatic Feed
Tapping Stand, Automatic Feed, Feedscrews

Automatic Feed Tapping Stand

M3 to M8 Thread Tap Holders and Feed Mechanisms

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All pictures can be clicked on to provide a larger view

Metalworking

Workshop Projects

The feature that makes this tapping stand differ from most, if not all others offered for the home workshop, is that it automatically feeds the tap at the correct rate for the pitch of the thread being cut. This eliminating the need for the user to apply any down feed pressure to get the tap started.

 

The main advantages are:-

1. The thread can be made using just a plug tap, taper taps not being required.

2. No partial threads at the start as often occurs when using a taper tap as the thread is complete from the first thread. This is not that important with deep threads but very beneficial when tapping thin sheet metal.

3. The controlled feed mechanism can be held in the tailstock drill chuck and the feature is then also available for holes being tapped on the lathe.

4. The feed mechanism uses a normal screw to control the feed rate so there is no need to turn and thread parts, except where screws to the required pitch are not available.

5. The feed mechanism is not diameter dependant. Typically therefore, a single feed mechanism for 40 tpi will suit all diameters of Model Engineers threads having that pitch.

6. Like all taping stands it produces a thread that is, with a little care, perpendicular to the surface being tapped.

7. In manufacturing terms it is very easy to make.

Tapping Drill Sizes

When tapping using this tapping stand or purely by hand, do use a drill size that gives between 60 and 70% thread depth for all but the most demanding applications, See Recommended Drill Size tables

 

 

Design Drawings

The design drawings for this can be found in my book

Model Engineers’ Workshop Projects” See number 39 in the

                      Workshop Practice series.

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