Charles Lamont's Model Engineering Pages -> IQC Toolpost -> Toolholders

Model
Engineering An Indexing Quick-Change Toolpost
Introduction Description Construction Toolholders

This is the current set of toolholders, as at March 2003

Holders for small boring tools come in four shank sizes: 3/16, 1/4, 5/16 & 3/8 inch.
The boring tools are made from silver steel, as described by George Thomas in The Model Engineers Workshop Manual.
Height adjustment of the toolholder is by means of the screw in the centre of the strap. The small grub-screw in the front of the strap is used to compresses a nylon plug (strimmer cord) until the adjusting screw is finger-tight.
So far, I have made one boring bar holder, for a 1/2" bar. I think this will be stiff enough for most work, but 5/8" or 3/4" bars are a possible future additional luxury.
This extended toolholder has proved to be very useful for jobs needing tailstock centre support, and for working between centres.
This type of work presents two problems. The topslide tends to foul on the tailstock body, and the toolpost body tends to foul on the rotating centre. The 3/4" extension of this toolholder is sufficient for all but the smallest workpieces.
I have made only the one to try out. Several more are a high priority for the next batch.
These offset toolholders are intended to provide extra clearance whenever it is needed. The offset angle is 15°.
They are also intended to allow a tool bit to be ground to give clearance angles without creating a neck in the tool. For zero-rake tools, such as for turning brass, a single tool can be used for turning and facing cuts.
As with the plain toolholders, they are made for 5/16" square tool-bits.

This dial-gauge holder has four positions where the arm can be clamped by either of the locking screws.
The locking screws have a broad, flat end, and the shank of the arm has a flat on top. This ensures that the dial-gauge is always on centreline.
To avoid mistakes, the usual height adjusting screw is not proved. A grubscrew is used instead. It is set and locked.
The most recent additions are a holder to take the Ball Turning Attachment and this holder for a die grinder.
This one is an assembly of four bits of aluminium alloy. I wanted something fairly quickly so that I could re-grind the jaws of the 3-jaw chuck. I used aluminium because I had it to hand and it is easy to machine. The holder would not stand up to rough use and it does not need to, it is not going to get it.

Model Engineering	An Indexing Quick-Change Toolpost
	Introduction	Description	Construction	Toolholders


This is the current set of toolholders, as at March 2003

	Holders for small boring tools come in four shank sizes: 3/16, 1/4, 5/16 & 3/8 inch. The boring tools are made from silver steel, as described by George Thomas in The Model Engineers Workshop Manual. Height adjustment of the toolholder is by means of the screw in the centre of the strap. The small grub-screw in the front of the strap is used to compresses a nylon plug (strimmer cord) until the adjusting screw is finger-tight.
So far, I have made one boring bar holder, for a 1/2" bar. I think this will be stiff enough for most work, but 5/8" or 3/4" bars are a possible future additional luxury.
	This extended toolholder has proved to be very useful for jobs needing tailstock centre support, and for working between centres. This type of work presents two problems. The topslide tends to foul on the tailstock body, and the toolpost body tends to foul on the rotating centre. The 3/4" extension of this toolholder is sufficient for all but the smallest workpieces. I have made only the one to try out. Several more are a high priority for the next batch.
These offset toolholders are intended to provide extra clearance whenever it is needed. The offset angle is 15°. They are also intended to allow a tool bit to be ground to give clearance angles without creating a neck in the tool. For zero-rake tools, such as for turning brass, a single tool can be used for turning and facing cuts. As with the plain toolholders, they are made for 5/16" square tool-bits.
	This dial-gauge holder has four positions where the arm can be clamped by either of the locking screws. The locking screws have a broad, flat end, and the shank of the arm has a flat on top. This ensures that the dial-gauge is always on centreline. To avoid mistakes, the usual height adjusting screw is not proved. A grubscrew is used instead. It is set and locked.
The most recent additions are a holder to take the Ball Turning Attachment and this holder for a die grinder. This one is an assembly of four bits of aluminium alloy. I wanted something fairly quickly so that I could re-grind the jaws of the 3-jaw chuck. I used aluminium because I had it to hand and it is easy to machine. The holder would not stand up to rough use and it does not need to, it is not going to get it.