Longer T-nuts – Warco HV4 4″ / 100mm Rotary Table

I saw a set of long T-nuts being used in a jig boring machine and made me wonder if this idea could work for the HV4 rotary table.

The long T-nuts with 8mm bolts fitted – I have now machined the upper thread on these down to 6mm so that I can use the Unimat 3 clamps as they are very neat and compact.

The round ends of the nuts were machined using this table and this allows them to push right into the T-slot – obviously cut using a milling cutter and hence round end to groove and the lower T-slot.

The table clamps have to be removed to allow the T-nuts to fully rotate.

If you want to use the T-nuts and table clamp then it will be a case of probably only using one of them and the one that is clear at any point in time.

The issue with these long t-nuts is that of clearance. So the locking T-bar bolt had to be replaced.

Here it is clear to see the supporting bolt on the back of the clamp reacting the force against the longer T-nut that exntends beyond the table.

This is what allows maximum use of the table diameter.

An odd reaction of forces here, but the clamping force is very high and works brilliantly – I might have to make some special bolts with rotating bases to more evenly distribute the force on the supporting bolt.

The nuts are threaded 8mm and so if needed I can just fit 8mm bolts and go for a higher clamping force – not sure this is needed for the machining that I normally do.

Both T-nuts in use and as you can see they just clear the base casting.

I did have to remove the locking bolt for the worm drive and replace it with a screw – this actually works much better than the T-bar that was supplied with the HV4 from Warco. I would actually like to use a grub screw for this, but the 6×1.25mm thread makes this difficult to find.

Leave a comment