I have 3 of those planet ones,2 small 1 large,had them 24 years ,keep one in the van even,amongst the most used tools,amazing value,as said so unfamiliar to other tradesmen,even the local industrial supply rep stated he’d never seen one.
Most of the holes I drilled were 2mm clearance so, provided I took care over marking out, I never had a problem. On the odd occasions things went adrift, some surreptitious use of a hot spanner and/or a large drift soon sorted the problem.
I made a small transfer punch that works on flat sheet for any size hole in the range 3 - 10 mm. View media item 10976It consists of three parts that slide in each other.
In the centre is the punch with a 60 degree point made from hardened steel.
Around the punch is a steel sleeve with a 90 degree conical point. The 90 degree cone centres the punch in the hole.
Around the sleeve is a sliding collar. The ends of the collar are machined on the lathe.
To use the tool the conical sleeve is centred in the hole and the collar is pushed down. The collar ensures that the punch is at right angles to the surface. The punch is then struck with a hammer to transfer the hole position to material under the hole.
This basic punch could bve scaled up or down to suit other rangfes of hole sizes.