One frequently reads questions about how to lock the camshaft, injector pump, and crankshaft when changing the toothed timing belt. Tools can be bought from quality toolmakers to do this job, but I have found they can be easily made at home, and at times home-made stuff can be better than bought items.

I have made many such items over the years. Below is a simple tool for blocking the camshaft wheel and the injector pump wheel on the Ducato 1929cc engine as fitted in the 1993 or so TD10. I made it from mild steel strip, bent to the shape of the gear wheels, with pieces of old timing belt stuck on the provide a firm seating for the tool. This tool would work for other engines where the distance between the wheels is similar, changing the belt strips would accommodate differing tooth pitches.
Here is one I made for my sons Seat Leon. For this one I did not glue pieces of old timing belt, instead carefully bent the locking teeth to fit the tooth pitch of the belt. The method of use is obvious in both cases, adjust the pressure between the two gear wheels until they are firmly locked together, using the lock-nuts on the threaded rods.
Here is a tool I made for removing the Ford Escort diesel crankshaft toothed wheels, which have no lip behind which a normal extractor can be located. Such a tool of appropriate diameter would work for most toothed crankshaft pulleys. Tightening up the nut and bolt causes the clamp to squeeze the pulley, with the piece of old belt between, enough to grip and pull off the timing wheels, which become locked over the years by the 'O' rings with which they are pressed onto the crankshaft nose.
The trade sells timing pin sets like the one I bought below, quite honestly they are a waste of money as ordinary twist drills will substitute for most of the plain pins, and the specials in the set are in this case specific to only one engine, in this case the Ford 1753cc diesel. Save your money.
The large puller I made from two big nuts such as used to bold street lamps down to the ground anchors, two lengths of rebar, two short pieces of thick steel strip, and a length of threaded rod. It has been altered several times to suit differing requirements such as pulleys, drop arms, and the like. I regard it as expendable and modify it as necessary.
The home-made items below cost me nothing except a bit of simple fabrication, welding, and paint, after thinking out the simplest construction that would serve the purpose.
I think all of these can be bought commercially, mine cost nothing, from your SnapOn dealer or similar you would have spent a few hundred euros or pounds perhaps.