How do you fit a belt on a bosch rotak 32 mower?

Answer 1

The symptoms for a new belt, or at least the need for belt intervention will be that the motor spins and the machete does not. There is no access from underneath the mower so do not remove the machete at this stage. With the mower in its normal position, remove the 2 recessed Phillips screws nearest the handle, which hold the cover on. The cover will now pivot off, hinged at the front. Lay it upside down, with the two screws safe in one of the moulded cavities.

The cover over the motor is loose and just lifts off. Before you do that, take a picture of the the wiring connections using your smartphone. You don't need to disconnect them, but one might pop off. It will help to tug the wires out of the slots in the plastic housing that hold them in position. To the left of the motor, you will see a a torsion spring wire with a screw at each end. Remove the two Phillips screws and the spring and place them safely in the upturned lid.

Grasp the motor firmly and rotate it clockwise until the lugs on the motor housing line up with the slots whereupon you can then lift it out carefully and lay it on its side. Before you lift it out, mark the slot and the lug with a felt tip, so you know how to re-insert later.

What you now see will determine whether just a belt change will suffice. If the belt is severed then clearly a new one is needed. However, when the belt self destructs, it often takes the pinch roller housing, especially the base, with it. With the belt out, swivel the pinch roller clockwise to its limit and it will lift out. When I did that, it was clear that half the base moulding had vanished, thus allowing the belt to come off the main drive cog and jam underneath everything with manky consequences.

I find it significant that the best firm for Rotak 32 parts that I found on the web, Segmüller, www.electrowerkzeug.net, only offer the belt, the pinch roller and the machete as spare parts for the Bosch 32. If a German firm regards these as the 3 consumables, then they are. Incidentally, Bosch Germany do not sell the 32 and the new Bosch original belt, when I got one, had "Made in UK" stamped on it. Bosch has a UK arm; I forget who they absorbed.

Remove the pinch roller if you haven't already. Forget anything you might have read about soaking the new belt in boiling water to soften it, it goes on the main cog OK with gentle persuasion, although the gap between main cog and housing wall is narrow. The main cog has two chords cut into the circle and this allows you to feed the belt in and slowly rotate the wheel, using the machete blade, until it is seated. The belt teeth go on the inside, against the wheel, even if the dud belt when you found it, had its teeth on the outside. Belts can do this sometimes in their death throes.

When the belt is nicely seated, re-insert the pinch roller and swivel it anti-clockwise, past the extra bit of belt loop. With the spring tensioned against the plastic housing, now let the roller press the belt against the main cog. You will see that the belt has now arranged itself with a secondary loop, just waiting for the motor drive cog to be inserted into it, rather like a hand kitchen liquidiser. Do this, after aligning the felt tip marks you made earlier. Swivel the motor anticlockwise to lock it in position. You might hear a click on the way as the spring toggle latches into the motor housing.

Screw back the torsion spring wire. Tighten both screws by finger first and then use a screwdriver. If you tighten one before you put the other screw in, it might be problematic.

Now rotate the machete by hand and check that you can see the motor armature rotating through one of the slots in the motor housing. I like to rotatate the machete about a dozen times and if I do not hear any expensive clicks, then all is good.

Drop the loose motor cover on, re-connect any wires that might have popped out and press any loose wires into their captive holding slots.

Finally, insert the top machine cover hinge prongs into their holes, lower the cover into position, having checked that the mains cable is routed through its proper slot and screw it shut using the 2 Phillips screws that yoiu removed right at the start.

Now for the acid test. Connect to the mains and give a short dab on the power. If you hear a smooth Rolls-Royce type whirring noise and the machete rotates, stop, pour yourself a drink of whatever and mow the lawn later. If it makes an expensive clatter, then you have just discovered that it was more than just the belt and pinch roller, or you failed to follow these instructions.

I then replaced the machete with the new one that I bought with the kit and I took the old one to my workshop, gently hammered it flat against a block of wood using a rubber mallet and then ground a fine edge on the leading cutting side.