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Collection, Preservation and Display of Old Lawn Mowers

Qualcast classic 35s blades won't stop spinning

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My blades have started spinning on startup without engaging the separate clutch and never stop.  I can see the cylinder clutch cable appears to be working. Any ideas how I can stop them spinning?

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Double stripes Fri, 07/08/2020

Does anybody have any idea as to what is causing the cylinder to keep spinning after safety clutch has been released?

hortimech Fri, 07/08/2020

there were several machines with this name, so a picture to identify yours will help.

wristpin Fri, 07/08/2020

As has been suggested an image of the drive side of your machine with the cover off will assist. Machines that tension the belt to engage the drive usually rely on the belt springing clear (slightly) of the driving pulley to disengage the drive. To assist this there’s often a peg or arm that restricts the sideways bulge in the slack belt and causes it to slightly lift off the top driving pulley.  Such pegs are often adjustable.

A couple of decent images of the belt in both the engaged ( tensioned) and disengaged positions may give a clue to the cause of your issue.

wristpin Sun, 09/08/2020

Good images. It does look as through the cable operated jockey pulley is still pressing on the cutter drive belt even though in the disengaged position. Perhaps the cable is hanging up a bit and not allowing the jockey to fully return or perhaps the pulley arm's  pivot is in need of lubrication . 

You haven't mentioned changing the belt but is it the correct one?

Double stripes Sun, 09/08/2020

I have not changed the belt so assume it is correct as this was working perfectly fine up until last week. How do I allow the cable more slack as I have adjusting the screw cable as much as I can all ready?

wristpin Sun, 09/08/2020

Difficult to diagnose remotely but the inner cable may be sticking in the outer. Can you push the jockey wheel further away from the belt than its present natural return position?

Alternatively has the belt  become "hairy or sticky" ?

Double stripes Sun, 09/08/2020

Yes I can move it further to the left and its resting position, however the tension just means it goes back when I let go.

hillsider Wed, 12/08/2020

If you take a close look at the plastic bearing housing behind the upper belt pulley there are spikes that act as belt belt rests when the tension is released. It looks to me as though the spike in front of the cylinder drive belt has worn away at it's tip allowing the belt to bypass it.

 

wristpin Wed, 12/08/2020

Similar but not the same but it's just possible to make out the belt sprung away from the V of the pulley.

The split pinion is interesting. When the "plastic" pinions were first introduced they were splitting on a regular basis so Qualcast upgraded them to a tougher material and to help with stock control and Warranty etc they were tinted pink. So unless they eventually went back to plain white your white one has survived well.

 

 

Double stripes Thu, 13/08/2020

Thanks chaps. If it is the plastic pinion which indeed has snapped off, how do I get a replacement as it appears part of the overall back plastic frame?

wristpin Thu, 13/08/2020

I think that I’ve confused you by talking about the pinion ( cog if you must) ! In one of your first images.

Hillsider was pointing out what appears to be a keeper peg that has been worn away. I would file the top edge flat, find something that’s a good fit in the hollow stem that remains. ( may be a nail with the head cut off) then find something hollow of a similar diameter to the remaining stump  - perhaps the barrel of a ball point pen - insert and glue nail followed by pen barrel . 

Other options are available but all preferable to renewing the whole fangdangle !  

Double stripes Fri, 14/08/2020

Thanks, are the keeper pegs there to stop the cylinders from engaging at start up and rest then?

hillsider Sat, 15/08/2020

Here is the part that you require for your mower, strangely when looking at parts lists for your chassis number a completely different arrangement is shown for the belt guide all very confusing and I had the same problem myself a while ago.

https://www.jungle-busters.co.uk/Atco-Balmoral-Qualcast-Classic-Suffolk…

You will see here  that there are four spikes that act as belt guides the two shorter ones are for the rear roller drive belt and it was one of those missing on the machine that I repaired. In my case the mower drove off as soon as the engine fired up.