OutdoorKing Repair Forum Forums General Discussion Forum Show and Tell Deutscher H660 26" walk behind w/B&S Intek 10.5hp - needs TLC,now what?

Hi Nick,

The washers between the blade plate and hub isn't the recommended way of lowering the blades because of the lost surface
area that no longer supports the blade plate so any stress is concentrated on the flat washers now and can eventually crack
the blade plate at the bolt holes.

The recommended way is to machine up a spacer hub that will lock into a shoulder on one side and the other side of
the spacer it has a machined protrusion that locks into the blade plate ,but I haven't seen the diementions of the
blade plate or hub on this mower so as Norm mentioned a round plate with a hole will have more support than smaller washers.

Here are some factors to consider:

Surface Area Support: The blade plate mounting surface must maintain adequate support. If the washers increase the distance of the bolts from the blade plate to the mounting surface too much, it can lead to stress concentrations at the blade plate bolt holes, which may cause cracks over time.

Load Distribution: The large flat surface of the hub is designed to distribute the load evenly across the blade plate. By using only small washers, you are reducing the contact area significantly. This can lead to stress concentrations around the bolt holes, making them more susceptible to cracking, especially under the forces generated during operation.

Alignment and Stability: Spacing the blade plate away from the hub with washers can lead to misalignment. If the blade plate is not stable and secure, it can vibrate or flex during operation, increasing the likelihood of failure.

Material Stress: The blade plate is subject to significant forces, especially during cutting. If the current design relies on a flat surface for proper engagement and support, adding washers may not provide adequate support against these forces, leading to eventual cracking.


Alternative Solutions: If you need to lower the blade plate for any reason, consider using a properly engineered spacer that maintains the original mounting surface area. This solution would preserve the load distribution and alignment.

In summary, while it might be tempting to use washers for spacing, it's generally advised against in this scenario due to the potential risks involved. It would be best to find an alternative method that maintains the necessary support and load distribution for the blade plate.



The D hole on the blade plate is easily drilled and shaped using a Dremel and small stone.

I have a blade plate here that is multi drilled for different blades ,see image below.

Example of a spacer below showing machined hole on one side with equal sized outer shoulder on the other side.

Also blades can be made from cutting up a bar blade and drilling bolt holes like the ones below that have a 13mm step.

Cheers
Max.