If you get some rough measurement I will see is there is anything here Norm as I don't know the width of the hub ,there is an old balancer here somewhere that looks similar to the pic below and is solid steel ,alloy may be too expensive, thinking about It, I could cut the end off an alloy oxy tank ,can't remember how thick they are maybe 19 mm. might be a few here. Probably have some steel tanks to cut the end off.
I wasn't thinking of using alloy ,for a more robust and long-lasting solution, steel would likely be the better choice.
Strength and Durability: Steel is generally stronger than aluminum and can handle more stress and wear over time. If you expect the spacer to take a lot of load and stresses, especially while mowing, steel might be the better option.
FWIW I located a decent source for some cheapish 6061 alloy discs: https://vi.aliexpress.com/item/1005006973943538.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.1.2c54nLujnLujeg&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40196.404796.0&scm_id=1007.40196.404796.0&scm-url=1007.40196.404796.0&pvid=75ca5da4-8175-49ad-8173-f9e908a10711&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40196.404796.0,pvid:75ca5da4-8175-49ad-8173-f9e908a10711,tpp_buckets:668%232846%238116%232002&pdp_npi=4%40dis%21USD%2110.75%2110.75%21%21%2178.10%2178.10%21%402101c5ac17354659910146186e841d%2112000038907149219%21rec%21AU%21704119413%21X&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_from%3A
100mm x 30mm thick is ~$USD30 delivered from China. WOuld be a lot easier on Norm's lathe than steel - point taken on longevity etc - but I think for domestic usage - the 6061 would be as good. Just an idea anyway - you guys are amazing with your ingenuity. Very impressed.
Max, Don't go to too much trouble, I can probably get a steel flange from my mates factory that is 20mm thick, I just have to cut it down, and thinking about it, if I'm going to cut it down I might as well cut it out of a bit of plate scrap up there
Hi Max, I'm guessing that would be too small in diameter. I just need to get a bit more space in my shed so I can tip the 660 on its side, I have to change the oil anyway. I should get to it in the next few days