Looks like you're making really great progress. One thing im a little concerned about is using single keyways for the gears. Ive had problems over the years with the preseeders I use even though they use 6 spline shafts. I think there's a high chance that keys wont hold up. another thing the preseeders had issues with was they were originally built with a single #80 chain that failed commonly and was eventually upgraded to a #100. I know you aren't doing really heavy work with it but keep a close eye on if the chains are stretching or wearing. They tend to pile up in the case when they fail and bend either the shaft or the case. I don't want to come across as negative because thats a really cool project but just wanted you to be aware of some of the failures ive had to deal with so maybe you can avoid them.
Thanks for the feedback. I don't really know anyone with PTO driven equipment so I appreciate the feedback. I've done a disturbing amount of research and can't disagree with anything you're saying. There's a lot of hints in building a good power rake in
all ground engagement equipment so thanks for sharing the weak points on a preseeder.
I wasn't feeling too confident in a single key either after researching the drive systems on tillers however some of the cheaper power rakes seem to use them.
To mitigate I'm using stronger cold rolled steel on the shaft and eccentric locking collars on the bearings. The keys are sanded-to-fit and require a good tap to fit so I'm hoping that helps too. I might scrap the box store (princess auto) key stock and get something from the local industrial supplier... the key stock cut way too easy on the bandsaw for my liking. I could see myself laying a good bead of weld if there's ever a simple key failure.
For the chain I'm going to look into filling with a small amount of oil instead of grease to keep from wearing. It's remarkable how little wear\stretch is on an automotive timing chain so I'm hoping to barrow from that too. I'm not left with a lot of room for stretch as you can see. Something i learned; I was about to run out and buy an 'offset link' until I read the footnotes -
35% reduction in capacity when using offset links! 50-2 or 80-1 chain is common for a power rake of this size\capacity (or even a step or two bigger) I had to buy about 3x more than I needed so i have a few lives. 50-2 chain would be equivalent to single "70" chain if there was such a thing FWIW.
I have a mostly random potato sized rocks on my property and my dad has a few roots, so we'll see if the weakest link is strong enough.
