Help needed, Craftsman wood planer.
I get it Tony, that it will be used occasionally and likely on softer wood for an indoor green house. Also get it about the correlation to the hand planer speeds and ratings. My point about the bearings should have been clarified.
Just because a bearing is rated at some speed based on being sealed or not and what type of lubricant doesn't mean the rest of the system is rated for that maximum or under load because bearings are off the shelf items to fit a myriad of purposes. Additionally the Static and Dynamic loads play into that rating system. Not sure how I would rate the bearing loading of hand fed wood on a Jointer but think it may be higher than expected...again guessing on wood quality, but do know my 6" old iron gets with the program depending on depth of cut and will slow down slightly and get a trashier finish if I get too aggressive.
An example of bearing rating is my 1950 Craftsman/King Seeley Drill press uses 6202 and 6205 bearings...basically all 6200 series are rated at 13k-24k rpm with a static load of 3750N and Dynamic of 7800N (plenty for a drill press). Mine were rubber sealed, original and 65 years old, therefore rated at 13k, 65 years ago. It came with a middle pulley system that would allow speeds from 310-9835, meaning in new condition they would run at ~75% max...plenty of safety factor from an engineering standpoint, however the 5/8" spindle if out of round or bowed or the taper chuck wasn't true would likely would play havoc at those speeds and be worrisome...to me. Also the RO/balance of the 3-5way pulleys, one a splined pulley on the spindle...belts, motor, etc...it's a system. If I wanted to use circuit board drills occasionally I would probably be ok with that...if the RO is within reason and very light loads. Soooo your 78% may be valid if the rest of the system will handle it, but have no clue what the system speed originally was that I could find.
I too have often wondered about this topic for wood working and would love to understand it better. Then I realize most wood working is esthetic and tolerances of 1/16" and finishes in the 125-250 range or greater, instead of metal working to thousands or tenths and finish down to 8 that we have worked with for many years. Inquiring minds!! Hopefully someone can enlighten us all.
Had another thought if you have one laying around. Depending on motor type, perhaps put a single phase VFD on it and set your pulley/belt system up to match that 12K speed and experiment with it. If the VFD can be set up for constant torque it would be good...just another thought?
Either way good luck in what ever direction you choose and do look forward to seeing what you come up with. Hopefully it doesn't discourage your motivation to get this done so you can tackle the green house. ~Ņ@