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View Full Version : Jet JJP-12HH how to tighten chain?



Kenneth Walton
01-08-2018, 9:13 AM
Hi, so I have a Jet JJP-12HH jointer planer combo, about 4 years old. Recently when planing stock there have been clunking noises, with the wood stopping for a second with each clunk and I have to really push it through. Looking at the manual the big causes are too much pressure on the rollers, too little tension on the chain, and worn sprockets.

I took it apart and did all the tune-up I could (reduced the pressure on the feed rollers, cleaned the rollers, made the tables coplanar again, replaced the drive belt with a link belt, cleaned and waxed the tables, etc). The sprockets and chain look fine to me. The chain is quite slack, however. My problem is there's nothing in the manual to tell you how to adjust chain tension and I can't seem to figure it out. There is what appears to be a tensioning pulley but it looks fixed in place to me.

I contacted Jet customer service, but while I wait for them to get back to me does anyone have any idea how to adjust chain tension on this machine? Thanks guys.

Ken

J. Greg Jones
01-08-2018, 9:38 AM
It's been a few years since I had mine apart to convert it to a helical head, but I'm pretty sure that the chain wheel is how you adjust the tension.

Kenneth Walton
01-08-2018, 10:20 AM
That's exactly where I'm at - I just can't figure out how to get it to move! The nut "seems" to only tighten and loosen the wheel. Do you know how that moves?

J. Greg Jones
01-08-2018, 10:36 AM
The cabinet is slotted to allow the assembly to move L-R. Look where the carriage bolt #131 goes through the cabinet in this diagram from the manual.

Kenneth Walton
01-08-2018, 11:15 AM
Oooooh, I see. That's not obvious looking from the outside. I'll loosen the nut on the wheel then, and see how much slack I can take out. Thank you for your help!

Harry Niemann
01-08-2018, 5:03 PM
The other possibility is that the chain is stretched and needs replacement.