I have been refinishing floors for 10+ years and never experienced this. My lagler hummel is the gold edition. Not sure of its age because I bought it used 2 years ago. In that time all I have had to replace on it is a c - clip for the drum handle. I take it to my distributor twice a year for a maintenance check up. So I'm a little concerned about 2 of my last 8 jobs show a bit of waves across the grain about 2-3 inches apart. I know it's not chatter cause I've seen chatter. Where should I start with trouble shooting a solution? Would replacing my rear wheel be a start? Thanks

form the distance of the waves , it can very likely be rear wheel..

first make sure belts are tight, particularly fan belt.

you can check the ear wheel with a precision strait edge.place in on the wheel then spin the wheel slowly and see it is gives wobbly out of round effect.

i suspect most likely culprit is top roller or top roller bearings.

Thanks james,
Do you have a link with a more detailed description on how to check my rear wheel? And how do I check to see if my upper roller/bearings are bad?

no link..

just flip the machine over..no need to remove thr wheel.

take a metal edge ruler and hold it against the wheel..then slowly rotate thr wheel with edge of ruler against it..the wheel should remain flat against the ruler..if you see space/light through it, it is out of round and can be contributing to the waves.

the top roller can be removed..there are 3 allen bolts on the side..take them out and pull out roller.

you can do the same think with the ruler..hold it against roller and make sure toi stays flat..if it looks wobbly and you see space the roller is worn and needs to be replaced..it is good, simply spinning it and listening to bearings..if they sound loud and grindy,thy need to be replaced which is a lot cheaper than replacing whole roller....these are the most likely sources and can be all 3 or 1 of 3 or any combo..

as mentioned i suspect problem is in the roller or bearings..the wheel is easy to eliminate as source without spending any money

Thanks James,
back wheel checked out fine. I took out the upper roller and it was a little more beat up than I last recall looking at it. And when listening to compare sound with a new one. It is clear I must have a bad bearing. Can't wait to sand this 500 ft of r.o. I have lined up for tomorrow.

cool..did you replace the bearing or buy a new roller? changing bearing much cheaper..

Hope it solved your problem.. check back and let us know!

I went ahead and replaced the whole roller. My distributor had one for a little over $200 and it looked much better. Mine had grooves in it and grit in it. I was kind of embarrassed because I take pride in blowing out all my machines on a regular basis.