We recommend you replace a HUMMEL sanding drum once per year to maintain quality sanding results.
Two important things you need to know about the Lägler HUMMEL sanding drum:
*Do not dress the drum
*Drum replacement is easy
The HUMMEL sanding drum has a slight “football” shape to it. Dressing it ruins that design, affecting wood floor sanding results. Dressing a HUMMEL sanding drum causes poor sand paper tracking and chatter, among other problems.
Replacing the drum takes only one to two minutes, whether at your shop or on the jobsite. Instructions for “Replacement of the Sanding Drum” are in the operating instructions manual that comes with the purchase of each new HUMMEL.
Here are the highlights for how to replace the Lägler HUMMEL sanding drum, as shown using a 1983 HUMMEL and new parts in the short video above. We’re assuming you’ve already unplugged the machine, have removed the side cover, and have tilted the machine back to rest on its handles and the safety guards at the bottom.
1. Remove the sanding belt from the tensioning roller and the sanding drum.
2. Loosen and remove the drum nut, using the box wrench that comes with purchase of a new HUMMEL, by turning it clockwise (that means righty-loosey, not lefty-loosey). You will need to loosen the nut with a mallet tap on the wrench handle.
3. Turn the sanding drum so that the key way is at the top of the drum, pointing toward the ceiling.
If the drum does not move easily from its shaft, use the handle of your mallet or an appropriately sized piece of wood to gently pry it loose, starting to move it off the shaft. Do not hit it with a hammer; that will damage the drum.
4. Clean the shaft. Mild lubrication is helpful.
5. Slide the new drum onto the shaft, making sure to align the key way as needed.
6. When putting the drum nut back onto the shaft make sure to put the side that has a few “missing” threads toward the drum. Otherwise, the drum will not be secured in position; it will move on the shaft during use, which can cause chatter on the floor.
7. Put the side cover back on, stand the machine up, and get back to work.