Pete’s Pride: The 8″ Lagler Hummel floor sander.

The HUMMEL belt sanding machine is the best-known floor sanding machine in the world.
Designed by Eugen Lägler in Germany in the late 1960s, it was the first floor sanding machine in the world to feature an endless belt for continual sanding.
Hummels are the BMWs of the sanding world: German-built, and beautifully engineered for smooth handling and aggressive performance.
But Hummels get their increased performance from their 220v motor, which means that you can’t just plug this machine right into a wall outlet, as you can with conventional sanders (read Pete’s Bonus Tip “Bringing Power to the Hummel” below).
So, it takes some additional planning to rent this heavier and more powerful machine, but you will find that it cuts a floor much more quickly than 110v sanders; customers who have graduated to the Hummel rarely go back to using the smaller sanders.
Pete’s prides itself on carefully maintained Hummels!
But the best way to take care of a finely-engineered machine is to make sure that it doesn’t get damaged in the first place.
So, you’ll find us a bit protective of our Hummels; we won’t rent to just anybody, and we make you promise to take care of them like they were your own.
That means agreeing to follow Pete’s Guidelines of Hummel Love:

Always separate the Hummel motor from the chassis during transport or when the machine is done for the day.
Not only does this make it safer for you to lift the machine, but it keeps the wheels from developing flat spots and keeps the belts from permanently kinking (kinked belts and lumpy wheels lead to waves and chatter on your floor).

We like nice, smooth sanding drums.
We will inspect your machine drum before we load it into your vehicle and again when you return to check for damage. Feel free to point out any existing drum damage prior to your rental and it will be noted on your contract.
Making sure that your floor is well-secured and free of any protruding nails or staples will prevent you from having to pay for costly drum damage.

Always use the motor switch to turn the Hummel off.
The big red emergency stop button on the side of the dust pipe is a delicate mechanism; if it is used repeatedly to turn the machine off, it loses sensitivity.

Do not make any adjustments to the drum leveling mechanism
Our Hummels are adjusted for even sanding drum pressure so we ask that you do not make any adjustments to the drum leveling mechanism.
You can adjust the drum pressure using the spring switch at the base of the dust pipe.
If you have any issues about about machine performance, please call the store immediately at 651-698-5888.
Our Hummels are adjusted to track smoothly for 3M brand sanding belts.
If you are using a different brand, you may have to adjust the tracking mechanism at the upper roller. This is not a machine defect!
We include a hex wrench and a socket wrench so you can make the appropriate adjustment at the upper roller. See tracking instructions in the Bonus Tips below.
Download the Hummel Operator’s Manual!
Get detailed operating instructions for the Hummel belt sanding machine
Includes machine features, preparing the machine for operation, application tips, transport and storage, emptying the dustbag and more.
From the manual:
The HUMMEL belt sanding machine operates with a contact sanding drum featuring a specially profiled rubber coating. The belt tensioning fixture with integrated automatic belt guidance is located vertically above the sanding drum. The work zone is covered by the machine housing and detachable side cover.
On the machine housing, the electric motor is fixed in a motor bearing bracket. The plug for connection to the mains is located at the switch box of the motor.
The motor switch with the switch positions START / WORKING and TEST is located at the switch box. On the left under the belt guard is the belt drive unit. The machine is moved by means of a steering wheel at the back and two lateral wheels.
Two handles are attached to the guide tube, where the drum lowering lever is also located and the cables and dust bag are attached.
Pete’s Bonus Tips
Bringing power to the Hummel.
If you have an existing wall connection that matches any of these configurations, we have a 220 adapter plug that will allow you bring power to the Hummel without hiring an electrician to tie into your breaker box.
You can adjust the Hummel’s belt tension!
Always set the Hummel's belt tracking using a sanding belt with as fine a grit as possible; the more flexible the sanding belt, the more precisely you adjust the tensioning roller.
Mount the sanding belt and test (leave the side cover off so you can see the belt!)
If the belt is running out of true, turn it around and try the test again. If the belt runs to the front but after turning over runs to the back or vice versa, the belt is slightly conical and should be discarded. But if the belt runs in the same direction both times, the tensioning roller requires readjustment.
To adjust, release the lock nut at the drive unit and adjust the hexagonal socket head screw. Rotating the hex head right will allow the paper to move closer to the door; rotating it left will allow it to move away from the door.
If the belt tracking is seen to be correct after adjusting once, tighten the lock again. If not, repeat the process.
Incorrect vs correct drum sanding technique
Incorrect drum sanding looks like this.
When you first start sanding an old floor, you can tell exactly where the sander has been and how effective your feathering technique is, just by looking at your sander mark.
The photo above illustrates what happens when you are using the drum sander incorrectly - you can tell that the drum was still touching the floor when the sander stopped at the wall to change direction.
Correct drum technique looks like this.
In this photo, it is clear that the operator was smoothly lifting the drum off the floor as she prepared to stop at the wall to change direction.
The photo also shows that the drum was correctly feathered onto the floor as she began her backward pass.