Here is an old thread about the Dynabrade 61379/61384:
My friend Mike bought the Dynabrade Dual-Action Buffing Head:
The aluminum housing measures 4-3/4” in diameter.
With the backing plate removed, the innards are easy to see.
When the power slide button is engaged, this latching pin is raised.
This locks the entire housing to the drive, and the backing plate is forced to rotate.
When the power slide pin is disengaged, the latching pin is lowered.
The aluminum housing is able to rotate freely. This is set to the random-orbital mode.
We removed the backing plate to cut the size down. It uses a standard 5/16”-24 spindle.
Our plan was to remove the white foam along the outer edge.
This way, we could fit the Meguiar’s 7” pads to the backing plate.
This shot shows the overall diameters of the housing and the three plates we were going to use.
The Mirka plate will be used as the primary plate for the 7” pads.
The modified Dynabrade plate will be used as a backup.
See? the Mirka plate is nearly identical in size to the plastic part of the Dynabrade plate.
This is the Meguiar’s Soft Buff 7” Foam Cutting Pad. It is getting rave reviews.
Our goal was to allow Mike to attach the trio of foam pads to the attachment.
Mike will also be using the So1o Pad system, which wil fit nicely once we are done.
An X-acto knife and some hand sanding easily removed the unwanted foam.
Another way to cut the foam is to mount the backing plate onto a drill.
Then, carefully push the X-acto into the foam as the drill rotates the plate.
Voila! The plate fits perfectly into the recessed part of the foam cutting pad.
The Meguiar’s WWHC7 So1o Wool Heavy Cutting Pad will work well with this machine.
Here is a shot of the pad mounted to the machine. You can really see the offset!
The slide pin.
Wow, what an offset. This machine feature a 3/4” (12/16”) diameter orbit.
For comparison, the Meguiar’s G110 features a 5/16” diameter orbit.
We run the Makita at various RPM settings. It seemed to like 2,700 rpm with this 6-1/2” pad.
Keep in mind that this attachment was designed for use with larger pads than we were using, so the counterbalance was weighted accordingly.
From what I understand, Dynabrade spent a lot of time dialing in the balance for 8” and 9” pads.
If you plan on using smaller pads and plates, count on some vibration.
In terms of comfort, the optimum speed setting will be easy to find by adjusting the speed on the fly.
Thanks to the 3/4” orbit size and the power and rpm capabilty of the rotary machine, you will be hard pressed to stop the rotation of the pad in random-orbital mode (even at slower speeds). I did not remember to weight the unit... D'oh! It wasn't unusually heavy, that is certain (credit the aluminum housing for the weight savings).
This is a time saver, and if you are comfortable with a rotary machine, you will really dig this baby!
I wanted the one with the button!!! I can't believe that the one with the button costs less. Dang!! Well maybe this one is better because it costs more.
