G21 Backing Plate Failure

G21 Backing Plate Failure



Hi guys,

I recently purchased a new G21 orbital polisher to replace an older 6" orbital unit I had for about a year.

Loved it out of the box in terms of ergonomics and features. I used it for general sealant and waxing application on one vehicle. The next day when I moved to the second vehicle, I encountered a bit of a disaster. I was using the Griot 3-in-1 liquid wax with the orange pad. After working through 2 doors and the hood, the backing plate suffered a catastrophic failure right through the hub and flew clear out of the garage.

On the way, it unfortunately put a ding in the car door and a cut in my finger along the way (PPE fail on my end).

I was running the buffer at a speed of 3 to 4 so it was nowhere near full speed luckily. I was also working on a relatively flat surface. I can't figure out how or why this type of failure would occur but I noticed an older thread here from 2016 of something similar on an older design (Fast Eddie posted about "Holy Griot's BOSS G21 fail").

I can't think of any conditions under which the friction at the pad-car interface would cause something like this to occur. I would expect a stall condition or worst case a pad failure but not the backing plate itself. I sensed a minor vibration in the buffer before this happened but no major abnormal vibration or heat indicating something was wrong.

I'm attaching some pictures. Note the counterweight has some superficial scratches on it now. I assume it's from the backing plate but I'm not certain.

I've contacted and sent these picture to Griot as well but I figured it wouldn't hurt to check here. They are sending a replacement backing plate but without a root cause, I'm very hesitant to continue under the assumption this won't happen again.

Incidentally, my older unit is being replaced with a newer G9, which should keep me going on the project.

Any thoughts and input is much appreciated.


Attachment 70097

Attachment 70098

Attachment 70099

Attachment 70100



:)

Hi Mantis,

Sorry to hear about this mishap.


Because this is your first post to the forum,

Welcome to AutogeekOnline! :welcome:


Upon getting ready to leave for the day, it's almost 5:00 O'clock, I always check the Admin Panel for any new pending accounts. I can also see any NEW threads that for some reason are flagged and placed into the Moderation Queue.

So I've approved your thread and am now replying and also letting you know why after typing out the above and hitting the [Submit Thread] button you didn't see it. I've been a tick busy today so apologies for not finding this thread stuck in the Moderation Queue sooner.


Happy to see Griot's is taking care of this, I have know idea how this could have happened. I would definitely say this is,

The exception to the rule



:)

Pic #1 shows a brittle fracture in the casting but it will take metallurgical analysis to determine the root cause.

Never had that happened, bad luck I suppose

Get yourself a Makita PO5000C 5in plate for the boss machine..it's solid delrin style plate

LC udos plate may be an option

Heres the 5in Makita po5000C Plate on my 25mm...will work on any 15/21mm tooMakita plate 25mm shine struck - Image on Pasteboard