Festool Domino DF500 cracked Pendular pot

[solo]

Hi all

Bought my first Festool on the 26 March 2020 and needed to change the bit only to discover a cracked Pendular pot. Has anyone else experienced this and what could have caused it?

 

[Michael Kellough]

I could speculate on why it happened but at this point you should just consider it a defect and exchange the machine for a good one.

 

[solo]

Great will do. However i'm really doubting the durability of this product as I just used it for pine [sad]. I did not over tighten the bit, was very careful when using it, used a vac and took it slow when drilling. Maybe its just a friday batch.
   

 

[Michael Kellough]

Are you sure it wasn’t like that before you used it?

 

[solo]

I did check it and didn't notice it before so don't think it was there before I used it

 

[semenza]

Great will do. However i'm really doubting the durability of this product as I just used it for pine [sad]. I did not over tighten the bit, was very careful when using it, used a vac and took it slow when drilling. Maybe its just a friday batch.
 

Welcome to the forum!

I think it is probably just a bad one.  Certainly, not every broken tool issue gets reported here. But I don't recall any other cracks like that in a Domino being reported here. There are lots , and lots of them in use. If that was a regular problem it would have come up on FOG.

Seth

 

[solo]

Thanks for the assurance guys, will definitely return this one as soon as our country's lockdown is lifted.

 

[oldie]

Presuming you're in the USA.  Wonder if worth contacting Festool HQ, to let them know what's happened, and, what you want to do - can they make any suggestions wrt domino being collected and delivered to them?  Here in UK, some courier services, still allowing for parcels to taken to some depots for example. 

 

[xedos]

The armchair machinist in me thinks that was caused when the bronze bushing was pushed in into the casting. 

You'll notice the casting is thinnest at the point of the crack.  It's also on the side perpendicular to the oscillation.

My guess is the initial stress happened at manuf. but didn't show because there was no use.  That would explain why you didn't see the crack initially - it wasn't visible.

 

[solo]

Presuming you're in the USA.  Wonder if worth contacting Festool HQ, to let them know what's happened, and, what you want to do - can they make any suggestions wrt domino being collected and delivered to them?  Here in UK, some courier services, still allowing for parcels to taken to some depots for example.

Unfortunately I'm in South Africa and everything is locked Down til the end of April [sad].

 

[ChuckM]

End of April? If it sticks, you're lucky.

Here, everything planned up to the end of June has been cancelled. Possible that events will be cancelled till end of Sept. as we get closer to the summer.

One Japanese Olympics official is hinting today that even July 2021 could be pushed further back. But the worst news is that Korea is reporting that some recovered patients are tested positive again. If true, it could mean that getting infected and cured may not lead to immunity.

 

[harry_]

from the first picture, to me it looks like a casting defect. If you look at the 12:00 position or just to the left of the crack you can see a little 'smile' in the casting that looks like it wants to flake off if given a bit of persuasion which happens to end on the actual crack.

As said upthread, if this was more than a 'one-off', we would have likely heard about it here by now.

 

[Jiggy Joiner]

There’s a few possible reasons but, from what you say, I suspect a weak casting.
I have a friend who is a traditional blacksmith, he often apart from re-shoeing  horses, does a lot of artistic stuff, which may include casting work.

He has had many castings fail, his theory is moisture getting in when pouring the metal, possibly from the packed sand. It does happen quite often in casting.

 

[Mike Goetzke]

There’s a few possible reasons but, from what you say, I suspect a weak casting.
I have a friend who is a traditional blacksmith, he often apart from re-shoeing  horses, does a lot of artistic stuff, which may include casting work.

He has had many castings fail, his theory is moisture getting in when pouring the metal, possibly from the packed sand. It does happen quite often in casting.

Plus if that's a pressed in bearing/bushing that wall looks awfully thin.

 

[Jiggy Joiner]

There’s a few possible reasons but, from what you say, I suspect a weak casting.
I have a friend who is a traditional blacksmith, he often apart from re-shoeing  horses, does a lot of artistic stuff, which may include casting work.

He has had many castings fail, his theory is moisture getting in when pouring the metal, possibly from the packed sand. It does happen quite often in casting.

Plus if that's a pressed in bearing/bushing that wall looks awfully thin.

I totally agree Mike, so much so, that I inspected both of my DF 500’s one being a very early model that has seen a lot of use. They both seem fine, and this surprisingly isn’t an issue I’ve heard of before?
Could even be the cast casing was not machined to the normal tolerance, making the bushing tighter than normal, and vibration from use caused the crack. Although I have to say, usually Festool machining tolerance are spot on, so maybe a flawed casing is the reason.
I think if it was a weak spot, we’d hear of many more failures.

Edit: Just noticed in the first photo, at about 2 o’clock there is a ding in the casing, which might suggest the tool took a hit of some kind, causing the crack?  [scratch chin]