Diamond wheel defect - safe?

[Bryan]

This 100mm wheel turned up from CTC. The big hollow is about 13mm long and 1mm deep. There's a very small spot about 9 oclock, and a small but quite deep hole about 11 oclock. They look like casting defects to me. Would these aluminium wheel bodies be cast? I guess that makes more sense than carving them out of bar stock. The big hole and the deep one were both covered by an inspection sticker. :~ I just can't fathom the attitude.

So is it safe to use or should I send it back?

[SC_RUFCTR]

It doesn't look too bad but if that was mine I would "send it back".

I don't expect perfection but the defect was covered up with and inspection sticker... :((

[Steamwhisperer]

Mine arrived today Bryan. It's a 75mm but no defects but looking closely at it I would say mine is from a casting too. It should be ok. Might improve balance or make it worse.

Phil
http://img.tapatalk.com/7cb4c97a-69a0-7c46.jpg

[Dave J]

I would say it's safe to use. I also think it would be cast like the brackets that come with DRO's.

He is only selling gear that he buys from companies, so he probably never noticed it because of the sticker on it. Either way let him know and he will get onto them about it.

Dave

[Dave J]

Gee I type slow, there are already 2 other replies, LOL

Dave

[steran50]

HI:),
Personally I wouldn't be worried about the Big Hole as its quite close to the Centre. Being so close to the Centre it shouldn't effect the balance to much if at all. I am concerned though with the small deep Hole as its more outward. The small Hole possibly indicates that the Casting may be slightly Porous or with Flaws. If this is so then there is a possibilty that it could Fail ie seperate upon use.

I would Send it back. I would image they would be Cast and finished on a Lathe. The Idiotic Inspection Guy should be given the Sack.

[matthew_g]

Send it back.
You payed for quality and you should expect quality..Email him he might give you a partial refund. That should compensate a bit.
Matt

[Greg Q]

I think that I'd ask Heine to look at thos thread and then let him decide the remedy, up to and including a free replacement and a store credit for future purchases which is what I'd expect from a (for example) U.S. seller.

I shall let the response from CTC be MY guide to future purchases. Its a piece that should be good for hundreds of hours of spinning. But NOT with that defect. Its a stress riser that can lead to eventual radial cracking.

The inspection sticker over the defect would be for me an invitation to find the guy and ram the entire piece directly into his duodenum the short way. But that's just me.

Greg
Proctological justice since 1954

[Bryan]

Thanks guys. I will certainly be informing Heine of the issue. I just wanted some advice on the safety factor first. I'm feeling it's not something you want to be wondering about every time you spin it up. I've found Heine ok to deal with so we'll see. I don't imagine it's his fault. It's a QC issue at the factory. I'll leave it there for now.

[pipeclay]

You mention QC are these wheels manufactured somewhere other than China?

[Bryan]

I got a reply from Heine almost immediately - around 8pm HK time - saying he didn't think it was unsafe but was happy to replace it and reimburse postage - an offer I will accept. So far so good.

Pipeclay, point taken. If they would rather have returns so be it. At least in this case we seem to have a go-between worth his salt.

[Dave J]

I have returned 2 things out of all the gear I have bought off him, and he has always been good about and paid return postage.

Dave

[eskimo]

So is it safe to use or should I send it back?
send Hiene a picture....he'll probably send you a new one and you'll have that as a spare

[.RC.]

I would vote for safe as well.. Look at the size of a car fly wheel and the speed it runs at... This is only 100mm diameter and will run at 2900rpm...

[Anorak Bob]

It gets shared around.:no: I might just bore the pot hole away given that I have to make an adapter to mount the wheel on my grinder.

[Dave J]

It looks like there is a bit of thickness there, I really don't think you have anything to worry about. As Bob said, just clean it up. With a washer either side it's going to be encased anyway.

Dave

[RayG]

+1 for safe. minus several million for putting the QC sticker over the defect :no:

I'd be more concerned about balance, but you could always put it on an arbor and knife edges and see how it balances, then drill a few well placed holes to get the balance back.

Regards
Ray