Imitation Knurling

[SincoTC]

Can anybody help please.

I'm sure that many people will have admired the beautiful knurled figer grip rings on SLR cameras and zoom lenses. Closer inspection reveals that most are no longer produced by knurling and anodising, but are moulded in a relatively soft plastic/rubber in the form of a wide band that fits into a plain recess on the outside diameter of the lens housing.

Does anyone know where these can be sourced or what they are called? I have tried countless searches without success, maybe I just need the correct keyword. I have also asked our Japanese agent to try camera manufacturers there, but he has had no luck either.

Thanks in anticipation.

Trevor Clarke. (R & D) Scientific Instruments.

 

[MikeHalloran]

Make a complete drawing of exactly what you want. It doesn't matter what you call it, but be sure to put the dimensions and tolerances you can live with on the drawing. Try to minimize the use of notes, because not every craftsman can or will read them, especially if they are in a language foreign to him.

Be sure to include a truncated cone or whatever in the title block to show exactly what projection you use.

Get out a trade magazine or ten, look for molded rubber producers, and fax the drawing around the world. I'd start with Taiwan.

If you're looking for a clone of a part that's already in production, one bidder will come in a lot lower than anyone else, with essentially zero tooling charge. That's the guy who's making them already.



Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

To prepare a quote, they will need quantities and environment of use.

Tool amortisation and production set up can be a lot more than incremental part cost.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[SincoTC]

Thank you Mike and Pat for your helpful comments. I would like to avoid the route that Mike suggests because of the relatively high tooling and set up costs that Pat pointed out; alhough the various quotations may well smoke out an existing manufacturer. Although, in the end this approach may be the only way, as I have looked at virtually every website in Taiwan/China that deals with this type of moulding and directly asking the consumer goods guys that use them has been fruitless so far.

We make highly specialised equipment for cancer research, so our production volumes will always be low and whilst our customers are prestigious, they are always pleading poverty, so we have to keep our manufacturing costs down wherever possible and can make small design changes to accomodate the sizes in someones existing range, hence the desire to find out who is already making these items or what they are called so that I can better target my searches. I am not inexperienced in web searcing, but these are proving to be elusive little devils, despite the limiting boolean criteria, many an eyebrow has been raised here at the things searching for soft rubber mouldings has trawled up!

Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK

 

[MikeHalloran]

The molder you want to find can't advertise directly, e.g. on a website, that he has the tooling for so- and- so's lens handgrip or whatever, because so- and- so paid for the tooling, and nominally owns it. That's why I suggested a drawing, which specifically should not hint at what the prototype's actual intended use might be, and fax.

The other choice is getting your own part injection molded in a thermoplastic elastomer in aluminum tooling, which will probably cost less than you've spent so far on web searches.



Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

Can You buy spare parts from a lens manufacturer. They may be prepared to sell a small batch from time to time if they are sure your application does not compete with their product.

As Mike says, moulders are not free to sell you parts made on someone else's mould.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[SincoTC]

Thanks for the comments guys.

We CAN buy them as spare parts, not directly from the so-and-so manufactures, but from their repair departments. However, these all want the camera model/lens part number first and have no idea what size they are. I have spoken to a multi manufacturer, specialist repair shop, who had used these items and was fairly sure that they were not made by the companies themselves but by a third party. He recalled that they came in common packaging and not that of the camera maker. Therefore, we should go directly to them, as they would probably be able to offer a range of sizez and patterns, but he didn't keep any in stock and didn't know who "they" were. He just ordered them as genuine spares with the listed part number from the original manufacturer. He tried but couldn't get a name from any of the so-and-so's, so he's getting me a couple of types and I hope that the packaging will reveal something.

If not, as Mike suggests, our own custom mould could work out cheaper. We have a couple of parts made for us already, but when I sent our moulder the drawings for these, he said that he'd seen something like them in a trade magazine a while ago and it would be cheaper to try and track them down, especially as we need a number of different sizes, arghh!

It can stay on the back burner for a while to see what the packaging for the spares says, but it does seem like a bit of a challenge now!

Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK