[Guest]

If the guy relly works with polyurethane rubber in moldmaking, he also knows to get the part out of the mold, they use sometimes a spray of "separation aid" (in German "Trennmittel"). And this spray is oilbased and able to leave smears. It's a god thing, though, to point out, those sticks have to be used without force and not to me move elsewhere than only in rectangular direction to the sensor.


It's fair enough to point out the downsides, especially the costs of the raw material. But one should also consider, those parts are not to be made on a kitchen table with ice cube molds. I thought you were joking and took the joke as well.


The stick itself has a special geometry to hook into the cushion. There must be at least two molds or a very expensive two component mold for producing the stick with cushion in one go. Material costs only become relevant by injecting millions of parts, but in lower quantities the cost of the mold is determining the price of plastic part much more. Mold costs can easily be a couple of 1.000 € or even 10.000 and you need to sell a lot of this stuff to get the costs in. So, the temptation is getting earlier to the break even point by adding 200 or 300% to the manufacturing costs. There are zillions of examples doing it that way. Buy a car and buy the parts for it... then see what's cheaper.


But also swabs can be difficult to handle: Special sizes for different sensors (DX and FX) and if you leave the sensor's surface with the swab, it's easy to bring smears onto the sensor from oily particles around the sensor. Or even bring back dust or greasy particles which were already blown/brushed off the senor and stuck in the border area.


The idea of a training with a piece of glass is excellent. I could also try to snap the success?

Therefore first rule to me is: Only do it if it's dirty enough. Using wide open apertures and not shooting against the sky or an evenly lit surface, you'll have a hard time to detect speckles even if the sensor has some of them on it's surface. My cameras do have to be able to take bumps, humidity and dust without getting rid off one particle each time it managed to "attack" the surface of the cam. I'm not cleaning sensor after each walk I took when a lens was changed.

 

"separation aid" (in German "Trennmittel")". Excellent point, that may be the reason that it streaks? This could or should be cleaned off?

 

"There must be at least two molds. " Yes, I am aware that such molds are quite expensive, so that you make a run for several thousand sticks, and those would not be made on a kitchen table. I think it's made of two parts, the stick/handle, and the rubber top. If my guess is right, the way the two are merged is by hanging the stick/handle into something that does look like ice-cube molds, and the rubber is poured into the molds and solidifies around the stick.  

Alternatively, since rubber is soft, if the rubber is made with the hole, the stick could just be pushed into the rubber, and pops into place.

It should be possible to source some type of stick from China, either already on offer, or from a factory that makes these sticks to specification, example http://www.alibaba.com/product-gs/848600...esale.html