Mr. Orange problems

[Tristan6628]

Hi, was wondering if anyone has come across this problem I'm finding with the Mr. Orange?
im finding that high vertical prism jobs are impossible on this machine as it can't grip the lens properly. The lens doesn't twist off axis but rather lifts or falls depending on the prism being up or down. The best way to describe it is that it's like gripping an orange pip that's wet and pops out your fingers? Datum becomes either too high or too low.
Looking to find if others have come across this problem?
Thank you

[Lensman11]

Hi
The problem is not the machine it is caused by image displacement when laying out the lenses. If the lens was slipping in the edging process it would slip at some undetermined angle. When you layout the lenses have Plano prism to hold over the lens to neutralize the prism. This happens with all lenses where you are laying out not using the oc as a reference. Example would be the top of the seg in a bifocal but usually both lenses are similar in Rx so the displacement is equal and only cause both to be off in height equally by usually an acceptable amount.

[Tristan6628]

Hi
Thanks for your response and I know exactly what you mean, as this was my initial thought, so I blocked the lenses up by hand. I measured and measured again but the problem recurred. I got in touch with Essilor and they have admitted that this is an inherent problem in the machine and there isn't anything they can do to cure it, other than try to sell me the Mr. Blue. They claimed this problem existed in the old Kappa but it didn't. At the time of the Kappa generation, of course, Essilor didn't glaze these type of lenses in their RX labs, as they would only glaze their own lenses but wouldn't surface any lenses over 4 base prism. The problem only occurs in vertical prism, not horizontal, so horizontally I can get perfect o.c.'s. I think it's more to do with how the lens is presented to the wheel with the initial non movement of the lens chuck as it touches the wheel, hence moving the lens off line rather than off axis?

[PRECISIONLAB]

Closely exam both sides of chuck when you insert lens and clapping begins. You may notice right chuck binding or shaft shifting up or down depending on amount of prism in the lens. Consider replacing right slide clamp with one that has a broader movement to allow for back side yoke of lens.

http://precisiontooltech.com/catalog...ASH/index.html See page 66 part number PTT 2378 or 2423

[Chris Ryser]

Lenses slipping in an automatic bevel edger originated way back when the one step roughing, followed the finishing wheel got introduced, sometimes in the early 1980 s.

One cure was to precut the lenses to a smaller size in the correct decentration to eliminate the slippage due to the larger size and or prism and the finish it to the correct size.

These days another reason for slipping, is also AR coated lenses with a hydrophobic topcoat which is refusing a good adherence of most blocking stickers.

One can get the Hydrophobic solutions in a bottle, and dip the lens into it before mounting the lens into the frame, problem solved.

[Tristan6628]

Hi Chris, when I started troubleshooting this problem i did, of course, consider the coating issues but having obtained a batch of high prism scrap lenses that I could experiment with, I found this issue occurred with both coated and uncoated lenses? I am a product myself of the 1980's and tried all the old methods, of rough cutting and re-blocking. The old Kappa came with a prism clamp that was spring loaded and could move in any direction. The MR orange on the other hand have a hex nut that the clamp fits on and maybe can't move in as omni directional way as the Kappa clamp could?

[Tristan6628]

Hi, I think that this may help but Essilor here in the UK says they make no other clamps other than the large and small sizes. In the old Kappa that I had previously, it came with a prism clamp that was omni directional but unfortunately the fitting on the orange is different to the kappa or I would have used that as I never had these issues with the kappa?

[Chris Ryser]

Hi, I think that this may help but Essilor here in the UK says they make no other clamps other than the large and small sizes.

If Essilor does not want to make other clamps, there is another solution.

Go and find a precision mechanic in your neighbourhood and have him make one.