Merit Optical suction cup

I have a Merit Optical suction cup mounted diopter which I use on my specs for range muzzleloading shooting.

The rubber suction cup has gone hard in the twenty plus years I have used it. The mechanical bit still works well.
I am trying to keep the suction cup supple by using a small amount of automotive rubber grease with limited sucess.

It won't last forever.

I have emailed the Merit corporation twice in 2 weeks but received no answer on any possible replacement space.

Are these blokes still in business or are they into ignoring overseas inquiries?

Has anyone had to repair /replace their suction cup. I am open to suggestions.

A complete replacement down here in Australia will set me back Au$250 including shipping, so I am unwilling to travel down that road.

If no suction rubber is available I might consider unscrewing the diopter mechanism from the rubber and make a bracket to clip to my specs.

Any ideas on solving this problem, fellas?

Thanks

Grahame

The Merit company is no longer in business.

The bracket is probably a better solution anyway. If you do it, please post photos.

Merit is back in business. They should be answering their emails, though they may have a new one now, so a web search is probably in order.

Brake fluid works well to rejuvenate dry rubber. Give it a try if you can’t find a replacement.

Post a picture of it with a scale to get an idea of size. Maybe someone can come up with an idea of something, that can be modified to replace it. Does 3D printing work with rubber?

Quote:

---

Originally Posted by GregLaROCHE

Post a picture of it with a scale to get an idea of size. Maybe someone can come up with an idea of something, that can be modified to replace it. Does 3D printing work with rubber?

---

Hi guys , thanks very much for your responses thus far.

I am not sure that printing is possible with rubber / rubber substitute compound-ie neoprene type material.The attaching of a screw thread into a brass insert moulded into the rubber makes the printing process tricky.If the process were to work it will need to account for the hole to epoxy glue the the brass threaded insert to the cup.

I have not has anything to do with plastic printing as yet ,so I am a novice in that department.

Never the less I'll ask around to find out if this is possible locally and what is possible.

I had been looking on ebay and else where for some neoprene suction cups but there are none small enough at around 21/32" diameter.If there where it might be relatively easy to epoxy a threaded insert into the suction cup.

There are questions that I shall need to find answers for if I use a neoprene suction cup.

Can the neoprene rubber be drilled to provide the hole for the insert.?

Is the neoprene able to be glued using epoxy or other glue. I have some doubts about both and more research on my part shall be required.

Should I fail to obtain a replacement suction cup, plan B will be to use an older pair of spectacles that has parallel bars above the nose bridge piece. I have an old pair that is suitable for the job

My intention is to fit small brass plates on the front and back sides of the parallel bars. The parallel bars shall be sandwiched between the brass plates.

This arrangement should provide a mounting point to attach the small arm of the diopter frame to the brass plates.

Fortunately, I have a good mate who is a retired watchmaker and jeweler who can assist in drill and tapping the small holes and providing suitable fine threaded fasteners.

Yes! I will provide some phone pics of the work as I decide which approach that I choose .

I remain open to new ideas.



Thanks again

Whitesmoke

Then there is this: https://www.midwayusa.com/product/1015159971

and this: https://www.lymanproducts.com/eyepalr

I have found the Eye Pal to be very effective. I also have a Merit with suction cup that doesn't stick anymore, and a Merit with a clip to go on eye glasses, which also doesn't work very well.

How big is that suction cup? The smallest I found at Mc Master-Carr was 1" in Dia. with an 8-32 screw in the middle. However a search on Amazon or similar places Ali Baba in your neck of the woods might yield a different product that is close to what you need.

I know for a fact that Merit was not making those cups in house. They were buying them from someone who makes them, and integrating them into their product. Lots of difference between molding rubber and making Iris's.

We now have this wonderful thing called the internet, and just about everything known to man is on there someplace.

Look at these sizes are 2MM in dia and up. https://www.bimba.com/en/detail/bfg

Here's some more that might work for you. Tons available on Amazon.

https://www.amazon.com/Rubber-Suctio...r+Suction+Cups

None of these are expensive and you usually have to buy like 10 of them for <$5

Really the Clear Silicon ones look like the hot tip. I have one that has been stuck on the mirror in my bedroom for years.

Randy

I got tired of the suction cup coming loose at the wrong time and started making diopters from .005 shim stock ( aka known as soda can material). Cut a piece about 3/8 x 3/4 inch and drill a 5/64 hole near one end. Tape it to your safety glasses - you may have to shorten it to get it some depending where on your glasses you want it. This might get you by until you can find the suction cup or figure out something else.

Hi guys,

In answer to a previous response, I measured the cup at 21/32".

I have looked all over the bloody place for a similar dimension cup preferably in rubber but all I can locate are clear silicon /neoprene types and they are around "1"(25mm) , far too big to fit on the spectacle lens in that position I need the eyepiece to be in.

There are too many potential problems associated with the silicon/neoprene even If I can find one small enough.

* No one this side of the pond has a suitable size I can find.
* I won't bugger about trying to import a substitute across unless I absolutely have to. Time is big factor.
* In the event I was able to find one, will I be able to drill a hole to take a brass insert.? Might be akin to drilling jelly.
* Will epoxy glue bond the insert to the plastic /silicon / neoprene(what ever the hell it is )?

To tell the truth I don't like the suction cup as it has fallen off before. The spectacles are the previous prescription so they are no loss if the project does not work.

That is too many if's and maybe's for me.

For now, I am going with with mounting the original Merit arm through its mounting hole( and its diopter ) to a drilled and tapped spigot ( if that's what its called) soldered to the brass metal frame and in turn epoxied between the spectacle parallel bars you can see in the photo.

Does any one know the thread diameter and pitch of the Merit screw.?

I have that feeling I may have to substitute metric if its UNF - if it is UNF as here in Australia the very small and fine pitch taps are likely unavailable. You know how it works of course, if you need it, it is unavailable or hugely expensive.

Here are photos of the work in progress.Attachment 281470Attachment 281471

Pic 1 Scribed out on a brass sheet ready to cut.

Pic 2. Hole drilled for spigot and brass sheet (roughly) cut out and held on spectacles with bits of blue-tac for trial fit.

It remains for me to talk to my good mate and see if he has a usable drill, tap and suitable thread size.

More later

Cheers
Whitesmoke

Quote:

---

Originally Posted by C.F.Plinker

I got tired of the suction cup coming loose at the wrong time and started making diopters from .005 shim stock ( aka known as soda can material). Cut a piece about 3/8 x 3/4 inch and drill a 5/64 hole near one end. Tape it to your safety glasses - you may have to shorten it to get it some depending where on your glasses you want it. This might get you by until you can find the suction cup or figure out something else.

---

I made my own for a while with a the whole lense covered bar the tiny hole.Nowdays I prefer the utility of an adjustable iris. Alternating light conditions change the sight picture and I need to react to them and change the iris size rapidly.

Thanks
Whitesmoke

Quote:

---

Originally Posted by C.F.Plinker

I got tired of the suction cup coming loose at the wrong time and started making diopters from .005 shim stock ( aka known as soda can material). Cut a piece about 3/8 x 3/4 inch and drill a 5/64 hole near one end. Tape it to your safety glasses - you may have to shorten it to get it some depending where on your glasses you want it. This might get you by until you can find the suction cup or figure out something else.

---

Making your own like that is an interesting idea. I think I can imagine the setup, but if you had a picture or two of how you did it, would be great.

If you want a true diopter (not peep) sight, the hole should be 1.0 mm or smaller.

Didn’t see this post when I posted in Our Town, but Merit is back up and running in a limited basis.

I bought a Merit a few years ago. Nicely made piece. But last year the suction cup stopped holding it to the lens. I think the rubber dries out pretty fast.

http://www.meritcorporation.com/about_us.html

The email address resolves to: grantedward@msn.com

Quote:

---

Originally Posted by GregLaROCHE

Making your own like that is an interesting idea. I think I can imagine the setup, but if you had a picture or two of how you did it, would be great.

---

I am not making a new diopter, but merely using the existing Merit model. The change is in the method of how the diopter is fixed to my spectacles.
The drilled plate ( pictured) is trial mounted to the specs has a 4mm diameter hole drilled through it.

I will solder in a piece of 5mm circular rod, stepped to 4mm to fit the hole and solder .

The other end of this circular rod will be drilled and tapped axially to receive the mounting screw which carries a flat washer and small coil spring. The coil spring and washer pushes against the arm (from the diopter) so it locates in place, but can be swung aside if required.

Naturally the rod will be stepped and drilled and tapped in the lathe - before the solder operation.
I phoned my mate this arvo and he is pretty sure he has a 2mm screw and tap, so we should be in business, I HOPE!

What C.F.Plinker is referring to is just a shield with a tiny hole in it. He used a soda can but I made mine different than that. My effort was cut from a plastic ice cream container and attached to the specs with a tiny letter clip.The clip had foam glued to the jaws so as not to scratch my glasses.

I lost the tiny letter clip and have yet to see another quite as small.

Talk to you blokes tomorrow.

Whitesmoke

If you want to make your own very easily, you need two pieces of smooth wood, a piece of electricians tape (or similar), and a drill with appropriate bit. Put the tape on one piece of wood, clamp the other piece of wood on top of the tape, slowly drill through all. Unclamp, remove the tape, and put the tape on your shooting glasses.

Sounds like you've got it figured out.

Randy

The mate and I got a bit done on the project yesterday but I forgot my phone,so no "on the spot pics"
No worries I will take some pics and post them.

The ended up using a 2.5mm diameter screw because that is what we could find and have the matching tap for same.

The screw was around the same diameter as the original merit screw but metric instead of imperial.

We drilled the connecting arm and found it was made from copper, believe it or not.

There's just the silver solder job to do on the 4mm spigot step joint to the flat sheet that fits between the spectacle parallel bars and
then epoxy the flat into them and Bobs your uncle.

All is good ,then. More pics soon as soon as I complete a few "Honey do" jobs.

Whitesmoke

Hi Fellas,
It's all completed bar the epoxy gluing in of the brass sheet to the spectacle frame.
You will see by the pic that the sheet is currently held in by some blue tac.

I will not expoxy it in place until I take it to the range and test it.


Thank you for the advice and suggestions.

Whitesmoke

Attachment 281647

That looks good. I need to make something similar. Thanks for sharing!

Quote:

---

Originally Posted by ndnchf

I bought a Merit a few years ago. Nicely made piece. But last year the suction cup stopped holding it to the lens. I think the rubber dries out pretty fast.

---

I have two , one I bought recently off ebay and one my pap gave me 50 years ago or more . Both still work with no issue with the cup . You can find them on ebay fairly often and mine only cost me $14.00 or so and shipping . If the cups dry out quickly it is news to me , mine is stored in temps that range from the 20's to slightly over 100F . Might try soaking your cup in ArmorAll vinyl conditioner, good for rubber and vinyl both.

Quote:

---

Originally Posted by Eddie Southgate

I have two , one I bought recently off ebay and one my pap gave me 50 years ago or more . Both still work with no issue with the cup . You can find them on ebay fairly often and mine only cost me $14.00 or so and shipping . If the cups dry out quickly it is news to me , mine is stored in temps that range from the 20's to slightly over 100F . Might try soaking your cup in ArmorAll vinyl conditioner, good for rubber and vinyl both.

---

Hi Eddie,
I have owned my Merit diopter from new - probably around 25 years.
Can't speak for anyone but me but the rubber is dried and hard. However its the same with a fellow shooter who also has one. I will try the Armorall.

The unit has always been stored in its square plastic box which was kept in my shooting box. Put it down to climate perhaps.

For those who don't have the suitable spectacle frame a possible alternative is to use a letter clip which can clamp over the spectacle lens. I have attached a picture in case you blokes call the thing by another name. the on I have found had a magnet attached.Down here they are the sort of thing that hangs on the fridge and you can hang stuff in the clip.

It is simplicity itself to drill out the magnet and drill a mount hole in the clip. For scale the length of the clip is 1" but could be shortened.

The clip is fitted with some sponge rubber cut to suit to avoid damage to the lense.

I hope this helps somebody.
Attachment 281871




Whitesmoke

Quote:

---

Originally Posted by Whitesmoke

I have a Merit Optical suction cup mounted diopter which I use on my specs for range muzzleloading shooting.

The rubber suction cup has gone hard in the twenty plus years I have used it. The mechanical bit still works well.
I am trying to keep the suction cup supple by using a small amount of automotive rubber grease with limited sucess.

It won't last forever.

I have emailed the Merit corporation twice in 2 weeks but received no answer on any possible replacement space.

Are these blokes still in business or are they into ignoring overseas inquiries?

Has anyone had to repair /replace their suction cup. I am open to suggestions.

A complete replacement down here in Australia will set me back Au$250 including shipping, so I am unwilling to travel down that road.

If no suction rubber is available I might consider unscrewing the diopter mechanism from the rubber and make a bracket to clip to my specs.

Any ideas on solving this problem, fellas?

Thanks

Grahame

---

E. Arthur Brown Co or EABCO has NEW Merit products in stock
so it appears that Merit is back in business . I just ordered 2 new #4 Discs . The new suction cups are clear and look like they might be larger as pictured on their web site . If you contact them they might be able to supply spare suction cups of a better material than the originals had . The discs were under $60 each and the attachment style is $84 .

https://www.eabco.com/merit_apertures.html
https://www.eabco.net/Merit-Peep-Sig...s_p_13475.html