Suction cups

[Gary Anderson]

I have a question for all you CNC guys, the rubber thats glued to my suction cups are starting to come loose. I called CMS and they dont know what type of adhesive is used to glue them to the pod itself. So I either buy new suction cups or find out what others may be using.

Anyone else have the same problem???

[Camzl1]

Its not recommended to re-glue your friction pads on the CMS pods unless first, you completely remove the old adhesion, and then once glued you re-calibrate the height with a planing tool. The reason is as you can see, is, how thin those friction pads actually are and if you use too thick of an epoxy then your pod height of 100 or 200mm dependent upon machine, will be off and you will start to have vacuum issues. It should be able to be done just take that into consideration.

[barbianj]

What kind of planing tool is used?

[Camzl1]

The same tool that we use to surface tables with, or simply the one from Blick that does both

http://www.blickindustries.com/cgi-bin/dressingtool.asp.

[Ken Lago]

I have the same problem with my Blick cups, are you saying that you can actually use that tool on the rubber pad it self?

[barbianj]

Right, the tool is used on the rubber. Is it for rent?

[badboat]

I've got the same issue with my blick pods. What is the adhesive? Contact cement? When you cut with that tool blick says to use a criss cross pattern not just a linear one.

[Camzl1]

Ken. Yes that is the tool for doing that but it is more complicated than just running it across the pod. You have deflection and above all other things you need a friction plate that is thicker than your current one so you can machine it to the proper height. I don't want to speak out of place but blick highly recommends that this be left up to them to do as they are better geared to guarantee accuracy. What I am not saying is that it can't be done. You just have to assume all liabilities that come with trying to repair them yourself. Take care

[Ken Lago]

I agree Eric I wouldn't mess with this myself.

[Steve A]

I send mine out for repairing this problem. Sent them out with one of our suppliers, don't remember if it was GQ or Derusha... Either way they likely send them to Blick for the repair.

I recommend removing any with lose or peeling rubber from your production floor.

[Ken Lago]

I don't get it, with all these almighty glues around why do they use one that obviously doesn't work very well?

[Todd B]

I don't get it, with all these almighty glues around why do they use one that obviously doesn't work very well?

Ken just for you $$$$$$$$$$ that's why. Just like why they wont tell you the glue, and why they must do it. Don't let them take the piss try yourself if you are good at that type of thing. If it don't work then sen away.

[DavidL]

If you know how to plane correctly then use 3m contact cement. Also your cups will last longer if you don't stand you stone up on them. Use wood blocks to rest your stone on prior to laying it down or as you are lifting it up. Cups generally don't come unglued when used this way. On my old machine I have cups that are from 2007 with no adhesion problems. I got a call about two cups starting to come unglued, guess what...

[K.O.]

Gary, I can tell you why we don't recommend it for our product. Our rubber pads aren't glued to the 1/8" aluminum sheet, rather they are mechanically bonded through the process of vulcanization (check out Wikipedia). The spec on our drawings that are sent out to our rubber sheet manufacturer call for a rubber ripping bond which means the rubber should rip apart from itself before it de-laminates from the aluminum plate. Now for the most part it does not de-laminate, but due to the enviorment and use over time it can happen. If you have purchased or repaired suction cups within the last year, you should definitely not see any de-lamination as we have been working with our supplier in an effort to eliminate this. (On a side note we also warranty all pads for the 1st year, I will have some exciting news about warranties coming out soon)

Sorry for the digression, back to why we don't recommend it... it is because 99.99% of the time it does not solve the problem. It's like rust and corrosion, once it starts if will not stop until you cut it out and replace it. Sure you can clean it up and patch over it, but as always something goes undetected and sure enough it continues to grow. Same with the rubber pad, gluing only stops the bleeding but doesn't cure the cancer.

If you are in a pinch and need to use those suction cups you can repair them using a wet-suit glue (something with water resistant properties). Clean the area well, make sure it is totally dry and apply a thin layer of glue to the surface area. Let it dry and recalibrate your pods. You should get about 2-6 months more out of them, but sure enough, they will pull back apart.

I will stop my rant now...

[Cevin Moberly]

Gary,

Klint is correct.

The Pad is not glued to the Aluminum base but vulcanized and I have not seen any glue yet that can hold in these conditions.

Cevin

[BenJ]

I'll add that another fatal condition to the bonding is the advent of floating your parts. Vacuum is is conducive to maintaining the bond, compressed air is the adverse. While it is very helpful in everyday fabrication, it does add some wear and tear.

[Ken Lago]

Maybe its a dumb question but that wouldn't be a first time for me Why use rubber? couldn't you use something solid that could be mechanically fastened with screws or such?

[K.O.]

Ken-

No stupid questions, just stupid (insert name here). I am joking! That is a good question, but it goes back to a few things that we found out when developing the product years ago.

1. Rubber pads produce the best friction while under vacuum.
2. The rubber pads we use in our product do not leave marks, scratches or scrapes on the surface of the slab
3. The rubber that we use (shore and compound) seem to be quite stable at the temperature ranges shops operate in. (Certain materials are not thermally stable).

But after testing a multitude of other products, the most important reason why we use rubber is because it just worked.

Suction cups are just like tools, they need to be replaced from time to time. (Not to mention shite happens-See my thread on pod carnage). There other reasons as to why you should send in suction cups for repair or replace your damaged pods, but that is a whole other thread.

Klint

[clhilde]

And I thought it was because you make them suck just right

[Cevin Moberly]

Maybe its a dumb question but that wouldn't be a first time for me Why use rubber? couldn't you use something solid that could be mechanically fastened with screws or such?

The environment is another reason we use rubber. Can you imagine trying to back out small screws that have been sitting in water and mud for 2-3 years? Besides not marking or scratching the stone it also doesn't swell up or get water logged in wet conditions.


Cevin

[Ken Lago]

Maybe its a dumb question but that wouldn't be a first time for me Why use rubber? couldn't you use something solid that could be mechanically fastened with screws or such?

The environment is another reason we use rubber. Can you imagine trying to back out small screws that have been sitting in water and mud for 2-3 years? Besides not marking or scratching the stone it also doesn't swell up or get water logged in wet conditions.


Cevin

Klint brought up an answer that I had not thought about, friction, and I believe that is probably # 1 reason for using rubber. Small screws sitting in water for years? maybe, but I got tons of small screws on the cnc that usually don't give me any problems when removal is needed. Marking or scratching the stone and swell up is a good point but not unique to rubber. I'm not saying that rubber is not the answer but questioning the way it is attached.
In other industries such as joinery glue is always in conjuction with mecanical hold, either screws, nails, ducktails or failure is bound to happen at some time.
I did look up vulcanization of rubber and did gain a little insight to the process, what was not described was the part where you take the rubber and aluminum plate and fuse them together. I assume one takes soft rubber, aluminum plate, vulcanize and then voila they are stuck together. am I wrong?

[Cevin Moberly]

yea, so in the end, there is not one big reason to use vulcanized rubber pads, but many small reasons.

C

[Ken Lago]

yea, so in the end, there is not one big reason to use vulcanized rubber pads, but many small reasons.

C

C'mon Cevin I'm trying to learn here not not argue, teach me please.

[Cevin Moberly]

Ken,

Unfortunately, I am not an expert in the process of vulcanization and don't know exactly how it works. I believe it is a Thermal-Chemical process.

[clhilde]

I used to vulcanize conveyor belts in the mines and it was basically melting two pieces together with a bonding fluid heat and pressure.The bonging fluid was like a cleaner primer in one and was heat activated at 475 degrees.

We had to cook and press for 4-5 hrs depending on how thick the belt was