Some tricks for grommet installation

[alexey 6]

I allways damage SS grommet in the final stage of installation :(
I know about oiling, about do not force too much, but ... yet no lack...
Can somebody tell me few tricks?

Lexa

[hookitt 0]

Erasing post due to better suggestion from Mick

My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto

[riggermick 6]

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I allways damage SS grommet in the final stage of installation :(
I know about oiling, about do not force too much, but ... yet no lack...
Can somebody tell me few tricks?

Don't hit it so hard, it takes a while to set them. Many softer blows as opposed to fewer hard ones. Once the grommet is at the point where it is about to split or fold, stop and remove the tool. Place the outer (finish) side on a flat tempered steel block. Use a body shop hammer from this point for the final set. A body shop hammer is made of very tough plastic and filled with lead shot. Using the tempered steel flat block as a base gently start to hammer the washer side until it sets. Do a few practice runs before you attack someones rig, as hammer force, positioning and technique will all affect the outcome. Tempered steel block can be found at any machine shop (they will probably give yo a free off cut)and body shop hammers can be found at most hardware stores.

Mick.

[alexey 6]

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Smash it really hard as few times as possible. Don't be shy. The more times you hit it lightly the more apt to splitting the grommet will be.

and

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Don't hit it so hard, it takes a while to set them. Many softer blows as opposed to fewer hard ones.

Two expert - two ways...

I use new Stimpson spur grommer inserting die (S7685 from Para-Gear), and tomorrow will try body shop hammer

Lexa

[hookitt 0]

Well, He probably has more insite. The press I used most was a hydraulic press and it seldom split the grommet once I replaced the die. That's why I erased my post.

The die I used to hammer it in by hand with, works rather well, and I used to smash it pretty darn hard. It seldom gets used anymore.

The nifty trick of turning it over before it's completely seated is a a good one though.

My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto

[riggermick 6]

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Well, He probably has more insite. The press I used most was a hydraulic press and it seldom split the grommet once I replaced the die. That's why I erased my post.

The die I used to hammer it in by hand with, works rather well, and I used to smash it pretty darn hard. It seldom gets used anymore.

The nifty trick of turning it over before it's completely seated is a a good one though.

Old engineering axiom "if it doesn't fit, get a bigger hammer!"

[masterrig 1]

I use the proper die-setter, (#4-setter for #4 grommets, etc.) a large rubber mallet and use several whacks with the mallet, while turning the part of the setter I'm holding in my left hand. Using one or two harsh blows with the mallet tends to split the 'SS' grommet. I periodically check to see how the grommet looks, after the first 2 - 3 whacks with the mallet, till I get the right 'set'. The die setters are expensive but, it beats the alternative.


Chuck


Chuck

[masterrig 1]

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Quote

Smash it really hard as few times as possible. Don't be shy. The more times you hit it lightly the more apt to splitting the grommet will be.

and

Quote

Don't hit it so hard, it takes a while to set them. Many softer blows as opposed to fewer hard ones.

Two expert - two ways...

I use new Stimpson spur grommer inserting die (S7685 from Para-Gear), and tomorrow will try body shop hammer

________________________________________

2 to 3 hard blows with your mallet works on brass grommets. Brass, is more malleable than Stainless Steel, whish is more 'brittle'. You want to 'coax' Stainless Steel, into shape. That's been my experience. As was mentioned earlier, try a couple practice runs before tackling the 'real' job.


Chuck

[wimdevos 0]

Spray a very thin layer silicone spray on the setting tools !
(not more than you need to clean/ lubricate release cables)

[masterrig 1]

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Spray a very thin layer silicone spray on the setting tools !
(not more than you need to clean/ lubricate release cables)

__________________________________

Great idea! Keeps the grommet from 'sticking'.


Chuck

[masterrigger1 2]

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I allways damage SS grommet in the final stage of installation :(
I know about oiling, about do not force too much, but ... yet no lack...
Can somebody tell me few tricks?

The grommets today are cheaper made, even the SS ones.
Because of that, you need to sand the forging/stamping cracks from the top of the grommet before starting the installation.

I use 120 to 180 grit sand paper to do this.

If you look really close, you can see the little cracks that are at the top on some of them.
That is one reason why some split during installation and some do not.

Blue ones,
MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[alexey 6]

Quote

The grommets today are cheaper made, even the SS ones.
Because of that, you need to sand the forging/stamping cracks from the top of the grommet before starting the installation.
I use 120 to 180 grit sand paper to do this.

The same answer I recieved today from local manufacturer :)

And, now
grit sand paper + many soft blows = nice looking work


Thanks a lot to all....

Lexa

[riggerrob 558]

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Quote

I allways damage SS grommet in the final stage of installation :(
I know about oiling, about do not force too much, but ... yet no lack...
Can somebody tell me few tricks?

The grommets today are cheaper made, even the SS ones.
Because of that, you need to sand the forging/stamping cracks from the top of the grommet before starting the installation.

I use 120 to 180 grit sand paper to do this.

If you look really close, you can see the little cracks that are at the top on some of them.
That is one reason why some split during installation and some do not.

Blue ones,
MEL

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Smoothing the edge with emery cloth may be nice with stainless steel #0 grommets, but it is ESSENTIAL with the brass #8 grommets in sliders.

[NovaTTT 1]

Wondering if anyone uses a grommet setting machine rather than the hand tools, and how do you find them in comparison to the hand tools?

"Even in a world where perfection is unattainable, there's still a difference between excellence and mediocrity." Gary73

[ChrisClark 0]

I have experienced the problem you have mentioned with #0 & #2 Stainless Steel. I spoke to a rigger at a leading manufacturer and he said that it was the quality of the grommets and they were having to grind the edges of the shank before insertion.

Obviously the grommets split because the end of the shank has to stretch and spread over the washer and steel isn't that flexible. You should be looking to reduce the amount of shank left and also remove away any imperfections on the grommet shank. Grinding some of the end away or increasing the thickness of the material where the grommet is to be set will help produce a better finish.

I was using a standard SS#0 hand tool purchased from Para-gear, however this tool broke whilst in use and I bought a replacement hand tool direct from Stimpson. This tool is I believe designed for the long shank grommet (#0L) and it sets the grommet with a more pronounced fold of the shank instead of spreading out the steel across the washer. This new tool gives a superior finish to the one from Para-gear and I can now set stainless steel grommets perfectly with about 5 hard blows. I now only use #0L grommets for just about every application.

[riggerrob 558]

Even foot-powered grommet-setting tools are vastly superior to hammered dies, however, you would have to set a few thousand grommets to pay for a grommet-setting machine.
Electric or compressed air powered machines are so expensive than only factories setting dozens of grommets per hour can afford them.

[masterrigger1 2]

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I spoke to a rigger at a leading manufacturer and he said that it was the quality of the grommets and they were having to grind the edges of the shank before insertion.

Grind is a very aggresive word.

You should only remove enough metal just to remove the cracks at the end before installation.

Also, never use a bench grinder to grind soft metal like brass or aluminum as it will load the grinding wheel and may explode.

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Obviously the grommets split because the end of the shank has to stretch and spread over the washer and steel isn't that flexible.

Somewhat true, but the biggest reason is because a split is already present and will continue unless removed before installation.

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......was using a standard SS#0 hand tool purchased from Para-gear

The standard dies from Paragear are not designed for SS Grommet installations.
They do sell the Stimpsons though. Stimpsons (painted blue) can be used for all types of grommets, not just SS.

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This tool is I believe designed for the long shank grommet (#0L) and it sets the grommet with a more pronounced fold of the shank instead of spreading out the steel across the washer. This new tool gives a superior finish to the one from Para-gear and I can now set stainless steel grommets perfectly with about 5 hard blows. I now only use #0L grommets for just about every application.

The tool that you speak of is a "Rolled Rim" die which is different that the standard "flared" die.

The length of the gromment should be regulated to the thickness of the material., not the die.

You should not be using long barrels for short work.It can damage both the die and/or the workpiece with the added blunt force needed to set them.


Cheers,
MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[NovaTTT 1]

Thanks, Rob.

The machine I'm considering is powered by elbow grease, not elec. or air. It's similar in appearance and operation to a single-stage cartridge reloader and is more or less inexpensive. Surprising, I know!

"Even in a world where perfection is unattainable, there's still a difference between excellence and mediocrity." Gary73

[ChrisClark 0]

If you had read my post properly you would have seen that I mentioned the original hand drive and die was the "SS" set sold by para-gear. I only purchased the new hand tool part of the set from Stimpson. They informed me that the new hand tool is stainless steel and the ones from Para-gear are not, only the die is stainless steel (blue base). I have attached a picture. As I said before this now works perfectly. For thinner materials I use normal length #0 stainless steel grommets and for thicker materials the #0L stainless steel grommets. However I use mostly long shank grommets as they are now the most commonly used grommets on modern equipment. See attached photos. 3 layers of type 3 tape (white) with standard grommet and 2 layers of type 17 webbing with long shank grommet. This took me a few minutes to do without preparing the grommets and with 5-6 blows. The point I am making is that since I purchased the new hand tool from Stimpson I have not had a problem with grommets splitting.

[nt8us 0]

the stimpson tools work very well for setting grommets because the grommets were made by stimpson. if you compare the stimpson tool to the cheaper osborne tool you will see quite a lot of difference in the actual shape of the die. when Para Flite designed th swift system back in the 80's they used aluminum grommets ,but had major problems with them splitting. Manley Butler consulted with Stimpson and had a "coiling area " machined into the tool. this allows the grommet edge to roll instead of just smashing it over.

[masterrigger1 2]

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If you had read my post properly you would have seen that I mentioned the original hand drive and die was the "SS" set sold by para-gear.

Writing it more clearly would have helped some.
Para-Gear sells both the Osborne (cheaper) and Stimpson die sets.
You never stated that the ones bought from Para-Gear were Stimpsons, That Information would have helped to identify exactly what you had to us.

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For thinner materials I use normal length #0 stainless steel grommets and for thicker materials the #0L stainless steel grommets. However I use mostly long shank grommets as they are now the most commonly used grommets on modern equipment.

In your earlier post you stated "I now only use #0L grommets for just about every application."

This statement lead me to believe exactly what you stated.

My post just pointed out that you should use the proper length grommet, not just a "one size -fits all".


Also just for clarity, the two parts of a hand set die are sometimes called the Base and Mandrel.

They are also called from other manufacturers, the Top Set and Bottom Set.


Cheers,
MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com