98mm Nozzle Washer

Looking for a 98mm (3.5" OD) snap ring nozzle washer with an ID of 2.75" or so. The largest ID McMaster has in this size is 2.5" which is too small an opening for me.

Anyone know a good source? Someplace like Grainger would be ideal, in-line with my moral dislike of ordering these kind of parts from rocketry sources.

https://m.grainger.com/mobile/product/GRAINGER-APPROVED-Retaining-Ring-for-Bores-38DP11 ?

dhbarr said:

https://m.grainger.com/mobile/product/GRAINGER-APPROVED-Retaining-Ring-for-Bores-38DP11 ?

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WASHER, not snap ring.

I was also unable to find one. Perhaps some dremel work on the 2.5" ID washer?

My bad, reading comprehension fail ^_^

Maybe have a local fab shop or steel supplier CNC cut one to your specs?

Just fire it a few times , the ID will open up lol .

Eric

AlnessW said:

...in-line with my moral dislike of ordering these kind of parts from rocketry sources.

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Dude, sometimes you have to throw a vendor a bone. Other options would be ideal, but not always an option.

https://lokiresearch.com/secure/storeDetail.asp?id=52120032311620

Really ...what's wrong with rocketry vendors????
How's that attitude work for body tubes, NC's and the like?

You need to discover the local sources....
I've found suitable washers at the better HW stores in the area (Park Rose, Ace in FG) plus you can get them at McGuire Bearing.

OK guys, some of you are taking my "avoiding buying from rocketry vendors" a little too seriously... Justin - Loki is a good example there though. $20 when a similar product can be sourced for $5.
Fred, obviously I have no issue with sourcing fiberglass from vendors.

Tonimus said:

I was also unable to find one. Perhaps some dremel work on the 2.5" ID washer?

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That may be a good approach. I wonder how well a Dremel would handle cutting steel?

dhbarr said:

My bad, reading comprehension fail ^_^

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3stoogesrocketry said:

Just fire it a few times , the ID will open up lol .

Eric

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Now we're talking! Especially with the kind of loads I usually fly...

Loki's washer is not the same as ANY $5.00 washer you are comparing it to. Spend the money for the right product here.

AlnessW said:

That may be a good approach. I wonder how well a Dremel would handle cutting steel?

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I don't think it would be that hard, you might go through a whole grinding wheel in the process, though. I would scribe the 2.75" ID with an engraving tool or a carbide point if you can, as sharpie/pencil might wipe off too easily.

AlnessW said:

Anyone know a good source? Someplace like Grainger would be ideal, in-line with my moral dislike of ordering these kind of parts from rocketry sources.

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After you get a lathe and can open up the ID on stainless steel without work hardening it and having to resharpen your carbide tooling a few times, give a good hard thought on what you would charge for your work and tooling. Sometimes rocketry vendors are not gouging, they are just needing a fair price for their labor which is way less than machine shop rates BTW.

AlnessW said:

That may be a good approach. I wonder how well a Dremel would handle cutting steel?

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Nozzle washers are stainless steel. It work hardens very easily with heat and friction. When that happens, it is harder than your tooling usually. That's why you can't machine a nozzle washer once it has been fired on a motor.

Binder Design said:

Nozzle washers are stainless steel. It work hardens very easily with heat and friction. When that happens, it is harder than your tooling usually. That's why you can't machine a nozzle washer once it has been fired on a motor.

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I was thinking they were mild steel, stainless is terrible to grind on.

Even Loki's $20 price is cheap considering. Here's what you do: price out flat sheet thick stainless steel, then take to a place that does water jet cutting. I don't think Scott is making any profit on these. Biggest problem with pricing is that people just look at it as a "big washer" and there is a limit for what people will pay for a washer no matter how much it costs to produce them.

Scott also then takes them by hand and removes any imperfections in the washer and grinds them to a perfect fit and finish.

GRIFFIN said:

Loki's washer is not the same as ANY $5.00 washer you are comparing it to. Spend the money for the right product here.

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+1 your going to spend 300-400$ or more on the propellant cough up the $20