Where to get custom-made fittings?

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Joined: Mon Jul 20, 2020 8:58 pm
Real name: Robert Mendelsohn

Where to get custom-made fittings?

Post by RobertMendelsohn » Tue Jun 01, 2021 8:17 pm

Hello all,

I have an odd diffusion pump fitting, and I'd like to have a custom-fabricated adapter made, as well as at least 2 other similar adapters.
Has anyone done this? Good companies to recommend? Does anyone here do this for a fee?

I wish I knew enough about metalworking / had the tools to do it myself, but I do not.



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Rich Feldman
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Real name: Rich Feldman
Location: Santa Clara County, CA, USA

Re: Where to get custom-made fittings?

Post by Rich Feldman » Sun Jun 06, 2021 10:38 pm

Can we see a picture of what you want to adapt to?

In my limited experience, amateur and professional fabricators want to see a conventionally annotated mechanical drawing of desired part.
There are different drawing conventions for machined parts, weldments, etc.
Some shops welcome a 3-D CAD model, as from SolidWorks,
but fab drawing is generally necessary and sufficient. Could even be drawn neatly on paper.

The one exception I've encountered is 3-D printed parts, where two commercial shops and one "friend at work" wanted STL files and nothing more.

Hey, how 'bout 3-D printed plastic parts for vacuum applications that never need to get hot?
Maybe even with inexpensive "extruded filament" technology; I know one person who overcame the natural porosity with some kind of paint.
https://www.instructables.com/3D-Printe ... re-Vessel/
All models are wrong; some models are useful. -- George Box

Chuck Sherwood
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Real name: Chuck Sherwood
Location: Naperville, IL

Re: Where to get custom-made fittings?

Post by Chuck Sherwood » Sat Jun 12, 2021 12:42 am

I am curious if you have found any place to make custom flanges. A good source would be useful to all.

My guess is you can find them, but the price will very likely be sticker shock. I had a couple mechanical engineer friends that regularly worked with machine shops and they constantly complained about how difficult it was to get these places to do small jobs. They just didn't want to do small jobs and would bid them out of sight to make them go away.

I have made a couple custom flanges for odd ebay purchased pumps salvaged from leak detectors and old electron microscopes. I made these out of brass because they had to be made from multiple pieces and then soldered together. Even taking that simple route it took a fair amount of time and material. If you need an O-ring or two, the complexity goes up (and the risk of failure) and so does the time required.

I am now using a Varian HS2 diffusion pump with a standard ASA flange. This makes connecting things much easier. It bolts right up to a old Temescal gate valve and then to ASA to KF50 adapter. Yea, its water cooled DP, but the ultimate pressure is significant lower than an air cooled DP. After an hour from power on, it is down into the low "6s". My air cooled pump from a old leak detector is doing good to cross over into the 6s.


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