Author Topic: O-rings for an old MHM Synchro-Print S  (Read 539 times)

Offline Sbrem

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O-rings for an old MHM Synchro-Print S
« on: April 29, 2019, 10:08:00 AM »
We run a fairly old MHM Synchroprint S, 10/12, and one of our heads lifters is leaking air; according to Rodney at Hirsch, it's probably the O-ring, but good luck finding one. Any suggestions on secret places that would sell Austrian O-rings? If not, we'll just replace the cylinder, but I'm pretty O-rings is a less expensive fix...

Steve
I made a mistake once; I thought I was wrong about something; I wasn't


Online Frog

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Re: O-rings for an old MHM Synchro-Print S
« Reply #1 on: April 29, 2019, 10:18:02 AM »
If you can replace the o-ring, that means that you can pull the old one and should be able to measure or visually match it up.
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Offline mk162

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Re: O-rings for an old MHM Synchro-Print S
« Reply #2 on: April 29, 2019, 10:30:44 AM »
mcmaster-carr.  order on sizes either side you think it is and you'll be set. 

Offline inkman996

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Re: O-rings for an old MHM Synchro-Print S
« Reply #3 on: April 29, 2019, 10:52:43 AM »
There isn't an o ring on earth that cannot be found especially through Mccaster. You just need the ID and OD plus the cross section measurement, or width. But you also need to know the material, Buna N is typical. Honestly tho Hirsch should just be able to give you the specs or dash number for what you need. If you are measuring them for your self use a dial indicator with decent resolution.
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Offline mk162

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Re: O-rings for an old MHM Synchro-Print S
« Reply #4 on: April 29, 2019, 11:05:20 AM »
we replaced all of them on our RPM screen holders.  We went with the high temp ones since the flash would heat them up.  Worked fantastic.

Offline Sbrem

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Re: O-rings for an old MHM Synchro-Print S
« Reply #5 on: April 29, 2019, 11:34:06 AM »
A friend of ours who is ridiculously knowledgable, and builds miniature engines from scratch, and I mean a block of metal from scratch, and he measured it, and could not find on through McMaster-Carr, which is a pretty big surprise. But the suggestion to get one each size over and under is a good one, we'll go with that first; the cylinder is $500.00, O-rings probably a little less...

Steve
I made a mistake once; I thought I was wrong about something; I wasn't

Online Frog

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Re: O-rings for an old MHM Synchro-Print S
« Reply #6 on: April 29, 2019, 12:46:30 PM »
A friend of ours who is ridiculously knowledgable, and builds miniature engines from scratch, and I mean a block of metal from scratch, and he measured it, and could not find on through McMaster-Carr, which is a pretty big surprise. But the suggestion to get one each size over and under is a good one, we'll go with that first; the cylinder is $500.00, O-rings probably a little less...

Steve
I've some times successfully faked in-between sizes, by using a ring with a little fatter cross section, but smaller inside diameter. The result was that the stretch made it a little slimmer, and closer to the original.
"Adversity does not build character, it reveals it"

Offline inkman996

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Re: O-rings for an old MHM Synchro-Print S
« Reply #7 on: April 29, 2019, 01:49:57 PM »
A friend of ours who is ridiculously knowledgable, and builds miniature engines from scratch, and I mean a block of metal from scratch, and he measured it, and could not find on through McMaster-Carr, which is a pretty big surprise. But the suggestion to get one each size over and under is a good one, we'll go with that first; the cylinder is $500.00, O-rings probably a little less...

Steve

Share the measurements if you have them.
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Offline Sbrem

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Re: O-rings for an old MHM Synchro-Print S
« Reply #9 on: April 29, 2019, 02:30:34 PM »
A friend of ours who is ridiculously knowledgable, and builds miniature engines from scratch, and I mean a block of metal from scratch, and he measured it, and could not find on through McMaster-Carr, which is a pretty big surprise. But the suggestion to get one each size over and under is a good one, we'll go with that first; the cylinder is $500.00, O-rings probably a little less...

Steve

Share the measurements if you have them.

My partner took it to his old boss (from 30 years ago) and didn't keep the measurements after they couldn't find it in McM-Carr, or course... I'll get the measurements, and will share. Thanks all, we really appreciate the help.

Steve
I made a mistake once; I thought I was wrong about something; I wasn't