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I have come into possession of a very old Ro-Tap, made under license by Eberbach & Sons, Ann Arbor, MI. S/N 8817.
For those who might be familiar with these old machines, it is the model with the oil-filled base.
Tyler says it is obsolete and they can supply no parts.,
The only thing I need is the top lid and the cork block. Is there a reason why those items from a newer machine would not work? It is set up for 8" round sieves.
Does anyone have one of these just sitting around and would sell the top cap?

I have lusted/ desired/ wanted a Ro-Tap for the entire time I have been in this industry. Now that I am this close, I need to make it work. We got it from another firm which was going out of business. The manager of this office didn't know what it was and was ready to send it to the trash. I intervened.
Please help me save this vintage Ro-Tap.....or educate me why I should let it go to the junkyard.


I inherited one of these and passed it on to a testing firm friend. My son works for him and I still give reasonably free consulting advice. I'll check, but guess he may still want to use it. Otherwise that cap is pretty simple and any machine shop should be able to make one.
OG back here:
Well that machine is in use. The cover is a cast thing, but my son has it and can make a sketch of the dimensions so any shop, even he (my son) could make it, but no nicely machined (flame cut circle, etc.)

OG back: Well son figures making q new cover would be too expensive.

go to this link and you may find what you need. The parts likely can be made to fit if not the exact model.


Thanks, OG.
Exactly what I thought...its only a cover for the sieves and a holder for the cork block.
I was thinking I could have a local machine shop cut it out using their plasma cutter. I could rivet a regular 8" round sieve cover to the plate and provide whatever mounting ears or such that were needed to hold it in place. Do you think 1/4" steel would be heavy enough, or would 3/8" be better?


I have not had this machine in many years, but the diagram in the link shows a holder ring, so I would think machining and welding would need to make sure it fits. As to thickness the original casting probably is at least 3/4" in places so I'd opt for 1/2" thickness. That cork is pretty large diameter as I recall at least 1-3/4". You might look at something else than cork, say a chunk of hard rubber from a LARGE tire. It would not have to be round, but has to fit inside a collar of some sort welded to the plate. As I recall the cork sits up at least 1-1/2". Run the machine to see where the hammer has to be at the end of the blow.


Mike...great find! I've done similar with old Rainhart equipment. Well worth restoring.....just watch that it still meets ASTM standards. You might want to split a few samples and run through two machines to check.


Good idea, thanks, Ron

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