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tmc-okc
08-30-2013, 05:45 PM
I have an old (1970) Ohaus Model 7200 Du-O-Measure that I need a new drop tube for. The original drop tube has a crack in it and since this tube is a friction fit tube, it will no longer stay in place when using the measure. A replacement is no longer available from Ohaus. The original tube appears to have been made from acrylic type plastic and possibly coated to facilitate proper dropping of the powder. Currently I am using the tube with a small automotive hose clamp on it to keep it in place but I really dislike this arrangement.
Anyone got any ideas as to what to use to replace this tube with ?

Your assistance is greatly appreciated

Ron

sprinkintime
08-31-2013, 12:32 AM
I have an old (1970) Ohaus Model 7200 Du-O-Measure that I need a new drop tube for. The original drop tube has a crack in it and since this tube is a friction fit tube, it will no longer stay in place when using the measure. A replacement is no longer available from Ohaus. The original tube appears to have been made from acrylic type plastic and possibly coated to facilitate proper dropping of the powder. Currently I am using the tube with a small automotive hose clamp on it to keep it in place but I really dislike this arrangement.
Anyone got any ideas as to what to use to replace this tube with ?

Your assistance is greatly appreciated

Ron

tmc-okc; is the RCBS Du-O Measure the same, I know its made by Ohaus also, will some of the later powder dumps tubes of RCBS work, I know they are around.
Sprink

country gent
08-31-2013, 12:56 AM
A local machine shop could turn a replacement up but finding the right material is the problem. Possibly a mold could be made from the old one with plaster of paris and a new one "cast" from an epoxy or fiberglass body filler.

sprinkintime
08-31-2013, 11:39 AM
tmc-okc; I looked at the one I had, and if yours only has a crack in it, could you epoxy the crack and then sand down the end that goes into your powder measure, if not they are quite easy to make on a lathe and I don't believe that you have to use the material that they used. I would think a Delrin or a Polycarbonate both would work.
Sprink

tmc-okc
08-31-2013, 01:15 PM
Sprinkintime - I was not aware that the RCBS Duo- Measure was made by Ohaus - Thank you. The RCBS website shows replacement parts for the Duo-measure as no longer available. Guess I will try to pickup a used RCBS Duo- Measure at a less than reasonable price as all I need is the drop tubes. My Ohaus Du-O- Measure has been an excellent unit and I dont look to give it up.

Country Gent - I attempted to cast a new drop tube using bowling ball compound but the results were less than desirable. Trying to get the correct taper on the upper and lower sides on the drop tube are a real problem.

I have been looking for a used Ohaus unit but those are scarce as hen's teeth.. Ohaus discontinued manfacturing them simply because the cost of a quality unit drove the retail price up to the point Ohaus could not compete with all the lower priced measures on the market. Really sad this quality unit is out of manufacture..

Thanks for everyones input..

Ron

Pavogrande
08-31-2013, 08:03 PM
Try repairing the crack by "welding" -- If it is acrylic acetone will weld it --

Maven
09-01-2013, 10:50 AM
Ron, If all else fails, telephone RCBS parts dept. and request a few [green] plastic inserts for the current Uniflow powder measure. You'll have to drill out the base of the Ohaus Du-O-Measure for one to fit, but it will fit and work perfectly.

okshooter
12-31-2014, 08:33 PM
tmc-okc,
Mine dates back to '75 and I am having the same issues stated here and in a post regarding hopper replacement. I made an adapter to be able to use the drop tubes from my RCBS Uniflo measure. I bought a 7/8 - 14 nut for the O haus and scrounged a series of washers and a nut (18 tpi x ?; the RCBS tips measure approx. .541" across the threads using a dial caliper) to arrive at a stack height that would allow the RCBS drop tubes to fit snugly against the bottom of the O haus measure (a must since powder migration in to the cavity formed by the washers would eliminate accurate drops) and J-B welded these parts together.
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Hope these pics help. The stack height wound up such that I can screw an RCBS drop in to the smaller nut all the way and then run the big nut on the O haus measure and have the right fit per above. I believe a machinist could probable make something like this out of aluminum or brass bar stock but I do not know how costly it might be. Good luck!
The last pic shows the P.-C. (Pattern Control, Garland, TX) red baffle and MEC shot/powder bottle in place. This idea comes from the post regarding hopper replacement I found on this site by doing a search "Ohaus powder measure". It also turned up your post.
Please ignore the attached thumbnails - I do not know how to get rid of them!

tonyb
01-01-2015, 12:21 AM
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Drilled and tapped to take RCBS drop tubes

OuchHot!
01-03-2015, 03:48 PM
The Ohaus duo-measure that I have has the same diameter (OD) on the threaded bottom spigot as the drop tubes that come with the red plastic lee powder funnel. Maybe just a little collar and some glue would join the two together and you would have a 4" long purpose made drop tube.

ViragoSEPA
03-15-2021, 04:46 PM
What size threads are on the RCBS Quick Change Drop Tube Adapter??? I want to do the same thing; thought they were 5/8" x 18 TPI but saw a post suggesting they may be 9/16" x 18 TPI!!! Hlep please!!! Here's what I want to use after drilling and tapping my DUO Measure discharge... Thanks!
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UPDATE: The RCBS Quick Change Drop Tube Adapter threads ARE 9/16" x 18 TPI

mdi
03-16-2021, 12:37 PM
If you want to try making you own tubes here's some plastic rods; https://www.mcmaster.com/bars/wear-resistant-easy-to-machine-acetal/

ViragoSEPA
03-16-2021, 07:05 PM
Enlisted my son's help to 3D print an adapter from the Ohaus discharge 7/8" x 14 TPI to the RCBS Quick Change Drop Tubes' OD. Still playing with the basic design, and I'll post updates as found. We made two styles (slight changes to Ohaus end), and here's a picture.
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