Lyman 55 Powder Measure - Anyone know the drop tube threading?

[Dimner]

Hello gents,

I bought a vintage lyman 55 off of the ebays and I would like to create a custom drop tube funnel to it with my 3D printer.

Mine is the grey version, from what I would guess is the 80's?

https://i.imgur.com/cHZiBTk.jpg

The drop tube is threaded, looking like this:

https://grafs.com/uploads/product-picture/192/77636.jpg


Does anyone know what the threading of the end of the drop tube would be? Or have a guess? I'm not going to have a chance to get to the hardware store until the weekend and even a guess would help with designing something in cad.

[dsh1106]

The threads are the same as the 310 dies.

[farmbif]

Lyman used to sell an adapter to 7/8-14 thread, I sure could use one too to screw the 55 right into the powder through expander die

[Pressman]

That ,is an odd ball thread. If you want a tap and die, figure $200+

Commonly called 5/8" thread, it is not. Actual size is .6075" x 30 tpi.

[Dimner]

with my 3d printer i can CAD then print any standard imperial or metric threads. So no need to buy adapters or dies/taps.

So if I can get close enough with one of the preset threads in autocad, then I can tweak to get it good to go.

I guess if I am not able to match the threads well enough I can 3d print my funnel with a correct ID tube that uses a set screw.


So far, upgrading the 55 has been pretty easy. Given how little powder the 55 holds, I figure a baffle in necessary.
While designing one it was really easy to just turn the baffle into a large powder hopper that nearly doubles the powder capacity of the 55. I should have made the portion of the 3D printed hopper above that is outside/above OEM plastic hopper flare out into a wider cylinder, but I already printed it.

https://i.imgur.com/7TL9q3x.jpg

In the bottom of the hopper is an integrated baffle.

https://i.imgur.com/Rl2ctGP.jpg

[Dimner]

Here is the thread profiles I have access to. Do you guys see anything that I should use as a starting point?

https://i.imgur.com/Q0QiA2J.jpg

[dsh1106]

That ,is an odd ball thread. If you want a tap and die, figure $200+

Commonly called 5/8" thread, it is not. Actual size is .6075" x 30 tpi.


I have the TAP, the die is a special order buy. I haven't found enough need to spend the $200 to get a die.

[onelight]

Could you print the whole drop tube with size and threads you need ?

[Dimner]

Could you print the whole drop tube with size and threads you need ?

GENIUS!!

Perfect solution. Sometimes it's hard to see the forest from the trees, eh? Thank you very much for the suggestion.

[onelight]

Your welcome , I am a tree guy to and sometimes I need to be poked to change direction [smilie=s:

[jimkim]

Measure the thread and chase it on a regular lathe.

Sent from my VS880 using Tapatalk

[pworley1]

Unless you are going to mount it on a press why thread it at all. If you are going to mount it a press it would be standard die thread.

[Green Frog]

Unless you are going to mount it on a press why thread it at all. If you are going to mount it a press it would be standard die thread.

^^^ What he said! ^^^ Why do all that work to make a part that will then be harder to use? Unless you are going to mount your 55 on a Lyman TruLine Jr, those threads would be at best inconvenient, but likely useless and problematical. If you really want a drop tube with the original threads, I’ve probably got a few spares laying around. :)

Froggie

[mattw]

OMG that baffle/extension would be awesome! I have longed for an adapter that would allow the 55 to be mounted on the steel arm of the RCBS powder measure stand that then would take the screw in RCBS powder drop tubes.

[Dimner]

Thanks MattW. I will put the STL file on thingaverse as soon as I can figure out how to do that.


And the reason I want my 3D printed drop tube threaded is so I can add adapters to the drop tube.

The current drop tube will not allow me to put a 223 case under it and throw powder, I have to use a funnel as well as the case. So why not design a drop tube that negates that?

doing threads with 3D printing is a piece of cake. As long as you know the specs of the threads.

[Carrier]

Thanks MattW. I will put the STL file on thingaverse as soon as I can figure out how to do that.


And the reason I want my 3D printed drop tube threaded is so I can add adapters to the drop tube.

The current drop tube will not allow me to put a 223 case under it and throw powder, I have to use a funnel as well as the case. So why not design a drop tube that negates that?

doing threads with 3D printing is a piece of cake. As long as you know the specs of the threads.

Could you post a link to it here when you get it figured out?

[Green Frog]

The part of the original drop tube that actually fits into the bottom of the measure is a straight sided tube with a divot or groove for the lock screw... what comes below is of no interest since you want to make an adaptor around that part anyway... so design the bottom that you need then put the shank on top to fit the socket in the measure. Don't get hung up on the design of the lower portion since you already know you would have to adapt around it anyway, right?

BTW, the offer still holds for an original small diameter drop tube if you are determined to start from an original tube to do your project, although I'm still not sure why you would want to.

Froggie

[Negster]

I turned a small piece of aluminum to hold my #55 in a redding stand. I also made it accept RCBS extended drop tubes. It is held in the stand with 2 small set screws.
https://thumbs2.imagebam.com/be/0f/75/1cd2e21350066743.jpg (http://www.imagebam.com/image/1cd2e21350066743)
https://thumbs2.imagebam.com/45/ca/94/3ab0b81350066748.jpg (http://www.imagebam.com/image/3ab0b81350066748)
https://thumbs2.imagebam.com/a3/07/9c/aad9821350066756.jpg (http://www.imagebam.com/image/aad9821350066756)
https://thumbs2.imagebam.com/23/a7/ae/acfaae1350066759.jpg (http://www.imagebam.com/image/acfaae1350066759)

[lightload]

The adaptors are on ebay. Lyman still has #55 parts. Call. Website not right.

[Green Frog]

By the way, Negster’s post reminded me... the original, first production #55s came first with steel, then with aluminum (or do I have it backwards?) unthreaded drop tubes! They were intended to attach to the bench or a shelf above it with the built in clamp. In fact, I used the predecessor, the #5, on the bench a lot of times, just clamped to a bracket on my scope stand, those measures had a smaller diameter drop tube and were smooth on the outside all the way down.

Froggie

[Pressman]

Mr. Frog Person, Sir: I recieved news last night that there may be very big news coming shortly regarding the 55 Project. Stay tuned!!!!

Ken

[KCSO]

I simply bored my drop out and glued in a large aluminium arrow shaft, works fine for the last 30 years or so.

[Dimner]

As mentioned above, I went ahead and designed and 3d printed a new drop tube for my lyman 55. No threads, thanks for that suggestion guys. I do not plan (at this time) to mount it on a press, so threads are unnecessary. If I want one with threads, I will just design a new one. For my purposes, I will be mounting to the edge of my bench (office desk) with the lyman built in clamp on the back side of the powder measure.

I designed this drop tube to mimic the MTM funnel I use for my normal hand loading while measuring each lode on an RCBS 10-10 scale. Here is a cross section of the design I came up with:

https://i.imgur.com/K0JlcpR.jpg

I need to test the final 3d print with some larger extruded and flake powders, but I think this is going to work very well.

https://i.imgur.com/7goFIWv.jpg

Here's something I thought was interesting. The original lyman drop tube that I have, has the groove for the set screw located. 1/4" too low. So that groove is really doing nothing that I can see. So for my version, I moved the groove up so it would meet the set screw.

[Shawlerbrook]

Wash them in Dove detergent to eliminate static electricity. Are you going to make any for sale ?

[onelight]

Very nice , that should serve you well.

[GONRA]

6+ decades ago, GONRA used to cut these Lyman/Ideal 30 thread/inch's on my boyhood 12 inch Sears metal lathe.
Records are looong gone but standard set of die cast Zamak change gears is all that's needed.......

[Green Frog]

Mr. Frog Person, Sir: I recieved news last night that there may be very big news coming shortly regarding the 55 Project. Stay tuned!!!!

Ken

:happy dance::happy dance::happy dance: HIP, HIP, HOORAY! :awesome: I'll be waiting by the computer in expectation. :coffeecom

Froggie

[Green Frog]

As mentioned above, I went ahead and designed and 3d printed a new drop tube for my lyman 55. No threads, thanks for that suggestion guys. I do not plan (at this time) to mount it on a press, so threads are unnecessary. If I want one with threads, I will just design a new one. For my purposes, I will be mounting to the edge of my bench (office desk) with the lyman built in clamp on the back side of the powder measure.

I designed this drop tube to mimic the MTM funnel I use for my normal hand loading while measuring each lode on an RCBS 10-10 scale. Here is a cross section of the design I came up with:

https://i.imgur.com/K0JlcpR.jpg

I need to test the final 3d print with some larger extruded and flake powders, but I think this is going to work very well.

https://i.imgur.com/7goFIWv.jpg

Here's something I thought was interesting. The original lyman drop tube that I have, has the groove for the set screw located. 1/4" too low. So that groove is really doing nothing that I can see. So for my version, I moved the groove up so it would meet the set screw.

Looks like modern technology has struck again! That looks like a winner from here. It's good to see that we can meld 125 year old design with 21st Century technology. The only concern I would have is the "choke point" where the top taper and bottom taper meet in the middle. Be sure and keep a close eye out for bridging, especially if you use any large grain or flake powders. I think for most powders you should be fine, but I would continue with my longstanding practice of using the "knocker" after each throw to insure complete drops.

Froggie

[Three44s]

Wash them in Dove detergent to eliminate static electricity. Are you going to make any for sale ?

I would also be interested as I have a “55” that I bought off the net and it came without drop tubes (seller portrayed it as such).

I also do not need threads because I will “clamp it” to something.

Three44s

[Dimner]

Looks like modern technology has struck again! That looks like a winner from here. It's good to see that we can meld 125 year old design with 21st Century technology. The only concern I would have is the "choke point" where the top taper and bottom taper meet in the middle. Be sure and keep a close eye out for bridging, especially if you use any large grain or flake powders. I think for most powders you should be fine, but I would continue with my longstanding practice of using the "knocker" after each throw to insure complete drops.

Froggie

Yeah, I am using the knocker all the time for sure. Just because I'm a nerd and I want all those 8 extra bits of powder to come out :)

I do need to make a revision to this. It works great for pistol case filling, but for small caliber rifle, even with ball powder the powder gets backed up at that choke point. When you pull out too early (insert jokes) it makes a mess of powder that wasnt able to get into the case. So I will make a revision that has the upper part of the internal funnel a bit wider and make the choke point a bit longer. I think the revision I have in mind also may work well for extruded and flake powders.

I should mention, as designed, it works well on large caliber rifle cases, since the mouth of the case is further down the bottom portion of the tube.

[Dimner]

:happy dance::happy dance::happy dance: HIP, HIP, HOORAY! :awesome: I'll be waiting by the computer in expectation. :coffeecom

Froggie

What is this mysterious 55 project you speak of? My interested has sparked :shock:

[Green Frog]

Over a decade ago several folks of the Antique Reloading Tool Collecting ilk started contributing to a website started by one of their number to explore the history of the #55 Powder Measure as well as subchapters on several other contemporary measures. Unfortunately, Life got in the way for the webmaster, and many pages of super-informative stuff disappeared in a flash of electrons.

Somewhat like the Knights of the Round Table, several of us have been on a quest to retrieve this Holy Grail of Powder Measure History.

Froggie

[mattw]

I turned a small piece of aluminum to hold my #55 in a redding stand. I also made it accept RCBS extended drop tubes. It is held in the stand with 2 small set screws.
https://thumbs2.imagebam.com/be/0f/75/1cd2e21350066743.jpg (http://www.imagebam.com/image/1cd2e21350066743)
https://thumbs2.imagebam.com/45/ca/94/3ab0b81350066748.jpg (http://www.imagebam.com/image/3ab0b81350066748)
https://thumbs2.imagebam.com/a3/07/9c/aad9821350066756.jpg (http://www.imagebam.com/image/aad9821350066756)
https://thumbs2.imagebam.com/23/a7/ae/acfaae1350066759.jpg (http://www.imagebam.com/image/acfaae1350066759)

I would pay money for that kind of adapter with standard die threads on the outside.

[onelight]

If you cut the groove on both ends you could make 2 sizes on 1 tube

[Green Frog]

Negster, I just noticed the rest of the story... you have a #55, but it has a Culver Conversion on it. Is it an actual Culver-made unit or one of the clones? Regardless, it looks good from here, and I like your solution for a stand/drop tube as well. :drinks:

Froggie

[Negster]

It is a clone marked "JJ Nagy" but has a nice click action and drops accurate. I went with the RCBS tubes because I like to dump into a pan and I just hold the pan tight to the bottom on the drop tube so no powder jumps out but it still falls free from the measure.

[44magLeo]

The stock drop tubes originally came in two sizes. One small for up to around 27 caliber the other for anything larger.
They are all over Ebay for sale.
I have three 55's. They are all orange. One has a much thicker walls on the powder reservoir. The drop tube in it is much shorter than the other two. It is knurled on the bottom. This one took a bit of work to get it working. On the screw that lock the main slide in place someone brazed it solid. This only let you adjust the two small slides. After drilling out the braze enough to remove the slides I used the threaded section of a Tee nut that had the right threads for a new stop screw. I "glued" it in place with a bit of JB Weld.
A bit of polishing to get the last of the braze out of the way so the slides work it's back in operation. If I painted you couldn't tell it was ever bubba'ed.
The other two, one has a small tube, the other a large.
MTM makes a funnel set that has interchangeable pieces on the bottom. The long drop tube in that set is an almost perfect fit in the 55, just a tiny bit small.
Being transparent and long any bridging is easy to see.
Leo

[44magLeo]

I just wanted to add that on my drop tubes the shorter knurled one has the groove for the set screw. The other two had both drop tubes and all have just a dimple for the set screw.
Leo

[Green Frog]

It is a clone marked "JJ Nagy" but has a nice click action and drops accurate. I went with the RCBS tubes because I like to dump into a pan and I just hold the pan tight to the bottom on the drop tube so no powder jumps out but it still falls free from the measure.

Thanks for the response... that is one of about 4 kinds of clones of the original Homer Culver design that was made a few decades ago primarily for the bench rest fraternity. They were all noted for being very accurately throwing consistent, easily repeatable volumetric charges. Once you have checked it with the scale once, it's probably overkill to drop every charge onto the scale, in fact many bench rest shooters just count clicks and don't use a scale at the range.

BTW, do you have any history on your Nagy conversion? That's one of the clones that I don't have much information about.

Regards,
Froggie

[gwpercle]

I simply bored my drop out and glued in a large aluminium arrow shaft, works fine for the last 30 years or so.

You did that ... without ... a 3-D printer ...That's Amazing !
I Like It !
Gary

[Dimner]

So here is where I ended up with my large stick/flake powder version. Working perfectly. I threw about 200 556 powder charges last night. variation in weight at about +/- a tenth of a grain variance. I was testing every 7-10 loads. Sometimes I was at (Ball powder) 27.5 grains, sometimes 27.6. This is using my RCBS 10-10 scale.

https://i.imgur.com/xJtj3e6.jpg


I dump the load with the same technique each time. Bring the measure up, give it a two count, bring it down, wait for a two count, and use the knocker twice.

I'm not super picky. If this is the best resolution I can expect with the 55, great, if not, is there any other tricks I should try?

[44magLeo]

I think on your first try if you moved the choke point down closer to the bottom and used a different angle on the bottom inside and reduce or eliminate the straight section it might work also.
You don't really need any straight section between the upper taper and the bottom taper. The bottom taper only needs to be deep enough so the case mouth can set snug up to it.
This long upper taper will not crowd the powder together as quickly and should let the powder come together easier to pass out the bottom and into the case neck.
Looking at the drop tubes I have they are shaped that way inside.
Leo

[Green Frog]

Dimner,

I’m trying to figure out why you are putting in more of a choke point... maybe I didn’t make my meaning clear(?) Any narrow portion in the overall path of the powder through the tube gives it the potential for a slowing or stoppage, what some writers refer to as “bridging” of the flakes or kernels. While opening up your upper chamber allows the powder to start its downward path quickly, putting that long narrow section in negates any advantage you gained. In fact, I would hypothesize that the big upper chamber would actually provide sufficient pre-loading to make that long, narrow neck an enhanced choke point that would encourage blockages. It’s a matter of scale though and the grain size will determine how significant this effect will be.

As for a drop consistency of +/- 0.1 gr on a 27.5 grain charge is a range of 0.36%, is that precise enough? Actually, you’re probably also bumping up against the limits of accuracy of your scale. You may be hitting weights of 27.52 and 27.58 and having it show up as 0.1 grains different! I wouldn’t worry about it.

Of course the bottom line will be on the range when you see how your loads do. Whether you are checking with a chronograph for deviations in velocity (SD) or group size on the target, this will ultimately tell you whether you’ve improved anything or not.

Froggie

[Dimner]

Good points about the choke point. My reason for the extended area was to get more of a "drop tube" like action with the device. What I mean by that is trying to restrain the rate of fill into the cartridge. That way it will fill the case more efficiently with extruded powders.

I'm probably using all the wrong terms here. But here is an example. When I am loading H4895 for my CMP Highpower loads or coyote loads for my CZ 527, my pet load fills the case up very close to 100%. Sometimes it looks like when I am about to seat a bullet, that the bullet will compress the powder. But if I cover the myth of the cartridge and tap the base of the cartridge on my desk, the powder settles a bit and lowers. Then there is no compression when seating the bullet.

I probably can achieve the same thing if I just remove most of the choke point tunnel and extend the upper funnel to take its place.

[Pressman]

It seems to my non-engineer mind that a long taper from the measure to the cartridge mouth would be the best. And you are not limited by length with your printer.

Ken

[Dimner]

Oh also....it's a balance scale. The 10-10, so the pointer on the scale is telling me that they are different weights. As I figured 0.01 grains isn't that bad.

[onelight]

I have the best results with my 55 when I knock once with the lever up to settle the powder in the chamber and once with the lever down to make sure it all drops .
With your new drop tubes I would weigh a bunch and experiment with the powders you use and see what works best.
But the results you posted aren't bad at all. I often get better but + or - a tenth is acceptable to me , if I want perfect I trickle every charge.

[44magLeo]

As I recall reading when the 222 was a popular bench rest cartridge they used a very long drop tube when loading 4198.
A short tube the powder flowed slower when it reached the case and powder could over flow the case.
Using a long drop tube of 12" the powder was moving faster when it entered the case, thus compacting the powder, no over flow.
I don't know how to use computer art work type programs so I can't draw a picture of what I meant.
On the bottom of the tube the taper can be about 45*. The top would taper all the way from the top down into the bottom taper leaving a hole just a bit smaller than your case mouth.
If you picture in your mind how the measure dumps the powder out of the measuring chamber, long tubular kernels are every which way. Some point down other sideways. Now as the kernels hit the taper in the drop tub those pointing down flow well. Those sideways one end will hit the side of the tube. A short taper the kernels won't have time enough change position to point down before they hit the choke point.
The longer the taper the more time the kernels have to move to pointing down.
Most measures have a tube length that the manufacturers feel will work well enough for most loading. Those who need something more are in the minority and these people don't create enough sales for the larger companies to make such a product. A lot of the people that need such tooling make their own or find someone who makes them.
As I mentioned MTM's funnel, it has a drop tube that is about 4" long. It has 4 tips that fit in this long drop tube for different size cases.
When I have a powder charge that fills a case full enough so I think it will cause bullet seating issues I use this long drop tube.
Leo