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Posted: 11/12/2009 1:29:04 PM EDT
[Last Edit: AeroE][Edited]
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How to make a powder measure baffle Baffles of the type sold by RCBS for their Uniflow powder measure are simple to design and fabricate. The advantage from making your own baffles is cost, and the flexibility to experiment with your own ideas about regulating the flow of powder through the baffle. I suppose in the extreme case, a person could create custom baffles for use with particular gunpowder types, i.e., one baffle for long extruded powders, another for ball powders, still another for flake powders, and so on. These baffles can be combined with circular washer type baffles to regulate the passage way from the powder reservoir to the measuring drum. The purpose of a powder measure baffle is to improve the uniformity of the charge weight dispensed by a drum type measure. Baffles accomplish this by regulating the supply of powder to the drum chamber over the broadest possible volume of powder held in the reservoir by supporting the weight of the powder column above the entrance to the measure’s drum, and forcing the powder to flow into the chamber via an indirect route. Several materials may be used for a baffle. I’ve used 0.020 inch thick aircraft aluminum from my scrap box. Aluminum flashing from the hardware store is a candidate, although a slightly heavier gage is prefered. A good grade of heavy card stock or light cardboard could be used, and made more durable and stiff by soaking with CA cement, thin epoxy, fingernail polish, or other plastics. A beer can or a sheet of thin brass from the hobby store will also give up the stock material, as well as other common materials. The baffle laid out in this article is an elliptical shape, the same as obtained by cutting a cylinder on an angle 45 degrees to its centerline, hence the description, “45 degree ellipse”. The basic shape of the ellipse can be had by four or five methods, but only one will be described in detail here – make a copy of the sketch below, measure the inner diameter of the powder measure reservoir, then scale the template for the baffle up (or down) on a photocopy machine so the minor axis (the narrow dimension across the template) is the same length as the inner diameter of the measure. Other methods - If you are so lucky to own a 45 degree ellipse template with the same minor axis as the inner diameter of your powder measure, the correct ellipse can be drawn directly on the stock material for the baffle. (I recommend drawing a minor axis to serve as the bend line.) Coordinates for the ellipse can be calculated from the equation for an ellipse, then used to plot points from which to draw the ellipse using a French curve to fair the outline. Computer aided drafting. Layout of the major and minor axes and the foci of the ellipse, then drawing the outline using the constant length string method. This requires a means of holding the pencil dead normal to the surface (“square to the world”) of the drawing for an accurate shape. Use the first ellipse made to serve as the master template for all future baffles. Glue the paper template to a durable material that will hold up to tracing many times; a thin piece of aluminum or brass sheet is perfect, or a piece of stiff plastic, say from the lid of a container. Carefully cut the master template out, file the edge to match the outline on the paper template, and deburr the edge. Add a tiny notch on each edge at the ends of the line for the minor axis; this is the bend line for forming the baffles and the notches help locate this line on each baffle drawn with this master. Once this work is complete, mark the master with something like, “Master, DO NOT BEND”, although the notches will serve that function, too. Peel the paper off if desired. Trace the outline of the template on the stock you want to use for your baffle. Mark the ends of the minor axis. Cut the baffle out, file or sand and deburr the edges of the blank, then add the cutout shape you want to try where the gunpowder passes through. Adding the cutouts now are a little simpler than after the blank is bent, but they can be added or modified afterwards, too. Now bend the legs of the blank to form a 90 degree angle. Several methods can be used to make the bend if the stock is metal. The simplest is to clamp the blank in a vice with the bend line (the minor axis) aligned parallel to the vice jaws and about one thickness above the jaws. Bend the blank until it forms the 90 degree angle. Lay a wood block on the bend and hammer to form the baffle down hard against the vice to firm up the bend line and shape. Your new custom powder baffle is ready to use. Fabrication hint: If you want to cut the blank out of metal with sheet metal shears, first cut outside the outline by about 1/8th of an inch, then cut close to the outline. This will keep the edge fairly smooth and free of little bends and notches that ruin the template. The template:  Examples of cutouts to try; use your own ideas, too:  This thread is linked through the Gateway thread at the top of page 1 in the Reloading Forum. |
It's true, Obama is the Leader of Fools deluded to believe, "Everything is going to change now".
As for me, I will embrace what is Right more tightly than ever.
1 lbf = 32.174 lbm-ft/sec^2
As for me, I will embrace what is Right more tightly than ever.
1 lbf = 32.174 lbm-ft/sec^2
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Originally Posted By machinisttx:
why didn't I think of this?  I wrote that and made the drawings months ago. I decided to clean up the writeup a little and get it posted, since I've been slacking off here and all. So, here's your chance; I started a tutorial about how to make a poor man's shotgun loading rig. All I need is a slick method for priming that doesn't require machining or blacksmithing and gets the shell pointed away from the loader while the primer is seated. Machining limited to drilling, hacksawing, and filing is okay, it has to be a tool anyone can make with tools on hand. I have an idea for a tool similar to the ones that were sold with old time loading sets, where the shell slips into a ring in the middle of the handle on pliers, but either made from scrap aluminum or a couple of wood handles hinged at one end. |
It's true, Obama is the Leader of Fools deluded to believe, "Everything is going to change now".
As for me, I will embrace what is Right more tightly than ever.
1 lbf = 32.174 lbm-ft/sec^2
As for me, I will embrace what is Right more tightly than ever.
1 lbf = 32.174 lbm-ft/sec^2
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Originally Posted By SteelonSteel:
Nice. I've read a fender washer that fits inside will work too. I have a commercial RCBS one. (At least I think it was RCBS). I have a handful of fender washers I found that fit the inside of an RCBS measure perfectly. The measure on my bench has the screw on bottle conversion from Sinclair. That adapter has a conical inside shape that helps uniform powder throws. I think a combination of a fender washer and 45 degree baffle might be a good combination on an unmodified measure. |
It's true, Obama is the Leader of Fools deluded to believe, "Everything is going to change now".
As for me, I will embrace what is Right more tightly than ever.
1 lbf = 32.174 lbm-ft/sec^2
As for me, I will embrace what is Right more tightly than ever.
1 lbf = 32.174 lbm-ft/sec^2
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I made my own too, a year or so ago. I had downloaded the picture of the RCBS baffle, that Midway uses on their website, because the picture appears to show the shape of 1/2 of the ellipse and AeroE hadn't yet posted his great picture. Then I used my office printer/copy machine to size it as close as I could diameter-wise. Then I cut out a poster board pattern and scissor-trimmed it until it fit. Once I was happy with it, I transferred the thing to aluminum.
Many years ago I bought an airbrush on line. The company sent me a sample aluminum blank license plate. (The type used by air brush artists selling such things in malls) That stock is the perfect thickness for this use, bends only where you force it to bend in a vice. Worked great for me and that's an example of why I never throw anything away.
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Well I saw another approach to uniforming powder throws.
It's completely.... umm..... different, instead of holding off the weight of the powder column they vibrate the whole measure to pack the cylinder. I won't post pictures but the one I saw was an adult novelty toy taped to the side of the powder measure hopper.  
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"They wanted to put Chuck Norris on Mount Rushmore, but the granite wasn't tough enough for his beard."
I finally decided to make a baffle for my Lee Perfect Powder Measure –– got one done and it really does even out my throws of Varget, especially. I intended to make one like AeroE's but pop cans require a 10 cent deposit here in MI (and yes, I'm that cheap). I found something perfect and free (not exactly, but you get the idea). I used the cap from a prescription bottle –– about 2-1/8" across. I removed the soft plastic liner from inside, then cut out 4 sections of the short ridge in the inside of the lid (maybe unnecessary), then drilled 4 holes (3/8" each). Then I cleaned up the holes a bit with a round needle file and a knife. I put the lid in the measure (upside down), and filled it with powder. If you have that measure, you know that it's funnel-shaped at the bottom. This baffle rests perfectly at the top of that funnel and powder flows evenly down through the holes to the bottom of the measure. I'd guess about 250-400 or so grains of powder rest below the level of this baffle, so there's a light but consistent amount of downward pressure on the powder below it. Sure, a baffle shaped like the one above would look nicer, but this was fast, free, and easy (and it seems to work ok too). Thanks for the inspiration, AeroE!
(ETA: sorry about the giant pix the first time –– looked smaller @ home than they were) |
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Originally Posted By chrisbaker:
I finally decided to make a baffle for my Lee Perfect Powder Measure –– got one done and it really does even out my throws of Varget, especially. I intended to make one like AeroE's but pop cans require a 10 cent deposit here in MI (and yes, I'm that cheap). I found something perfect and free (not exactly, but you get the idea). I used the cap from a prescription bottle –– about 2-1/8" across. I removed the soft plastic liner from inside, then cut out 4 sections of the short ridge in the inside of the lid (maybe unnecessary), then drilled 4 holes (3/8" each). Then I cleaned up the holes a bit with a round needle file and a knife. I put the lid in the measure (upside down), and filled it with powder. If you have that measure, you know that it's funnel-shaped at the bottom. This baffle rests perfectly at the top of that funnel and powder flows evenly down through the holes to the bottom of the measure. I'd guess about 250-400 or so grains of powder rest below the level of this baffle, so there's a light but consistent amount of downward pressure on the powder below it. Sure, a baffle shaped like the one above would look nicer, but this was fast, free, and easy (and it seems to work ok too). Thanks for the inspiration, AeroE! http://www.chrisbaker.com/pix/lid1.jpg http://www.chrisbaker.com/pix/lid2.jpg http://www.chrisbaker.com/pix/lid3.jpg (ETA: sorry about the giant pix the first time –– looked smaller @ home than they were) "Look nicer" is secondary. This is like rifles; only accurate powder measures are interesting. |
It's true, Obama is the Leader of Fools deluded to believe, "Everything is going to change now".
As for me, I will embrace what is Right more tightly than ever.
1 lbf = 32.174 lbm-ft/sec^2
As for me, I will embrace what is Right more tightly than ever.
1 lbf = 32.174 lbm-ft/sec^2
This thread inspired me to make a baffle for my Redding PM, I have a store bought baffle in my Hornady PM, and it works well.
Made mine out of a piece of copper I had. Here is the whole thread on how I made mine. |
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Shooting and Reloading, one hobby feeds the other.
Shooting and Reloading, one hobby feeds the other.
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Has anyone taken the plastic hopper off of the RCBS Uniflow? Seems like I'm gonna break it before it comes off. ETA: Now I see from another thread it has to be broken off. ETA2: It eventually pried off using a small flat screwdriver going around it, slowly. |
| Just to make things easy the lid from a empty Hodgdons powder 1lb. bottle just fits in a Lee powder measure. Turn the lide upside down and drill 4 opposing 3/8 opposing holes in the lid close to the edge. To make it meter a little better with the lid upside down take a ball peen hammer and place the lid on a sost board and placing the round part of the hammer over the holes and striking the flat part of the hammer with another hammer this witll bevel the holes for the powder to meter better. So far I have used this with cfe223 and Varget and it solves your metering problems. Just place the lid upside down in the powder ho[[er and push it down to the funnel part of the measure. Works for me[size=4]Just to make things easy the lid from a empty Hodgdons powder 1lb. bottle just fits in a Lee powder measure. Turn the lide upside down and drill 4 opposing 3/8 opposing holes in the lid close to the edge. To make it meter a little better with the lid upside down take a ball peen hammer and place the lid on a sost board and placing the round part of the hammer over the holes and striking the flat part of the hammer with another hammer this witll bevel the holes for the powder to meter better.. |
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I see you have the drop holes facing front to back, Is this the preferred position for baffles?
Thanks, Paul Originally Posted By dryflash3:
This thread inspired me to make a baffle for my Redding PM, I have a store bought baffle in my Hornady PM, and it works well. http://i250.photobucket.com/albums/gg272/dryflash3/Powder%20Measure/P3210428.jpg Made mine out of a piece of copper I had. Here is the whole thread on how I made mine. |
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Originally Posted By santacruzpaul: I see you have the drop holes facing front to back, Is this the preferred position for baffles? Thanks, Paul Originally Posted By santacruzpaul: I see you have the drop holes facing front to back, Is this the preferred position for baffles? Thanks, Paul Originally Posted By dryflash3: This thread inspired me to make a baffle for my Redding PM, I have a store bought baffle in my Hornady PM, and it works well. http://i250.photobucket.com/albums/gg272/dryflash3/Powder%20Measure/P3210428.jpg Made mine out of a piece of copper I had. Here is the whole thread on how I made mine. Welcome to Arfcom and the Reloading Forum.
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Selling agent for Algores carbon credit scam.
Shooting and Reloading, one hobby feeds the other.
Shooting and Reloading, one hobby feeds the other.
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Thanks for the welcome and reply,
I used the RCBS baffle in a inflow for the first time yesterday, dropping 24.2 gn. of H335, with baffle positioned holes front to back as yours, I got great results with charges varying only about a tenth. I used the double tap at top stroke method, maintaining the hopper level no lower than 2/3. Paul Originally Posted By dryflash3:
The holes could be anywhere, I happen to prefer front/back as my preference. Just "looks right" to my eye. Welcome to Arfcom and the Reloading Forum.
Originally Posted By dryflash3:
Originally Posted By santacruzpaul:
I see you have the drop holes facing front to back, Is this the preferred position for baffles? Thanks, Paul Originally Posted By dryflash3:
This thread inspired me to make a baffle for my Redding PM, I have a store bought baffle in my Hornady PM, and it works well. http://i250.photobucket.com/albums/gg272/dryflash3/Powder%20Measure/P3210428.jpg Made mine out of a piece of copper I had. Here is the whole thread on how I made mine. Welcome to Arfcom and the Reloading Forum.
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