I figured I’d share this on the few sites I’m on. I’ve been working on this for a few months now with many failed attempts, but it’s finished. A completely 3-D printed powder dispenser (D3, third version that I’ve built so basically Dispenser 3 or D3) that will work with Beam scales and digital scales. For beam scales, it is completely automated. For digital scales, it’s simply time based. The cheapo digital scales don’t have an interface like the much more expensive one, but it will still work.
If you have seen the ones that I built in the past, it’s a similar principle. Set the time and it will spit out an amount of powder. No matter the powder type, it will dispense it out. I liked the idea of 2 dispensing tubes. 1 for the “bulk” of the charge and a much smaller tube for the trickle to fine tune. As you will see, I designed it very small and modular. It can be broken down for cleaning or just storage in an even much smaller place. My wife’s iPhone 11 is as big as the assembly. So, it doesn’t take up a lot of room on your loading bench. However, the hopper will hold approximately 1lb or close to 1lb of powder.
I also tried to design it as simple as possible. Not a lot of buttons and switches, but still get very accurate charges. Simply plug the 12v power supply into the back of the unit, and the timer will power on. This timer is different from the old one I used. This particular timer will allow .1 sec increment adjustments, so the bulk charge can be fine tuned to get much closer to the desired charge. Whether your using a beam or a digital scale, the principle is still the same. It will take a certain allotment of time to dispense a set amount of charge weight.
For example, one of my go to loads is 49g or Varget and 50g of TAC. That charge will take a time of 5.9 seconds. Because I use a beam scale, I will also plug in the beam scale sensor into the D3 unit. So once the power cord is plugged in, the timer will come on. The light will also come on the scale sensor.
Set the desired time. Then press the cycle button. Both the large and the small tube will dispense powder for the set time of 5.9 seconds. After 5.9 sec, the large tube will stop and the smaller will continue to dispense powder and a much slower pace for a “fine tune” effect. Now this is the best part I like about it and the locals here at the range as well. The unit is completely adjustable.
For beam scales:
Let’s say 5.9 sec is too slow, you can:
1) simply add time. By adding time you will increase the time that both the large and small will operate.
2) Adjust the legs. Remember this unit is modular and the legs are threaded. So if 5.9 sec is too slow, adjust the rear legs so that its tilted toward the powder pan. Thus more powder will dispense at the same allotment of time.
3) Adjust the PWM controller (small knob at rear near 12v power plug in). This is a voltage controller that works like a rheostat. It will only control the small tube. So if for some reason the trickle effect is taking too long, simply turn up the PWM and increase the speed. Just as you would increase the intensity of a light bulb.
Not if the set amount of time is too fast and you over throw a charge:
1) decrease time
2) remember those adjustable legs. Well if the time is very close and you don’t want to adjust the timer, then simply adjust the front legs. This will lean the unit toward the rear and not dispense as much powder out.
3) adjust the PWM controller slower by simply turning it down.
All of these adjustments take approximately seconds to do so there isn’t this long drawn out adjustment to get it correct.
There is a slight difference for digital scales. I had an AWS gem 20 that for a cheapo, was actually really accurate. It just recently crapped out but did get a chance to test the unit on it. So for those using digital scales, same principle. The only difference is you won’t have all the relays, diodes, sensor and such for automation like the beam scale. But both tubes will operate once the cycle button is pressed. The difference is that when the time runs out, the smaller tube will stop as well. It will not continue to run like the beam scale. Because there is no sensor to kill power with digital scale use, both motors will turn off when the time runs out.
So, for digital scales:
Plug in power, the timer will light up (no sensor to light up on beam scale because not used). Set the amount of time as you wish just like mentioned above.
Let’s do 5.9 sec again and it’s too slow, you can:
1) simply add time. By adding time you will increase the time that both the large and small will operate.
2) Adjust the legs. If 5.9 sec is too slow, adjust the rear legs so that its tilted toward the powder pan. Thus more powder will dispense at the same allotment of time.
3) Adjust the PWM controller and increase the speed.
Not if the set amount of time is too fast and you overthrow a charge:
1) decrease time
2) adjust the front legs. This will lean the unit toward the rear and not dispense as much powder out.
3) adjust the PWM controller slower by simply turning it down.
Once you get to the desired charge stopping point, then you can simply bump the second button and only the smaller tube will operate. The bump switch works with the beam scale setup and the digital scale setup.
My beam scale is 1 kernel of Varget sensitive. I like to set my sensor stopping point just shy of the actual setpoint so that I can bump a few times to get to my charge. The slotted sensor mount for my type of scale allows me to adjust the stopping point to exact or whatever I want. This allows me to be as precise as I want. The same can be done for a digital scale, just set the time to stop a grain or 2 before your desired charge. I also found that by adjusting my rear legs to tilt it forward worked for my scale. So, I also printed out some 1mm thick spacers, like shim washers. Slide them over the threaded shafts before putting rear legs back in. So that if I ever take it apart, those spacers will insure that it goes back in the same setup every time.
As far as emptying the hopper for powder swaps, I have tube covers. Place the plastic covers over each dispensing tube, remove the Hopper cap and simply dump all your powder back into the container. The caps prevent any from spilling out the tubes. Once the main hopper is dumped, pull the caps off the tubes and dump the tubes into the container. Any static charge that is created on the clear hopper, simply rub your hand on the outside of the hopper and then re-dump it. Quick and easy.
You will also notice that on the bottom of the unit, there is a hole or opening. This is a tell-tell opening. If your shaft bushings get worn out, you will notice a few kernels or ball powder on your table. This means that you need new bushings. Empty the hopper, pull the hopper, pull both shafts out the front of the unit. Simply reach in and slide out the bushing and replace with new. I inspected mine after 150 loads and there isn’t the slightest sign of it starting to wear. So, they should last a very long time.
I’m posting this because I was talking to some of the local guys at our range and I brought it out there for them to see it, to which I made 9 of them for those guys. It takes approximately 10 hours or more to print out all the parts so it’s not a quick build, but it just works. Sure there are units out there that cost 5x’s this, and this isn’t for everyone. But not everyone has $1k+ to throw around on a scale and dispenser setup.
If you have seen the ones that I built in the past, it’s a similar principle. Set the time and it will spit out an amount of powder. No matter the powder type, it will dispense it out. I liked the idea of 2 dispensing tubes. 1 for the “bulk” of the charge and a much smaller tube for the trickle to fine tune. As you will see, I designed it very small and modular. It can be broken down for cleaning or just storage in an even much smaller place. My wife’s iPhone 11 is as big as the assembly. So, it doesn’t take up a lot of room on your loading bench. However, the hopper will hold approximately 1lb or close to 1lb of powder.
I also tried to design it as simple as possible. Not a lot of buttons and switches, but still get very accurate charges. Simply plug the 12v power supply into the back of the unit, and the timer will power on. This timer is different from the old one I used. This particular timer will allow .1 sec increment adjustments, so the bulk charge can be fine tuned to get much closer to the desired charge. Whether your using a beam or a digital scale, the principle is still the same. It will take a certain allotment of time to dispense a set amount of charge weight.
For example, one of my go to loads is 49g or Varget and 50g of TAC. That charge will take a time of 5.9 seconds. Because I use a beam scale, I will also plug in the beam scale sensor into the D3 unit. So once the power cord is plugged in, the timer will come on. The light will also come on the scale sensor.
Set the desired time. Then press the cycle button. Both the large and the small tube will dispense powder for the set time of 5.9 seconds. After 5.9 sec, the large tube will stop and the smaller will continue to dispense powder and a much slower pace for a “fine tune” effect. Now this is the best part I like about it and the locals here at the range as well. The unit is completely adjustable.
For beam scales:
Let’s say 5.9 sec is too slow, you can:
1) simply add time. By adding time you will increase the time that both the large and small will operate.
2) Adjust the legs. Remember this unit is modular and the legs are threaded. So if 5.9 sec is too slow, adjust the rear legs so that its tilted toward the powder pan. Thus more powder will dispense at the same allotment of time.
3) Adjust the PWM controller (small knob at rear near 12v power plug in). This is a voltage controller that works like a rheostat. It will only control the small tube. So if for some reason the trickle effect is taking too long, simply turn up the PWM and increase the speed. Just as you would increase the intensity of a light bulb.
Not if the set amount of time is too fast and you over throw a charge:
1) decrease time
2) remember those adjustable legs. Well if the time is very close and you don’t want to adjust the timer, then simply adjust the front legs. This will lean the unit toward the rear and not dispense as much powder out.
3) adjust the PWM controller slower by simply turning it down.
All of these adjustments take approximately seconds to do so there isn’t this long drawn out adjustment to get it correct.
There is a slight difference for digital scales. I had an AWS gem 20 that for a cheapo, was actually really accurate. It just recently crapped out but did get a chance to test the unit on it. So for those using digital scales, same principle. The only difference is you won’t have all the relays, diodes, sensor and such for automation like the beam scale. But both tubes will operate once the cycle button is pressed. The difference is that when the time runs out, the smaller tube will stop as well. It will not continue to run like the beam scale. Because there is no sensor to kill power with digital scale use, both motors will turn off when the time runs out.
So, for digital scales:
Plug in power, the timer will light up (no sensor to light up on beam scale because not used). Set the amount of time as you wish just like mentioned above.
Let’s do 5.9 sec again and it’s too slow, you can:
1) simply add time. By adding time you will increase the time that both the large and small will operate.
2) Adjust the legs. If 5.9 sec is too slow, adjust the rear legs so that its tilted toward the powder pan. Thus more powder will dispense at the same allotment of time.
3) Adjust the PWM controller and increase the speed.
Not if the set amount of time is too fast and you overthrow a charge:
1) decrease time
2) adjust the front legs. This will lean the unit toward the rear and not dispense as much powder out.
3) adjust the PWM controller slower by simply turning it down.
Once you get to the desired charge stopping point, then you can simply bump the second button and only the smaller tube will operate. The bump switch works with the beam scale setup and the digital scale setup.
My beam scale is 1 kernel of Varget sensitive. I like to set my sensor stopping point just shy of the actual setpoint so that I can bump a few times to get to my charge. The slotted sensor mount for my type of scale allows me to adjust the stopping point to exact or whatever I want. This allows me to be as precise as I want. The same can be done for a digital scale, just set the time to stop a grain or 2 before your desired charge. I also found that by adjusting my rear legs to tilt it forward worked for my scale. So, I also printed out some 1mm thick spacers, like shim washers. Slide them over the threaded shafts before putting rear legs back in. So that if I ever take it apart, those spacers will insure that it goes back in the same setup every time.
As far as emptying the hopper for powder swaps, I have tube covers. Place the plastic covers over each dispensing tube, remove the Hopper cap and simply dump all your powder back into the container. The caps prevent any from spilling out the tubes. Once the main hopper is dumped, pull the caps off the tubes and dump the tubes into the container. Any static charge that is created on the clear hopper, simply rub your hand on the outside of the hopper and then re-dump it. Quick and easy.
You will also notice that on the bottom of the unit, there is a hole or opening. This is a tell-tell opening. If your shaft bushings get worn out, you will notice a few kernels or ball powder on your table. This means that you need new bushings. Empty the hopper, pull the hopper, pull both shafts out the front of the unit. Simply reach in and slide out the bushing and replace with new. I inspected mine after 150 loads and there isn’t the slightest sign of it starting to wear. So, they should last a very long time.
I’m posting this because I was talking to some of the local guys at our range and I brought it out there for them to see it, to which I made 9 of them for those guys. It takes approximately 10 hours or more to print out all the parts so it’s not a quick build, but it just works. Sure there are units out there that cost 5x’s this, and this isn’t for everyone. But not everyone has $1k+ to throw around on a scale and dispenser setup.
