My homemade black powder

[Vettepilot]

Ok guys, DON'T BUY THAT MOTOR I referenced.

It may say it's .65 amps, but I don't believe it. Harbor Freight lists the original at .23 amps I believe. They also say 25 watts and that doesn't figure mathematically. Anyway, the original motor has a .50 amp tag/decal right on it. This new motor has a magnet frame that is only 1/2 the thickness of mine, and a much smaller coil. .65 amps my butt!!

Oh well... I've saved a ton of money over the years making my own tools and fixing or improving things most people would throw away, but so far, this isn't one of them.

I'll keep looking. Motors aren't very cheap any more. I think I'll run by the second hand store. A motor from a blender would be too speedy I think, but one from a baking mixer should have good torque and might be a good candidate...

Any other ideas?

Vettepilot

[maillemaker]

Tonight's batch of boom cookies! I went through about half the green meal I made up last week. I got cold so this is where I quit.



Steve

[DoubleBuck]

dondiego, I'm glad you straightened me out on that. All I know is if you pull a new aluminum wheel out of the furnace and throw a penny on it, it will set there for a second and melt into the wheel, without a trace. That's why I thought the new pennies were aluminum. I knew the clads were not silver, but figured there was silver in the mix. I believe what you said. Have you milled with any money?

[DoubleBuck]

VettePilot;
I think you totally misunderstood my premise and my meaning. haha. You were talking about buying a replacement motor. I was talking about making a totally different motor work in direct drive. Like 1500 RPM, but more torque, or horsepower or watts, or amps or whatever. haha. I didn't mean to use the existing motor, or the one you bought. I was talking about scrapping all that and using a motor that is small enough, thermally protected and strong enough to turn a drum 80+ RPM. Like a refrigerator fan motor possibly.
My drums are 4.5" outside diameter. My bare drive roller diameter is .315" outside diameter. If my math is correct and 90 RPM's is target speed, a motor with a LOADED rpm of 1285.27 rpm would be needed.
On the hose; I bought it at O'Reilly Auto. It is just 7/16 braided core black fuel line. I took the picture with the writing on it up, so it could be read, but cutting the picture makes it not legible. Here is what the writing on the hose says: Gates 4219XL SAE 30R7 Fuel Line PCV/EEC 7/16"/11.1MM 35PSI 12.4 BAR SAE30R7 Not For Fuel Injection Systems Made In Mexico AXO90121 10:58
That hose is .750" in outside diameter.
My rollers came with clear plastic tubing on them, which is .451" outside diameter. 7/16" is .4375" It fit tight and great. I lubed the inner tube with dawn dish liquid and water and put a little water in the outer hose and bopped it with my palm and then a hammer, to hydraulically force the hose on. That's an old oilfield trick.

[Nobade]

dondiego, I'm glad you straightened me out on that. All I know is if you pull a new aluminum wheel out of the furnace and throw a penny on it, it will set there for a second and melt into the wheel, without a trace. That's why I thought the new pennies were aluminum. I knew the clads were not silver, but figured there was silver in the mix. I believe what you said. Have you milled with any money?

Pennies are plated zinc. For fun you can put one in the blueing salts and end up with the copper shell left over.

[Nobade]

I have a couple of treadmills laying around. A future project is going to be use one to make a ball mill. Plenty of power, infinite speed control, bearings and stuff to build out of. Sometimes you find them on curbs that people are giving away.

[DoubleBuck]

maillemaker;
Those 'boom cookies' look boomalicious!

[mmb617]

All you said about the drive ratios is true. I think you've forgotten one factor though. When the final output/drive is reduced, the torque is increased. That's how such a tiny little 25 watt motor can turn a heavy drum at all. If one took out one of the two drive reductions in the system by running the motor to drive roller direct, it would increase the load on the motor by a large amount. It can, and has, been done in some mills, but the motor must be stronger to allow it.
Vettepilot

Good point. By my calculations the final drive ratio on the HF tumbler after both drive reductions is 84:1, so it's significant.

When thinking of, and/or modifying or working with mills, I think basic milling is good to keep in mind. It's not quite as simple as it seems at first glance, with regard to mill speed, and milling media. If you go back and look up the reference link I posted on milling, it is very, very interesting; particularly the drawings and videos on the effects of mill speed.

Vettepilot

In my case I know that my current speed is probably not optimal, but I am happy with the product it produces. With that in mind all I really want to do is replace the motor with one that is more reliable and thus safer, and as a bonus get rid of the belt so it's no longer a failure point.

Ok guys, DON'T BUY THAT MOTOR I referenced.

Any other ideas?

Vettepilot

Thanks for the feedback. I was waiting to see if that was a viable alternative before proceeding in a different direction.

VettePilot;
I think you totally misunderstood my premise and my meaning. haha. You were talking about buying a replacement motor. I was talking about making a totally different motor work in direct drive.

This is my line of thought now. I want to replace the original motor and belt drive with a stronger DC motor that drives the drum driveshaft directly. So I took a bunch of measurements and did some calculations that seem right to me, but if anybody sees an error please don't hesitate to point it out. I have this info in a spreadsheet but took a screenshot so it's easier for everybody to see:





Since I am happy with the results I get now I'm not concerned with increasing the speed even though my calculations show I'm only at 40 rpm drum speed. With that in mind the current driveshaft speed is 405 rpm and I found a DC motor with a planetary gearset that has an output speed of 435 rpm, which should give me a drum speed of 43 rpm. Close enough to what I have now that it shouldn't make a difference. Here's the motor I'm looking at:


https://www.servocity.com/5202-serie...-3-5v-encoder/


It gives a listed stall torque of 260 oz-in but I don't have any idea how to relate that to what I want it to do. That converts to 1.3 lb-ft which seems to me should be plenty to get the drum rolling since I'd still have the 10:1 gear reduction working for me between the driveshaft and the drum. The listed weight of the motor is 15 oz so even though the gearset would account for some of the weight it still seems like it would be a much larger motor than the stock one. I can buy a coupler that will join the output shaft to the driveshaft so all I'd need to do is modify the tumbler case to accept the motor in line with the driveshaft.

I'm seriously considering giving this a try. The motor is $40 and I can buy a power supply for $20, so my total investment should be under $100, and hopefully I'll have a bulletproof tumbler that will last for years.

Anybody want to point out a reason I shouldn't do this? I'm asking for your input and won't get upset if you tell me I'm way off base.

[Vettepilot]

Hmmm... not sure there, about the torque, or the motor. On the torque required, one could overload a jar/drum by double, and then use an inch/pound torque wrench to turn the drive roller and see what it takes. (Double overload to provide a safety margin, plus start-up torque.) That should get you in the ballpark.

As far as the motor you've chosen, I really don't know about continuous long term use with it. Contact the manufacturer?? Electric motors are generally rated for continuous duty or not. You might be able to convert that gearset to oil bath to help it live, but what I am unsure about is motor cooling, brush life, etc.

I wonder if a cordless drill motor would work? The gear set might provide a packaging problem. I think I have a salvaged one here with a unitized gearset. It would definitely have the torque, but again I'm unsure about suitability for continuous duty.

Fun stuff to think about, and this is how neat things get made/"invented". Like Almar's PID controlled charcoal oven!!

EDIT TO ADD:
That motor you're looking at is meant to be controlled by a PWM, (pulse width modulation) controller, and it's pretty low voltage. Just as a side note, most DC motors are tolerant of a fairly wide voltage range, and can somewhat be rpm adjusted by varying the voltage.

One last thing to at least consider. Moving from induction motors to brushed motors carries a penalty. Brushes arc/spark. Many studies have shown that an electric spark won't light off black powder, but if that's really true, what caused the various explosions in manufacturing throughout the years??

Vettepilot

[DoubleBuck]

I don't know if this will help anyone, but kind of fits the narrative.
I was looking at one of my ceiling fans and got the bright idea to look up the fan motor speed.
Low Speed: 57 RPM
Medium Speed: 118 RPM
High Speed: 163 RPM
Most fans are reversible, use very little electricity and some are variable speed, with a remote control. They spin a generous amount of weight, with five blades. I would think gear reduction would help them spin a heavy tumbler barrel. And, some of them are very reasonably priced, and there many in the junk pile.
There are also some discussions on the net of powering ceiling fans on D.C. current, if that appeals to you.
Carry on.

[Vettepilot]

Thanks for those hose specs, and for reminding me how to get tough slip fit tubing on DoubleBuck. That's also an interesting idea I hadn't thought about on the ceiling fans. That's what's great about forums with good members!

I had a crap load of nasty errands to run today, but it worked out well. I stopped at a nice little motor repair shop, and scored a motor that's going to be a great replacement for my HF mill. It's far from a drop in/bolt on solution, but it's a much stronger motor, and it only cost me 10 bucks flat!! I'll adapt it in there, and that little sucker will be better than ever and last forever!! Meanwhile, I sent that other joke motor back for a refund.

Vettepilot

[Vettepilot]

I have a couple of treadmills laying around. A future project is going to be use one to make a ball mill. Plenty of power, infinite speed control, bearings and stuff to build out of. Sometimes you find them on curbs that people are giving away.

Here's another way to go NOBADE. This is mine:

https://castboolits.gunloads.com/sho...61#post5173661

(POST #3668 THERE) It works super great and I'm so glad I made it.

Vettepilot

[Vettepilot]

Don't ya just hate how forum search functions don't work?? Ever!?

I knew that post of my treadmill/ball mill existed. I searched for it several different ways, including "advanced search" and my name. No Dice! Finally I had to go to "all my posts" and go through 17 pages to find it!!

AARRGGHH!

;~)

Vettepilot

[ChrisPer]

Just set my mill going after a few months idle. Felt goot. First batch dampened for pucking, second milling. I have tossed all the 4F in to be repucked, as the grades needed are more 2F and 3F.
I just sold some bought powder, and gave away a remnant of Swiss, to minimise the odd batches and bottles in my powder trunk. No-one bought my Pyrodex though. Having kept bottles bottles of sizes and batches separate, I am mixing past batches together as the performance is not distinguishable to me.

[DoubleBuck]

VettePilot;
The other day I had something on my mind I knew was some pages back. I must have read 30 pages before I found it. I did the search deal, too. It wasn't my post, but I couldn't remember who's it was. What was going to be a couple of minutes turned into a mission.

[DoubleBuck]

ChrisPer;
I did the same thing last week. I had a couple of powders that were pretty equal, and I just mixed it all together and made a new batch out of it all.

[Nobade]

Here's another way to go NOBADE. This is mine:

https://castboolits.gunloads.com/sho...61#post5173661

(POST #3668 THERE) It works super great and I'm so glad I made it.

Vettepilot

Thanks, I remember seeing that and thought it was pretty innovative. That way you could still use the treadmill if you wanted to as well. I'm planning on cutting mine up so it takes up a lot less space, which is at a premium in the new shop. If anybody wants to get some ideas of what to do with these little powerhouse motors, the motorcycle engineer Tony Foale has some pretty good youtube vids on them and ways to modify them to do various jobs you might want to do.

[mmb617]

Hmmm... not sure there, about the torque, or the motor. On the torque required, one could overload a jar/drum by double, and then use an inch/pound torque wrench to turn the drive roller and see what it takes. (Double overload to provide a safety margin, plus start-up torque.) That should get you in the ballpark.

As far as the motor you've chosen, I really don't know about continuous long term use with it. Contact the manufacturer?? Electric motors are generally rated for continuous duty or not. You might be able to convert that gearset to oil bath to help it live, but what I am unsure about is motor cooling, brush life, etc.

I wonder if a cordless drill motor would work? The gear set might provide a packaging problem. I think I have a salvaged one here with a unitized gearset. It would definitely have the torque, but again I'm unsure about suitability for continuous duty.

Fun stuff to think about, and this is how neat things get made/"invented". Like Almar's PID controlled charcoal oven!!

EDIT TO ADD:
That motor you're looking at is meant to be controlled by a PWM, (pulse width modulation) controller, and it's pretty low voltage. Just as a side note, most DC motors are tolerant of a fairly wide voltage range, and can somewhat be rpm adjusted by varying the voltage.

One last thing to at least consider. Moving from induction motors to brushed motors carries a penalty. Brushes arc/spark. Many studies have shown that an electric spark won't light off black powder, but if that's really true, what caused the various explosions in manufacturing throughout the years??

Vettepilot

This is the beauty of spitballing ideas on a forum with knowledgeable members who can point out things you may not have considered. I had not considered whether the motor can handle continuous duty by running 8 hours at a time. I would think the reduction gearset might be the weak link there.

One problem I did pickup on with the motor I was looking at is it's speed. I was thinking that since it's listed as 435 rpm no load speed it would be perfect hooked up direct to 12 volts DC since I calculated my present driveshaft speed at 405 rpm and by all accounts that's slower than most guys are running, so a slight increase might even be a good thing. But then I saw that the loaded speed was listed as 389 rpm +/- 10%, so it's probably too slow. There's a similar motor listed with a no load speed of 612 rpm with a loaded speed of 540 rpm +/- 10% that might be a better choice, but if I go that way I think I'd want a speed control in case it spins faster than I want. Another problem with the 612 rpm motor is that it used brass and nylon gears and carries a warning that stalling the motor may result in gear damage, while the 435 rpm motor uses steel gears and doesn't have that warning so I assume it's more durable.

I'm thinking that if I go with the 435 rpm motor I won't need a speed controller as it won't be too fast and if it's too slow I can use the trick Doublebuck mentioned of slipping tubing over the driveshaft to increase drum speed.

I'm not real worried about a spark hazard. As you said most studies have shown it's really hard to ignite black powder from an electric spark and also with the powder being inside that rubber drum any spark near the closed end couldn't reach the powder in any way I can think of.

I'm inclined to give this a shot as I think it will be a fun project even if it doesn't work out the first time. I could probably figure out what needed changed and tweak it till it does work. In the end it might not be real cost effective but I like to tinker with things like this. I previously built an annealing machine to prep centerfire rifle cases for reloading and that was a fun project. It used two smaller DC motors with speed controllers to regulate the rotational speed of it's two drums and it works great. Here's a short video of it's operation:

https://youtu.be/4_cmGs1TUVw

[maillemaker]

I'm not real worried about a spark hazard. As you said most studies have shown it's really hard to ignite black powder from an electric spark and also with the powder being inside that rubber drum any spark near the closed end couldn't reach the powder in any way I can think of.

While it does seem true that BP is relatively immune to static discharges (I tested my homemade with a stun gun), I'm not sure this dynamic applies with an electric motor. My 1/2" drill gets quite warm on the outside when used for hard work. I would fully expect BP dust sprinkled into the guts of such a motor to ignite.

One thing I have found in this endeavor is that blackpowder dust (and even the dust of the ingredients by themselves) is pervasive and insidious. And I have had one of my Harbor Freight drums' lids pop off during milling, dumping the contents in the grass.

Whatever mechanism you choose for any process of making BP I still advocate for doing it outdoors.

Steve

[Vettepilot]

This is the beauty of spitballing ideas on a forum with knowledgeable members who can point out things you may not have considered. I had not considered whether the motor can handle continuous duty by running 8 hours at a time. I would think the reduction gearset might be the weak link there.

One problem I did pickup on with the motor I was looking at is it's speed. I was thinking that since it's listed as 435 rpm no load speed it would be perfect hooked up direct to 12 volts DC since I calculated my present driveshaft speed at 405 rpm and by all accounts that's slower than most guys are running, so a slight increase might even be a good thing. But then I saw that the loaded speed was listed as 389 rpm +/- 10%, so it's probably too slow. There's a similar motor listed with a no load speed of 612 rpm with a loaded speed of 540 rpm +/- 10% that might be a better choice, but if I go that way I think I'd want a speed control in case it spins faster than I want. Another problem with the 612 rpm motor is that it used brass and nylon gears and carries a warning that stalling the motor may result in gear damage, while the 435 rpm motor uses steel gears and doesn't have that warning so I assume it's more durable.

I'm thinking that if I go with the 435 rpm motor I won't need a speed controller as it won't be too fast and if it's too slow I can use the trick Doublebuck mentioned of slipping tubing over the driveshaft to increase drum speed.

I'm not real worried about a spark hazard. As you said most studies have shown it's really hard to ignite black powder from an electric spark and also with the powder being inside that rubber drum any spark near the closed end couldn't reach the powder in any way I can think of.

I'm inclined to give this a shot as I think it will be a fun project even if it doesn't work out the first time. I could probably figure out what needed changed and tweak it till it does work. In the end it might not be real cost effective but I like to tinker with things like this. I previously built an annealing machine to prep centerfire rifle cases for reloading and that was a fun project. It used two smaller DC motors with speed controllers to regulate the rotational speed of it's two drums and it works great. Here's a short video of it's operation:

https://youtu.be/4_cmGs1TUVw

Look into robotics motors. They seem to use high torque/low speed motors a lot. Again, there's the question of continuous duty being ok or not. Most all motors of any reasonable power rated for continuous duty have built in fans, for one thing.

It looks like this motor I scored yesterday is going to work out great, though it's an entirely different form factor and will take some work to fit it. I don't mind; it'll be a good rig in the end. I wasn't worried about rpm adjustability on this one, since I already have one with that capability. I have two other good mills, and just wanted this one back in service for brass cleaning and maybe small, quick test batches of BP. This motor is the same rpm as original, so I'll up the mill speed a bit with the hose trick; changing the secondary drive ratio.

Vettepilot