Homemade Shell Wrapping Machine

[Raceman17]

Hello Everyone,

 

First off I want to thank everyone who has added any content to this website. These is a lot of useful information that is shared. It is very much appreciated from a newbie like myself.

 

Here is a little background info on myself. I have always been fascinated with fireworks. Growing up trying to make bang bangs and things of that nature. At 12 years old, I convinced my grandma to buy the "Poor Man's James Bond Book" for me. Don't ask how I did it but I was able to get it delivered to her house. This past July 4th I went out and purchased a few hundered dollars worth of fireworks and shot them off in my backyard. IDK what happened or why I decided to do some research but I did a search on the googles and I was amazed at all the info that was available for making your own fireworks. Now almost three months into this new hobby I am knee deep into it and having a blast.

 

After hand pasting several shells it became obvious to me that pasting sucks and takes a lot of time. I did a few searches on the googles and found out about the WASP. I was real close to buying one but did a little more research and saw a few homemade machines on YouTube. Being and Mechanical Engineer with a lot of resources at my fingertips I decided to build my own. I had already seen a few good concepts on YouTube and decided to try to improve on the idea. Here is what I came up with. If you have any questions let me know. I am more than happy to give back to this community.

 

https://www.youtube.com/watch?v=3Yf50QBs2PY

 

Here is the build details:

A 12 volt computer power supply is used for the power source. I removed all the excess wires that were not needed and only used the 12 volt outputs on the power supply. The motor that is used to turn the tape dispenser was purchased from Surplus Center. It is a 12 volt 500 rpm right angle gear motor that is used to power adjustable car seats. An adapter had to be machined to convert the 4mm square output of the gearmotor to accept the gear that is used to spin the assembly. The motor that slowly rotates the shell is a 12 volt 3.5 rpm gearmotor purchased from Amazon. The lazy susan bearing is a 200mm aluminum bearing purchased from amazon. This bearing works 100 times better than the stamped steel lazy susan bearing of the same size. The ring gear is from a Briggs and Stratton flywheel/starter assembly. This can be purchased from Amazon or Ebay. The sponge/water holder is a 4oz metal tin container from ebay. The revolution counter was purchased from Surplus Center along with a small micro switch. The motor speeds are controlled by two separate 12 volt pulse width modulation controllers from Amazon. The shell clamping "C-Clamp" uses a small 1.125' OD X .5" ID roller ball bearing. A bearing is needed to allow the c-clamp to rotate freely while the shell is clamped securely. The bearing was purchased from Mcmaster-Carr. The rotating shaft is 1/2"-20 thread rod. Two 9/16" hole saws are used to hold the shell and both are threaded on both ends of the shafts. A 1/2"flanged bearing is used to support the small gearmotor shaft. Without this bearing the c-clamp assembly has a lot of flex. The support helped to secure it. A 1/2"-20 coupling nut is used to complete the assembly. The machine uses 1/2" wide gummed paper tape. Using a half width of tape overlap gives a even distribution of tape around the shell. I am using 60 revolutions to tape a 3" shell.

The estimated build cost is as follows:
500 RPM Motor $17
3.5 RMP Motor $12
200mm Bearing $18
9/16 hole saws $4 each
1/2-20 threaded rod $6
1.125" ball bearing $7
Briggs and Stratton Flywheel/starter Gear $22
Metal Tin container $4
Flanged Bearing $1
Revolution Counter $5
PWM Controllers $12ea
12 volt switch $2
Hardware $10
Computer Power Supply - Free
Steel frame Tubing - Free
Total = $136

 

 

Edited October 2, 2016 by Raceman17

[NeighborJ]

I love it, great work. I'm sure you will get a lot of use out of it.

[calebkessinger]

uh.... I hate to sound like a little kid.. but,

 

Wanna come over? I'm thinking we could build some cool stuff!

Wow..

That's really cool.

 

Now start on your star roller.

[Raceman17]

uh.... I hate to sound like a little kid.. but,

 

Wanna come over? I'm thinking we could build some cool stuff!

Wow..

That's really cool.

 

Now start on your star roller.

The star roller was the first thing I made! After reading about the different star making techniques I figured it would be a heck of a lot easier rolling stars than cutting them. I make an estimated 2500 stars at a time when I make mine.

 

For the star roller I used a 16 quart stock pot and a right angle gear motor to drive it. It works like a champ!

[NeighborJ]

OK everyone, sleepover at Caleb's tonight. Make sure you bring your cool toys.

Can the shell pivit on its axis so you can add some wraps to its equator? If not you can always reset and wrap it on all three axis.

[Raceman17]

OK everyone, sleepover at Caleb's tonight. Make sure you bring your cool toys.

Can the shell pivit on its axis so you can add some wraps to its equator? If not you can always reset and wrap it on all three axis.

The pivot point can be manually adjusted be loosening the c-clamp pivot bolt and rotating the assembly clockwise. I really have not experimented with that aspect of the machine though.

 

In my opinion I am getting good symmetrical breaks with the wrapping pattern now. I will post up some drone footage from some of my shells. For the past 3 times I have fired my shells off I have overshot the drone by a huge margin. Last night I had the drone at about 550 feet and was able to get a few of the shells in the frame. I'm still trying to dial in my lift charges. I know I'm shooting these shells up to 400 feet according to the drone.

[pyronoob]

The star roller was the first thing I made! After reading about the different star making techniques I figured it would be a heck of a lot easier rolling stars than cutting them. I make an estimated 2500 stars at a time when I make mine.

 

For the star roller I used a 16 quart stock pot and a right angle gear motor to drive it. It works like a champ!

i would love to see pics or a video of the star roller.....if you have them.....Love the paste machine!!

[Raceman17]

Here's a few pics of the star roller. I usually don't use wood for projects like this but it was something I threw together in about an hr. I used a dc gear motor I had laying around and used a bridge rectifier to convert it so I could use a cheap harbor freight router speed control to regulate the speed. The pot is a cheap 16 quart stock pot from Walmart. I machined an adapter to connect the pot to the motor. There is a hinged piece of wood on the bottom that folds down so you can dump the stars out.

[uncrichie]

Great design Raceman! What size shells are you able to wrap? Also curious if there is a larger fly wheel starter gear set available which would probably make it more manageable for larger ball shells? I really like the design over the large rotating bicycle wheel styles out there, you gave this some serious thought. I have collected all the parts necessary for one of the bicycle wheel machines. I may have to rethink everything now. Kurt

[Raceman17]

Right now all I have is 3" shells. I'm thinking the max size with this setup would be a 5" shell. There is various lazy Susan bearings of the same design that could be used that are much bigger. The stamped steel lazy Susan bearing would work but not long term. It has too much slop in the bearing and makes a ton of noise when it rotates. I tried that bearing out first and quickly realized that it was adding a lot of drag to the rotating assembly.

 

You would just need to find a flywheel that would work that was bigger. If you could find one from a bigger lawn mower engine it might work. I have a larger Kohler brand engine in my shop that looks like it has a bigger flywheel on it but I didn't want to tear it apart to see if it would work. You could also use a flex plate off of an early model 350 Chevy engine if you cut out the inside of the flywheel. I know there is several different diameters based on applications and they can be bought for less than 20$ on the Internet. It shouldn't be too hard to make it work.

 

The only other issue would be mounting the bearing. I'm fortunate enough to have a tig welder and can weld aluminum. I suppose you could bolt some tabs to the bearing for mounts. If you have any more questions let me know.

[uncrichie]

Using a flex plate is a great idea. It would be pretty neat cutting the center out and hoping it doesn't warp like crazy. I have Mig, Tig capability but DC only. If I used an aluminum bearing race I might try that pot metal rod stuff for soldering aluminum? Or another project HF for my a/c arc welder. I'm not that familiar with auto engine parts so heres the question. Are the teeth on flex plates and starters all the same size? Or do all the major manufacturers have their own ideas? Kurt

[Raceman17]

Cutting the flex plate should be pretty easy. The inside material is pretty thin. You could just get a bearing that was smaller than the OD of the flex plate and trace out your cut line. It wouldn't take to long to use a side grinder with a cut off wheel or a plasma cutter if u have one. Then you could use the remaining lip left on the flex plate to mount the bearing to that. If you can't weld aluminum you could just drill through the bearing and bolt the mounting tabs to that. The one bearing I used was about 1/2" thick and there was plenty of material to drill through without getting into the race portion of the bearing. As a side note the bearing does come apart by taking out a small set screw along the edge and dumping all the ball bearings out.

 

I really not sure about the flex plates and if there is any published data on the Googles about gear dimensions that they use for manufacturing. I do know that there are two different diameters of 350 Chevy flex plates. One is 168 tooth and the other is 153 tooth. I probably have a stack of them out in my shop from all my years of doing circle track racing. You may be able to find a Chevy starter rebuild kit that has the starter gear as well without having to buy a starter just to rob the gear off it.

 

I know I have interchanged all models of older Chevy starter/flywheel/flex plates and have never had any issues with the gear mesh not lining up correctly. Also I'm sure any flex plate /stater combination would work from the same manufacturer I just recommended the older model Chevy stuff because it is so cheap and relatively easy to find.

[Raceman17]

I just did a quick search on the Googles and you can buy replacement starter gears for about 14$ on eBay and a flex plate can be had for around 24$

 

That right there is the one big piece of the puzzle that was pretty easy to solve. Check out surplus center for motors. They have a ton that would probably work for the application since you want to step up in size. The larger aluminum bearings are also dirt cheap (less than 25$) and come in sizes that seem to work with the diameter of a flex plate.

Edited October 4, 2016 by Raceman17

[pyronoob]

Thanks Racerman17. Looks easy enough.....

[Arthur]

I think that the project is superb. Keep it for small shells. IMO a bicycle wheel is a starting point for a pasting machine for bigger shells. A 24 or 26 inch wheel should work right up to a 16" shell, -allow for using 2" wide tape.

[MondoMage]

I've seen several taping machines based on gummed tape that function similar to this one. Several had the ability to reorient the arm holding the shell to different angles, allowing tape to be applied along slightly different axes (but obviously not to the extent of a WASP). My question is does it make much of a difference to do this? I know Raceman (and others) get good breaks using just a single axis for taping, but seeing the open poles on each end just looks wrong (for lack of a better word) to me.

 

Also, as I sit here daydreaming about building one of these and going over the parts list/pictures I'm having difficulty seeing how the 1/2" threaded rod used to hold the shell can freely rotate in the "C-clamp" assembly. Can you clarify?

 

An excellent machine. I am continuously amazed by (and left in awe of) the creativity of the pyro community.

[Raceman17]

On the c clamp assembly...

If you can imagine just a regular c clamp clamping something. What's clamped does not rotate freely because the clamp is clamping the item tightly. To make the shell rotate freely there has to be something that is used to apply clamping force and then something that allows the item to rotate. I took a piece of aluminum rod and machined it out to hold a 1.125" x. 5 ID ball bearing. Then a 1/2" bolt is inserted through the bearing and a nut holds the bolt to the bearing tight. Then the bearing is pressed into the aluminum piece. The back side of the aluminum fitting is drilled and tapped for 1/2"-20 threads. Here's a few pictures to hopefully explain.

[MondoMage]

Ah! That does clarify thing nicely. Thank you. I know you mentioned that you used a bearing in there but didn't realize that it was inside that piece.

[Raceman17]

If anybody is trying to build on of these wrappers I have some information on the ring gear/starter gear. The one I built used the plastic starter gear that came with the Briggs and Stratton ring gear kit. I luckily had an old starter laying around and was able to use the starter gear mount off the old starter.

 

I am in the process of building another machine for a fellow member and I needed to find an alternative to the plastic starter gear. The issue is the plastic starter gear doesn't have any real good way to mount it to a shaft. It's designed to rotate up and make contact with the ring gear on the lawn mower engines. There really is no good way to mount a plastic gear to a metal shift unless you can do some fancy machining or buy the replacement starter end.

 

I wad able to spec out a replacement gear that meshes perfect with the ring gear.

The gear has a 14.5 degree pressure angle and a pitch of 12. I used a gear with 16 teeth. The gear I used has a 5/8" bore.

 

I machined a rod that connects up to the motor and the gear is just welded to the shaft. It works like it should.

[MondoMage]

Would you happen to have the part# for the ring gear? In looking around online there are several different ones and I want to be sure to grab the right one.

[Raceman17]

Stens #150-435

[Col]

Great job on the machine, it`ll be a real time saver.

[ivars21]

Nice work indeed. Thanks for sharing!

[dkerner]

Ordering parts as we speak to build raceman's shell pasting machine. Anyone else build one yet? Any different ideas?

Thanks.

[sirlancelot]

Greetings All;

 

First, my apologies for posting somewhat off topic - I am unable to create new post, only reply.... but this is close to the topic at hand. I am fairly new to making fireworks (but am a Chemical Engineer with a little over 4 years experience in pyrotechnics now), and have followed traditional techniques when wrapping shells - primarily Italian type cylinders. I was just placing an order for Kraft paper from ULINE when I found that they have "reinforced kraft" paper, which appears to have a synthetic string scrim embedded within the kraft paper. I searched the forum, but could not find where others had used or tried it before.... it seems a natural for shell building - possibly even eliminating the need for spiking. Was hoping one of the experts here might advise why this isn't more utilized for shell building?

 

Many thanks,

Edited November 13, 2016 by sirlancelot