Zinger
Active Member
Here's Mark II of my Mage bat. I've been working on it for 2 months. The biggest improvement is I fit the battery pack into the barrel of the bat. The Mark I used an external battery. I hid it in the pocket of a trench coat and ran the power leads down the sleeve. Mark II is completely self contained, so I can now cosplay the Hero Discovered Kevin who didn't wear a coat.
Details below.
My first Kevin Matchstick costume and bat were a hit at Awesome Con in May.
A friend of Matt Wagner saw me, took my picture and it ended up on Matt's Facebook page.
https://www.facebook.com/photo.php?...959.1073741828.100006699972788&type=3&theater
I documented that build here - https://www.therpf.com/showthread.php?t=275544
Improved Mold and Casting
For the Mark I, I made the glove mold with the handle of the bat as the open end. In that configuration, I couldn't stretch the silicone over the barrel to get the bat out of the mold. I had to cut a slit in it. That left a wonky seam in the casting and made it hard to get the silicone mold locked into the mother mold.
In the Mark II, I made the barrel the open end. After all the work I'd put into making the wood bat positive, it killed me to cut it up like that. But we all have to make sacrifices. I was able to get the mold off the bat without cutting it this time.
Here it is after 4 coats of Rebound 25 https://www.smooth-on.com/product-line/rebound/.
Here's the demolding.
I said I got it off. I didn't say it was easy. I think the Rebound was bonding with grain in the bat positive. Physically, not chemically. If I ever try this again, I'll use Sonite wax to fill the grain. Hopefully that will make demold easier.
The first time, I used plaster bandages for the mother mold. They fell apart during the slush casting process. This time I made a much sturdier mother mold out of Plasti-Paste. In hind-sight, that was over kill. I could have made a lighter mother that was much cheaper and just as solid out of fiberglass and resin.
Internal Battery
The main goal of this rebuild was to mount the battery pack inside the bat. That presented several challenges, some of which I've only half solved.
Surprisingly, battery life wasn't a problem. At Awesome Con, I found I was only lighting the bat between sessions. Maybe 10 minutes out of every hour. It would have been very rude to use it during a panel. The 6500 mAH battery I used easily lasted all day. I think I could have gone two days without recharging.
The big power challenge was finding a battery pack which would fit in the barrel, leave room for the LED strips and provide enough amperage to drive them. I decided on a 7800 mAh pack from Tenergy http://www.tenergy.com/31045. It's capacity is total overkill. I could probably go 3 to 4 days without recharging. But it was the best fit I could find for the other requirements.
The battery came with bare leads. The charger had large battery clips for connectors. I replaced those with XT60s. I chose the XT60 for their ease of soldering, low profile, amp rating and secure physical connection.
Also, the hobby shop was out of everything else.
IMPORTANT NOTE ON BATTERY SAFETY!!!
This is a big lithium ion battery pack. Mistreated, it could be very dangerous. I've taken several precautions to make this about as safe as a cell phone or laptop battery pack. This pack has a protection IC built in. It prevents over-charge, under-charge and over-discharge, all things that can damage a pack and make it dangerous. It also has a PolySwitch. It's a resettable thermal fuse which kicks in if there is a short circuit.
Not all li-ion battery packs have this kind of protection built in. The packs used by RC hobbyists usually have the protection circuit in the RC model, not the pack. Do not use these in a prop. You don't want to be the person who forces a hotel evacuation because your prop caught fire.
The other big danger with lithium ion packs is they burst into flame if punctured. I've mounted this pack in a padded sleeve inside the hard shell of the bat. It would take quite a hit to puncture those.
Mounting
The only thing left was figuring out how to mount the battery pack, LED strips and on-off switch. I recycled the 3D printed caps for the handle and barrel from the Mark I. I also reused the MOSFET power control circuit. It uses a magnetic reed switch to control the MOSFET so there's no external push button. I think it's pretty cool.
I used a dowel rod for the strips in the handle. I hot glued three strips to the dowel. I also hot glued 12 strips around the sleeve for the battery pack.
With the Mark I, I had a problem with the LEDs showing up as hot spots. It looked great in pictures because the camera's CCD saturates. That makes everything looks brilliant white. IRL, the hot spots were very noticeable.
For the Mark II I salvaged the diffuser sheets out of a couple of broken laptops. They helped a lot.
I'm still getting some hot spots in the barrel, along with some shadows from the wiring. You can see those in the picture above. I have some ideas for a neater mounting system which should take care of those.
Mage The Hero Denied #1 comes out tomorrow. https://imagecomics.com/comics/releases/mage-the-hero-denied-1-of-15
I've been waiting 18 years for this. I think I might dress up for the occasion.
Details below.
My first Kevin Matchstick costume and bat were a hit at Awesome Con in May.
A friend of Matt Wagner saw me, took my picture and it ended up on Matt's Facebook page.
https://www.facebook.com/photo.php?...959.1073741828.100006699972788&type=3&theater
I documented that build here - https://www.therpf.com/showthread.php?t=275544
Improved Mold and Casting
For the Mark I, I made the glove mold with the handle of the bat as the open end. In that configuration, I couldn't stretch the silicone over the barrel to get the bat out of the mold. I had to cut a slit in it. That left a wonky seam in the casting and made it hard to get the silicone mold locked into the mother mold.
In the Mark II, I made the barrel the open end. After all the work I'd put into making the wood bat positive, it killed me to cut it up like that. But we all have to make sacrifices. I was able to get the mold off the bat without cutting it this time.
Here it is after 4 coats of Rebound 25 https://www.smooth-on.com/product-line/rebound/.
Here's the demolding.
I said I got it off. I didn't say it was easy. I think the Rebound was bonding with grain in the bat positive. Physically, not chemically. If I ever try this again, I'll use Sonite wax to fill the grain. Hopefully that will make demold easier.
The first time, I used plaster bandages for the mother mold. They fell apart during the slush casting process. This time I made a much sturdier mother mold out of Plasti-Paste. In hind-sight, that was over kill. I could have made a lighter mother that was much cheaper and just as solid out of fiberglass and resin.
Internal Battery
The main goal of this rebuild was to mount the battery pack inside the bat. That presented several challenges, some of which I've only half solved.
Surprisingly, battery life wasn't a problem. At Awesome Con, I found I was only lighting the bat between sessions. Maybe 10 minutes out of every hour. It would have been very rude to use it during a panel. The 6500 mAH battery I used easily lasted all day. I think I could have gone two days without recharging.
The big power challenge was finding a battery pack which would fit in the barrel, leave room for the LED strips and provide enough amperage to drive them. I decided on a 7800 mAh pack from Tenergy http://www.tenergy.com/31045. It's capacity is total overkill. I could probably go 3 to 4 days without recharging. But it was the best fit I could find for the other requirements.
The battery came with bare leads. The charger had large battery clips for connectors. I replaced those with XT60s. I chose the XT60 for their ease of soldering, low profile, amp rating and secure physical connection.
Also, the hobby shop was out of everything else.
IMPORTANT NOTE ON BATTERY SAFETY!!!
This is a big lithium ion battery pack. Mistreated, it could be very dangerous. I've taken several precautions to make this about as safe as a cell phone or laptop battery pack. This pack has a protection IC built in. It prevents over-charge, under-charge and over-discharge, all things that can damage a pack and make it dangerous. It also has a PolySwitch. It's a resettable thermal fuse which kicks in if there is a short circuit.
Not all li-ion battery packs have this kind of protection built in. The packs used by RC hobbyists usually have the protection circuit in the RC model, not the pack. Do not use these in a prop. You don't want to be the person who forces a hotel evacuation because your prop caught fire.
The other big danger with lithium ion packs is they burst into flame if punctured. I've mounted this pack in a padded sleeve inside the hard shell of the bat. It would take quite a hit to puncture those.
Mounting
The only thing left was figuring out how to mount the battery pack, LED strips and on-off switch. I recycled the 3D printed caps for the handle and barrel from the Mark I. I also reused the MOSFET power control circuit. It uses a magnetic reed switch to control the MOSFET so there's no external push button. I think it's pretty cool.
I used a dowel rod for the strips in the handle. I hot glued three strips to the dowel. I also hot glued 12 strips around the sleeve for the battery pack.
With the Mark I, I had a problem with the LEDs showing up as hot spots. It looked great in pictures because the camera's CCD saturates. That makes everything looks brilliant white. IRL, the hot spots were very noticeable.
For the Mark II I salvaged the diffuser sheets out of a couple of broken laptops. They helped a lot.
I'm still getting some hot spots in the barrel, along with some shadows from the wiring. You can see those in the picture above. I have some ideas for a neater mounting system which should take care of those.
Mage The Hero Denied #1 comes out tomorrow. https://imagecomics.com/comics/releases/mage-the-hero-denied-1-of-15
I've been waiting 18 years for this. I think I might dress up for the occasion.
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