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Years ago, I played with a magnet connector for my prop shaft. It did not work for me. It kept slipping and did not have that gription (not a real word, but I like it). Recently, a gentleman named Nick, made one that he liked. That got me back to thinking about it again and using magnets for the drive line and while I am at it, the pushrods too. I think my issue before was woefully too weak of magnets, but did not feel like spending more time or money on it. So, this time around, I injected some testosterone into the mix (think "Home Improvement"). To add to this, technology has changed, we now have 3D printing and I can now express my thoughts better into a tangible result.
Here is the 3.5” prototype, In the center is the geared magnetic drive. The rod coming out of the hole is attached to a cylinder magnet.
With everything removed, There is a nipple in the center that a bearing rides on. In this prototype there are 3 holes that are more like cups in that it is sealed at the end. What is missing (and will be put in the next print) is the water intake for the piston.
This is the wet side showing the three cups or sealed tubes that the magnet moves inside. Also like the dry side there is a nipple here too. I am concerned the cylinders getting broken. However making the tubes go inward rather than outward adds more issues that I might need to tackle if these are too vulnerable.
A side view of the assembly put together. I needed to drill out the cylinders a little to make the movement smooth with the internal magnet. The outside needed a little bit of sanding to knock out the nibs of the supports. However, the motion and strength of these magnets is really good. Maybe too much strength, but really pleased with the outcome.
This shows the magnet used on the wet side and the pushrod magnet from the dry side.
Another shot without the dry side pushrod magnet.
The geared magnet drive is setup with a bearing in the center and 4 magnets. The nipple will rest on the center ring of the bearing. the outer surface of the bearing is affixed to the drive. As it rotates it will spin freely.
The wet side is identical to the dry just designed to attach to a 3/16” shaft to the prop.
Issues - I made the nipples a little too small. I was being very conservative and trying to keep the distance as close as possible. However, once the magnets came in I realized (well tested) even with 5mm of resin between the magnets they held up. So, I know if threes an issue with the thinner wall, I can add more thickness to it. You can see in the photos that they are rubbing against the end cap. For giggles, I will drill out the nipple and insert a brass rod to see how it rides.
Here is the 3.5” prototype, In the center is the geared magnetic drive. The rod coming out of the hole is attached to a cylinder magnet.
With everything removed, There is a nipple in the center that a bearing rides on. In this prototype there are 3 holes that are more like cups in that it is sealed at the end. What is missing (and will be put in the next print) is the water intake for the piston.
This is the wet side showing the three cups or sealed tubes that the magnet moves inside. Also like the dry side there is a nipple here too. I am concerned the cylinders getting broken. However making the tubes go inward rather than outward adds more issues that I might need to tackle if these are too vulnerable.
A side view of the assembly put together. I needed to drill out the cylinders a little to make the movement smooth with the internal magnet. The outside needed a little bit of sanding to knock out the nibs of the supports. However, the motion and strength of these magnets is really good. Maybe too much strength, but really pleased with the outcome.
This shows the magnet used on the wet side and the pushrod magnet from the dry side.
Another shot without the dry side pushrod magnet.
The geared magnet drive is setup with a bearing in the center and 4 magnets. The nipple will rest on the center ring of the bearing. the outer surface of the bearing is affixed to the drive. As it rotates it will spin freely.
The wet side is identical to the dry just designed to attach to a 3/16” shaft to the prop.
Issues - I made the nipples a little too small. I was being very conservative and trying to keep the distance as close as possible. However, once the magnets came in I realized (well tested) even with 5mm of resin between the magnets they held up. So, I know if threes an issue with the thinner wall, I can add more thickness to it. You can see in the photos that they are rubbing against the end cap. For giggles, I will drill out the nipple and insert a brass rod to see how it rides.
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