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One of the main objectives of making my own pig roaster is making it mechanised. With the cogs and a few bits from eBay this is how I did it! (More pics and a video, click read the rest of this entry below)
First up was securing the crank onto the shaft. I’d come up with several ways in my head, originally I needed a bit of scrap which would go over the stainless rod which I’d weld onto the crank. I’d drill through them both and attach with a bolt.
I did already have 3x 25mm collars I’d bought off eBay, and whilst perfect, I didn’t think I could weld stainless. Turns out I can! It’s perfectly aligned (it seemed to be made for the collar!
Above you can see the bar resting on the bearings. Turns very easily!
Crank mounted onto shaft. It has the added benefit of having 6 small holes drilled into the crank plate which line up perfectly with the bearing support bar. This means I can insert a screwdriver into the holes (or bolt) and manually turn the spit if it all fails! You can see the holes clearly in the video at the bottom of this post!
View of the gears. These freewheel only in one direction.
I used two large washers and several nuts to extend a 10mm screw. Gary aligned them perfectly whilst I made the obligatory bacon sandwiches!
After degreasing the chains we added the motor. We made use of the original mounting bracket off the motor and put another gear cog onto it. It came off a bike but I’ll be honest, I have no idea where such a cog came from, it was just in a bits box at reCycle in Southend!
The motor came from NSEC in Hullbridge from an old Ford Mondeo and cost me about £10 – this was a very good price and you may struggle to find a pulled windscreen motor for this! It has the advantage of having a thread on it suitable for mounting a cog.
I welded a small bit of plate onto the cog as the hole was too big and drilled it. I also had to weld the bearings solid because otherwise the spit would freewheel if not perfectly in balance.
Done! I linked it up to a 12v mains power supply, found that the motor seemed to speed/slow randomly but achieved about 6rpm. That would have been sufficient if a little fast, but we found toying with the electrical connections we could reduce it to 3.5rpm. Still a little fast, and Jon suggested we try it at 5v. This did the trick and it dropped to 2rpm. The torque oddly seemed noticeably more torquey. Two of us could just about stop it spinning by gripping the shaft and really really squeezing. I think it’s definitely powerful enough to drive the pig!
Just the suspension for the charcoal pit and a few support bars left to do and we’re done!