Well, made some more progress and received my batteries for fit-up these past few weeks. The motor mounts are test fitted and just tacked to the group 24 battery tray I made and I'm tweaking a few things on the frame as I go. Discovered one of my split rim tires is mounted backwards for my purposes (valve on inside) so I'll have to take that apart and re-mount it. Never did this to a split rim before, so that will be interesting.
Someone asked me why I used angle iron rather than square tube. Firstly, I had it on hand. But I also used it because it can be punched, which tubing can't. I knew I would be doing a lot of tweaking to the frame and so didn't want to do all that drilling. Punching lets me do oblongs, which are adjustable. It takes seconds instead of hours.
Still waiting to see if the 1/8" motor mounts and 12 gauge will be strong enough or if I have to switch to 3/16" plate. So far I think I am OK—touch wood. The batteries are about 20 lbs. each and the motors about 15 lbs. each. But the weight is on the drive shafts, so it's not like the rear assembly is supporting all the weight.
One hub is a little tight so may have to machine it a bit...we will see. Also not super confident about my swivel caster system on the front. I may reinforce those either with a gusset arrangement or make some bushings myself. Also I would prefer pneumatic tires for the front, but haven't found stem casters with pneumatics yet. I can find the tires—so if these prove to be an issue I will make my own swivel casters for them.
Will be mounting the electronics up front. Generally these are at the rear, but I designed the battery tray to hold the batteries side by side instead of stacked sideways, which leaves no room for electronics. I know AGMs are supposed to be fine on their sides, but I've had two failures in the past when I have done this. It may just be coincidence, but you never know. If all works well I hope to build a little mini shed for the unit, one with a drive-in charging station. Front will also have a safety bumper bar that disables the mower if it hits something head on (also reverse). I plan to make this a training mode feature that can be toggled on or off remotely depending on the experience of the operator (or his blood alcohol level
).
Once I complete the frame adjustment and add a support member up front, I'll move on to the Arduino sketches for failsafes, shut down, tilt, etc. The receiver has built-in shutdown for out of range, which seems like a really good idea for a spinning lawn mower. I also need to do some load testing and decide if I will leave the magnetic brakes on or not. My yard is pretty flat, but who knows in the future? Because they consume power I may remove them.
Someone asked me why I used angle iron rather than square tube. Firstly, I had it on hand. But I also used it because it can be punched, which tubing can't. I knew I would be doing a lot of tweaking to the frame and so didn't want to do all that drilling. Punching lets me do oblongs, which are adjustable. It takes seconds instead of hours.
Still waiting to see if the 1/8" motor mounts and 12 gauge will be strong enough or if I have to switch to 3/16" plate. So far I think I am OK—touch wood. The batteries are about 20 lbs. each and the motors about 15 lbs. each. But the weight is on the drive shafts, so it's not like the rear assembly is supporting all the weight.
One hub is a little tight so may have to machine it a bit...we will see. Also not super confident about my swivel caster system on the front. I may reinforce those either with a gusset arrangement or make some bushings myself. Also I would prefer pneumatic tires for the front, but haven't found stem casters with pneumatics yet. I can find the tires—so if these prove to be an issue I will make my own swivel casters for them.
Will be mounting the electronics up front. Generally these are at the rear, but I designed the battery tray to hold the batteries side by side instead of stacked sideways, which leaves no room for electronics. I know AGMs are supposed to be fine on their sides, but I've had two failures in the past when I have done this. It may just be coincidence, but you never know. If all works well I hope to build a little mini shed for the unit, one with a drive-in charging station. Front will also have a safety bumper bar that disables the mower if it hits something head on (also reverse). I plan to make this a training mode feature that can be toggled on or off remotely depending on the experience of the operator (or his blood alcohol level
).Once I complete the frame adjustment and add a support member up front, I'll move on to the Arduino sketches for failsafes, shut down, tilt, etc. The receiver has built-in shutdown for out of range, which seems like a really good idea for a spinning lawn mower. I also need to do some load testing and decide if I will leave the magnetic brakes on or not. My yard is pretty flat, but who knows in the future? Because they consume power I may remove them.
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