Toughbox Hex Shaft With Magnet
 

I hope everyone's off to a good start to the season! My students are currently working on mounting wheels to their gearboxes using the Long 1/2" Hex Output Shaft with Magnet for Toughbox Series Gearboxes. Problem is, the magnet in the end is too long to use with the SRX Mag Encoder.

With it inserted into the gearbox correctly, the end sticks out about 7mm past the encoder mount pad. Given that the mag encoder requires that the magnet be between 0.75 and 1.5mm away from the end of the encoder, we're at a bit of a loss. Is the only option to use some spacers before the pad so that the encoder sticks way out? Or should we just say forget it, cut the end off, and install our own magnet?

Thanks!

Re: Toughbox Hex Shaft With Magnet
 

This is a very interesting new product. The product page does say: So it most likely can be used for a Mag Encoder easily in it's stock configuration. It seems easier to make a little spacer then to do the lathe work to install your own magnet. The magnet isn't required for the E4T, so it is basically designed for the SRX Mag encoder, so should be ok to use.

This guide by CTRE

has a section on adapting the ToughBox shaft for a .25" magnet, so it might help you fix the problem that you are having or if not, it'll help you install a magnet( which will hopefully also fix your problem).

Re: Toughbox Hex Shaft With Magnet
 

Note that Andymark is now selling a short version of the shaft (probably a bit short, considering the long only sticks out 7mm). I'm not sure about the construction of the toughbox, but can't you just cut off a couple millimeters from the non-magnet side and push the shaft the outwards further?

Re: Toughbox Hex Shaft With Magnet
 

Not really possible without some serious modification, the 1/2" hex gearbox shaft is turned down to 3/8" at the end to fit into a 3/8" round bearing. There is an E-clip which retains the shaft and also ensures good meshing of the gears( if you don't use the E-clip the shaft can fall out).

Re: Toughbox Hex Shaft With Magnet
 

That's what we thought as well! Turns out that it's not really made for that, in any way. Does anyone think it would work if we just chopped the magnet side to length?

Re: Toughbox Hex Shaft With Magnet
 

I wouldn't cut it. Cutting the magnet is going to be messy. I would give AM support a call and let them know what you're seeing. I suspect they can help with a fix or suggesting one.

Re: Toughbox Hex Shaft With Magnet
 

I have not seen this product in person, however if the magnet is the only part too long, perhaps you can remove the magnet, then drill the hole in the shaft deeper with a standard drill in a vise (since there is already a hole) and then push the magnet down farther.

Re: Toughbox Hex Shaft With Magnet
 

Hi there!

I'm sorry that this hasn't gone together as planned for you. We're currently working on a couple hardware kits (one for encoder mount pad-based gearboxes, one for molded gearboxes) that help relocate the encoder mount points that the SRX Mag Encoder require. These aren't quite ready yet, as we're slowly converting all of our shafts to have this magnet embedded in them. In the meantime, I recommend either purchasing (or making your own equivalent,) spacer from www.aluminumspacers.com, part number #MAS8-5-7. I would also pick up some #10 shim washers from a hardware store, as the magnet placement in the shaft has an approximately 0.025" range of where it seats. The shim washers would let you fine-tune the placement of the encoder. You can check this by looking at the indicator lights inside the SRX mag encoder; it should be green if the encoder and magnet are the correct distance from eachother.

A quick note for all; please do not attempt to machine this magnet or attempt to remove it. It is a tight press fit, and clamping down on it with something like vise grips will result in magnet fragments everywhere.

Sincerely,
Nick

Re: Toughbox Hex Shaft With Magnet
 

AM Crew to the rescue. You guys are quick.

Re: Toughbox Hex Shaft With Magnet
 

Hello all,

A couple CAD members of 226 worked on designing a 3d printable spacer for the toughbox + am-0801a. Our measurements for the distance between the edge of the magnet and the gearbox were between ~7.8 mm and ~8.4 mm on our test chassis. The CAD can be found here. The spacing is 9.226 mm off of the gearbox, so it should work anywhere from 8.476 mm to 7.726 mm, we highly encourage teams to take measurements for themselves and make edits to our design.