Build Log | Caractacus - Any Tips?

[willcaddy]

All the best ideas come from sheer desperation at the last minute!

I keep thinking about mounting wheels on separate bearings and driving them with a belt or chain, to minimise shocks and impacts getting to the gearbox bearings. That would seem like the best approach overall but it also feels like a lot of work compared to just bodging wheels straight onto the gearbox output shaft.

Yea xD It turned out well though!

That's exactly what I have been thinking of doing but again not sure if it's worth it. I had an idea about mounting a bearing into the shell of the bot and having that connected to the other side of the wheel and attach to the gearbox like it is currently. Maybe that will provide some extra strength without building a whole drive train? Any thoughts?

Short of welding the wheel to the shaft with a metal plate, the "pin through the shaft" idea is the best method I can think of. However, you could also drill a small indentation, attach a wheel hub onto the shaft and then screw in a grub screw into the indentation on the shaft (remembering to thread lock it) and then mount the wheel to the wheel hub. That is the method I use to hold down the pinion gear on my Middleweight's axe and has yet to come off.

Yea I think the pinning idea is the best one for me! What is your thoughts on a drivetrain? Worth it?

[Ocracoke]

In your opinion then is there a more reliable way of mounting wheels other than pinning straight to the gearbox?

Short of welding the wheel to the shaft with a metal plate, the "pin through the shaft" idea is the best method I can think of. However, you could also drill a small indentation, attach a wheel hub onto the shaft and then screw in a grub screw into the indentation on the shaft (remembering to thread lock it) and then mount the wheel to the wheel hub. That is the method I use to hold down the pinion gear on my Middleweight's axe and has yet to come off.

Thanks for watching! Sorry about the slow reply!

Not intentionally but it did end up that way a little ha ha. The idea came out of sheer desperation because I wanted to compete in the event and couldn't get the axe on Caractacus finished in time lol so wanted the daftest idea I could find and that was it xD

All the best ideas come from sheer desperation at the last minute!

I keep thinking about mounting wheels on separate bearings and driving them with a belt or chain, to minimise shocks and impacts getting to the gearbox bearings. That would seem like the best approach overall but it also feels like a lot of work compared to just bodging wheels straight onto the gearbox output shaft.

[willcaddy]

Nah. If they are rated for 24v, the 22.2v LiPo and the 85A speed controller are more than enough. I've ran 4x of the Gimson motors on my middleweight robot Kaizen and that had enough grunt to work happily for a little while but couldn't take the pounding so often ended up blowing one or two after each event. Your arrangement is OK.

It may be worth checking your gearbox at the moment to see if any of the stages are plastic. An all metal affair will be more reliable when it comes to a pushing contest or flooring it. However, pinning the wheel to the shaft will be the same regardless of the gear material because the shaft will be made of metal.

Thanks a lot for the reply! Sorry for the long reply, been one of those weeks!

That's good to know In your opinion then is there a more reliable way of mounting wheels other than pinning straight to the gearbox? I'm looking for the most robust thing I can find at the minute being as my robot currently only has a spike ha ha

Thanks a lot!

[willcaddy]

Love your videos Will, and the glitter!

Was the "spike" meant to look that rude?

Thanks for watching! Sorry about the slow reply!

Not intentionally but it did end up that way a little ha ha. The idea came out of sheer desperation because I wanted to compete in the event and couldn't get the axe on Caractacus finished in time lol so wanted the daftest idea I could find and that was it xD

Love your videos Will, and the glitter!

Was the "spike" meant to look that rude?

[Ocracoke]

I'm using a 22.2v 6s LiPo with 2 BotBitz 85a Esc's. The motors are Rs-550s motors which I checked can handle 24v but maybe I'm just pushing them too hard?

Nah. If they are rated for 24v, the 22.2v LiPo and the 85A speed controller are more than enough. I've ran 4x of the Gimson motors on my middleweight robot Kaizen and that had enough grunt to work happily for a little while but couldn't take the pounding so often ended up blowing one or two after each event. Your arrangement is OK.

Would an all metal gearbox be tough enough to mount straight too then? Cus at the minute the wheels are screwed straight onto the original cordless drill gearbox.

It may be worth checking your gearbox at the moment to see if any of the stages are plastic. An all metal affair will be more reliable when it comes to a pushing contest or flooring it. However, pinning the wheel to the shaft will be the same regardless of the gear material because the shaft will be made of metal.

[willcaddy]

For general power, what sort of voltage are you running this at? P60 boxes are generally quite strong (all metal affairs as I recall) but if you were after a simple solution as the box would need to be assembled, Gimson sell a neat geared motor for about £50 which I've used before in The Honey Badgerquite happily (https://gimsonrobotics.co.uk/categor...tary-gearmotor). That comes with a 775 type motor that has plenty of oomph for the FW class.

Thanks for the reply!

I'm using a 22.2v 6s LiPo with 2 BotBitz 85a Esc's. The motors are Rs-550s motors which I checked can handle 24v but maybe I'm just pushing them too hard? The pin idea is a good one! I'll try that because we did have a wheel come loose. I'm ok with a little complexity with gearboxes but I'm still rather new to all this lol. Would an all metal gearbox be tough enough to mount straight too then? Cus at the minute the wheels are screwed straight onto the original cordless drill gearbox.

Thanks again!

Will

[Ocracoke]

So my question would be is there a way of having a more robust drive system then attaching the wheels directly to the gear motors?

You could drill through the shaft where the wheel overlaps and put a bolt and nylon nut on it. I ended up having to do this with another robot at EXR Manchester to keep their wheels on but it works.

This worked well but as you can see in the video, wasn't all that strong compared to the other robots there. Would it be better to have a chain driven drive for example? Also I have been looking at the P60 gearboxes for more strength also, any thoughts? Andy mentioned Johnson 600s too?

For general power, what sort of voltage are you running this at? P60 boxes are generally quite strong (all metal affairs as I recall) but if you were after a simple solution as the box would need to be assembled, Gimson sell a neat geared motor for about £50 which I've used before in The Honey Badgerquite happily (https://gimsonrobotics.co.uk/categor...tary-gearmotor). That comes with a 775 type motor that has plenty of oomph for the FW class.

[willcaddy]

The pink unicorn was a resounding success!........ish xD

Hello again everyone!

It's been a little while since I've been able to get on but the Cheltenham Extreme Robots show which seemed so far away went extremely well!

Big thanks to my brother, my friends Jon, Nathaniel, Dave Paul, Matt Andy and Joe for getting me through the event!

Here is the build video and part 2 is the actual event in case you want to see
https://youtu.be/eIWPur0QD8I

The main problem from the event was that I had two motors fry themselves and a gearbox is also toast now lol I learnt a hell of a lot about motors and gearboxes and how they fit together etc. So my question would be is there a way of having a more robust drive system then attaching the wheels directly to the gear motors? This worked well but as you can see in the video, wasn't all that strong compared to the other robots there. Would it be better to have a chain driven drive for example? Also I have been looking at the P60 gearboxes for more strength also, any thoughts? Andy mentioned Johnson 600s too?

Thanks a lot everyone as always xD

All the best

Will

[willcaddy]

Hey there Will. Regarding links, what I've done on both my FW's is bury the link connection a couple of inches deep within each & attach a cable tie to the loop on the link so it's much easier to pull out without risking the wire getting damaged.

On Neophyte, I've also made a small HDPE flap held on with tape on one side so it can stick to the armour, but still be opened & closed easily by hand. Blacksmith hit the cap with it's axe during one fight, taking the cap off, but in the process saved the link itself (I wasn't using the cable tie method then).

Regarding specific placement, I'd personally recommend placing it somewhere towards the middle or the back of the bot, making it as difficult as possible for an opponent to reach. I wouldn't worry too much about random knocks taking it out, as long as the connectors have a good grip you should be fine.

Thank you for your advice The cable tie idea is a good one!

[James Williams]

Hey there Will. Regarding links, what I've done on both my FW's is bury the link connection a couple of inches deep within each & attach a cable tie to the loop on the link so it's much easier to pull out without risking the wire getting damaged.

On Neophyte, I've also made a small HDPE flap held on with tape on one side so it can stick to the armour, but still be opened & closed easily by hand. Blacksmith hit the cap with it's axe during one fight, taking the cap off, but in the process saved the link itself (I wasn't using the cable tie method then).

Regarding specific placement, I'd personally recommend placing it somewhere towards the middle or the back of the bot, making it as difficult as possible for an opponent to reach. I wouldn't worry too much about random knocks taking it out, as long as the connectors have a good grip you should be fine.

[willcaddy]

Yeah, using a standard LED, you can add in a resistor to reduce the current to stop it from destroying itself. Ebay has lots of prewired 24v leds that have the resistor and series wired leds.

I used a strip of Leds and then placed it inside the bot and used some 10mm thick acrylic as a guide pipe to illuminate an exposed section of my frame. Worked well.

Awesome thank you, i didn't know that was a thing

Sorry didn't see your last reply. THIIS https://botbitz.com.au/collections/f...eed-control-v2

Unfortunately they are out of stock so best chances of getting th axe working would be either buy feathertwo single, tz85 or bb80 of someone which will definitely work and run all day everyday. Or using a 30a you ESC which should take it but will not be as happy

No worries! I ordered one of the replacement 80A BotBitz ones but wont be here in time so I'm going to build a ridiculous looking push bot for experience xD

[Maxamuslead]

Sorry didn't see your last reply. THIIS https://botbitz.com.au/collections/f...eed-control-v2

Unfortunately they are out of stock so best chances of getting th axe working would be either buy feathertwo single, tz85 or bb80 of someone which will definitely work and run all day everyday. Or using a 30a you ESC which should take it but will not be as happy

[Roboteernat]

Yeah, using a standard LED, you can add in a resistor to reduce the current to stop it from destroying itself. Ebay has lots of prewired 24v leds that have the resistor and series wired leds.

I used a strip of Leds and then placed it inside the bot and used some 10mm thick acrylic as a guide pipe to illuminate an exposed section of my frame. Worked well.