Banebot 56mm gearbox - double D related

[Cascade]

So after reading all the posted information and an experiencing an appropriate amount of panic, we are ditching the 56 mm planetary gearboxes for a pair of Andy Marks.

It does not make much sense to us to have worked hard over the last year to build a better organization, recruit more team members, mentors, and sponsors and hope a fundamental piece in the KOP will hold up. Imagine the frustration, tears and anger that would follow if the transmissions fail. Oh and the Rule 7 updated posted today did not make us all warm and fuzzy either!!

Switching was a no brainer.

[Dan Petrovic]

We will be manufacturing many of these carrier plates out of 4140 steel. We are going to purchase 2 foot long stock of it and maybe make as many as we can out of it.

I don't know about drawings for them, but we will create one if we can't find it.

We suspect it will increase the strength about twice as much.

[lips]

I saw this mentioned on another threat in a previous post, has anyone tried welding the two (gear and plate) together? Are there any significant downsides to attempting this, as it seems like a relatively simple (if welding is available) fix...

Also, has anyone tried pinning the two? That idea was tossed around this evening, milling and pinning at three or four points the gear to the plate. This would support the central pivot on the double D, if nothing else.


Just some thoughts, drawing and (hopefully good) results forthcomming

[Joe Johnson]

Originally Posted by lips

I saw this mentioned on another threat in a previous post, has anyone tried welding the two (gear and plate) together? Are there any significant downsides to attempting this, as it seems like a relatively simple (if welding is available) fix...

Also, has anyone tried pinning the two? That idea was tossed around this evening, milling and pinning at three or four points the gear to the plate. This would support the central pivot on the double D, if nothing else.


Just some thoughts, drawing and (hopefully good) results forthcomming

Good suggestions.

My thought on welding is that it will be hard to do without damage to the bearings and if the bearing survive the heat, I am not sure that the joint will be that much stronger -- the problem is the base metal gets pushed out of the way.

Pins are another thought. It may be that a pin in the middle of the rounds could take more torque without taking away more than they give. I think it would take an FEA to be sure as the loading gets pretty complex for pen and paper guys like me. Anyone up for an FEA optimization problem? How many pins and where to locate them to reduce the stress by a factor of 2?

PM me and I will coordinate efforts.

Thanks. Keep the ideas coming.

Joe J.

[cbpetrovic]

Here are a couple of slides with a solution cooked up by one of our MEs...





C. B. Petrovic - Team 166

[Joe Johnson]

Originally Posted by cbpetrovic

Here are a couple of slides with a solution cooked up by one of our MEs...





C. B. Petrovic - Team 166

Can anyone else see these slides? I can not.

Joe J.

[cbpetrovic]

Originally Posted by Joe Johnson

Can anyone else see these slides? I can not.

Joe J.

Dunno what's u, I can see these from my house, I'm at the school now and cannot. Let's try this.

[Kevin Sevcik]

So, unbeknownst to me, one of our mentors has connections and is trying to get the 52mm carrier plate spectrally analyzed to determine alloying materials and carbon content, hopefully by tomorrow or friday if I'm really lucky. I'll keep everyone posted as soon as I have results.

[ZZII 527]

Originally Posted by Kevin Sevcik

So, unbeknownst to me, one of our mentors has connections and is trying to get the 52mm carrier plate spectrally analyzed to determine alloying materials and carbon content, hopefully by tomorrow or friday if I'm really lucky. I'll keep everyone posted as soon as I have results.

Can we start a pool? If so I will take 1018. Didn't do any analysis, but it is in that range of hardness and won't harden with plain quenching. I'm very interested to see the results. I wish I could have gotten to the machines here, but I have more MechE connections than materials connections.

[Joe Johnson]

Originally Posted by cbpetrovic

Dunno what's u, I can see these from my house, I'm at the school now and cannot. Let's try this.

Got em now, but I am at home. Must be a firewall issue.

Joe J.

[Joel J]

Originally Posted by Joe Johnson

Got em now, but I am at home. Must be a firewall issue.

Joe J.

Interesting. I quoted the message to get the actual links, and when I tried to open them directly, I got a 404 Not Found error.

[Joe Johnson]

This thread is getting way too long. I fear that folks with dial up will miss the shipping date waiting for it to load.

Also, there is a lot of valuable information but it is pretty diffuse.

I am closing this thread. But no worries. I will start another one here:

Banebot 56mm gearbox - double D - RELOADED

It has what I think is the best information we have up to this point.

Joe J.