pic: Madtown Robotics Drive Proto

[R.C.]

Originally Posted by lilstogi11

What cut of Al are you using for those front bumper-like thing? I've never seen anyone use that before. Looks clean and light. All welded I'm assuming?

The front bumpers are extremely funny, our teacher 3 years ago thought it would be cool if our bumpers weren't rectangular. So he got a piece of 1x2 aluminum and made slits on the ends, then bent the pieces to that U shape on the front and left the back flat. Then we weld them shut. You can't notice the welds on the front due to powder coating. BTW, we weld everything.

Originally Posted by gorrilla

are those gearboxes custom?

Yes, those gearboxes are custom. For some reason we lost sponsorships but got some weird grants over the summer. We have a brand new CNC, a ton of broaches for keyways and hexes, and other random stuff in our shop. So we figured to start making custom stuff, it's pretty fun. Especially when CD gives such brilliant suggestions.

I forgot, in the grant that we wrote for our CNC, it stated that we had to help other teams machine out parts. So i don't know if i should start another thread, but if any teams needs anything milled (can be possible to do with a 3 axis) we would do it for free (you pay for shipping, the product and $1 for the labor/SO as close to free machining.) Contact Me

[gorrilla]

where do you get powder-coating done? isent that really expensive?

[ironbears]

I work in a custom machine shop that has full CNC capabilities as long with powder coating. Is there a rule against powdercoating in FIRST/ or anything like it?

My employer has allowed us to use all equipment during build season. Do you guys always do that drive train?

[rutzman]

I'm sorry if I'm missing something, but what are those shafts extending from the gearboxes? They don't appear to be attached to anything.

[AdamHeard]

The 1.5 lb gearbox seems fishy to me. What are the gears? Are you accounting for fasteners, cylinder, bearings, shafts, etc...

Originally Posted by AdamHeard

The 1.5 lb gearbox seems fishy to me. What are the gears? Are you accounting for fasteners, cylinder, bearings, shafts, etc...

I can see them being 1.5 lbs without motors. Two motors are more than 1.5lbs.

That being said: Due to all the changes being made to the kit, with electronics and all, don't secure yourself on the CIM motors. Whatever you do, be ready for a change in case it comes.

[EricH]

Originally Posted by ironbears

I work in a custom machine shop that has full CNC capabilities as long with powder coating. Is there a rule against powdercoating in FIRST/ or anything like it?

Not for as long as I can remember. Any team that has wanted to powdercoat/anodize/paint/otherwise treat their metal has pretty much been free to (aside from the cost limits).

This may change in 2009.

[R.C.]

Originally Posted by gorrilla

where do you get powder-coating done? isent that really expensive?

We have a wide range of sponsors that do not donate money, instead they offer resources such as powder coating, we have gotten it for free and yes it is pretty expensive.

Originally Posted by ironbears

I work in a custom machine shop that has full CNC capabilities as long with powder coating. Is there a rule against powdercoating in FIRST/ or anything like it?

My employer has allowed us to use all equipment during build season. Do you guys always do that drive train?

No, there is no rule against it. The pink team, poofs and a handful of other teams do it.

Originally Posted by rutzman

I'm sorry if I'm missing something, but what are those shafts extending from the gearboxes? They don't appear to be attached to anything.

The shafts are attached to the gears, it is an andymark supershifter without the last stage of gears.

Originally Posted by AdamHeard

The 1.5 lb gearbox seems fishy to me. What are the gears? Are you accounting for fasteners, cylinder, bearings, shafts, etc...

The gears are all steel, but they have been faced down (from a 3/8 to a 3/16) and they have holes drilled into them by using an index. The weight is accurate but it does not include motors. BTW, there are only five gears (exclude cim gears) in this assembly and we have found a sponsor that will anodize the gears for us.

Originally Posted by Speedfiend

I can see them being 1.5 lbs without motors. Two motors are more than 1.5lbs.

That being said: Due to all the changes being made to the kit, with electronics and all, don't secure yourself on the CIM motors. Whatever you do, be ready for a change in case it comes.

I was thinking the same thing, I created this drive before Bill's statement. It would be kinda cool to get some Mag Motors. lol.

[Brandon Holley]

Originally Posted by rc_cola1323

The gears are all steel, but they have been faced down (from a 3/8 to a 3/16) and they have holes drilled into them by using an index. The weight is accurate but it does not include motors. BTW, there are only five gears (exclude cim gears) in this assembly and we have found a sponsor that will anodize the gears for us.

What grade steel were you planning on using? Did you feel that this grade was not going to be strong enough? I was under the assumption that its not possible to anodize steel.

[Cory]

Originally Posted by rc_cola1323

The gears are all steel, but they have been faced down (from a 3/8 to a 3/16) and they have holes drilled into them by using an index. The weight is accurate but it does not include motors. BTW, there are only five gears (exclude cim gears) in this assembly and we have found a sponsor that will anodize the gears for us.

Have you done the math on this? 3/16, while probably OK on the first stage of reduction is scary thin for your output stage.

Also as Brandon pointed out, you can't anodize steel.

[R.C.]

Originally Posted by Cory

Have you done the math on this? 3/16, while probably OK on the first stage of reduction is scary thin for your output stage.

Also as Brandon pointed out, you can't anodize steel.

Sorry, I didn't mean steel. I was thinking about the aluminum gears.

[Cory]

Originally Posted by rc_cola1323

Sorry, I didn't mean steel. I was thinking about the aluminum gears.

You're making aluminum gears? I would think very hard about that before committing to a design that revolves around them. Travis has posted on here how there's no way we would have attempted the gearbox we did in 2007 if it hadn't been able to take care of his and Kirk's senior design project as well. There's hundreds of hours of machining alone put into them. The resources are really better spent elsewhere.

Regardless of the material, you need to do the math to see if 3/16" face width will work for you. It probably will for the initial reduction, but my gut instinct is there's no way it will hold up on the output.

[R.C.]

Cory I was thinking about this, what if we used a 3/16 face on the first reduction. Then moved up to 3/8 face for the rest, shouldn't that be fine. We are not going to go with an aluminum gearbox yet. In the offseason we will be attempting and testing one out, but for the season it will be steel. I just pointed out that we could anodize if we needed to harden up the aluminum gears(if we used it). I have already checked out your aluminum gearboxes and Cory, if we wanted to make an aluminum gearbox, what steps do you recommend or what is your opinion about creating an aluminum gearbox. We have the time and resources to make one over winter break. But not during the season it we don't make a proto, thanks Cory.

[AdamHeard]

Originally Posted by rc_cola1323

Cory I was thinking about this, what if we used a 3/16 face on the first reduction. Then moved up to 3/8 face for the rest, shouldn't that be fine. We are not going to go with an aluminum gearbox yet. In the offseason we will be attempting and testing one out, but for the season it will be steel. I just pointed out that we could anodize if we needed to harden up the aluminum gears(if we used it). I have already checked out your aluminum gearboxes and Cory, if we wanted to make an aluminum gearbox, what steps do you recommend or what is your opinion about creating an aluminum gearbox. We have the time and resources to make one over winter break. But not during the season it we don't make a proto, thanks Cory.

They spent hundreds of hours. Hundreds. If you worked nonstop for a week, that's 168 hours.

You know what your best bet is if you want a nice, light, simple to make gearbox? Make custom sideplates for the AM supershifters, pocket them like you did, and use standoffs rather than the extrusion casing, like you did. It'll be real fast to make, and you *know* it will work and be very reliable. It may not technically be the lightest gearbox out there, but it will be done fast and done right. You could probably drop the 4.6 lb super shifter to at least 3.5, probably closer to 3 if you lighten the gears (but do not, do not reduce the face width unless you really know what you're doing). A 3-3.5 pound, 2-speed, bulletproof gearbox is still pretty light overall.

This is our exact plan on 973. We technically have the resources to make lighter gearboxes (from Steel gears, we won't dabble in aluminum without some serious effort and planning), but it's not worth the additional time and risk in our opinion.

[R.C.]

Originally Posted by AdamHeard

They spent hundreds of hours. Hundreds. If you worked nonstop for a week, that's 168 hours.

You know what your best bet is if you want a nice, light, simple to make gearbox? Make custom sideplates for the AM supershifters, pocket them like you did, and use standoffs rather than the extrusion casing, like you did. It'll be real fast to make, and you *know* it will work and be very reliable. It may not technically be the lightest gearbox out there, but it will be done fast and done right. You could probably drop the 4.6 lb super shifter to at least 3.5, probably closer to 3 if you lighten the gears (but do not, do not reduce the face width unless you really know what you're doing). A 3-3.5 pound, 2-speed, bulletproof gearbox is still pretty light overall.

This is our exact plan on 973. We technically have the resources to make lighter gearboxes (from Steel gears, we won't dabble in aluminum without some serious effort and planning), but it's not worth the additional time and risk in our opinion.

I totally agree, but we will be facing down steel gears b/c

a. we have the resources
b. engineers are gonna help us with details
c. a great learning experience for the team