Re: AndyMark transmissions at IRI
 

emphasis addedPardon me for changing the subject ... but ...

Prototype design of WHAT??

The 2007 season is over, '08 is months away, and it is the middle of the summer !!

Re: AndyMark transmissions at IRI
 

We, too, are about to start working on a drivetrain. It's a great way for us to work out the kinks in design and manufacturing philosophy and to teach our kids about the work that goes into the robot at a more relaxed pace. We try our best to explain everything that's going on, but six weeks' time is hardly enough to really examine the form of function of each part and assembly.

Re: AndyMark transmissions at IRI
 

We took our 2007 season base that we developed with 687 and updated it greatly. We made everything easier to work with (whatever bothered whoever had to maintenence it) and maintain. We also made the frame easier to weld and more modular. Our final addition was incorporating off the shelf components such as AndyMark shifters to make production easier.

In terms of drive, all sorts of prototyping can be done during the off-season. Even if this base design doesn't get used for '08, the lessons learned from it will carry over. It also never hurts to have a fully assembled and running base to test with.

Re: AndyMark transmissions at IRI
 

Someone please explain what I am seeing here. First, are the sides open or made of a black material? Second, is the gray thing sticking out of the side a metal holder for the black thing, which I assume is the servo. Third, does someone have a hand-drawn picture that they can show?

Re: AndyMark transmissions at IRI
 

The gearbox is enclosed with a black anodized aluminum box beam section.

the piece sticking off the side is maybe 1.5" aluminum angle, with a pocket milled out of it for the servo to mount to (with the exception that on the real thing, the shifter is located on the non-output shaft side of the gearbox. It also has an encoder built into the same area. The standard pneumatic shifting fixture remains in the same place.

Re: AndyMark transmissions at IRI
 

When I looked at it, wasn't it just black plastic? There is no flanges on the gearbox.

Re: AndyMark transmissions at IRI
 

Nope. It's definitely anodized aluminum.

Re: AndyMark transmissions at IRI
 

Yes, that is my poor rendering skills at work there. Everything said above is true, I will redraw what I remember of it, but I'm thinking that everyone is going to have to wait for Mr. Baker to find time to get the real thing out. I just thought I would give a little teaser!

P.S. NO BOTHERING ANDY FOR A PHOTO!

Re: AndyMark transmissions at IRI
 

There is a Super Shifter page on the AndyMark website. More details (CAD, assembly drawings) will be released within 5-6 weeks. Here are the key features and improvements:

An additional shaft, with 2 standard ratios (2.25:1 or 2.82:1) that would reduce the speed in addition to the current output speeds of the AM Shifter

An included encoder, US Digital model E4P-250-250, located on the final drive shaft

Common shift hardware used both for pneumatic or servo shifting, so choosing between one or the other is easier

An enclosed gearbox, much like our http://www.andymark.biz/am-0011.html, but wider (and a bunch more stuff included)

A 1/2" output shaft, with a 1/8" keyway and a 1/4-20 threaded hole on the end

Ability to mount 2 CIM motors (not enough room for a Large CIM motor)

1/4" thick aluminum side plates

The same gearing (mostly) as the AM Shifter in the cluster gear shaft and output gears

We have not set a price yet, but we are looking at $370 as a target. Keep in mind that 2 gears, 1 shaft, and 1 encoder are all being added. Also, we are debating about providing both the pneumatic and servo shift options for each gearbox. It is super.

Andy B.

Re: AndyMark transmissions at IRI
 

Can u give us the dimensions of the square hole pattern in the 4 corners?

Re: AndyMark transmissions at IRI
 

The side plates are 5"x5"x1/4". The mounting holes are 0.312" in from the sides, and therefore 4.376" apart from each other. Those 4 mounting holes are for 1/4-20 bolts. The 5"x5" extrusion enclosing the gearbox is 2.00" long.

Andy B.

Re: AndyMark transmissions at IRI
 

Could we have the weight of the assembly as shown in the pictures?

Re: AndyMark transmissions at IRI
 

The weight of this gearbox, without the motors is 4.6 lbs. This is 1.1 lbs heavier than the AM Shifter.

We have made no effort to fabricate lightening holes or features in the gears or side plates. That would take machining time, which would add significant cost, driving the price way over $400.

Three main places that teams could reduce weight in this gearbox would be to replace the aluminum extrusion with spacers (about 0.7 lbs), lighten the final drive gear and the cluster gears (about 0.4 lbs), and put lightening features into the 2 side plates (about 0.4 lbs total). Using these 3 methods alone, 1.5 lbs could be reduced for each gearbox.

As we prepare documentation for this gearbox, I will make more detailed designs regarding how and where to lose weight.

Andy B.

Re: AndyMark transmissions at IRI
 

that's nice!

and you'll be selling small broached steel #35 sprockets to put on the output shaft? hint hint hint

Re: AndyMark transmissions at IRI
 

Yes... and what if those 12 tooth sprockets were offered in steel and 7075 aluminum?

We already offer the 12 tooth sprockets.

The 7075 aluminum sprockets will be new for us. We are initially putting out a 12 tooth version, but may make 14 tooth and others if the demand is high.

Andy B.