16-09-2004 20:47

Tytus Gerrish

Re: pic: 1305 Frame design with trannies

ah, baker transmitions with a box tube frame. OHH! and whats this? sinking the drill motor into the box tube. Somone stole my idea, Or mabye its a good idea and you came up with it too?

16-09-2004 20:54

Hunter

Re: pic: 1305 Frame design with trannies

They are a completely new trannsmission That I designed. Although I was definetly heavily influenced by Baker's design. It is designed to have Brecoflex tracks in the gap between the The 2x4s and the outsice plates, So the driveshaft out of the Trannies is designed to turn the back drive pulley for the tracks. The trannies are 2 speed with approxiamte speeds (70% of free speed) at 3.4 ft/sec and 9.5 ft/sec. Kinda slow compared to other designs but This is designed like a bulldozer.

16-09-2004 20:58

Hunter

Re: pic: 1305 Frame design with trannies

I know the drill motors are cancelled but this was designed before then, and besides, it would take only a very small effort to convert the trannsmissions to use any other similar motor. And I'm hoping we get the Dewalt drill motors, they would swap in easily.

16-09-2004 21:02

Arefin Bari

Re: pic: 1305 Frame design with trannies

How much do the transmissions weight... just a suggestion... make sure the robot weight is balanced... our 2003 robot was back heavy since the transmission was in the back like your design... but i think we only flipped once... the overall design looks great... the frame looks strong... you might have to change your transmission depending on what motors they give us this coming season... good luck...

p.s. Never mind my changing tranny comment... i think you just click submit just a second before i did...

16-09-2004 21:07

sanddrag

Re: pic: 1305 Frame design with trannies

What is the thickness on the outer plates and on the wall of the tube. I'm guessing it is 1/8" If so, the plate needs standoffs between it and the tube, and the tube needs some serious HOLES. Also, other than mounting your trannies? is there any reason that tube is so big, I mean, for the rest of the way down the frame?

16-09-2004 21:08

Hunter

Re: pic: 1305 Frame design with trannies

The trannies wheigh 9.3 pounds With everything on them you see there (according to inventor anyway). We still have to build them, we are waiting for gears. So they might not even work, but thats why we are building them now.

16-09-2004 21:15

Hunter

Re: pic: 1305 Frame design with trannies

Like I said before it designed to fill the bulldozer role on the field. Those are the 2x4x1/8 tubes like we got in the kit last year, and the outside plates are 3/16. there will be standoffs as part of the track system, but I didn't add them in yet. both the 2x4's and the outside plates will likely end up full of holes in the final robot (If it turns out that we can even use this design next year), then we will just Epoxy a piece of 1/16 lexan over the holes on the outside plates to keep stuff from getting caught in them (bad experience in atlanta with stuff catching in holes).

If we end up building this we will deside where mechanisms need to be mounted before drilling any lightening holes to make it easy to mount stuff.

By the way the bottom plate is only 1/16, just to help keep the frame square and mount stuff like the battery and electronics to.

16-09-2004 21:29

sanddrag

Re: pic: 1305 Frame design with trannies

3/16" looks like a good choice for those plates. I know your not anywhere near this point, but if you could get EVERYTHING laid out in Inventor (like early in the build) then you could get some really (big) nicely lasercut or waterjetted holes in those tubes and plates. As for the bottom pan, you could probably go with a little bit thinner even and then roll some beads in it (or get it embossed) and it will really stiffen it up and look cool too.

16-09-2004 21:33

Justin Boudreau

Re: pic: 1305 Frame design with trannies

Haha, unfortunatly laser or watercutting isn't an option for us. It would be nice, but we'll be lucky to afford the gears.

17-09-2004 01:53

Travis Covington

Re: pic: 1305 Frame design with trannies

It never hurts to ask. The worst they can say is no, or tell you a price. Alot of businesses will openly donate services to teams, but they will never know you want their help unless you ask.

17-09-2004 16:34

K.Shaw

Re: pic: 1305 Frame design with trannies

all i have to say is if those drill motors die or crap out its gunna b a pain in the $@#$@#$@# to changed them.....cool design though

17-09-2004 17:34

J Flex 188

Re: pic: 1305 Frame design with trannies

looks pretty awesome guys.. by bulldozer.. i wonder how what the torque stats are . we can keep up a canadian way of being able to push everyone around, just not in real life .

i hear you about the waterjetting *sigh*

17-09-2004 18:11

Paul H

Re: pic: 1305 Frame design with trannies

Just put the battery in the front.

21-09-2004 18:34

Hunter

Re: pic: 1305 Frame design with trannies

The Drill motors actually come out quite easy, just a couple of set screws that Protrude into the holes in them and some gental taps and they should come right out all the way through the 2x4.

As for tourque, it has approximatley 31.5 theortical ft/lbs of tourque at 40 A per side in low gear, giving it pushing theoretical pushing force of 378 pounds at 40 A not taking any friction etc. into account. That is about 1100 pounds of push at stall in low gear, Which is impossible to reach since the battery can't provide that kind of current. Combine that with VERY grippy tracks and we should be somewhat of a bulldsozer out there, with good intentions of course.

22-09-2004 12:17

Pat Roche

Re: pic: 1305 Frame design with trannies

Great design looks good and rugged. One quick tip, If your gonna use a track like brecoflex, which has alot of grip add in a center idler wheel which is larger than your drive wheel. It will aid in turning your machine. We used brecoflex this past year and without the larger idler our machine couldn't turn. This thread might also help you:
http://www.chiefdelphi.com/forums/sh...ghlight=tracks

22-09-2004 12:36

petek

Re: pic: 1305 Frame design with trannies

Looks like a great drive unit! Nice and compact, too. One suggestion: install them so the motors on both sides are turning in the same direction. (DC motors are almost always optimized for higher efficiency in one direction) Generally speaking, you want your highest efficiency in the robot's forward direction. This will give you slightly better torque and will be easier to balance for driving in a straight line.

24-09-2004 21:28

Robot Dude 0101

Re: pic: 1305 Frame design with trannies

That is a very nice design. Too bad you stole that other person's idea! J/K

I will soon begin work on a robot with 4 wheel drive using heavy duty gas engines. I don't know how to use any computer programs like you so mine wont be as advanced.

24-09-2004 21:47

Hunter

Re: pic: 1305 Frame design with trannies

Thats Awsome! A gas powered robot. About the Computer programs though, they don't make a design good or bad, they really helped me figure out stuff with the trannsmissions but I already had the major details worked out before I put anything down in Inventor. You can make cool designs without a computer. 1305's 2004 robot was designed entirley on graph paper and on the fly and it turned out very well for us. Don't say that you can't make an advanced design just because you can't use CAD. 50 years ago CAD didn't exist and that didn't stop anyone.

Good luck with the gas robot, let me know how it turns out, I think that is really cool.

25-09-2004 01:13

Tristan Lall

Re: pic: 1305 Frame design with trannies

Not for FIRST you won't! I know you're new to FIRST, so I'll point out that gas engines aren't allowed, and very likely will never be allowed as long as FIRST maintains its current format. Fuel storage and spillage are of major concern in the pit areas, and on the playing field.
Also, the emissions and heat from those engines would make working around them hazardous in a FIRST pit area.

If the robot's for something else...enjoy.