I’ve worked once before on an elevator type robot, having 2 pinions move up a rack, when I noticed that the robot had no way of holding unto the wall! I got frustrated and destroyed it.

Now I wish to create that type of robot again. I’m having some sort of intake, leading to a platform that will move upwards to drop a tennis ball off at a collection area up top, then head back down again.

I am limited to one starter kit, 1 chain and sprocket kit, an advanced gear kit, and 6 extra 25x25 plates along with four 2x2x25 angles.

Also, I may use the chain and sprocket kit as intake, though it would probably only be 1/2 of the total amount of chain that came with the kit.

I don’t really like taking other peoples ideas, but would you be able to maybe start me on the right path?

Thank you,

I believe that you are going for a scissor lift type of device. There are a couple images of scissor lifts in the gallery if you want to take a look. With the parts that you listed, you should be able to come with a scissor lift type device very easily.


P.S. sounds like your making a Bridge Battle type robot

Well, seeing as many FTC competitions have to do with moving things, and IFI’s competition is moving around tennis balls, I thought I’d get used to these kinds of things :smiley:

If my friend and I combine with his previous private school (TMSC/TMA in CT) We’ll have:

5 Starter kits
1 tank tread kit
2 chain and sprocket kits
Lots of metal plates, angles, and chassis parts
9 ultrasonic sensors
1 Sound sensor
8 optical shaft encoders
1 UV candlelight sensor
and much more…

might as well start getting used to competition bots :smiley:

I’m planning to create a Bridge-Battle type bot using only my parts, not mine and my friends/school’s listed above.

I do want it to have an elevator type lift, a scissor lift looks nice but has anyone made a robot like the mammoth except with rack and pinion instead of sprocket and tread? I’m going to buy a tread kit but use it for intake or driving, which is why i want to put my racks to use.

I have:
1: Starter kit
1: Chain and sprocket kit
1: Advanced gear kit
6: Extra 5x15 plates (7 total lost one starter kit one)
4: 2x2x25 angles
1: Set of replacement axles for starter kit (still have starter kit axles though)
1: Set of replacement 12 and 36 tooth gears (still have from starter kit though)
1:Rechargeable battery set

Going to buy:
1: Tank tread kit (definetly)
2: Motors (definetly 1)

What else would you recommend buying for a BB type bot?
Please remember that I do not like bending parts (except for my already bent 5x15 plate) and cutting is a pain (buying a dremel soon but currently use metal saw)

Tank Tread Kit and Motors were the (2) I would recommend. I notice you’ve already got those on your list.


It sounds like you are going after this type of design. I could post another pic of the back if you want me to.

The front intake is probally a little too big for your budget, but you can kind of see the lift comming up to score.

if i order the motors and tank tread I had an idea for my elevator, it would consist of a 5x15 plate with 2 2x2x15 angles on it. There would be a bar lock on each angle with a chain and sprocket attached to it, which would be attached to 2 chain and sprockets attached to a motor or servo. this would create a drawbridge like effect, so I could scoop under tennis balls then use the drawbridge to throw them backwards. the tennis ball would land on a 2 plate elevator, with low-friction wheels motored for intake. Also on the elevator would be a plate on bar locks and a servo. when the elevator is full, it moves up and the bar locked plate closes. You can then steer it to the goal/bridge, and open the bar locked plate to drop out the tennis balls.

in case this is sounding confusing, heres a diagram that will confuse you more:


ignore the periods, they’re just representing air…

the ____o is the bar-locked plate with sprocket and chain,

the /------\ is the elevator

and the two | is the openable/closable door to block the tennis balls from falling while the elevator is lifting.

this 2 motor 1 servo mechanism would be attached to a chassis with tank treads, with either a motor turning a sprocket or turning gears which will turn two sprockets.

now just to get the parts!

Note: Please tell me if you can actually understand the diagram or description, :slight_smile:

Last night I ordered tank treads and the chassis rails that complement my 2x2x25 angles. If I had bought the motor(s) I would’ve also needed collar shafts, which would have drained up all my money.

I find that its easier to make money when you have money, and if i went down to 48 cents I wouldn’t be able to make much more money for vex parts :slight_smile:

:frowning: none of my designs work…

i always run out of keps or collar locks!

and yet i have

1 medium chassis ( and 2 extra 2x2x25 angles)
tank tread kit
chain and sprocket kit
5 extra metal plates(5x15)
advanced gears
battery kit
replacement precut drive shaft bundle
line tracker kit
starter kit

is it possible to build a competition type robot with this stuff- and no extra kep nuts or collar locks? I built the medium chassis with my microcontroller, reciever and battery and only have 6 kep nuts and 8 collar locks :frowning: (yet surprisingly lots of parts left)

should i just build a squarebot size chassis and just use me other parts for the mechanisms (as to save parts)? im really frustrated that im being creatively stumped by something as simple as fasteners :frowning:

this is why i should’ve spent all my money instead of now needing to pay an additional $8 for shipping if i want to order fasteners

has anyone made a competition robot with minimal parts? if so, please link

I think that you are going to have to bite that bullet. Each of these kits is going to cause you want to mount things on shafts/axles. Each time you mount one you are going to use at least one collar…

I always seem to use up way more 1/2" screws, collars and bearings than I expect to use. I also go through the white nylon spacers at an alarming rate.


I run outta metal shafts a lot. you might find some appropritely sized nuts at a hardware store, but you wouldn’t find any collar locks. I would just order them both, as it should cost about the same for shipping either way.

I made a perfect elevator with the parts you listed. You don’t even need some of them (advanced gear kit, chain and sprocket kit, etc.) Keep trying and you will eventually get it. My competition elevator took me a LONG time to finish.

Good luck


Would you mind posting a picture of the back? What kind of a lift does it use? Looks like a really efficient bot – nice work!

It uses the rack gears from the advanced gear kit on a custom made linear slide system. Here’s a link to another pic.

Need opinions:
I’m once again buying more parts. I have $31.76 to spend, and mom is chipping in a max of $30 for my straight A’s. What I know I’m buying is
100 keps nuts- $2.45
10 Delrin Bearings- $4.99
16 Shaft Collars- $10.49
1 Vex Motor- $19.99
Ups Ground Shipping- $7.45

Total: $45.37

This would mean I have $16.39 left to spend. However, the shipping usually goes up to $8.11, which would mean I really have $15.73 of parts to buy.

I was weighing the regular* gear kit** vs. the 25x5 plate***vs. 60-tooth gear pack.
However, I’m open for any suggestion within my price range. What should I get of the above three choices, or should I get something else entirely?

*have the advanced

**I already have an extra replacement pack to 12 and 36 teeth, want more for the 60+80 teeth.

*** I have the medium sized chassis and the 25x5 plates would make mounting my microcontroller and battery etc. easier. otherwise I’d have to use my two extra 2x2x25 angles with 5x15 plates connecting them, which uses fasteners and plate resources.

A quick shoot-from-the-hip answer:

Two parts I “love” are the 35 hole C-Channels that can be cut into smaller lengths if desired (I/we use tons of the stuff); and the White Nylon Spacers.

Mount your microcontroller on 1x25 Bars instead of on the plates.


I’d get some more 84 tooth gears myself.

Thanks for the pic. My son recently built a cup crusher that reminds me of it, except the racks are on the outside. It was originally hoped that it would crush an aluminum can, but we didn’t realize how much force was required – even 60:1 geared down was insufficient. Never thought of using it as an elevator – it’ll be interesting to see how much it can lift. Still working on the step-by-step sequence.

Are you ordering in preparation for a competition bot, or just building for fun?

For a non-specialized application, I always find more gears and greater variety (regular gear pack) a plus. However, to beef up for competition, I find the structural pieces (plates, longer chassis rails) useful. Or if you don’t mind waiting, you could wait until the challenge is released and make your order based on what design you plan to build.

im building a competition-style robot. I’m not actually entering, but I want to have parts to build something that can easily manipulate objects such as tennis balls such as first intaking and then moving to place in a goal.