Cutting Pieces?

[robohippo]

I am interested at getting a vex kit for myself for prototyping all kinds of moving robots and other assorted fun tasks. I've had quite a bit of experience from lego mindstorms and am slightly scared of the prospect of permanently altering pieces (cutting) Is there a standard length that you experienced users use when cutting down pieces for building many iterations of robots while on a budget.
Thanks
Mike

[Arefin Bari]

Tell you the truth Mike, I cut my pieces the way I want to. Whenever I design a robot, I make the pieces for that robot. Later, when I am building another one, those pieces come into use sometime. I also have an Edubot kit which helps me a lot (hardware wise). I use those pieces with my vex kit. If you think you can afford it, it would be good to buy the hardware kit. I also have small kits including, omni wheel kit, chain and sprocket kit (thanks to Neha), gear kit. You can do a lot with vex. Don't limit yourself when you are building. Good luck.

... I would like to see a post by Art in this thread to see how he manages his pieces.

[artdutra04]

Originally Posted by Arefin Bari

... I would like to see a post by Art in this thread to see how he manages his pieces.

I try to make my robot designs use pieces that I can use over and over again. Sometimes this isn't always possible, but most of the time I just try out mounting something differently to either use less metal, or to cut it to a "standard" length. I also try to avoid bending the metal parts too much, because if they are bent to less than 45° or so degrees, you can usually hammer the piece flat again if needed.

I would consider a "standard" length to be any of the places on the 90° Angle pieces or the C-Channel that has those grooves in it where you should cut it. As for the bar stock of the plating, I try to minimize the amount needed. You can cut the plates into thinner strips if needed. If you need to cut a small bracket that does not need to be strong, try to cut it out of the plate. If the part needs to be strong, or is longer than 5 holes, cut it out of the 1x bar stock. Choosing whether to cut something out of the 1x bars or out of a plate can really help you use less parts. (Otherwise, you would run out of the 1x bars quickly)

When you try to use the parts in a more efficient manner, you usually end up with a better end result. Your robot will usually become simpler and perform better. (When I build a Vex robot, I also like to also take aesthetics into account. If I don't like the way something looks (eg. if it looks cluttered, slapdash, etc.) I will usually try to find a better design. I like it when a robot visually looks 'sturdy' and 'well-designed', since this is normally what the actual performance would be as well.)

Also, if you begin to accumulate a collection of Vex parts, after a while, you will need to purchase less and less parts. By that time, you will usually have a piece that is just the right size for what you want.

Here is a picture of the sorting compartment tray that I use to store most of my small Vex parts. (I use the Vex Starter Kit box to store all the wheels, tank treads, etc. and a bunch of the new hardware I just bought from VexLabs, since they won't fit in this tray.)



These are all the small parts (except for the VexLabs stuff I bought) that I have left over from building the mini Triple Play and Holonomic Drive robots.

[robohippo]

Cool, so there are grooves on the pieces. Thanks. I was looking into the hardware kit as well.

[sanddrag]

As long as it's not for competition, there's always the option of buying raw materials and drilling the holes yourself.

[JVN]

Originally Posted by sanddrag

As long as it's not for competition, there's always the option of buying raw materials and drilling the holes yourself.

The Vex parts (like the EDU parts before them) all utilize a square hole grid. These square holes are what permit the Vex system to maintain good allignment of certain parts after they are installed (bearings, motors, etc...). Take a close look at how a Vex plastic bearing block installs into a piece of Vex metal, it is a pretty clever and simple solution. (I'm not just saying that because my boss designed it.)

Originally Posted by robohippo

I am slightly scared of the prospect of permanently altering pieces.

The Vex metal is designed to be a consumable resources. Though all designers try to minimize this (who isn't on a budget?) the true versatility of the Vex kit comes when you cut and bend custom brackets out of the raw-stock given.

Having said that...
I usually use the same construction techniques, and size pieces on most of the robots I build. I'm sure if you do some careful planning, you can get away with minimizing your "loss".

For some cheap replacement piece-parts, you should try www.vexlabs.com this way, you don't need to pay the full $80 for a Vex metal kit if all you need is a few $1.50 BAR-25 pieces.

Good Luck,
John

[gdo]

robohippo,
something that should help you with the regular metal (not the axles). Due to the density, thinness of the metal, and the way it was made, it is thin enough to cut with tin snips. You might need a coach to help as tin snips can require a good amount of force to cut. It is faster than cutting with a hacksaw, and will allow you to cut on parts where there are no groove, and on groove. Just be careful if you cut in a place where you lose structure integrity then you will have a problem in designing. Just remember "measure twice, cut once" and you should do just fine. Best of luck to you, can wait to see what you come up with. Any questions PM me here

bonne chance (best of luck)
~gdo

EDIT: robohippo, listen to JVN about how consumable the parts are, vex labs is the best place to get piece as you can get them in any quantity. they also carry the vex parts from radio shack and are fvc legal (except pneumatics)

[robohippo]

But wouldnt tin snips bend the edges where they cut? I imagine a hack saw would make a cleaner cut, unless you need a certain size tin snip.

[petek]

Originally Posted by robohippo

But wouldnt tin snips bend the edges where they cut? I imagine a hack saw would make a cleaner cut, unless you need a certain size tin snip.

Vex metal is thin enough to cut with snips - though dull ones will probably bend the edges alot! I used snips and dressed the edges with a file. YMMV

[Francis-134]

From my experience, tin snips do work, and they do cut the Vex pieces very well. However, you must be careful as they often make very sharp edges. Hack saws work very well and only require a little bit of filing to make them nice. Personally, I find that vices work better than your younger brother holding the piece on a tray-table in the basement. However, if you have access to a band saw by all means use it and use it often. This seems to be the Cadillac of cutting tools when it comes to Vex/Robovation.

As far as cutting pieces, you may want to chop a couple of the 15" angle pieces on the little notches just so you have some more pieces to play with.

[jeffmorris]

I have bandsaw, drill press, and belt/disk sander that I use to cut and drill metal pieces. When cutting metal pieces on the bandsaw, have the blade cut the metal pieces like this: L | where the "L" is the metal piece and the "|" is the blade. After cutting one side of the metal piece, rotate the metal piece to cut the other side like this: _| | where "_|" is the metal piece and "|" is the blade. A cut-off wheel in a Dremel tool is good for cutting axles.