I’ve been using a few Erector parts with my VEX and the measurements for the holes are exact. 
Weaker metal though, so, just use it for light, non-competition stuff. 
Okay… HIT THOSE GARAGE SALES! 
What??? couldn’t be that many parts!
hey, about 7 years ago i got an erector set, and now i am able to use it again with vex. but the metal is really alot weaker than VEX metal:(
how much does a normal sheet of steel bend of thickness?
ya garage sales are a great place to get erecter set parts.
I mostly use the little pieces:) .
Erector Sets like Vex are great! for making robots. Antique Gilbert and Meccano Erector Sets also have metal gears and a myriad of parts that can be adapted to work with Vex. The round holes match the Vex squares and the gears are easily adapted by bolting the Erector Set gears with holes to the Vex plastic gears. The Erector Set gears are made of bronze or steel alloy and are much stronger than the Vex Plastic gears. Now you have the choice of square shafts vs. round shafts. These Erector Sets may be found at your local antique stores, on E-Bay or even rusting in a friend’s basement. Check out my Erector Set and Vex based Robots featured in the ROBOT Magazine article.
http://www.botmag.com/articles/bionic_stamp.shtml
I found out that Erector/Meccano parts are usually compatible with VEX Robotics parts. I found my Meccano set in a blue plastic box yesterday. It was made in France, has seven printed manuals, and has screws with Allen key heads. Some Lego Technic parts are compatible with VEX Robotics parts.
I have made adapters that connect Vex motors with Erector Set metal gears and pulleys. Erector Set metal parts can be strengthened by stacking them together. This technique also works with Vex metal parts, when strong parts are needed for supporting heavy loads as in my Bionic Arm lifting a five pound weight (as seen in the Vex Gallery). For this application I had to stack two of the Vex plastic gears together.
I made adapters that allow me to use VEX motors and servos on projects built using Lego building sets.
That’s neat!
I think that it is more fun to build something that is kind of ‘hob-cobbled’ together, than building a robot out of their kit.
Been a while since I have heard “hob-cobbled”…
I think that Vex Labs would agree, since they only show you how to Build ONE robot in the Vex Inventor’s Guide, and that ONE robot does not use all the parts in the kit… Also there is lots of explanation on how Gear Ratios work and so forth, so you can ‘hob-cobble’ something together with the other pieces…
lol, hop-cobble, is that even a real term? and are you guys talking about the lynxmotion erector set (www.lynxmotion.com)
we can use an erector set with the robot???
NOT for First competitions!!!
For general experimenting Gilbert and Meccano Erector Sets have the same spacing, so you can use the metal pieces with the Vex Kit.
It has been 30 years since I worked with a Gilbert Erector Set, but I agree that the metal on that set is much thinner than the Vex metal.
I have been using erector sets for fun with vex, but there are some problems such as mounting motors to erector pieces.
Way cool!!!