Cat Road Grader

[doc222]

Since this project is more Technic for now. It could use nxt but in the end it would be just R/c too. Even X2 started out P/F Technic but it has a need for robotic control, just way to hard to drive a Biped. So since Grader may be in the end just a technic model I hope here in the "open" forum is good.

One place that has always been a great source of insperation for Lego and AFOL's is the construction industry. Having spent a great deal of my life in that field. Things like Cranes and very large equipment are a site too see up close and feel, they shake the ground.

One thing I found right away a Grader is rather complicated for such a simple idea. Some features they have I left out do to this complexity in Lego( well for now anayway), one thing was the ability to change the canter of the front wheels. Mock ups of all the other mechanicals and then figuring how to intergrate them and these thing have alot of things going on. trying to keep it in a scale that works to the eye becomes an issue too. Height to lenght and width; all need to fit the mechanicals as well wth out taking away from the later.

I'm a long time from finished here but have come along well in the last few months, laking parts as well, sice this is a side project. It also has a nother new project that in its self is a project as well. My new 60 degree V design Lego Pneumatic Engine(LPE). There are many LPE's out there they are all 90 degree V's. The trouble with any V motor is how wide they are a LPE V 90 degree is about 13 studds wide just to the across top of the pneumatic ram's. My 60 degree is 9. So it fits in the modles much better and more to a Lego scale. Really though in the end a straight 4 or less work even better, but have less coolness. This is work in progress.

Right now the Grader has a 60 degree V-4 LPE. working rpm 0-1000rpm
6x6 drive
front stearing
blade moves up and down from both sides so you can viticaly angle the grade. blade turns to adjust blade rotation.
Rear rake that goes up and down.
The blade and the rake can lift the Grader off the ground as well so they are powerfull, pluss it makes it so you do not need a jack to lift for a flat tire

What they look like;

I would like mine to have that side blade too.









Just a few secret pics of progress:)

Doc

[nxtreme]

Wow, very cool! It looks quite well made by my standards, but knowing you, it will end up looking even better later on! I'm surprised you were able to fit that many features into a Lego model... especially that LPE. Would I be right in assuming that it has more torque than any motor made by Lego? How do you supply enough air to keep the LPE going? All in all, very impressive!

[doc222]

LPE's use alot of air. Depending on how many cylinders and if they are moded. Most can run well from 0-30(max)psi to well if you dare 90psi(DO NOT TRY THIS at HOME) before things get wierd. But in Multi cylinders to get flow you need to watch how you split the air lines. So any LPE to run in a model you will need a air compressor used in a garage that can supply at least a few cubic feet per minute to run well. It will drag the air line(old school) that runs to my big air tank in the garage that can supply 6cfm @ 90psi. You must feed these motors oil too or they can and will melt, so pre running means Oil the axles and feed some down the air line this keep the Lego switches from melting and the rams. Think about how many times those little switches are going back and forthat 1200rpm or say like those straight 4"s that can do 5000rpm before checking out into the great Lego in the sky:) A switch must open and close two times per revolution, these babys are flying to say the least.

Done right these Lpe's are monster in power and rather hard to handle in a model. To much air at the start and you can turn a axle into a pretzel, break gears, you know a #12 axle can twist so many times that it looks like a twizzler. I have a few I left in the axle box and once in while I grab it thinking its a good one till I try to feed a gear on it. Oh and they do not seem to return to shape. I have tossed the rubber off rims in a little 4 banger before, it needed the rubber glued to the rim or the rim would slip at the start.

But the grader is geared WAy way did i say way yep SLOW, right now 24:1 wont know if thats the right # need to start it first and the motor would need to removed a pre timed, oiled and ran out of the model. It needs new hoses too the they have to be hand tied at each connection with fishing line so it can handle say 60 psi. I can not wait to hear what a 60 dgree V4 sounds like. each kind of motor has very special sound they make running.

Regards

Doc

[nxtreme]

Wow, sounds like they have power! If I ever try to build a Lego airplane (yeah, I know, highly unlikely it'll every fly...) I'll be sure to use an LPE. High RPM and torque would fit the aircraft engine needs just fine. Good luck on the grader, looking forward to seeing it plow through some Lego bricks !

[doc222]

A bit of topic but, There is a few guys that are working on lift with the new blades from the Wind power add on at Lego ed. From what I have read they hoped these new blades with buggy might get some lift. From what I read it did not work, I think those blades have the wrong pitch for a motor, great for "catching wind", but to much "bite" for a high speed prop. Pluss Lego is very heavy for such things, best bet is to go the "lighter than air ships" a Zep. I have always wanted to build one too.. AHHH so many ideas so little time.

When they did the test they lacked some of the things I would have liked to known
1 what was the rpm reached with blades.
2 we know it did not lift off but how much lighter was it? How much lift was gained. How much more lift is needed to the weight it was?
At least then we would know how close they were to getting to lift off. But even if it did lift there is no way to control it, but hey to be first in flight with Lego even if it crashes and burns it would still be a first in my book.



Doc