RC Crawler Glossary of Terms

[xwingman]

Thanks again crawler vets, I made sure I copied and pasted all the glossary of terms and added others and the FAQ as I made my own word.doc and printed it out. Its now my bible.

[Trubble]

Originally Posted by RMack

Can anybody point me towards some more info on OD/UD gears.

OD front means the front axle is 'overdriven' through the use of a smaller ring gear and/or a larger (axle) pinion.

UD rear means the rear axle is being 'underdriven' through the use of a larger ring gear and/or a smaller (axle) pinion.

You'd use this as sort of a pseudo dig. The rear wheels would be going slower and dragging behind and the fronts would be going hell bound for leather. Once you turn the front wheels, they'll really pull your front end in the direction of steer.

[Charlie-III]

Originally Posted by Trubble

OD front means the front axle is 'overdriven' through the use of a smaller ring gear and/or a larger (axle) pinion.

UD rear means the rear axle is being 'underdriven' through the use of a larger ring gear and/or a smaller (axle) pinion.

You'd use this as sort of a pseudo dig. The rear wheels would be going slower and dragging behind and the fronts would be going hell bound for leather. Once you turn the front wheels, they'll really pull your front end in the direction of steer.

Good reply, a little adder though...

The terms UD or OD are usually relating to a shaftie where there is a single motor, not dual motors like a XR-10 comp rig. Since there is only one motor, doing a UD or OD mod allows a bit of speed differential between the front & rear axles.
For a minor change do one axle and leave the other stock.
For a bigger change do a OD on the front and a UD on the rear.

[Blkout]

Great thread guys, here's one from a noob. What sort of tire/foam combination would be a good starting point for mild/medium trail crawling? Thanks.

[jeepgeek2002]

i found this site this morning look for radios.. it has a very detailed glossary list.( not sure if was mentioned before)
RC Glossary - A - Bonehead RC

[supermoturd]

So I have one that does not appear to be covered here. It took me a while to figure it out. SIDE HILLING: driving along a path that is transverse to the grade. That is, driving across the side of a sloped or incline instead of up or down it.

[gotmike]

still never saw a post explaining the # of turns to a motor... I.E. a 10 turn motor vs. an 80 turn motor...

[Trubble]

Originally Posted by gotmike

still never saw a post explaining the # of turns to a motor... I.E. a 10 turn motor vs. an 80 turn motor...

I guess I'm not understanding why you'd expect (what is essentially) a dictionary of sorts, to carry such a discussion. I could see coming in here to find out what turns (winds) are, and what an armature is, but the comparison discussions would likely be elsewhere.

Go over to the Electronics section, upper right corner click 'Search this Forum', enter " turns,winds " in the box, and it'll give you a variety of threads more pertinent to what you're looking for.

*THIS*..... what you were hoping to find?

[Phred]

OK, I tried the search, read this whole glossary thread. Tried the link to bonehead RC (dead link). I am constantly seeing references to BUMPSTEER. Can someone please explain that. My first guess was that it meant the steering was kind of sudden, with no real control, IE: A slight turn of the wheel resulted in full right or full left movement of the wheels. My next thought was that it meant the vehicle changed direction with every bump in the road, which they will depending on speed and how the bump is hit, but this makes no sense to me when it comes to discussions involving where the steering servo is mounted, and whether there is a single bellcrank or dual bell cranks, so I'm guessing my first thought was closer, but probably not exact.

[Olle P]

What's SuDu?

[douwe]

Originally Posted by Olle P

What's SuDu?

Sudu is a line of chassis made by ncd
Name Sudu stands for Suomi Dutch. As the chassis is designed by Tomi and me. Tomi is from Finland (Suomi) and I'm from the Netherlands.

Verstuurd vanaf mijn D6503 met Tapatalk

[Trubble]

Originally Posted by Phred

I am constantly seeing references to BUMPSTEER. Can someone please explain that. My first guess was that it meant the steering was kind of sudden, with no real control, IE: A slight turn of the wheel resulted in full right or full left movement of the wheels.

no.

Originally Posted by Phred

My next thought was that it meant the vehicle changed direction with every bump in the road, which they will depending on speed and how the bump is hit, but this makes no sense to me when it comes to discussions involving where the steering servo is mounted, and whether there is a single bellcrank or dual bell cranks,

On this board, bump-steer is usually brought up when discussing chassis mounted steering servos.
When the steering servo is mounted right on the axle (say on an SCX), the front suspension can cycle up and down, articulate, whatever, and the servo and steering knuckles will always be in the same spot "relative to each other". So no change in steering as the suspension cycles.
With a chassis mounted servo, as the suspension cycles up and down relative to the chassis, the distance from the servo to the steering knuckles will change. Since the steering linkage can't magically lengthen and shorten, the knuckles will get pulled out of straight-ahead position.
Try this. Take a baseball bat (or similar) and set the end on the floor next to a wall. set the handle against the wall so the shaft in use is at roughly 45° or so, (doesn't have to be exact, so don't even measure). Now, the handle represents the steering linkage at the chassis mounted servo, and the end on the floor is the steering knuckle attachment point. Since it's impractical to move the floor up, (representing the axle moving closer to the chassis), instead move the handle of the bat down the wall (representing 'pushing down' on the chassis). Notice how the wall is still in the same place (representing the axle moving straight up and down due to 3-link or 4-link suspension rods). However the tip of the bat is now a LOT farther away from the wall. In practice this would be the steering rod pushing the knuckle away from straight-ahead and the truck would steer, just by hitting a bump. Bump-steer.
To combat this, you'd need to reconfigure your suspension links so the axle can move laterally (side-to-side, vff). Then you'd hook a link from the chassis (near the servo) to the axle (near the knuckle), and the axle would then swing on a radius much closer to what the steering link is traveling. This lessens it, but doesn't completely fix it.
On buggies, truggies, and other vehicles with IFS and bellcranks, since the IFS links allow the knuckle to travel on one arc, but the arc from the steering cranks (or rack) to the knuckles is different, you get right back to bump-steer. Putting a single bellcrank in the middle gives you longer rods from the crank to the knuckle, so the arc is a little gentler, but it's still near impossible to escape.

[Phred]

Trubble-
Thanks, I understand it now.

[jeepersjustin]

This was super helpful for a newb. Thank you


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[xKILLROYx]

Tried Binging this term: Panhard - but it just comes up with a French Vehicle Manufacturer...

I see it alot in the SCX10 threads, just curious

TIA

[JDIRCC]

Originally Posted by xKILLROYx

Tried Binging this term: Panhard - but it just comes up with a French Vehicle Manufacturer...

I see it alot in the SCX10 threads, just curious

TIA

A pahard bar is a link that is used on a 3-link setup when you have a cms ( chassis mounted servo). It helps eliminate bump steer with the cms. It mounts on top of the axle and to the chassis. it is normally mounted close to the right axle c or c hub and connects to.thenleft, side of the chassis. They also use them in 1:1 crawling on 3-link setups as well.

[adamargue]

Originally Posted by xKILLROYx

Tried Binging this term: Panhard - but it just comes up with a French Vehicle Manufacturer...

I see it alot in the SCX10 threads, just curious

TIA

If you search 3link with panhard it should come up with some pictures of it.

[xKILLROYx]

Thank you, gentlemen!

[dlgone]

Great Thread, really clears some things up!

[Olle P]

What's the definition of and use for "Beef Tubes"?

There are many for sale but I can't figure out what it is and why I (perhaps) should want some. It's neither a tube made of beef nor tube to be used with beef. That much I have figured out...