Skyway 4WD Help
 

How should our team buy an axle for the Skyway wheels?

We also need another set of sprockets. (Is IFI the only place to get these?)

Where can we get these?

Re: Skyway 4WD Help
 

Depends what kind of wheel you're using.

If it's got bearings in it, and you're driving the wheel, not the shaft, you can use any standard shaft (The most common is 3/8" I believe)

If you're driving the shaft and not the wheel (ie: the hub is keyed) you need a keyed shaft of that size

Either kind can be found at www.mcmaster.com

P.S. I'm moving this to the technical forum.

Re: Skyway 4WD Help
 

Places like mcmaster or msc would be great places to get more sprockets. You can access their websites at: http://www.mcmaster.com and http://www.mscdirect.com . You can also get more shaft from them as well.

Re: Skyway 4WD Help
 

Be careful what advice you're giving people. Those kit sprockets have been custom bored. If you buy standard sprockets from a source other than IFI, then you will need to have them pressed onto the shaft.
See THIS.

Re: Skyway 4WD Help
 

You can use a bolt if you are putting it together like the kit does, at least that is what the instructions said if I read them correctly. We will be using bolts for our wheels as soon as we get them.

Re: Skyway 4WD Help
 

I'm so sorry, but I have found the section in the rules about the axles.

We still need help with the sprocket issue, thought.

Re: Skyway 4WD Help
 

a 4 sprocket set (2 big ones for the skyway wheels provided[28 tooth], and two smaller ones for the gearbox output shaft[20 tooth]) ARE available at IFI robotics they come as a PACKAGE and are ~80$ ($@#$@#$@#$@#....)

btw what was it about the shafts that you found in the rules?

Re: Skyway 4WD Help
 

In the Tips and Guidlines, they said that a ceartian type of bolt makes a good axle.

Re: Skyway 4WD Help
 

wich bolt is that? we cant find that part and we gotta order our...
Thanks

Re: Skyway 4WD Help
 

Any 3/8" diameter shoulder bolt with a shoulder the width of the wheel well should work fine.

Re: Skyway 4WD Help
 

Any 3/8" dia bolt will work.

I recommend: Part No. 91236A644
From www.mcmaster.com
But any equivalent part will work.

JV

Re: Skyway 4WD Help
 

The only bad thing about those sets are that you can't just get the sprockets for the wheels. Our team needs to buy 8 more to get our 6WD working and we are going to need to buy 4 sets at 80 bucks, that is not fun. We are currently trying to trade for them, otherwise, we are going to get them made. We hope to be able to get them for less than 40 bucks a piece

Re: Skyway 4WD Help
 

You may now buy individual sprockets from IFI.
http://www.ifirobotics.com/kitbot.shtml

Re: Skyway 4WD Help
 

Oh, Thanks. On monday our team called IFI and they said that they were not planning on offering individual sprockets anytime soon.

Thanks So much

Re: Skyway 4WD Help
 

the 3/8 bolt is to small for the bearings
the wheels end up being very wobbly

Re: Skyway 4WD Help
 

For the sake of accuracy, IFI is now selling individual kit sprockets.

Re: Skyway 4WD Help
 

our team is used 4 long bolt as a shaft, it fit nicly :)

Re: Skyway 4WD Help
 

Ya, but get it 5 in. long The chasis was made to fit that size bolt just right.

Re: Skyway 4WD Help
 

what about putting the axle onto the chassis? Do they sell a piece like the one diagramed (attached - sorry im not a good drawler)? Have you seen something like that before that we could buy instead of having to machine ourselves - we have limited resources?

Sorry if this was asked before.

Thanks.

Re: Skyway 4WD Help
 

That's called a pillow block. Search on MSC, McMaster, sdp-si, etc for them. They're easy to find, the trick is getting some that don't weigh 10 lbs.

Re: Skyway 4WD Help
 

Go to page 1027 on http://www.mcmaster.com (just type the page in the search box). Scroll down a bit and you will see stamped base mount ball bearings. The are lighter than their cast iron coutnerparts. Also, pillow blocks are sometimes referred to as "mounted bearings"

Re: Skyway 4WD Help
 

AWESOME!!! Thanks for your help!!!

Is there any difference between the shaft sizes, because the 1/2", 5/8", 3/4" shaft sizes each say they support the 3/8" axles (bolts) we bought.

In addition, can we use the polyester (with delrin raceway) base-mount bearings instead of the steel ones? I would think it would be lighter, however under the circumstances, is the increased price X3 worth the added benefit?

ALSO - if we were to use 1/2" axles/bolts (our two front wheels are andymark omnidirectional wheels) would the same "pillow block" work for it? Should we get a different size? I ask this because the steel section doesn't say it supports a bolt hole size of 1/2", only stainless steel has a 1/2" bolt hole size option at 5x price though.

One other thing - say you needed 8 of these (2 for each wheel, right) are we talking a lot of weight here? If they were 10 pounds each that would be 80 pounds!!!

Any help answering these rookie questions would be greatly appreciated.