Boostinjdm's Pilot

[Boostinjdm]

here's an update on the center section for the chaincase.  still looking for help drawing cvs and sprockets. 

[Boostinjdm]

No ooo's or aaawww's or even bashing?  Do I need to post boobies or something to get a response?

[Engineer]

Boobies are always good!


Are the seals going to ride on the cv's?  Which CV's are you planning?  Your looking at double 40 chain?  Have you checked the strength numbers?  Were you planning to bolt a sprocket on each side of the pink piece?  Do you want two chains, or double chain?  There is a difference.  For the double chain the width has to be right on.  They make double sprockets for double chain.  Go take a look at martin..... all the info you need:

http://www.martinsprocket.com/home.htm

it's easy to draw sprockets.  draw a line, polar array for the number of teeth.  offset some lines that represent the chain pitch.  the intersection of your chain pitch and arrayed lines are at the pitch diameter.  Draw a circle there the size of the chain roller.  Now array the circles.  Now look up the sprocket od on martin.  draw a circle that size.  draw some lines tangent to the chain rollers that meet at the od circle.  trim a bunch of shit, erase everything but one tooth, array it for the number of teeth, and bingo you have a sprocket. 

[Engineer]

I finally broke down and just bought a CV.  First decide if your serious about the project, then go spend $50 for a whole halfshaft, and start measuring.  No one makes any info available so you just have to buy the part, then work it into the design.

What I have found anyway.

[Boostinjdm]

Double single.  Two single chains.  I can buy sprockests with that bolt pattern for about $18 each from my karting catalog.  From what I have seen the two #40 chains together have a higher tensile than the one 530 the donor atv used, a little iffy on that. I don't different sources seem to have conflicting info but all say two #40 chains are stronger. yes seal runs on cv, so does bearing.  if I get a cv drawn up I will add it and "assemble"  all the parts.  Half shafts I am looking at have a type 2 inner I believe.  I was going to run that for starters and maybe swap it for a type 4 later. The sprockets bolt through the largest part of the magenta piece.  I am thinking I might add 6 more holes and thread that piece, but then I will have to run a sprocket with a multiple of six tooth count so all the teeth line up correctly.  I am now thinking 12/60 or 12/66 ratio and finding a larger driven pulley to make up for it, or I might drop to a #35 chain, which would be iffy on the power handling.  The bearings also center and tie the whole assembly together.  Maybe I'll draw the sprockets later tonite.  I'm building a staircase now and that's kinda using all my brain power.

[Boostinjdm]

I feel like I'm talking to myself here but here's the whole center section with cv's and sprockets added in assembled form. next thing to do is the case I suppose.

[SPEC]

Boost,
I'm just not following...Maybe I'm thick
Why 2 chians? The added I think is going to be a problem, Plus the maintenance on 2... I understand that if one fails...

[Boostinjdm]

With two chains I can run a smaller size chain which means smaller OD sprocket with the same gear ratio. Plus two chains = higher total tensile strength and in theory longer chain and sprocket life because load is spread over more surface area.

60t #530 pitch dia. = 11.95"
60t #40 pitch dia. = 9.56"
60t #35 pitch dia. = 7.17"

I am trying to get as much reduction in one step as possible without building a huge unit.

[Engineer]

I understand that if one fails...

Then it wads up and your DONE!

[Boostinjdm]

Then it wads up and your DONE!

can't argue with that.

[SPEC]

Gotcha, I never thought about the finer chains getting the gearing where you want it to be :-[

[Engineer]

You might think about gear drive, three gears....  Stronger, and probably more compact.  Jeffco's use gears.  I saw a picture of the inside once, and they are really simple, plus the gears can be smaller at the same ratio.

[Boostinjdm]

Gears would be prefered if I could find some that are off the shelf and strong enough, not to mention cheap.  That's a tall order, any Ideas on how to fill it?

[Carlriddle]

Gears would be prefered if I could find some that are off the shelf and strong enough, not to mention cheap.  That's a tall order, any Ideas on how to fill it?

Cant use those three in same sentence.  Very narrow rear.  I'm watching this one.

[Boostinjdm]

Cant use those three in same sentence. 

That's why I chose chain drive....If I wanted to spend that kind of money I would just buy a rpm box.  I just like to build shit, it's more about the process than the finished product.