Casting Aluminium (not aluminum, you yanks just cant spell gooder!!!!)

[fabr]

Fanx??? Yeah clever,cheap,lazy whatever.






































I'd do the same.

[artie on edge]

Im stoopid.    :'(

TWO FREAKIN DAYS!!!

To take a solid piece of 150mm bar and turn it into two bearing carriers.

that was all I did over the weekend. Nothing else.

Why didnt I use hollow bar? Had the solid stuff on hand, thats why im stoopid.   

Why didnt I use aluminium? I will next time (this is really "proof of concept" model, the final unit is next).

To top it off, I tapped that threads before making the last cut ( A chamfer to aid chain clearance when I snapped off the tap in the last 5 mm of the last thread.
So, stoopid AND pissed off.

At that point I threw my hands into the air and went home broken tap still in thread. You can see it in the first pic, hole closest to the unit.

I must say though that it was a truly satisfying experience to get it together.. Up until now all this has all been theory. Calculations.

In the design phase, I calculated that the carrier would have 3mm clearance to the sprocket. assembled I can now actually measure it and its got....... 3mm!

Before anyone asks, the groove outside the bolt holes is the o ring groove. This is oil filled and this is how it will be sealed. Same at the top shaft and the holes will be slotted for chain adjustment.

A couple of weeks off from the project now. So no more real progress until I get back into it.

By the way. I rolled my barracuda on the weekend. Not too much damage, just a broken mirror... blooody thing fell off the saw horses..damn didn that ring like a bell!

Until next time....

[fabr]

Any updates on this project?

[artie on edge]

Yes and no. Project moving ahead and almsot finished, time to think about manufacturing the suspension arms...

Yeah my pace might not be to everyones taste but it is my pace... like  alot of guys here I have a business to run as well as play in the shed. Over the last few weeks I havent had much leisure time to spare.... chissy time, social etc ..... oh my liver is sore.....

[artie on edge]

I'll check into it. I've always been led to believe that it was pretty reasonable.
We're constantly having new shapes made. Some of this R & D just ends up being scrap.
I work in design, not estimating. I really have no idea.

Yo Rick, any more on the cost of extruding this stuff?

[Boostinjdm]

Can I make a suggestion?  Your chaincase is exactly what I had going in my head with one exception.  if you would make the bearing carriers eccentric for chain tensioning then I could accuse you of copying my idea.   You would then have to add timing marks so you could clock them the same.  When Master was talking about flange width the other day the sandwiching the sprocket idea came to me, now I see you have already done it.  I'm dissapointed and excited at the same time.  what size chain are you running and how much power you plan on feeding through it?  I'm thinking this would work in my pilot frame with a polaris 400 in front of it.  good info!

[Boostinjdm]

are you going to run seals on the outside of the cv flanges or depend on the bearing seals to keep the oil in?

[artie on edge]

Hi Boostinjdm, if you have a look at the bearing housing you will see a groove outside of the bolts, this is the o ring groove. I have also removed the inner seal to allow it access to the oil in the unit. These bearings have been known to suffer from lack of lubricant, more is better (apparently).

Chain adjustement is easy, I calculated the ration of sprocket movement to linear chain tension movement and the sprocket doesnt have to move far to allow a goodly amount of slack take up, therefore I am using slightly elongated upper bearing housing holes and we will see how this goes. If more is require then I can eccentric or whatever is required

I dont know if we use the same ratings here in Oz as you guys but the chain is rated 10B and is a size or so higher than 520 as is used standard on the rear end of most of our buggies. Also the sprockets are flame hardened (heat treated). Chain is a high tensile (load) rated unit, naturally not o ringed.

The power plant is a std GSXR 1300 (busa)



Finished carrier

[Boostinjdm]

so does that o ring run against the cv flange then? 
My only concern with elongated holes is whether the bolts will have enough clamping force to keep the carrier from moving when under power.

[artie on edge]

the o ring runs against the side plate (wider than the cv flange), there wont be any movement of the (slightly) elongated bolt holes, if this is an issue an external plate can be fixed to the bolt pattern which can but against a threaded rod (bolt n lock nut) end which can take the load.

But I really dont expect this to be an issue (but as you can see, I had given it some thought as well).

The hole in the side plate will be a neat fit over the cv flange and just have enough lip to cover the outside edge of the bearing. This isnt required as a bearing retainer though as the design of the carriers retains the bearings.

Mate, thank you though for raising the issue as while I have given this great thought there are things I havent considered and your comments are valid and welcome, please keep it up!

[Boostinjdm]

I really like this type of box.  it seems simple and should be reliable.  Yours is going to be a forward only box, correct?  I was thinking this could easily be made out of plate.  I remember seeing alum plate up to 2" thick at the scrapyard where I worked.  Now if I just had access to some cnc equipment...
Is this a one off for personal use, or a prototype for production?  I wonder what a price tag would be for this type of unit assuming access to cnc equipment.  I bet it would be affordable.  Adding power? Just up the size of the chain and you'd be set.  Hmmmm.....

[Boostinjdm]

some type of cush drive in the center would be neat too. would make it a little wider though.

[artie on edge]

yes forward only and keeping it simple was the primary objective. This unit is 60mm thick (smallest I could get it down to which is about 2.5" (approx). I dont have access to cnc gear and I do own a foundry, to me it was simple....

I wanted to lower the cv line in relation to the rear suspension mount points compared to a 60t rear sprocket which requires a fair amount of cv angle before the suspension starts to compress. While the opposite is true when the suspension is at full droop, we dont spend much time there compared to full or partial compression.

This is for personal use but is a prototype and once it has been proven the final version will be produced.

Costing is interesting. I could produce this unit for $1200 australian which is about $700 USD so it isnt one of those out of the reach units (thats with a profit margin). Would I produce these for sale? Only after I have proven the unit on the track. Perhaps.

Its destined for a race car not a sunday play toy so it will be hammered and should it survive this (im confident), it should be able to take most anything.

I have seen another unit made by a member using morse chain and the chain and sprockets cost him around $1200 USD (his figures) let alone the rest of the project (he used a billet housing as well). So I am more than satisfied that this has met my objectives (so far).

Yes the power issue is not some thing I have given a lot of thought to. Mine was made for a specific situation (busa in a microlight race car) so upping the power wasnt a consideration at planning time. But I do see your point, could easily be catered for.

[artie on edge]

yes, it could b incorporated easily. I had width limitations (class rules) so I had to get this as slim as possible...

Also, as stated, this was for out and out racing use. Cush drives werent even considered at any time....

IS now though....mmmmm

[SPEC]

Wow
Thats a effen great write up Artie
And if you can produce them for 700 bux for a busa in a light car that would solve alot of guys problems...But make a new one for your leisure time