Chain Drive rear spool

[Rick S.]

If someone could provide actual dimensioned drawings of the splined shafts it would be no problem. I'd also need to know the dimension from the spline shoulder to the case.
The inside chain needs to run very close to the case.   

[Rick S.]

Almost done with the 52T dual sprockets.
I only need to pilot the center bore and c'sink or c'bore for the mtg. bolts.
I'd like to c'sink, but we haven't been able to find M10x1.25 pitch flat head soc. cap screws. Anyone know where to get these?

[Doug Heim]

I have flat head M10 X 1.25

Youll shit if i told you how much they are....

I use 6 on the PIRCV center hub. The plans call for M10 X 1.5 but I hate that thread. Not very strong IMO. I like Fine threads. They torque down better and you have more thread contact. Some people believe that Fine threads are easier to strip out. Not the case in my experience and knowledge.

Oh there $5 ea.!
So Rick want some? How long you need them?

[Rick S.]

I may want 8 of them. I'll have to check with the future owner of these sprockets. I can just barely get the SHCS's c'bore deep enough without blowing out into the sprocket's pilot bore. The FHSCS would really be the way to go. These would need to be 1" long.

[Boostinjdm]

why do they have to be countersunk?

[Reidy02]

I'm guessing so they don't hit anything!

[Rick S.]

The sprocket runs very close to the pillow block. Even with c'sunk SHCS the heads will have to be skimed down.

[avendlerdp]

Well Rick, those are going to be the nicest parts my crap can race-car has ever seen!  Really nice work. 

I can't wait to have a chain drive system that does not require hourly adjustment and maintenance.

[SPEC]

 
The plot thickens
 

[Doug Heim]

What the heck. I posted on here since my last and I dont see it. Ahh anyway. Mainly it was that the flat heads also offer more surface contact of the bolt head. The PIRCV center drive uses this method and I think it is the way to go wether you needed the flat heads for clearance or not.

[Rick S.]

Not only do they offer more surface contact area, but they positively locate. Similar to a dowel. With eight M10 flat heads the sprocket isn't going anywhere.

[Doug Heim]

Rick Ill check with my supplier tomorrow and get back to you.

[Boostinjdm]

Not only do they offer more surface contact area, but they positively locate. Similar to a dowel. With eight M10 flat heads the sprocket isn't going anywhere.

In theory yes.  At work we used them a lot to attach hardened wear plates in the balers and shears and I would say that 99% of them didn't have the head centered on the threads.  you could watch the head woble down into the hole as they were snugged down.  Try sticking one in the lathe and take a look.

[Boostinjdm]

I looked and looked last night and I couldn't find a source for your bolts.  That pitch is hard to find...  could you counter bore button heads maybe?  I couldn't find any of them in that pitch either, but it was a thought.  Or a regular old hex head cut down?

[Rick S.]

I have noticed how some seem to wobble down, but I've never had a head pop off.
The fine thread button heads may be just as hard to come by. But they would work if you can find them. I'm going to have our purchasing dept. check into the flat heads tomorrow. If they can't find them then we'll order from you Doug.
Can you get the 25mm length?