pic: Custom Machined Aluminum #25 Sprocket
 

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Looks nice... These were in the drive I assume.

How long did it take to machine? How many set ups? (I'm assuming one on a CNC mill and one on a waterjet/lathe)

do you know if the amount of weight saved (how much did it save?) was worth the extra time?

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Machining time was a little over an hour. 1 setup on the mill. Holes were tapped by hand afterwards. Slight tooth chamfer was done on the lathe afterwards.

Was it worth the time? Probably not, but they do look nice.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Did you cut the teeth on the mill as well?

If so, what diamater cutter was used?

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Are those radiused areas in the center contoured?

Or do they just happen to be the same radius as a ball endmill you ran through there?

Those are some sick sprockets.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Woah. I don't think I've seen a sprocket that sexy since one of 233's huge pink ones.... This one is just elegant though! It makes me wish more and more that my team had a CNC...

Nice job!

Re: pic: Custom Machined Aluminum #25 Sprocket
 

two words: SICK NASTY!

190 had AL drive sprockets (31 teeth, I don't know why they HAD to be 31 teeth), but they were no where near as sexy as that beast...nicely done

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Pretty snazzy!

Form does indeed follow functionality.:D

Re: pic: Custom Machined Aluminum #25 Sprocket
 

What feedrate did you cut it at? That's a lot of material to remove just to avoid using spacers. But it does look quite nice.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

TyTown those sprockets are absolutely ridiculous, I want one :yikes:

Re: pic: Custom Machined Aluminum #25 Sprocket
 

as Borat would say "Very Nice"

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Wow.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

It wouldn't take much to cover the teeth and powder coat it for an genuine look either. Very nicely conceived, though I'm curious as to what a F.E. Analysis on it looks like. It looks at first glance as though the dips on the inner ring between the sets of holes would be the weakest points.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Probably true, but it looks to be atleast as thick as the standard sprocket thickness there. So, it is no weaker than a normal sprocket most likely.

(this is just an assumption... If I had the model, I'd run FEA on it to verify)

Re: pic: Custom Machined Aluminum #25 Sprocket
 

I don't think the thickness is under question it is the webbing on the profile.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

A beautiful piece--great job!!

I'd love to see an FEA analysis as well.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Yes, the teeth were milled. Off the top of my head, I believe these are the operations we performed. It was a couple of months ago so the feeds and speeds might not be 100% accurate.

5/8" roughing endmill 1000rpm 4"/min roughs out tooth face and bore
1/2" ball nose endmill 1200rpm 2"/min put radius' around bolt holes
1/4" roughing endmill 1800rpm 2"/min roughs out medium sized pockets
1/4" plain endmill 2000rpm 6"/min finishes medium sized pockets and bearing bore.
1/8" plain endmill 2500rpm 1.25"/min mills small pockets, spot drills bolt holes, and outside sprocket teeth.

CAD files are available for anyone who wants them. As for FEA, if anyone wants to do it, go nuts.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Wow, those feeds seem really slow. Must have taken a while. What machine were you using?

Re: pic: Custom Machined Aluminum #25 Sprocket
 

i'd say those feeds look pretty good to me, based on the machines i have used and the total size of the sprocket

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Will the sprocket be anodized, or nicely buffed? (I'd tend to prefer buffing, since aluminum really works well)

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Would you mind posting the .dwg for this? You will be my BFF :)

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Seems really slow to me too.

I machine aluminum all the time at around 100 ipm (or even all the way up to 200ish).

Granted I believe 1114 has a small, benchtop CNC mill, which definitely isn't going to run like a VMC will.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Coolant coolant coolant... i know the machine we used had this very very bad spray coolant...if you have flood coolant i can easily see these rates skyrocketing, but based on what we had to do with hardly any coolant, we had to take things quite slow

Re: pic: Custom Machined Aluminum #25 Sprocket
 

Corey's right. 1114 uses a small bench top CNC mill by RedCAM. Our coolant system consists of a freshman with a squirt bottle. We recently upgraded to a fish tank pump and a bucket. This was a vast improvement.

We've broken more than our share of endmills, and we try to extend tool life as much as possible, so we stick to slow feeds. It can be very time consuming, but student labor is cheap.

Re: pic: Custom Machined Aluminum #25 Sprocket
 

(old thread... but im going for it anyway)

what kind of mill did you use?