Pulley grub screw location

[booski]

Unfortunately, I don't have access to a mill or broach set and we are talking of very small diameters here. I have found online (from china however) adjustable reamers.
I understand that a cheap reamer may not be wholly accurate whilst an adjustable one you can step it up until you get the right size. The trouble still arises when dealing with small bore like 1/8" for the motor.

Obviously, I could simply turn a length of aluminium down to a reasonable size, drill to 3.1mm and press onto motor shaft. Then with the motor shaft in the lathe, turn the aluminium down to the correct size.

There are many methods, I know, but I'm not really a machinist. I've completed basic machinist courses to the best in class and done various pieces of machining in my old job of which I was frequently called upon to perform but nothing really to this degree of accuracy.


Just to throw another spanner in the works, I have a reasonable size piece of aluminium available to me, what if I were to machine a V-pulley to be used with o-rings instead of buying T2.5 / T5 pulleys and machining them in the hope I don't ruin them?

[m_c]

If you want reamers, Tracy Tools do them for reasonable money - REAMERS

The adjustable ones are only listed in imperial sizes though.

[John S]

The adjustable ones are only listed in imperial sizes though.

That's gotta be a joke yes ?

Like the adjustable spanner marked out in inches one side and mm the other ?

ARC's reamers are far cheaper, Tracy wants £12 for a 3/8" reamer, ARC wants £5.70
Tracy only do metric as a set.

[Clive S]

That's gotta be a joke yes ?

Like the adjustable spanner marked out in inches one side and mm the other ?

ARC's reamers are far cheaper, Tracy wants £12 for a 3/8" reamer, ARC wants £5.70
Tracy only do metric as a set.

Yes ARC do a good service but for the record Tracy does Metric here :-http://www.tracytools.com/metric-reamers

[m_c]

That's gotta be a joke yes ?

Like the adjustable spanner marked out in inches one side and mm the other ?

ARC's reamers are far cheaper, Tracy wants £12 for a 3/8" reamer, ARC wants £5.70
Tracy only do metric as a set.

I could of maybe worded that better, but I'm sure you know what I meant.


I normally use ARC, but Tracy is handy for the more oddball stuff that ARC doesn't do, like the adjustable reamers I got last week for a bit head stock tweaking.

[booski]

That's all fairly reasonable. Not seen a 1/8 adjustable reamer yet but tempted with the 10mm.

What would be preferred though, interference fit or snug fit with grub screws?

And any more info on balancing with a scope?

My alu tube turns up soon so I can start building the spindle and once its done, ill get some pulleys.

I assume when turning shop bought pulleys its better to chuck up by the boss and not flanges?

[Jonathan]

And any more info on balancing with a scope?

Something like this:
Balancing Tool
Or you could use accelerometers...

I assume when turning shop bought pulleys its better to chuck up by the boss and not flanges?

Never hold them by the flanges - they're only pressed on and not very strong. Hold the pulley by the boss and it's sensible to check with an indicator that it's on center.