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New Hobby Machinist in Edmonton

Emery said:
very interesting... The speeds are definitely accurate enough to seem correct. 50 RPM is in the correct spot and 1500 RPM is in the correct spot everything else seems “normal”.

can you guys pass along some measurements to make sure mine are not “custom farm”.

If they just took off the top and put it on the bottom and vice versa without flipping the orientation the RPMs shouldn’t change.
Click to expand...

In what belt position do you get max rpm? Closest to the head stock or farthest from the head stock? Have you checked spindle RPM with a tachometer?

BTB - Your machine is cleaning up nicely....
 
IIRC the headstock pulley is a 6" 4 step and the motor pulley is a 5' 4 step. If the 6' is on the motor then your spindle speeds will be higher.
YYC - when you asked if the pulleys were swapped did you mean spindle pulley on the motor and motor pulley on the spindle?
Max rpm would be the small pulley on the headstock to the large motor pulley.
 
YotaBota said:
IIRC the headstock pulley is a 6" 4 step and the motor pulley is a 5' 4 step. If the 6' is on the motor then your spindle speeds will be higher.
YYC - when you asked if the pulleys were swapped did you mean spindle pulley on the motor and motor pulley on the spindle?
Max rpm would be the small pulley on the headstock to the large motor pulley.
Click to expand...

Bingo.... that's what I was thinking, and an on-line pulley calculator proved that it can make a considerable difference overall.
 
Okay, at first I thought you meant the pulley's being turned around on the shaft. On my machine the spindle pulley has the large pulley against the head stock.
 
YotaBota said:
Okay, at first I thought you meant the pulley's being turned around on the shaft. On my machine the spindle pulley has the large pulley against the head stock.
Click to expand...

That's exactly what I meant by swapped. The pulley being turned around on the shaft. His high range must be with the belt closest to the head stock which to me contradicts the face plate. Later it occurred to me that swapping the spindle pulley for the motor pulley would change things as well.
 
YYCHobbyMachinist said:
In what belt position do you get max rpm? Closest to the head stock or farthest from the head stock? Have you checked spindle RPM with a tachometer?

BTB - Your machine is cleaning up nicely....
Click to expand...

Closest to the head stock. What about you?

And thank you very much! =) slowly but surly. There is some serious built up grease on this unit.
 
YYCHobbyMachinist said:
That's exactly what I meant by swapped. The pulley being turned around on the shaft. His high range must be with the belt closest to the head stock which to me contradicts the face plate. Later it occurred to me that swapping the spindle pulley for the motor pulley would change things as well.
Click to expand...

What do you use to check RPM?
 
YYC & Yota... I have 4 1/4 inch pulley on my head stock and a 5 inch in my motor. Both with 4 steps.
 
Emery said:
Closest to the head stock. What about you?
Click to expand...

Farthest from the head stock. Take a look at your face plate speed chart, your pulleys are turned around. Not that it matters as long as you realize it. Now.... it your spindle and motor pulleys are swapped that's a whole different story.

I got a cheap optical tach from amazon to check my machines.
 
YYCHobbyMachinist said:
Farthest from the head stock. Take a look at your face plate speed chart, your pulleys are turned around. Not that it matters as long as you realize it. Now.... it your spindle and motor pulleys are swapped that's a whole different story.

I got a cheap optical tach from amazon to check my machines.
Click to expand...

I could swap them easy enough but now I have the issue of my one pulling being the wrong size... Yota said his are 6” and 5”. Are yours that size as well?

Can you send me a picture of your orientation?
 
Emery said:
I could swap them easy enough but now I have the issue of my one pulling being the wrong size... Yota said his are 6” and 5”. Are yours that size as well?

Can you send me a picture of your orientation?
Click to expand...

Don't sweat it. Your spindle RPM is probably well with in a usable range.

8885_d82f174a4e8c3aac5c763665311fc14a.jpg


This is the usual orientation for the pulleys. Note that the smaller one is on the motor.

I'll measure mine tomorrow and report. Who knows if any of us has OEM stuff or the correct pulley set to begin with.
 
Last edited:
@Emery there’s an iPhone app called “StrobeLight” it lets you change the flash rate of the phone flashlight till it matches a mark in a rotating object.
I use it somewhat often but it works well.


Sent from my iPhone using Tapatalk
 
YYCHobbyMachinist said:
Don't sweat it. Your spindle RPM is probably well with in a usable range.

8885_d82f174a4e8c3aac5c763665311fc14a.jpg


This is the correct orientation for the pulleys. Note that the smaller one is on the motor.

I'll measure mine tomorrow and report. Who knows if any of us has OEM stuff or the correct pulley set to begin with.
Click to expand...

Thanks YYC, I will also do some calculations tomorrow for my RPM
 
YotaBota said:
I'll measure my pulleys in the morning just to be sure. The Manual list the pulleys as a 64 and a 54 which I think is 6" 4 step and 5" 4 step.

I'll check that out, thanks
Click to expand...

You have a manual that lists the pulley sizes?
 
Emery said:
No, I think Yota is referring to the regular manual. It’s list the part codes are SCA-64 and SCA-54.
Click to expand...

Likely SCA-64 means 6”, 4 sheaves. Likewise 54 means 5” 4 sheaves.


Sent from my iPhone using Tapatalk
 
Okay,
I did some calculations.

With the stock 6 inch (spindle) and 5 inch (motor) @1750 RPM

slowest speed in high range. (Should be 250 RPM)

1750 RPM on the smallest side on the motor pulley (I am guessing it’s a 2”) Going to the 6” ring on the spindle pulley you have a 575 RPM going into the head stock. (20T gear)

The high rang gears then goes to a 48T to a 40T (which is your main spindle)

575 x 0.416 (20T to 48T) x 1.2 (48T to 40T)

= 287 RPM. Close enough...

When I calculate my ratio in the same slowest speed in the high range option which should be 250... mine equals 405 RPM


Looks like I might have to go shopping for some new pulleys.
 
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