cutting pully

[itowbig]

hey guys im making pullys for my hf milling machine . how do i & what do you guys use to cut the groves for the belt to ride in? i got sorta an idea but? ive made everything else for the machine now im down to the pullys. and yes ill post pics when im done maybe a vid too.
thank you

 

[Bogstandard]

Sid,

A little bit of info is required before a suggestion can be made.

It all depends on what type of belting you are going to be using, as the shape of the groove is dependant on the shape of the cross section of the belt. Be it flat, round or standard V shape.

John

 

[DickDastardly40]

Notwithstanding John's request for more detail on sizes and cross section, I have cut some Vee belt pulleys using a parting tool to get a groove the width of the flat and cutting the vee either by adjusting the compound to the desired angles or a vee tool similar to a HSS thread cutting tool with the correct angle ground to open out the sides.

Hope this helps.

 

[rake60]

If it is a V-Belt pulley, there is a very old but still valid
article on cutting "V" grooves on a small lathe at:
Grooving V-Pullys

Rick

 

[itowbig]

its a gates 2L130 belt a vee belt. im interested in the tool profile.
i cut the vee grooves this morning but one of the grooves grabs good and the other one does not. im making it of steel . maybe i should make one of aluminum and see if thats better. thanks rick ill have a look at that.

 

[Tin Falcon]

I re-cut a plastic and aluminum pulley for those belts. No expert here but a pulley and belt is a wedge so if you cut the same angle as the belt and have room for the belt to go deeper you should be fine the groove should be about .200 deep. it is my understanding a v-belt engages on the sides.
Tin

 

[Tin Falcon]

I just dug up my cutter it has a bout a 40 degree included angle and 1/8 flat nose.
Hope this helps.
Tin

 

[rake60]

The actual angle of an FHP V-Belt is 40 degrees included, (both sides are 20 degrees.)
The grooves a the pulley are usually cut to a 38 degree included angle, (19 degrees.)

The reason for that is as a belt flexes around a pulley it thins slightly.
That's kind of splitting hairs for an application like yours, but thoughts to consider.

Rick

 

[Stan]

Unless I misunderstood the question, Machinery Handbook gives the following angles for a 2L V pulley:
Under 1.5" - 32°
1.5" to 1.99" - 34°
2.0" to 2.5" - 36°
Over 2.5" - 38°

 

[tel]

I just ground up a pointed tool at the correct angle and waggled it from side to side to get the flat at the bottom

 

[itowbig]

haha Tel thats what i did too but the smaller pulley just wont grab the belt. i got the big pulley no problem but that dern small pulley is a pain.
i cant make small stuff one i cant see it too my fingers just dont move anymore. (they've been broken.once or twice) i never could build small stuff.
thanks for all the input ill keep at it but im getting frustrated at that dern 1" pulley. im going for a cold soda

 

[tel]

Ah! I did the small pulley in bronze. You might try deepening the groove a little, as long as you don't take any off the sides.

 

[itowbig]

ah man another design. hey how did you mount that big pulley.
was it press fit or did you use a set screw. that design looks as if i could use a bigger belt than the little one i got. i think i finallygot it. stiil more checking to do.

 

[tel]

Two setscrews at 90° in the bottom of the smaller groove. Not the best scheme in the world - you gotta nip 'em up now & then

 

[rake60]

Unless I misunderstood the question, Machinery Handbook gives the following angles for a 2L V pulley:
Under 1.5" - 32°
1.5" to 1.99" - 34°
2.0" to 2.5" - 36°
Over 2.5" - 38°

Stan's quote from the Handbook are exact.

The tighter the radius of pulley the more the belt will thin.
A deeper groove at a shallower angle will force the belt to grip, but it
will also lead to more wear on the belt.

Again, these are important issues for an application where the machine
will run 24/7 For this application, "maybe not so much".''

It's about making it do what you expect of it.
When you make it yourself and it works, that perfect enough.

Rick

 

[Stan]

I don't use any 2L belts but I make all my own pulleys for 1/2" and 5/8" belts. I just open up Machinery Handbook to the page with the chart with all the dimensions. I run a parting tool in the specified depth at the center of the groove, I then put in a 1/4" left hand bit, set the compound to one half the spec'd angle and cut with the compound until I reach one half the spec'd width. Change to a right hand bit and swing the compound the opposite way and cut the other side.

I find this to be one of the easiest jobs I do on a lathe. I make my pulleys out of 6061 which is far superior to the die cast pulleys from the hardware store and I have never worn one out. Most of our belt driven tools come with multi step pulleys and it is usually impossible to buy a mating pulley so I make one that mates so that motor adjustment isn't required when changing speed.

 

[philt214]

I replaced the motor on my HF 33686 mill several years ago and was faced with either replacing the motor pulley or adapting the stock pulley. I chose the later which required boring out the pulley then sleeving. On my HF 12 x 36 lathe I chose to made a new pulley. I started by measuring the angle of the existing pulley then I used the Duplex article as a guide to making the new one. The most time consuming part was using my trusty 4 x 6 bandsaw to cut off the piece of H-13 steel (this is one high quality pulley) I had on hand. The pulley works fine. I am not sure which method is preferable, but I had always wanted to machine a pulley. I got my chance with this project.