Some Mods To the Belt Drive On My Mill

[terry_g]

I made a pulley that would fit into the top of the cone pulley on the motor to give me a slower speed
160 rpm the lowest with the factory setup was 270 rpm.

Assemble these parts.

You will have this.

Slide it into the cone pulley and tighten the nut.

A shorter belt was required.

There is a wide space in the speeds in the middle between 490 rpm to 950 rpm.
By running a belt directly from the motor to the spindle pulley I was able to get 660 rpm.

 

[YYCHM]

What mill is that?

 

[RobinHood]

That is an excellent idea and a well executed project.

 

[terry_g]

Its a Craftex B048 milling machine.

 

[John Conroy]

Very nice work. What did you do to align the new motor pulley groove to the existing idler top pulley?

 

[terry_g]

The cone pulley was bored and had a key-way all the way through.
It just slid in and the expanding shaft holds it tight.

 

[DPittman]

Looks like a good solution.

 

[historicalarms]

Excellent, very worthwhile job, something I contemplated doing to my belt mill as well but just never "got around to it ".

 

[YYCHM]

Excellent, very worthwhile job, something I contemplated doing to my belt mill as well but just never "got around to it ".

The motor pulley on our machines has a blind bore with keyway. Something to keep in mind here.

 

[RobinHood]

The motor pulley on our machines has a blind bore with keyway. Something to keep in mind here.

You could always bore all the way through and extend the key way - if there is enough material on the step pulley.

 

[terry_g]

Its bored and keyed all the way through from the factory.

 

[RobinHood]

I think @YYCHM was talking about the pulley on the typical RF30 mill. Seems there may be a difference in design.

 

[YYCHM]

I think @YYCHM was talking about the pulley on the typical RF30 mill. Seems there may be difference in design.

Yup, @historicalarms (Doug) and I both had House of Tools branded RF30s. The motor pulley has a blind bore. Was just pointing that fact out to Doug.

 

[DPittman]

I made a pulley that would fit into the top of the cone pulley on the motor to give me a slower speed
160 rpm the lowest with the factory setup was 270 rpm.

Assemble these parts.

You will have this.

Slide it into the cone pulley and tighten the nut.

A shorter belt was required.

There is a wide space in the speeds in the middle between 490 rpm to 950 rpm.
By running a belt directly from the motor to the spindle pulley I was able to get 660 rpm.

I'm curious...what operation did you need the slower speed for, tapping?

 

[terry_g]

I was using a boring head with a long bar and was getting chatter because of the lack of rigidity.

 

[DPittman]

I was using a boring hear with a long bar and was getting chatter because of the lack of rigidity.

Did the slower speed fix the chatter?

 

[DPittman]

My similar milling machine only has .350" of room in the cone pulley so not much room for a shaft but I guess the key takes the majority of the forces anyhow and a bit of epoxy or loctite would suffice to hold the pulleys together

 

[terry_g]

Did the slower speed fix the chatter?

Yes the finish was much better.

 

[YYCHM]

My similar milling machine only has .350" of room in the cone pulley so not much room for a shaft but I guess the key takes the majority of the forces anyhow and a bit of epoxy or loctite would suffice to hold the pulleys together

In that case I would suggest a shaft with key for alignment and torque load and securing the new pully to the adjacent pulley with machine screws.

 

[Rotaxxx]

VERY INTERESTING!! I have the exact same mill and have the same complaints with mine as well! I wish it had a few lower speeds and this looks like a great idea! Thanks for posting it.