# Some Mods To the Belt Drive On My Mill



## terry_g (Apr 3, 2021)

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.


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## YYCHM (Apr 3, 2021)

What mill is that?


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## RobinHood (Apr 3, 2021)

That is an excellent idea and a well executed project.


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## terry_g (Apr 3, 2021)

Its a Craftex B048 milling machine.


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## John Conroy (Apr 3, 2021)

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


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## terry_g (Apr 3, 2021)

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.


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## DPittman (Apr 3, 2021)

Looks like a good solution.


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## historicalarms (Apr 3, 2021)

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


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## YYCHM (Apr 3, 2021)

historicalarms said:


> 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.


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## RobinHood (Apr 3, 2021)

YYCHM said:


> 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.


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## terry_g (Apr 3, 2021)

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


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## RobinHood (Apr 3, 2021)

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


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## YYCHM (Apr 3, 2021)

RobinHood said:


> 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.


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## DPittman (Apr 3, 2021)

terry_g said:


> 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.
> ...


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


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## terry_g (Apr 3, 2021)

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


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## DPittman (Apr 3, 2021)

terry_g said:


> 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?


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## DPittman (Apr 3, 2021)

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


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## terry_g (Apr 3, 2021)

DPittman said:


> Did the slower speed fix the chatter?


Yes the finish was much better.


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## YYCHM (Apr 3, 2021)

DPittman said:


> 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.


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## Rotaxxx (Apr 4, 2021)

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.


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## YYCHM (Apr 4, 2021)

Rotaxxx said:


> 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.



Throw a 3 phase motor and VFD on her and you'll never have to change belt positions again.  Second best upgrade I have made to my mill.


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## YotaBota (Apr 4, 2021)

Thanks Terry, I've been looking for someway to do the 600rpm range. I set up with a link belt today, motor to spindle, and it will work well.


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## Rotaxxx (Apr 4, 2021)

YYCHM said:


> Throw a 3 phase motor and VFD on her and you'll never have to change belt positions again.  Second best upgrade I have made to my mill.




I have a 2hp 3 phase motor here to put on it one of these days, how ever money is tight (been out of work for a while) and I shouldn't buy a VFD yet so I will have to make due with what I have and try this out first!


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## Dabbler (Apr 5, 2021)

terry I loved my B048 mill it is a great machine!


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