correct size v-belt for a Bench Master vertical milling machine

[rogee07]

I'm having trouble locating the correct size v-belt for my bench master vertical milling machine.

[rogee07]

the B M vertical milling machine is one of the later models if that is a consideration.

[mickeyf]

Do you have an old belt you are replacing or no belt at all?

If replacing, does the old belt have a visible identification number? If not, there are several methods of determining its length. I have found measuring to be better than calculating. My preferred method is to make a chalk mark on the belt and on the floor or workbench, align the two marks, roll the belt until the mark is again on the floor/bench, make a new mark there, then measure between the two marks on the floor or bench. The top width should easily let you know if it is an "A", "B" or whatever series.

If no belt, you can calculate based on the distance between the shafts and diameters of the pulleys, but I'd wait for someone here with the same machine to chime in before I did that.

[rogee07]

Thanks for your reply, I do have a V-belt on the machine, which is lose. But the previous owner has placed two plywood spacers between the motor, and it's mounting bracket. So it is obvious that the existing V-belt is not the correct one for the machine. So any help will be appreciated, as I would like to get everything as close to original as possible

[Cuttings]

Something you might consider is using a link type belt instead. I switched to them on my old mill and eliminated a lot of vibration. You can adjust the belt to whatever length you need. I have had those belts on the machine for a lot of years now and they are still running smooth and show very little wear. Right now I can't remember the name of the good link belts, but they are red in color. I could look at the extra links I have left over for a name or it may come to me in the middle of the night

Just had a look at the Busy Bee sight where I bought them. They are called power twist.

[david a]

Back when I was working as a mechanic, we measured for belt length with a tape measure led around the pullies.

[mickeyf]

Cuttings is talking about these things:

https://www.amazon.ca/PowerTwist-V-Belt-Profile-Width-Length/dp/B00CLG3FNU/ref=sr_1_3?dchild=1&keywords=link+belt+type+B&qid=1594842667&sr=8-3

But maybe cheaper elsewhere, or perhaps not lots more than you need, etc.

[CCWKen]

This is a better deal: https://www.harborfreight.com/vibrat...elt-43771.html . I've been running one on my lathe for over five years now. Smooth as silk and just as hardy as the high-priced spread.

[mickeyf]

This is a better deal

But not by much - my link was to the Canadian price, since that's where I am. In the US HF and Bezo-mart are pretty similar. If anyone knows of a low priced alternative in the Great White North, please let me know! You'd think this would be the sort of thing Princess Auto, or maybe Busy Bee carried, but apparently not.

[Ringo]

What is wrong with the belt you got now?
Too long?
too wide?
Too narrow?
Width is pretty much standard incremental sizes, 3/8, 1/2, 5/8. some are in 32nd increments, and 1/32 difference isnt gonna make much difference.
I can run a rope around the pulleys and get a length.
the angle of the vee-groove is a standard in USA. only difference is the width,

[J Tiers]

I'm having trouble locating the correct size v-belt for my bench master vertical milling machine.

Went and took a look at mine.

On mine, I have the wrong size belt. The spindle pulley takes a 3/8", but the motor pulley takes a 1/2", so I have a 1/2" on it, which fits the spindle pulley, just rides high.. That one is 53" measured around the outside, but since it is too big, and rides too high, a 52" is probably right when using a 3/8" belt. A 3/8" would about bottom put in the motor pulley, but that pulley is the one I had that keeps the belt constant for all speed settings.

There is some adjustment room, so you might even use a smaller than 52" I have about 1/4" of room left on the adjustment for a bigger belt, and I don't have a lot of room for a smaller belt, maybe 3/8" of movement, because the worm gear box for head tram gets in the way.

[jtrain]

My Benchmaster mill has a belt number 4L-520.

[J Tiers]

My Benchmaster mill has a belt number 4L-520.

That is about what I have on mine. It is too wide, but works.

[Cuttings]

For general interest I just found this Fenner web sight that has information on a number of link belts that they make. It might be of interest.
< https://www.fennerdrives.com/powertwist-drive/ >

[Ringo]

Sounds like you need a 3VX520
the belts that are the 'raw edge' do run much smoother than classic garden variety plied belts.
3VX series are cut to better width tolerances and run smoother

https://www.vbelts4less.com/v-belt-specifications

https://www.biedlers-belts.com/gates-3vx520-belt.html