Number of belts vs hp

[Josko Catipovic]

I got a 8" Delta 37-315 jointer with a 3 Hp (Baldor TEFC) motor but only a single 'A' belt to the curtterhead. I wonder whether it should have more than one belt given the 3 HP motor and the 6" and 2 1/4" pulleys. Seller is a boatbuilder who upgraded it to 3hp to take 'hefty' cuts off boat lumber. I found a Baldor manual on power transmission but frankly, got lost in the morass of technical details. Would anyone know what the rule of thumb is in this case? Would I gain anything by two belts? Thanks in advance

[Zachary Hoyt]

If you push it too hard, what happens? Does the belt slip or does the motor stall? This will answer your question, I think.

[Josko Catipovic]

Motor bogs down. Still, I wonder if I'm overstressing things.

[Dan Friedrichs]

It depends on the sheave diameters, but something like a ~3" diameter pair of sheaves should be capable of at least 2HP with an A belt. If the sheaves are larger (~5") you could get 5HP out of a single A belt.

It's primarily a matter of providing enough surface area on the belt to make sure it doesn't slip. Larger sheave = more surface area = more power transmission without slipping.

In your case, since you aren't slipping the belt, that's not the issue. Sounds like you're either:

1) Working the motor too hard (are the knives sharp? Is the table waxed? Are you taking reasonable width/depth cuts?)

2) Something is wrong with the motor or its power supply (does it have a sufficiently-large circuit supplying it? Does the motor have a 'run' capacitor and is it good?)

[David Kumm]

The machine was designed within certain load limits and although well built, is not overbuilt. A larger motor and extra sheaves just allows for more load to the machine and bearings. That machine isn't made to handle a 3 hp motor bogging down so I'd not add belts to allow even more stress. Dave

[Bill Dufour]

Given the work needed to add an extra belt I would not bother. You will have to cut the base open and maybe grind some of the fence off as well. Not sure if the motor mount has enough in and out adjustment or if you will have to machine new mounting slots and weld up the old ones.
maybe switch to a cogged belt to help on the smaller pulley.
Bill D

[Martin Wasner]

If it's not slipping, what's the issue?

I've got ten course shapers that get worked. Just a single belt on them.

[Warren Lake]

Martin

was that a ten course dinner?

or a ten horse shaper. Im planing on putting a chev 350 on one of mine, Maybe an Lt-1, never too many hp.

[glenn bradley]

On my gear, as delivered:
3HP 8" Jointer - 1 Belt
3HP Tablesaw - 1 Poly V-Belt (ribbed, mulit-vee, whatever)
3HP 15" Planer - 1 Belt

[Van Huskey]

or a ten horse shaper. Im planing on putting a chev 350 on one of mine, Maybe an Lt-1, never too many hp.

Might I suggest not stopping at a measly LT1. Get something with some REAL torque with ~1200hp and will run 24-7 for decades outside of maintenance.

Behold the 32 liter CAT C32, you will need to use more than 1 belt and maybe upgrade the spindle bearings...

000000000000000000000000000000001.jpg

[Martin Wasner]

Martin

was that a ten course dinner?

or a ten horse shaper. Im planing on putting a chev 350 on one of mine, Maybe an Lt-1, never too many hp.

Yeah yeah yeah. I suck at proof reading and I've got a phone that likes to auto correct things into incoherence.

This isn't anything new.

[Josko Catipovic]

Thank you, all. One belt it is. I was just wondering if it makes sense to get another belt given the motor upgrade. Not planning to abuse this in any way.

[Rod Sheridan]

Might I suggest not stopping at a measly LT1. Get something with some REAL torque with ~1200hp and will run 24-7 for decades outside of maintenance.

Behold the 32 liter CAT C32, you will need to use more than 1 belt and maybe upgrade the spindle bearings...

000000000000000000000000000000001.jpg

Funny timing, I'm load testing a Cat 3516 quad turbo 2,000Kw set today.

I think it's 69 litres, V16, makes the C32 look like a pup engine

Regards, Rod.

[Ole Anderson]

So now I am wondering why they put triple belts on 3 hp table saws?

[Warren Lake]

geez Van you dont mess around .

My sister sent me an auto correct thing conversations between kids and their parents, hard to believe they were not doctored but they were funny. Interesting on the belt thing some machines here have three then ones with almost double HP up to 9hp have one. I prefer the Cog belts if that is the right name, Belts on my table saws even from new are stiff and feel crappy if you hand turn something. Belts on the shapers with all the notches cut out, turn like there is barely a belt there.