My Homemade Multi Rib Pulleys To Reduce Vibration And Add A Brake To My G4003g

[737mechanic]

After reading post about vibration I noticed mine had a slight amount of vibration at times so I took a look at the belts while it was running and noticed how much they bounced around and I also noticed the large pulley was not running true as I could see wobble while it was turning and figured that could also contribute to vibration so this is what I did to fix the problem and at the same time allow me to add a brake to the lathe.

The belt I chose was a 10 rib 31in poly V belt.

I made a rotor/disc from .120 steel plate and attached it to the smaller motor pulley with 4 bolts. Later I will be adding a disc brake caliper so I can have a brake setup that will allow me to not only stop the lathe quickly but also let me lock the spindle so when I am hand tapping the spindle will not rotate.

The shaft the large pulley bolts to is tapered so I had to remove the original dual V belt pulley and use it to set up the compound so I could turn the proper taper on the new multi rib pulley.

There are a couple videos I posted of the before and after.

<---------Video showing original belts vibrating

<-------- Video showing new belts and pulleys running.

 

[coolidge]

Quite excellent, did it improve the lathe surface finish?

 

[Kernbigo]

i worked for a co. that made thread gages, and we fit our J&L thread grinders , wheel motors to grinding spindle with custom made polly v pulleys some what like yours. It did improve the finish and wheel slippage on large gages like 6" dia.

 

[dave2176]

I like what you have done. I'll file that on my todo list for my G4003G.

 

[Usmcdevildog]

i was actually gonna pull the trigger on a 4003g today should I go with something different? Is there too much vibration, what kind of tolerances does it hold out of the crate

 

[737mechanic]

I absolutely love my g4003g. I looked long and hard and after learning all that I could about lathes in this price range I went with the grizzly. The vibration isn't bad at all. In fact had I not wanted to put a brake on the lathe I wouldn't have even worried about it. But after thinking about how I would do the brake I figured I could also switch to a multi rib belt since they are low vibration belts to start with.

 

[Usmcdevildog]

well that makes me feel better, I was back and forth on the g0776 and the 4003g and kinda still am... Any opinions

 

[737mechanic]

The g4003g is a 12x36 lathe and the G0776 is a 13x40 which to me is the only thing the G0776 has over the g4003g. The biggest downfall I see in the G0776 is the same problem I saw in the PM1236 which is why I didn't go with the PM1236 and that is having to do a gear change for certain inch threads. If you look at the chart you will see half the inch threads are on one gear set and the other half require another gear set. With the g4003g you can choose from 4tpi through 112tpi with the same gear set. You only change gears on the g4003g for metric threading. The feeds work the same way depending on what feeds you want you might need to change gear sets to achieve this. With the G4003G I can select from .0011 to .0311 feed with the same gear set installed.

These are things you may want to look at before buying.

For me that was a deal killer.

 

[dave2176]

+1 for the G4004G. Regardless of the lathe you will have to make some adjustments when you receive it. Things like adjust the gibs, set the lash on the change gears. Minor things you must do regularly to keep it running in top condition.

 

[tmarks11]

well that makes me feel better, I was back and forth on the g0776 and the 4003g and kinda still am... Any opinions

ditto on what 737 said. The Norton gearbox in the 4003g (type that has two levers the you move left and right) is superior to the closed gearbox in the g0776 because it handles significantly more threads and feed rates.

The g0709 (13x40), which is what I have, has a closed gearbox is far superior to the G0776.

If you are considering paying the price of the G0776, I would look long and hard at the PM1340G. From all reports, it is a significant step up in quality over the G0709.