# 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

Usmcdevildog said:


> 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.


----------



## epanzella

Another vote here for the G4003G. Have mine over two years now, awesome machine. I don't know what all that noise was in the video. Mine is a lot quieter than that.


----------



## Usmcdevildog

it really does seem like the 4003g is about half and half from this thread to all the others I have, some love them some hate them, I guess it all depends if ping or ding put your lathe together that day>  lol  and who was in the better mood


----------



## tmarks11

Usmcdevildog said:


> it really does seem like the 4003g is about half and half from this thread to all the others I have, some love them some hate them...


Just so you know, I believe that Grizzly changed manufacturing facilities that produced this lath somewhere along the line.  So it is possible that the earlier owners of the lathe are much happier than the most recent purchasers.


----------



## epanzella

I don't know anything about a switch in manufacturing facilities but mine was made in China. I got my G4003G a bit over two years ago and I'm delighted with the machine. I'm just a weekend warrior but holding tolerances to .001 or better is a piece of cake since I added DI's to my X &Y axis. I've already built my first rifle on it and it came out perfect.


----------



## coolidge

Usmcdevildog said:


> it really does seem like the 4003g is about half and half from this thread to all the others I have, some love them some hate them, I guess it all depends if ping or ding put your lathe together that day>  lol  and who was in the better mood



Here's the deal on the G4003G unbiased, unfiltered...

*The Good* - There is no denying Grizzly made some key upgrades to this lathe. Upgraded spindle bearings. A MUCH beefier D1-5 spindle it makes D1-4 spindles look like a toy. Factory spider gear. Each machine comes with a detailed inspection report and the areas of the lathe covered by that inspection report will be within tolerance and setup properly and of good quality generally.

*The Bad* - Basically any area of the lathe not covered by the inspection report. The motor is lame, vibration, there are many a thread on the lengths people go to try to isolate this motor from the lathe. The motor mount is lame, many are miss drilled and tapped positioning the motor too far left, to compensate they just hung the motor pulley half off the shaft (face palm). THAT speaks volumes about made in China machines, they will intentionally ship defects if they can slip them past inspection. The tailstock is lame and sloppy and just down right designed wrong ejecting some tools like drill chucks. If I retract my tailstock beyond 1.375 inches it ejects the drill chuck. Which means the quill is stuck out there sloppy 1.5 inches eliminating 1.5 inches of the 4 inches of quill travel. (face palm) The drive pulley on the headstock is not exactly true turning and the bearings on mine with less than 20 hours of light use seem to already be going bad. That particular bearing is available in a couple of different qualities, one cost $1 the other cost $12 I'm pretty sure which ones they put in there. So while they upgraded the spindle bearings, did they go cheap on the other bearings? Probably.

*The Ugly* - Speaking again to intent, my motor pulley wobbled so bad, it was like watching a cartoon pulley it was that bad. How did that pass inspection without notice, it didn't imo. They knew it was bad and shipped it anyway since that wasn't part of the inspection report. The welded steel stands, first they didn't even finish painting them. I had to go buy some paint and finish the job myself. They were not welded square, they are probably out of square 1/2 inch top to bottom with the sides leaning left to right. I had to go through the electrical box tightening as many of the connections were loose. The stand is WAY too shallow front to back, if you put leveling feet on it its even worse/more shallow. This lathe is tippy front to back. Unless you are 6 foot plus tall the stand is also way too tall. Its inches taller than even big 16x40 lathes.

*Work Cube Fudging the Numbers* - On some lathes the carriage travel equals the advertised distance between centers. On some 16x40 lathes the carriage actually travels 40 inches. On other 16x40 lathes the carriage only travels 34 inches. On my G4003 the carriage only travels just shy of 31 inches so buyer beware. In fact for either lathes or mills you have to be very careful to research the actual travels of the axis vs the advertised travels, and be on the look out for travels that require you to over travel the ways or hang the tailstock off the end of the bed to get the advertised travel.

Is my new mill really 24 inches on X? No, I would have to over travel the ways 4 inches to get the advertised 24" of travel its really only 20.5 inches. Is the mill accurate if I over travel the ways? No so its not really useful right. Even with the table not over traveling the ways, is my 20.5 inches of travel accurate? No. With the table hanging more than half off the saddle in mid air, there's a good .001 to .002 sag on the outside end and .001 to .002 of lift on the inside. So is this really useful travel? No. I think its a combination of flex and a Y saddle with ways that are too narrow to support the weight of the table hanging off that far e.g. a design flaw. If I were buying a new mill today this would be something I would be paying a LOT of attention to, is the mill or lathe designed to be accurate throughout its advertised work cube. I faced an 18 inch long aluminum bar this weekend and put a precision Starrett straight edge across it, it wasn't flat, it was a shallow bow low .002 on each end. If that happens the machine isn't delivering its advertised work cube imo.


----------



## 4GSR

Coolidge,

That is a nice informative report.  Thanks for sharing.

737mechanic,

I think I would make the smaller sheave from steel instead of aluminum.  The aluminum one may wear itself out on the motor shaft from start-stops.
I too have a couple of machines in my shop that use poly-groove sheaves and belts.  They are nice and virtually vibration free.  Thanks for sharing.

Ken


----------



## dave2176

Usmcdevildog said:


> it really does seem like the 4003g is about half and half from this thread to all the others I have, some love them some hate them, I guess it all depends if ping or ding put your lathe together that day> lol and who was in the better mood



There are definitely a vocal few but there are far more that state they like their G4003G. To be fair my friend bought one and the motor let out the magic smoke within an hour. Grizzly promptly replaced it and it has run trouble free since.

My G4003G was purchased in May '13 and other than the paint coming off with the suggested shipping grease remover has been trouble free. The motor is silent. No, it is not a Baldor but that alone doesn't make it defective. Both the motor and driven pulleys run true, the motor pulley is .25 off the end of the motor shaft which seems okay to me.  My lathe has many hundreds of hours on it and the P5 NSK bearings are still quiet and smooth. The tailstock ejects the drill chuck at .750 but I have never seen a self ejecting tailstock eject at .001". The MT3 taper can be cut to length to eject at the desired point. I see no point in worrying because the quill is not sloppy. The tailstock itself is top notch. It can be torqued down, at 25 lbs. mine is dead centered on the spindle height and will not slip on the bed. The 12x36 has nothing do with carriage travel. The 12 is of course the maximum diameter of object with the gap section in place. The 36 refers to the distance between centers and if I put a dead center in the spindle and a dead center in the tailstock it will take the full 36". I can machine the 36" length if I had to by adjusting the direction the compound is pointed.

If I had $3,600 to spend on a lathe, this is what I would buy. If I had $5,900 I would look at the PM1340GT. Or maybe I would buy the G4003G and a TIG welder to boot.

BTW, I really like this pulley mod.

Dave


----------



## 737mechanic

4gsr said:


> Coolidge,
> 
> That is a nice informative report.  Thanks for sharing.
> 
> 737mechanic,
> 
> I think I would make the smaller sheave from steel instead of aluminum.  The aluminum one may wear itself out on the motor shaft from start-stops.
> I too have a couple of machines in my shop that use poly-groove sheaves and belts.  They are nice and virtually vibration free.  Thanks for sharing.
> 
> Ken



Actually the small one is steel. The big one is aluminum. I would have wanted both to be steel but I got a good deal the the 5" round aluminum so figured that would do. If it doesn't hold up I can always make another one using steel.




epanzella said:


> Another vote here for the G4003G. Have mine over two years now, awesome machine. I don't know what all that noise was in the video. Mine is a lot quieter than that.



I have been around 3 other g4003g's and all 3 of them are about the same as mine. I have also been around other gear head lathes and they too are about the same. I am sure the extra noise you think you heard is simply from me having my phone right up next to the machine. 

Next to my old belt driven atlas there is no comparison the atlas was so quite.


----------



## epanzella

737mechanic said:


> Actually the small one is steel. The big one is aluminum. I would have wanted both to be steel but I got a good deal the the 5" round aluminum so figured that would do. If it doesn't hold up I can always make another one using steel.
> 
> I have been around 3 other g4003g's and all 3 of them are about the same as mine. I have also been around other gear head lathes and they too are about the same. I am sure the extra noise you think you heard is simply from me having my phone right up next to the machine.
> 
> Next to my old belt driven atlas there is no comparison the atlas was so quite.



I agree, it was probably the phone that made it sound whiney.


----------



## amuller

737mechanic said:


> 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.
> 
> 
> 
> View attachment 116674
> View attachment 116675
> View attachment 116676
> View attachment 116677
> View attachment 116678
> View attachment 116679



Nice Job.  I'm a big fan of poly-vee drives.  In fact, I don't seem much reason to design V-belt drives any more unless one wants a clutching setup or a variable speed split pulley design.


----------



## tomh

+ 1  on the 4003g I haven't had any problems at all.  That being said I also had a enco 13x40 made in  Taiwan in the 80s that I wasn't impressed with,  however it came out of a local machine shop that would run their machines hard and replace all the lathes / mills with new ones from enco about every 5 years. The owner  would sell the retirees for whatever he could get for them saying it was cost effective as he would write them off on his taxes.  
That said,  they are all hit miss depending on the owners  view of what is good/bad what is acceptable and what is not ,  AND YES there are LEMONS out there and if your lucky enough to get one then such as  Coolidge   then your work is cut out for you.   Remember  After all It is a roll of the dice  depending on ping & ding having a good day


----------



## Bootsranck

Hello 737mechanic, love your mod to the g4003g. I'm new to the forum so sometimes I may not get the term right, learning. Wondered how you came up with 10 groove poly-v belt. Was it based on HP or just a happen stance?


----------



## Bootsranck

Read my post and thought I would/should explain "happen stance", no disrespect. Lots of time I will have sometime laying around the shop that I think will do the job. Might be over engineered, somtimes under. Don't know till I try it.
Happen stance!


----------



## tmarks11

tomh said:


> ...YES there are LEMONS out there and if your lucky enough to get one then such as  Coolidge   then your work is cut out for you.   Remember  After all It is a roll of the dice  depending on ping & ding having a good day


There are some factories where you dread rolling the dice bad and biuying one of the machines that were assembled on a Friday....

and there are some factories where you dread rolling the dice and buying a machine that was assembled on any day between Tuesday and Sunday...

....sometimes the stack up of tolerances makes things work!


----------



## 737mechanic

Bootsranck said:


> Hello 737mechanic, love your mod to the g4003g. I'm new to the forum so sometimes I may not get the term right, learning. Wondered how you came up with 10 groove poly-v belt. Was it based on HP or just a happen stance?


Basically figured if a car engine turning power steering pump, A/C compressor, water pump and alternator could be done by a 5 or 6 groove multirib belt surely a 10 multirib would be more than enough for a 2hp lathe motor. Also if you look I left just enough width so I could add one more groove on each side of the pulleys making them a 12 groove if I noticed any slipping.

BTW Its been 8 months now and everything is running perfect. I still haven't got around to installing the brake setup but when I do I will post it.


----------



## Superburban

737mechanic said:


> Basically figured if a car engine turning power steering pump, A/C compressor, water pump and alternator could be done by a 5 or 6 groove multirib belt surely a 10 multirib would be more than enough for a 2hp lathe motor. Also if you look I left just enough width so I could add one more groove on each side of the pulleys making them a 12 groove if I noticed any slipping.
> 
> BTW Its been 8 months now and everything is running perfect. I still haven't got around to installing the brake setup but when I do I will post it.



The one thing you are over looking, is the belt contact with the drive pulley (crankshaft pulley), most cars it is probably around 5 to 8 inches, vs your approx 2". But then , an alternator, A/C comp, and water pump can easily add up to 20 to 30 HP, vs your 2hp, and the big gear reduction of the driven gear ratio.


I have had a Shopfox, M1112, since 2011. It is the same machine as the 4003G (Who knows if quality is the same, better, or worse), and have run it hard without any hiccups or burps. If I were to do it again, I would buy either machine. Wow!, I just looked up the prices. $3625 for the Grizzly, VS $4729 for the Shopfox. When I bought mine, ($32xx sticks in my mind), it was under $50 more for the Shopfox, and it has the coolant pump built in that the Grizzly does not, that was my deciding factor. Even though I have never used it.

I thing I would like, is a lower bottom speed.


----------



## 737mechanic

Superburban said:


> The one thing you are over looking, is the belt contact with the drive pulley (crankshaft pulley), most cars it is probably around 5 to 8 inches, vs your approx 2". But then , an alternator, A/C comp, and water pump can easily add up to 20 to 30 HP, vs your 2hp, and the big gear reduction of the driven gear ratio.



Didn't overlook it, thats why I went 10 rib instead of 5 or 6.




> I have had a Shopfox, M1112, since 2011. It is the same machine as the 4003G (Who knows if quality is the same, better, or worse), and have run it hard without any hiccups or burps. If I were to do it again, I would buy either machine. Wow!, I just looked up the prices. $3625 for the Grizzly, VS $4729 for the Shopfox. When I bought mine, ($32xx sticks in my mind), it was under $50 more for the Shopfox, and it has the coolant pump built in that the Grizzly does not, that was my deciding factor. Even though I have never used it.



I looked at the shop fox and if I could have found the shopfox for the same price I would have went with the shopfox only because it comes with coolant pump but the best deal I could find on the shopfox was $1000.00 more than the G4003G and I wasn't going to spend the extra $1000.00 for a $100.00 coolant system.



> I thing I would like, is a lower bottom speed.



Agree and I was going to make the larger pulley 6in. to 6.5in. so the speeds would have been lower as I hardly ever use the top speed anyway but couldn't find a decent deal on a piece of steel or aluminum that size so ended up keeping it the same size as original.


----------



## rgray

Superburban said:


> I have had a Shopfox, M1112, since 2011. It is the same machine as the 4003G (Who knows if quality is the same, better, or worse), and have run it hard without any hiccups or burps. If I were to do it again, I would buy either machine. Wow!, I just looked up the prices. $3625 for the Grizzly, VS $4729 for the Shopfox. When I bought mine, ($32xx sticks in my mind), it was under $50 more for the Shopfox, and it has the coolant pump built in that the Grizzly does not, that was my deciding factor. Even though I have never used it.



I also have a M1112 the build date on it is 12/2011.
I originally ordered the 4003G but they were 4 months out. So I ordered the M1112 and it took 1 month to get it.
The other thing my M1112 has is a cast iron stand. Advertising called it vibration dampening back in 2011.
Not sure if the new ones have that still but if they do then the price difference might make more sense.


----------



## Superburban

737mechanic said:


> Didn't overlook it, thats why I went 10 rib instead of 5 or 6.



Yes, you did say that, my bad. My damm old brain keeps skipping words.


----------



## Superburban

rgray said:


> I also have a M1112 the build date on it is 12/2011.
> I originally ordered the 4003G but they were 4 months out. So I ordered the M1112 and it took 1 month to get it.
> The other thing my M1112 has is a cast iron stand. Advertising called it vibration dampening back in 2011.
> Not sure if the new ones have that still but if they do then the price difference might make more sense.


Mine is 3/2011. Had it in about a week. Then took another few weeks to get it in the shop, and setup.

Did not even think about the stands, A friend has a 4003G that is a few months older then my M1112, I'll have to compare the stands.


----------



## rgray

737mechanic said:


> BTW Its been 8 months now and everything is running perfect. I still haven't got around to installing the brake setup but when I do I will post it.



I have a crazy thought on gear drive headstocks and a brake. I'm wondering if the brake was set to drag if the mysterious finish issues would disappear.  Thinking the finish is affected by oscillations in the gears from the motor. Thinking that belt drive lathes have the belt to absorb some of that and so it doesn't show up in the finish as easily on them. The brake would need to be on the spindle to test this theory. Maybe I'm just grasping.


----------



## 737mechanic

rgray said:


> I have a crazy thought on gear drive headstocks and a brake. I'm wondering if the brake was set to drag if the mysterious finish issues would disappear.  Thinking the finish is affected by oscillations in the gears from the motor. Thinking that belt drive lathes have the belt to absorb some of that and so it doesn't show up in the finish as easily on them. The brake would need to be on the spindle to test this theory. Maybe I'm just grasping.



I like that theory and it makes sense. With that said though I have never had any finish issues that I have noticed. Something else that might be able to be done is put a hormonic balancer from a car on the back of the spindle and see if that has any positive effect.


About the stands that a couple have brought up. Are you guys saying that some G4003G stands are not cast iron because all the G4003G's that I have seen including mine are cast iron and weight a ton. In fact they look just like the M1112 other than the color.


----------



## rgray

737mechanic said:


> About the stands that a couple have brought up. Are you guys saying that some G4003G stands are not cast iron because all the G4003G's that I have seen including mine are cast iron and weight a ton. In fact they look just like the M1112 other than the color.



I was under the impression that they were different, but that is only from reading on this site and comments that have been made.
Looking at the grizzly site at the g4003g it says "heavy duty steel stand" 
I have been around an older grizzly 12x36 and it has sheet metal stands. It is not the gunsmith version.
I wonder if some were supplied differently depending on availability of cast stands.


----------



## rgray

737mechanic said:


> I like that theory and it makes sense. With that said though I have never had any finish issues that I have noticed. Something else that might be able to be done is put a hormonic balancer from a car on the back of the spindle and see if that has any positive effect.



I haven't had much finish issues either. With 1018 sure with about anything else no problem. 
I like the dampener idea. I think the automotive dampener would be to stiff as it is taking a huge shaking compared to what our lathes are doing.
When I think of a brake to curb the oscillation an antique dynamometer comes to mind where the output power was measured by wrapping the output shaft with a rope or leather strap and then adding weights which added braking effect.


----------



## Superburban

rgray said:


> I have a crazy thought on gear drive headstocks and a brake. I'm wondering if the brake was set to drag if the mysterious finish issues would disappear.  Thinking the finish is affected by oscillations in the gears from the motor. Thinking that belt drive lathes have the belt to absorb some of that and so it doesn't show up in the finish as easily on them. The brake would need to be on the spindle to test this theory. Maybe I'm just grasping.



I like that idea. I think it would only work if the brake is on the spindle, with the gears between the motor, and spindle. If the brake was mounted on the motor, or belt input to the head, then you still have the gears between the brake and spindle.

I have also wondered about going to a heavier chuck, say a 10"


----------



## 737mechanic

Here are the two lathes and the stands look identical to me.


----------



## Superburban

Shopfox changed theirs, my base is welded steel. I have been looking at them so long, I forgot I had the base from my friends 4003g. The old 4003g, is definitely cast. Interesting that Shopfox updated their picture, but still show the single piece jaws.


----------



## Superburban

rgray said:


> I also have a M1112 the build date on it is 12/2011.
> I originally ordered the 4003G but they were 4 months out. So I ordered the M1112 and it took 1 month to get it.
> The other thing my M1112 has is a cast iron stand. Advertising called it vibration dampening back in 2011.
> Not sure if the new ones have that still but if they do then the price difference might make more sense.


I was wrong, mine is also 12/2011. Must have been 3/2012 that I got mine.


----------



## 737mechanic

I remember unpacking my g4003g and the boxes the stands were in had the weight on them and one stand was 250lbs and the other was 300lbs.


----------



## Superburban

737mechanic said:


> I remember unpacking my g4003g and the boxes the stands were in had the weight on them and one stand was 250lbs and the other was 300lbs.



Having worked many years for an LTL (Less then load) trucking company. It is not unusual for items to be marked over the actual weight. Most of the regular companies have a contract, and are billed by the cube, over weight. Weights need to be on the documents, and are used to make sure a truck is not over weight, so many companies will guess way over, or round the figure to the next hundred. I am surprised Grizzley would be so far off. 

Sorry for hijacking the thread 737, I'll stop now.


----------



## Splat

I have the cast iron stands and there's no way each ways around 300lbs. More like 150lbs each. Switching to these iso mounts definitely helps cut the vibrations down to practically nothing. Speaking of which, here's a good thread with more about what we're talking about.


----------



## rgray

Superburban said:


> I was wrong, mine is also 12/2011. Must have been 3/2012 that I got mine.



Mine is 111390. Small world. oooppps another hijack.


----------

