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

[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]

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]

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]

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]

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.

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]

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]

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.



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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.