# Grizzly G4003G VS G0750G Lathes



## Alex Roy (Aug 23, 2014)

Hello All;

I have question for respective owners of these machines.

I am looking to possibly purchase one of these two and noticed that there is very little difference between them in terms of specs. 

Is there something I am fundamentally not seeing when looking at the machines. 

Presently I have a early 1940's (I think) Leblond Regal, it is not in terrible shape but I am looking for something that I do not have to compensate for constantly.  

The other option is to try to rebuild the Leblond, but that is another discussion.

In short, can the respective owners of these machines tell me the main differences between them? (Is one more rigid than the other? Etc.)

Look forward to hearing from you.


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## zmotorsports (Aug 23, 2014)

I don't own either one, the specs appear to be very similar but a big draw for me would be the Norton style quick change gearbox on the G4003.  I am not certain if there would be more gear changes on the side gears with the G750 or not.

The G750 looks very similar to Precision Mathews PM1236 which is another popular lathe.

Sorry I couldn't be more help.

Mike.


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## tmarks11 (Aug 23, 2014)

The QCGB.

The G750G has an enclosed oil-filled QCGB.  No chips get in it.

The G4003G has an open ("Norton" style) QCGB.  Chips can get in through the slots on front, you keep it lubricated by squirting oil through the slots on the gears.

The enclosed QCGB is a far superior design.

but.... BUT...

not so fast... read the manuals.  Both machines require you to swap change gears (under the cover on the left side) to cut different threads, but one is WAY WORSE than the other.  Read that closely since they are a bit different on what you have to swap.

G750G: 13, 18, 20, and 24 pitch (for example) are ALL different end gear combinations (ONLY 16 & 20 share the same arrangement).  Tells me that if I am cutting an inch thread, I will be swapping gears. Oh, and if you are cutting any threads but 16 or 20 pitch you will be swapping gears again to get power feed capability back.
G4003G: wait, what do we have here? All inch threads can be cut without swapping gears?  And I can still feed without swapping gears after threading? I only have to mess with change gears if I need metric threads?

So how was that enclosed QCGB so superior again?  I forget...

Other than that, no real difference between 4003 and 750. Should be same (lack of) rigidity. Both 2 HP, limited to 1400 rpm (ugh).

Bottom line (to me): if your budget restricts you to the 4003G or 750G, I would buy the 750G.  But, i think an extra $1000 to get the G709G with a fully enclosed QCGB, and no change gears to swap (unless you want metric), and 2000 rpm, is money well spent.  Which I did...

G750G inch threading:



G4003G Inch Threading:


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## Pmedic828 (Aug 23, 2014)

Hope this helps





G0750G
G4003G
Operation Info    Swing Over Bed
12 in.12 in. Distance Between Centers
36 in.36 in. Max Weight Between Centers
 
 
 Swing Over Cross Slide
7 in.7 in. Swing Over Saddle
11-11/32 in.11-11/32 in. Swing Over Gap
17 in.17 in. Maximum Tool Bit Size
5/8 in.5/8 in. Compound Travel
3-1/4 in.3-1/4 in. Carriage Travel
30-1/2 in.30-1/2 in. Cross Slide Travel
5-5/16 in.6-1/4 in. Other    Carriage Handwheel Graduations
 
 
 Carriage Handwheel Revolution
 
 
 Cross Slide Handwheel Graduations
 
 
 Cross Slide Handwheel Revolution
 Compound Handwheel Graduations
 
 
 Compound Handwheel Revolution
 
 
 Tailstock Handwheel Graduations
 
 
 Tailstock Handwheel Revolution
 
 
 Optional Stand
 Headstock Info    Spindle Bore
1.57 in.1.57 in. Spindle Size
 
 
 Spindle Taper
MT#5MT#5 Spindle Threads
 Number of Spindle Speeds
99 Spindle Speeds
70 – 1400 RPM70 – 1400 RPM Spindle Type
D1-5 CamlockD1-5 Camlock Spindle Bearings
High-Precision Tapered RollerHigh-Precision Tapered Roller Spindle Length
17 in.17 in. Spindle Length with 3-Jaw Chuck
21-3/4 in.21-3/4 in. Spindle Length with 4-Jaw Chuck
21-1/4 in.21-1/4 in. Spindle Length with Faceplate
18-1/2 in.18-1/2 in. Tailstock Info    Tailstock Quill Travel
3-3/4 in.4 in. Tailstock Taper
MT#3MT#3 Tailstock Barrel Diameter
1.575 in.1.563 in. Threading Info    Number of Longitudinal Feeds
3240 Range of Longitudinal Feeds
0.0020 – 0.0548 in./rev.0.0011 – 0.0310 in./rev. Number of Cross Feeds
3240 Range of Cross Feeds
0.0007 – 0.0187 in./rev0.0004 – 0.0105 in./rev Number of Inch Threads
3440 Range of Inch Threads
4 – 56 TPI4 – 112 TPI Number of Metric Threads
2629 Range of Metric Threads
0.4 – 7.0 mm0.2 – 4.5 mm Number of Modular Pitches
 Range of Modular Pitches
 
 
 Number of Diametral Pitches
 Range of Diametral Pitches
 
 
 Dimensions    Bed Width
7.126 in.7-1/4 in. Carriage Leadscrew Diameter
7/8 in.0.870 in. Leadscrew TPI
8 TPI8 TPI Carriage Leadscrew Length
46-3/4 in.44 in. Steady Rest Capacity
3/16 – 1-1/2 in.3/16  – 1-1/2 in. Follow Rest Capacity
1/4 – 3/4 in.1/4 – 3/4 in. Faceplate Size
10 in.10 in. Feed Rod Diameter
3/4 in.3/4 in. Floor to Center Height
46-1/4 in.46-1/4 in. Height With Leveling Jacks
 
48-1/4 in. Construction    Base
Cast IronCast Iron Headstock
Cast IronCast Iron End Gears
Flame-Hardened SteelFlame Hardened Steel Bed
Induction-Hardened, Precision-Ground Cast IronInduction-Hardened, Precision-Ground Cast Iron Body
Cast IronCast Iron Stand
Formed SteelCast Iron Paint Type/Finish
EpoxyEpoxy Fluid Capacities    Headstock Capacity
3.5 qt.3.5 qt. Headstock Fluid Type
ISO 32 (eg. Grizzly T23963, Mobil DTE Light)ISO 32 (eg. Grizzly T23963, Mobil DTE Light) Gearbox Capacity
1 qt.1 – 2 Pumps Gearbox Fluid Type
ISO 68 (eg. Grizzly T23962, Mobil Vactra 2)ISO 68 (SB1365, Grizzly T23962, Mobil Vactra 2) Apron Capacity
0.5 qt.0.5 qt. Apron Fluid Type
ISO 68 (eg. Grizzly T23962, Mobil Vactra 2)ISO 68 (eg. Grizzly T23962, Mobil Vactra 2) 


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## darkzero (Aug 23, 2014)

As tmarks stated, the main differences are the QCGBs. The 0750G has a fully enclosed oil filled GB where the 4003 norton style GB is a drip oil lube system that you lubricate by squirting oil through oil ports. 

There was a recent thread in regards to 0750G not having a neutral poistion for the GB.. Perhaps they felt that since the 0750G has an oil filled gearbox there is no need to disengage power to the GB to reduce wear. My PM1236 does have the oil filled GB yet still has the neutral position as well.

The 4003G has more thread pitch capabilities & as far as I can see that would be the deciding factor between the 2. Looked at the manual & the 0750G's doesn't seem to be much of a quick change. Although it looks similar to the PM1236 it does not function the same. Both should give you equal performance though.


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## dave2176 (Aug 23, 2014)

There must thousands of machines with a Norton gear box that have worked for decades without trouble. I bought the G4003G and that was one of the reasons, didn't want gear changes for American. Another reason it's that the number of threads available, all the way to 112 tpi translates to more feed speeds as well. That came up before in a discussion here where a enclosed gear box 1236 didn't meet the feed requirement and s running faster than desired. Having used my G4003G for more than a year I can confirm it is a very nice machine.

 Dave


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## epanzella (Aug 25, 2014)

I have my G4003G for just over a year and am very happy with it. The gear changes of the G0750 was a deal breaker for me. I have to change for metric threading but inch threading from 4 to 112 TPI is in the gearbox. The majority of the stock I use is unknown alloy from the scrapyard so I'm always changing speeds and feeds to dial in a material. I like to knock down OD's fast with carbide and then finish with HSS  so I would be changing gears constantly. It's enough of a hassle just changing gears for metric threading particularly since the gear cover is not hinged and has to be removed completely.  I'm sure others are more proficient at gear changes than I but throwing a lever or two is well within my capability.


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## Walsheng (Aug 25, 2014)

I was torn between the same two also.  I went with the G4003G because of the gear changes and the wider range of thread cutting.
I was concerned about the "noisier" G4003G but decided in the end I could just turn my hearing aids off and not worry about it.  It turns out that it is not very noisy at all, even in the smallish shop, about 12' x 20', that it resides in.
I have been running it for a few months now and I have been very pleased.  I have machined a bunch of stuff from a 6" diameter hunk of cast iron (riser block for a 6x26 mill) to a .062"x.032" steel bushing with a ,023" hole.

John


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## Earl (Aug 26, 2014)

I bought the grizzly 4003g because it was available when I bought a Grizzly mill off of Craigslist.  Both the G 0695 and the G 4003G were less than a year old and approximately half price!  I have a heavy 10 that I love but the Grizzly added some length that I didn't have in the Heavy 10, and a larger spindle bore.  The grizzly took a bit of work to get it working well (I consider all chineese machines  Kits).   I added a 3 phase motor that I had under the bench,  a hundred dollar vfd (huanyang), a 50 dollar tach (machtach), and a used BXA toolpost.  I took off the work light and tossed it in the garbage, Bought a 50 LED work light from costco,  built a bracket and mounted it about 18 - 20 inches above centerline.  (I think I may need sunscreen when I use the lathe).  I leave the gears set to the 1000 rpm setting and use the vfd to go from about 175 to about 1800 rpm with out shifting.  The acceleration and deceleration are much nicer than the harsh start and long slow down with the single phase motor.  I also purchased a d1-5 backplate I found on sale and fitted it to my Buck 6 jaw set tru.  I love the machine.   It does everything that I want / need.   I just purchased  a tpcatools DRO.  It has not yet arrived.   I doubt that I will like it as much as my Newall on the Heavy 10, but the price point fits right in with the lathe.    It is a great value.  

Earl


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## joshua_ (Aug 28, 2014)

I have the G0750G and it has been good for me so far.  

I can't say it's any better or worse than the 4003 though, sorry.  

When I was choosing I went with the G0750G by recommendation of the gentleman who was 'mentoring' me.  I did find my way to the 4003 and he said either way would be fine but he would do the G750G, so I did.  (I know that's of little help)

I do have to change gears out fairly often, but it is a very fast process.  I would be surprised if it takes me more than 3 minutes to swap gears.  For me that's not an issue.  Most of the time I'm either using 28 or 24 tpi, but I've used metric and a number of other tpi.  

Someone above mentions having to swap gears for power feed, but I haven't found that to be true.  It could be that I am misunderstanding what the person above meant.  

I am happy with the G0750G, but I have no reason to say it's any better than the 4003.  I can see how the easier gear changes on the 4003 would be nice, especially if a person was doing multiple tpi on one task.  It's rare that I use more than one tpi per task.  

If you have any specific questions or need any pics or info let me know and I'll help.  

I do want to try to see about getting my feed to have a neutral (G0750G doesn't have N).  I believe it is an easy fix, but will report back on that thread once I have a chance to dig in.


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