Longitudinal and Cross Power Feeds for G0602 Type Lathe

[LMMasterMariner]

I wasn’t happy with absence of power cross feed on my lathe, so decided to make one. After numerous drawings, I realized that with this modification I can also have longitudinal power feed. Didn’t want to cut keyway in lead screw, as I might ruin that one and then I would need to buy new lead screw. Anyhow this is obsolete design and lead screw suffers more than it is necessary. Other option was to install feed shaft. Didn’t even think of using DC motor and PWM controller like I did for power feed at my milling machine.

Not much space inside the apron, but there is plenty space outside of the apron. Cross feed wheel and half nut lever are still intact without any new hole in them and all are used for this modification. Carriage wheel got one new hole and apron got plenty holes. If I have to do it again, I would fabricate completely new apron and would use the very same design; feed shaft, wormbox, long/cross selector and engagement sear. But in that case I wouldn’t be limited with awkward positions of existing parts inside the apron.

Nice addition to this apron is automatic stop for longitudinal feeding. The same flat bar for automatic feed stop will be used for automatic threading stop, but more about it after I complete this job. Tried to make better system than one which can be found on cheap lathes; just selector which engage cross and long. gears. That’s why I used both; selector and lock, so it can’t get out by itself. Idea about that latch for the sear came after numerous drawings.

Feed shaft was made from 15 mm dia 316 SS and after keyway was cut, observed that shaft was bent upward about 5 mm in length of approx. 1 meter. Took me some time till I got it straight again.

Couple of drawings posted here are for information only. Not to be used for making parts. Drawings were made during my last contract, based on measurements which I got from my nephew. (I was on board and he took measurements at home.) Needles to say that these measurements were not accurate at all, so almost every part was modified. Some parts were fabricated couple of times. Drawings were not updated for that changes.

This job kept me busy couple of hours per day almost every day for 3 months and I still didn’t finish it. Expect to complete this job by the end of May.

Cheers
LMMasterMariner

[tonyfoale]

I wasn’t happy with absence of power cross feed on my lathe, so decided to make one. ......... Other option was to install feed shaft. Didn’t even think of using DC motor and PWM controller like I did for power feed at my milling machine.
Cheers
LMMasterMariner

OK I'll bite. Why did you not go for the motor option, something that you have had experience with? I would have thought fitting two motors would have been much less work.

[LMMasterMariner]

OK I'll bite. Why did you not go for the motor option, something that you have had experience with? I would have thought fitting two motors would have been much less work.

Two motors would be just a step towards CNC lathe which I don’t need. There are couple of CNC kits for this type of lathe on the market, but I wanted to make power feeds myself. Need lathe with all the features that good lathes have. Once I fabricate additional screw cutting gearbox (Norton type with only 7 gears inside gearbox) I will have the following feeds: Longitudinal: 0.059, 0.071, 0.083, 0.095, 0.106, 0.118, 0.142, 0.165, 0.177, 0.189, 0.213, 0.236, 0.295, 0.354, 0.413, 0.473, 0.591, 0.709, 0.827 mm and Cross: 0.008, 0.010, 0.012, 0.014, 0.015, 0.017, 0.020, 0.024, 0.025, 0.027, 0.030, 0.034, 0.042, 0.051, 0.059, 0.068, 0.084, 0.101, 0.118 mm and all metric threads from 0.25 to 3.5 mm without any gear change. There was an additional challenge; nobody did this kind of modification for this type of lathe so far. At least I can’t find any information about it. And yes, I agree with you that fitting two motors would require less work to do.

Cheers
LMMasterMariner

[tonyfoale]

Two motors would be just a step towards CNC lathe which I don’t need. ......
.... And yes, I agree with you that fitting two motors would require less work to do.

Cheers
LMMasterMariner

I had a chuckle when I read that. I was faced with that recently when my spindle drive modifications got in the way of re-installing the change gears. New feed drive method for a lathe. I kept thinking about motorising the feed, but like you I do not need a CNC lathe and it would have been impossible to resist the temptation to go all the way.

[DIYSwede]

There was an additional challenge; nobody did this kind of modification for this type of lathe so far.

Absolutely right! YouTube is literally filled with fellow machinists merely doing what hundreds have already shared.
Thanks for pioneering again into the hitherto unknown and uncharted realms of DIY!

Respect
Johan

[Canyonman44]

I can't find part 2 of the vids. Do I take it it will come in May?? And do you happen to know how/if the G4003G differs from G0602? I have had the Grizz folks direct me towards the G0602 for parts. And I hate to ask, due to the time involved, will there be dimensioned plans? And what if I just want the automatic tool stop as mine has the feeds. I would be IMMENSELY interested in that!!!!! And I think I missed what activates the auto-stop?
Thanks Ken

[LMMasterMariner]

I can't find part 2 of the vids. Do I take it it will come in May?? And do you happen to know how/if the G4003G differs from G0602? I have had the Grizz folks direct me towards the G0602 for parts. And I hate to ask, due to the time involved, will there be dimensioned plans? And what if I just want the automatic tool stop as mine has the feeds. I would be IMMENSELY interested in that!!!!! And I think I missed what activates the auto-stop?
Thanks Ken

Part 2 should be completed latest by the end of May. Still have 2 months till end of my contract and expect to be home beginning April.
As you can find in Grizzly adverts, G4003G is real machine allegedly the second G stands for gunsmithing and G0602 is much cheaper lathe but quite okay for hobby. Nothing needs to be modified on G4003G unlike G0602. Here I put one more drawing for clarification of automatic stop. When part called "AAA" come to carriage stop (of any kind, so many pictures on the web) and as carriage is progressing towards to the chuck, AAA as part of yellow painted flat bar is moving backwards and by doing that, it's moving the latch out of engagement. Latch was made from the key 15x10 mm, length 75 mm. Hope it's more clear now.

Cheers
LMMasterMariner

[Canyonman44]

Forgive me, I'm not as sharp as I used to be. Would it be possible to superimpose the schematic over a picture of the apron/carriage? Just a request, you are not obligated to do anything. Ken

[LMMasterMariner]

Forgive me, I'm not as sharp as I used to be. Would it be possible to superimpose the schematic over a picture of the apron/carriage? Just a request, you are not obligated to do anything. Ken

as you wished. schematic over the picture. Hope you got it now. if not, i'm afraid that you will need to wait for part 2.

[Canyonman44]

LOL, Thank You my friend. I don't know why I'm having trouble wrapping my head around this. I appreciate your time and patience. I look forward to the final chapter.
I'll try and not bother you further.
Ken