7x14 to 7x16 Rebuild

[dabear3428]

Mmmmm, waffles! Do you guys have them over there?





Maybe I can give some insight.

On a direct drive lathe of this size 1.5HP really is not out of the question. The issue comes in with low speed torque. With a DD lathe you need more mass in the windings to offset the heat buildup when running down at low speeds.

On My SD400 I'm keeping the belt reduction and going with a higher HP motor for a variety of reasons along with the heat issue. Im used to 7HP lathes with a low speed of 30ish and mountains of torque for performing certain tasks. Mush safer (Tooling wise) to be able to pull up low speed/high torque when you need it that to be stuck having make do.

I think when I cross multiplied, divided and carried the one and all, I came up with a low speed of 3.5rpm and a high speed of 5000 with the CC motor and 12 sheeve steps over 3 sheeves.

Should be OK.

or add an aux fan to run at full speed to cool the motor anytime the motor is running.

 

[RaisedByWolves]

or add an aux fan to run at full speed to cool the motor anytime the motor is running.

It really needs internal cooling and these motors are pretty much sealed.

Not a bad idea though and one I have pondered in the past.

 

[SouthernChap]

Why I say my good dude, you @Ed him 87 times in one post, he's probably in need of a pint right now.


As to the quoted post, yeah, look how well that turned out for me a few times.

I know; I was well aware it sounded like I'm the founding member and chair of the @GrifterGuru appreciation society.

But if you do it once, will the recipient take it oddly if you don't do it every time? What message are you sending when you @ someone and then fail to do it afterwards? Frankly, it's a terrifying dilemma.

(and whilst I am humourously mocking myself here, the above paragraph really isn't that much of an exaggeration of my internal state, oftentimes when writing a post that engages with or references someone. It's fun being me...and that's with my meds!)

Well, to hell with that. I'm going to take the easy way out and just @ GG to death for my own sanity (oh and I didn't @ him there...what is he going to thi...shut up, will the chatter in my head just not shut up! )

Anyway, for all the fact that GG appears to be somewhat obsessive and a little blunt (but eh, there are plenty of those on here, amongst them, thee and me! ), I really am enjoying his approach and the documentation of said approach.

Also, the lack of awareness of the capabilities and upsides (such as they are) of these little Chinese machines, plus the constraints some of us work under, is a subject I have some fairly strong views on (don't get me started on BlondiHacks "Please sir, I know I only have a Chinese 10x22 but it is from PM and at least it's not one of those horrid little mini lathe things", she's smarter than that and her audience deserve better ).

So yeah, that's why...since you asked...since you did.

 

[SouthernChap]

I agree with all of the above, please do not take my input as derogatory in any way. it is all fun in the end and it is not like any of us are trying to feed our families with the output of our shops, these are hobby activities and enjoyment/learning are the payoff not $s.
my question was, asking the OP if HE thought, not me trying to make that determination for him or what anyone else that has not done this to this level, thought , it is not up to me and should not be. as someone that has similar tendencies, i'm interested in his opinion about this approach to this project after he has done all of this work, again not saying anything just asking what the OP thinks about his project so far.
BTW i do not have any suggestions about how to do it better, because i do not know how to do this better. i guess i'm asking about lessons learned in this process.

Sorry, in addition to me being aware I was sounding like I was kissing GrifterGuru's ass, I was also aware after the fact that it might have sounded like I was wagging a digit at you. Honestly wasn't. I said the course GrifterGuru has taken was the sanest one, not an ideal to aspire to (unless re-engineering is one's thing I guess).

To be honest, with the delightful hindsight that all of us can call on, and absent budgetary and/or space constraints, I'd have to guess that few of us would willingly take on correcting and upgrading the standard Chinese mini lathe if we could avoid it. So I completely get people when they ask "Why...just...why?"

 

[dabear3428]

It really needs internal cooling and these motors are pretty much sealed.

Not a bad idea though and one I have pondered in the past.

if it is a brushless dc the rotor is a magnet and does not need that much cooling the exterior case is where the stator lives and needs the cooling so more airflow over the case helps, basically anyplace there is an external fan on a motor add more flow helps cooling, on Ac motors, not so much because a lot of heat is generated on the rotor and hard to cool. the external fan only helps when the motor is running below its designed speed and the flow from the shaft attached fan that loses flow with the square of the rpm falls way too low

 

[dabear3428]

Sorry, in addition to me being aware I was sounding like I was kissing GrifterGuru's ass, I was also aware after the fact that it might have sounded like I was wagging a digit at you. Honestly wasn't. I said the course GrifterGuru has taken was the sanest one, not an ideal to aspire to (unless re-engineering is one's thing I guess).

To be honest, with the delightful hindsight that all of us can call on, and absent budgetary and/or space constraints, I'd have to guess that few of us would willingly take on correcting and upgrading the standard Chinese mini lathe if we could avoid it. So I completely get people when they ask "Why...just...why?"

i did not take it that way and i'm also a member of the GG fan club. and as such interested in his take on all of this, as to him being gruff, i can see how when you put your ideas out like he has you may respond less that pleased if you think someone that is not in your shoes and has not done the work is poking holes in your ideas.
SC, we do not have any disagreement.
GG, love your work and just trying to take away as much insight as i can from your trials.
I'm on HM to learn and maybe share what little i can.

 

[SouthernChap]

i did not take it that way and i'm also a member of the GG fan club. and as such interested in his take on all of this, as to him being gruff, i can see how when you put your ideas out like he has you may respond less that pleased if you think someone that is not in your shoes and has not done the work is poking holes in your ideas.
SC, we do not have any disagreement.
GG, love your work and just trying to take away as much insight as i can from your trials.
I'm on HM to learn and maybe share what little i can.

Heh, if other people's ideas on here were gold, I'd now hold more than most countries reserves.

 

[GrifterGuru]

Ok, first up, I never take things personally, I have a (very) thick skin. I can certainly give as good as I get.

As to being Gruff? Thats to do with HF-ASD more than it is anything else and I do try to keep a lid on it. I am also aware that sometimes I can come across in ways not intended due to the way I write certain things.

Regarding the 7x16....

@SouthernChap I have 17-1/2" between centres on the rebuild. I am also in the rebuild due to the "pile of scrap" being delivered that was sold as a lathe, that I was refunded for and told to keep. This rebuild is not about sanity for me, it is a way to relax and engage in a lifetime hobby on my own terms and learn a few things along the way that I may not have known before as well as rehoning long dormant skills.

@dabear3428 keep the questions coming. I have more than a few of my own. We only learn when we ask questions. when we stop asking we stop learning.


Re Would I do this if I had the choice between a 7x and a better lathe? Yes. simply put I would. It allows a freeing of the mind to explore options and problem solve in an organic way which I find is a useful skill to maintain.

If I had room for a bigger lathe would I have one? . If I did have a bigger lathe would I still go for a 7x? yes, but only if I started from scratch the way it has worked out with this rebuild.

 

[SouthernChap]

Ok, first up, I never take things personally, I have a (very) thick skin. I can certainly give as good as I get.

As to being Gruff? Thats to do with HF-ASD more than it is anything else and I do try to keep a lid on it. I am also aware that sometimes I can come across in ways not intended due to the way I write certain things.

Regarding the 7x16....

@SouthernChap I have 17-1/2" between centres on the rebuild. I am also in the rebuild due to the "pile of scrap" being delivered that was sold as a lathe, that I was refunded for and told to keep. This rebuild is not about sanity for me, it is a way to relax and engage in a lifetime hobby on my own terms and learn a few things along the way that I may not have known before as well as rehoning long dormant skills.

@dabear3428 keep the questions coming. I have more than a few of my own. We only learn when we ask questions. when we stop asking we stop learning.


Re Would I do this if I had the choice between a 7x and a better lathe? Yes. simply put I would. It allows a freeing of the mind to explore options and problem solve in an organic way which I find is a useful skill to maintain.

If I had room for a bigger lathe would I have one? . If I did have a bigger lathe would I still go for a 7x? yes, but only if I started from scratch the way it has worked out with this rebuild.

I really don't think you need explain any bluntness, particularly not to me*!

When I said 'sanest course' I meant most sensible, given the space you have; I wasn't referring to mental health (maintenance of such or otherwise)

We're different in our preferences (and obviously the level of pre-existing skills and practical experience on purchase; I had very little). I'm happy that I've had the chance to learn so much during this 'enforced rebuild project' of mine, but I reckon, for me, there are other projects, less maddening to tackle, that I could have built my skills on, if I'd had the knowledge and patience to look for a decent example of old English iron (or if still insisting on buying new, spent a bit more money on the better manufacture, QC and rigidity of a Warco WM180 for example).

That said, for example, I'm still pondering on whether to buy one of the £200 1" x 42" belt sanders from AliExpress and use the it as a base to work out the 'bugs' from, or start from scratch using one of the 'open source' designs out there (there are quite a few) so maybe we're not that different in preferences at least!


*I personally often over-apologise/over-explain but that's not down to any virtue on my part, that's down to my family's ADHD genetic inheritance and the anxious, chattering internal dialogue in my head that's a particularly delightful 'feature' of my ADHD 'firmware'

 

[RaisedByWolves]

Soooo many words…..

The Horror……The Horror…..