Some pics of my workshop

[HennieL]

Your little lathe looks very nice. What brand is it? I can't believe the number of manufacturors of lathes in China--it's incredible. But who to trust?

Hi Richard,

It's manufactured by a Chinese company called Yangzhou Super Machine Tool Company Ltd. and is their Model C0632A x 1000. I believe that they supply the same model to the States as the Grizzly model G0776 - In fact, I downloaded the Grizzly manual, and refer to that, rather than to the non-understandable Chinglish manual that came with my lathe.

I have been using this lathe since April 2018, and so far it has worked quite well. TIR is less than 0.02mm over 300mm (about 0.0008" per foot in the archaic American imperial units ), but it is not bolted down, and could be adjusted better if I spent some time on it... The finish was not too great "as delivered", with some casting sand still apparent in places, but a good cleaning removed all of this (I hope...). I drained and changed the oil in the three gearboxes (spindle, change gears and carriage) directly after receiving the lathe with good quality Shell Oil lubricants, and will change it again during the next month or so (oil already bought for this...) - that should tell me if there was any unusual wear in the machine.

One thing that I'm not too happy about (but is probably par for the course if one buys a Chinese lathe), is that I discovered last weekend that the tail-stock casting has a small crack right where the crank wheel abuts onto the casting (hidden from sight, and only discovered when I stripped the tail-stock for the first time to properly service & lubricate it). This does not affect the performance of the lathe, but it does confirm yet again that their quality is still not up to scratch, and that the only thing made in China that has lasted much longer than expected is their $%^&* Corona virus

Regards

Hennie

 

[Richard Hed]

Thanks for all the good advice and feedback, everyone.

My mill (an Optimum BF20) frustrates me in that I can only make very shallow (0.1 - 0.2mm) cuts. More than this, and it starts to chatter. Having said that, I've been using it for some years now (probably about 7-8, but cannot remember...) and have done some quite heavy work on it, but it's like eating an elephant - one small bite at a time...



Interestingly enough, that huge chuck can grip a 1.0mm drill. Having worked on mainly knives, I've never been bothered with Z-axes space, but I take your point, and will seriously consider removing the swivel base (thanks for the tip, Andy). I do have a collet chuck of sorts that I use to hold the end mill cutters- it's visible in a wooden "shelf" on the wall to the right of the mill in the second photo that I posted. It only has four collets (6mm, 10mm, 12mm and 16mm), and is not of the "ER" type - that's been on my wish list for some time now...



Gear cutting - now that's opening a whole new can of worms I've been wanting to learn how to do this for many years, but the cost of a rotary table has in the past put a damper on that - but it's really something to seriously consider in the near future (perhaps a "from Dad to Dad" Christmas present )

I think that the long drills and reamers are probably quite necessary for me (but I agree, probably not for making model engines...) - I have made quite a few tools & tool holders for the lathe, and made axles and shafts for various machines, and quite a few projects required deep-hole drilling/boring. The problem (as I see it) is that the hole sizes are usually long in comparison to their diameters, and I think that it will be much easier to drill all the way through (say 120mm - 150mm deep) with say 5mm, 8mm and 10mm or 12mm "long" drills before doing the final finishing with either a boring bar or a reamer - and HSS boring bars also have their 4x diameter reach limitation, so it's either reaming or buying carbide boring bars... As an example, here's a 12mm boring bar holder that I made, mounted in my lathe quick-change tool holder

View attachment 116209



Mauro, I've heard about those, but have never tried making/using one - I do have some very good powder metallurgy steels that I used for high-end knives (e.g. Bohler M390) that would probably come close to HSS performance... guess that's one more thing to look into. Fortunately, I do have an electric furnace, and the knowledge & experience to heat treat high-end steels, and I do make bespoke wood turning "long & strong" chisels using M2 and M42 high speed steels such as this one

View attachment 116207



Agreed

Again, thanks for everyone's input - keep it going

Hennie

I recommend making your own ER chucks--just buy the ER nut on line and build your own body. I have a 1-1/2" 8tpi Enco I am making at the present time.; Altho' I ***** and complain about that crappy little lathe, I AM making progress.

 

[Richard Hed]

Hi Richard,

It's manufactured by a Chinese company called Yangzhou Super Machine Tool Company Ltd. and is their Model C0632A x 1000. I believe that they supply the same model to the States as the Grizzly model G0776 - In fact, I downloaded the Grizzly manual, and refer to that, rather than to the non-understandable Chinglish manual that came with my lathe.

I have been using this lathe since April 2018, and so far it has worked quite well. TIR is less than 0.02mm over 300mm (about 0.0008" per foot in the archaic American imperial units ), but it is not bolted down, and could be adjusted better if I spent some time on it... The finish was not too great "as delivered", with some casting sand still apparent in places, but a good cleaning removed all of this (I hope...). I drained and changed the oil in the three gearboxes (spindle, change gears and carriage) directly after receiving the lathe with good quality Shell Oil lubricants, and will change it again during the next month or so (oil already bought for this...) - that should tell me if there was any unusual wear in the machine.

One thing that I'm not too happy about (but is probably par for the course if one buys a Chinese lathe), is that I discovered last weekend that the tail-stock casting has a small crack right where the crank wheel abuts onto the casting (hidden from sight, and only discovered when I stripped the tail-stock for the first time to properly service & lubricate it). This does not affect the performance of the lathe, but it does confirm yet again that their quality is still not up to scratch, and that the only thing made in China that has lasted much longer than expected is their $%^&* Corona virus

Regards

Hennie

Yeah, but the price certainly beats US or European models even with a crack. I'm looking at the Grizz G4003G. As Grizz backs up their products it may be worth the extra $$ over a direct from China Model. I've been looking aqnd you can't believe the number of brands from China. A lot of nice models but how can you guess at the quality? Will they back up their products? etc., etc? They are generally about 10-20-% cheaper than Grizz. I thimk they have products that if they were US or European, the price would be about 4X as much for maybe twice the quality--as I'm retired and will not be making $$ from any lathe, I certainly cannot buy a Monarch or Logan or any of those really nice ones.

BTW, I've seen that model -- One of the most irritating things about the Chiniese are that they take photos of several models and post it on the page yuou are viewing, then they DON'T show a photo of the opened gears on the head, they don't show the ways clearly,l they don't show the tailstock clearly, they often don't show the chucks clearly and Worse than anything,l is many of them sell the 4 jaw, followers and other standard parts separately. (Other than than, Mrs. Lincoln, how was the play?) they usually show 3 views of the front which is quite useless.

The Chinese also display the irritating view that someone buying something from them makes them a friend. As for me, MY friends are peeps whom I invite home for dinner and who invite me to dinner at their place. I've had Chinese salesmen call me "buddy", amigo, "my friend" and a bundle of other crap too. Well, the are NOT my friends -- they are at most business aquaintance. Who would ever call a salesman a friend?

 

[HennieL]

I drained and changed the oil in the three gearboxes (spindle, change gears and carriage) directly after receiving the lathe with good quality Shell Oil lubricants

It was quite late when I posted this, and "Spot the error": The change gears are obviously on the outside of the machine, and does not have an oil sump I meant to say the internal speed-change gearbox... but I'm sure that everyone will forgive this "blond moment"

As Grizz backs up their products it may be worth the extra $$ over a direct from China Model

I fully agree - if there was a Grizzly company in South Africa I would certainly be doing business with them.

… the price certainly beats US or European models even with a crack... many of them sell the 4 jaw, followers and other standard parts separately.

I've been fortunate in that I bought my lathe directly from the South African importer, and it was supplied with the four-jaw, a face plate, two steadies, two centres, even a drill chuck... I suspect that these items are stripped and sold separately by the local retailers. On the other hand, trying to have a latent defect repaired back in China two years after the purchase (or even directly after the purchase...) is not a practical option, so I suppose the cheaper cost does come with the additional risk of having a worthless guarantee.

...they DON'T show a photo of the opened gears on the head, they don't show the ways clearly,l they don't show the tailstock clearly, they often don't show the chucks clearly...

Richard, drop me a PM if you would like me to take specific photos and email them to you.

 

[Richard Hed]

It was quite late when I posted this, and "Spot the error": The change gears are obviously on the outside of the machine, and does not have an oil sump I meant to say the internal speed-change gearbox... but I'm sure that everyone will forgive this "blond moment"



I fully agree - if there was a Grizzly company in South Africa I would certainly be doing business with them.



I've been fortunate in that I bought my lathe directly from the South African importer, and it was supplied with the four-jaw, a face plate, two steadies, two centres, even a drill chuck... I suspect that these items are stripped and sold separately by the local retailers. On the other hand, trying to have a latent defect repaired back in China two years after the purchase (or even directly after the purchase...) is not a practical option, so I suppose the cheaper cost does come with the additional risk of having a worthless guarantee.



Richard, drop me a PM if you would like me to take specific photos and email them to you.

No, no. It's not necessary to see YOUR lathe parts--I'm complaining in general that the Chinese either do not know how to take proper photos OR they are unartfully dissembling with their machines trying NOT to show what they should be showing--other words, they are lying and trying to trick their potential customers.

 

[awake]

You have seen a picture of my primary fly cutter. I can take a 20 thou cut in steel (0.5 mm) at around 450 rpm and about two to two and a half inches a minute in EN1. Double that in brass or aluminum. The fly cutter cuts 2.5" diameter and is 20 mm thick on a 20 mm shaft.

Baron, that is an impressive DOC with a fly cutter that large!

 

[BaronJ]

Thank you Andy,

That fly cutter and a couple of similar ones were built from scrap that I had to hand. The shaft was an off cut of 20 mm silver steel bar (drill rod) and the disc a slice from a 3" inch diameter stainless steel bar that I cleaned up on the lathe and drilled then bored so that the shaft was a press fit into it. I used the bench vise to press it in and then cleaned everything up in the lathe.

The hole for the tool bit was drilled to take 1/4" square HSS tool bits and secured with a 2BA hex socket grub screw.

The rationale behind the design is that the weight will have a flywheel effect and reduce deflection due to the thickness of the disc. Also because the very slight difference in weight that removing material by drilling a hole and filling it with a tool bit and grub screw makes, it would be very well balanced, so vibration due to the rotation would be minimal. This is born out by the lack of vibration spinning the fly cutter at the maximum speed of the mill, which is a little over 2200 rpm.

You do need to grind the HSS carefully to get the best out of it. I use a semicircular shape with about a 3 to 5 degree clearance and about the same back rake on steel. Aluminum and brass is far more forgiving with the angles.

I hope that this description helps.

 

[awake]

Baron, thanks for the details, and a good observation on the "fly wheel effect" of the design. All of the fly cutters I have made are the typical slanted design, with the corresponding lack of balance. I will have to give your design a try.

I noted the semicircular shape of the tool bit - very interesting. I would have guessed that would have been too broad a nose to work well except at very fine DOC. I wonder if a similar shape would work well on my shaper ... I'll have to give that a try!

 

[MADJACK]

Very cool, nice shop.

 

[HennieL]

Like Baron, I have often done boring using HSS tooling with more than 4x diameter in depth. (I had never actually heard that as a limitation with regard to boring - only for drilling, but I violate that one regularly as well.)

Andy, just for interest sake, see the following extracts from Sandvik, Mitshubishi and Dorian technical publications regarding boring bar overhang

I must admit that I too tend to push the limit with my larger boring bars, but have found that with the skinny ones (8mm and 10mm diameter) they do deflect even at 4x diameter overhang, and end up cutting tapered holes.

Regards
Hennie

 

[BaronJ]

Hi Hennie, Guys,

Yes I've seen that paper ! That information is for production work on automatic (CNC) machines where time is money. Also another observation is that Sandvic have an interest in pushing their own boring bars. These are a bar where they are hollow and have a tensioning bar inside and are supposed to reduce deflection and chatter !

Now I've never seen one, only read the blurb, but again they are aimed squarely at industry.

From a hobbyist point of view the boring bar should be the biggest diameter that will bore the hole without fouling and taking a spring cut generally works fine.

I've used slot drills and milling cutters before now to bore accurate relatively deep holes. Using one offers some interesting benefits.
"D" bits are another good way of getting a round straight deep hole.

 

[BaronJ]

Hi Guys,

This is a slab of unknown mild steel plate showing the fly cut surface. You can see that the cutter didn't quite cover the whole plate. I don't remember what speed or cut depth was, probably about 10 thou.

These two horrible pictures are the grind on one end of the tool bit, the other end is a more conventional shape.

Another view looking at the bottom with a better view of the tool bit.

 

[Steamchick]

Good stuff! - I think the cutter shape is the key, then it has to be used at the right speed and feed. You have obviously got that to a fine art! - Well done sir!

 

[BaronJ]

Hi Steamchick,

Good stuff! - I think the cutter shape is the key, then it has to be used at the right speed and feed. You have obviously got that to a fine art! - Well done sir!

High praise indeed ! Thankyou.

 

[HennieL]

Yup, I agree with Steamchick.

I will definitely try the heavy "flywheel" approach - thanks for the info Baron.

Baron:

Yes I've seen that paper ! That information is for production work on automatic (CNC) machines where time is money. Also another observation is that Sandvic have an interest in pushing their own boring bars. These are a bar where they are hollow and have a tensioning bar inside and are supposed to reduce deflection and chatter !

No argument with that I only responded with that extract (also confirmed by the two quotes that are from Mitshubishi and Dorian following directly after the Sandvik quote...) because Andy (Awake) stated earlier that he was not aware of a limit to boring bar overhang - only to drill depth in deep hole drilling.

From a hobbyist point of view the boring bar should be the biggest diameter that will bore the hole without fouling and taking a spring cut generally works fine.

Now that's where my lack of experience comes in - I assumed that in the model engine hobby one had to make very small, precise holes, and given my experience gathered with my 8mm diameter boring bar (that does deflect slightly in deeper holes, resulting in the hole ending up with a cone shape if not cut more than once, and "eyeballing" in some small extra depth of cut as one progresses into the hole), I assumed that this 4xDC rule was applied/known by everyone. Well, I guess that's another "assume" that proves the old saying it makes an "*** u me"

Regards,
Hennie

 

[BaronJ]

Hi Hennie, Guys,

I can't count the number of times that I've fallen for that mistake !
Drill a hole, bore it out then find that its bigger or smaller at one end.

I've just done some deep hole boring, 12 mm diameter 100 mm deep in 14.75 mm diameter EN1 steel rod. 10 mm diameter bar with a piece of 3 mm diameter HSS, a broken milling cutter. I didn't even need to grind it. I just used the corner of the flute.

I needed to make some 15 mm long spacers. So it was a case of turn the outside down to size, push an 11 mm drill down the middle and bore the last half a millimeter out.

There are two spacers in this picture ! The bottom one is 10 mm long, just under 1.375 wall thickness, the other 15 mm long and 20 thou wall thickness. Don't ask how I made that error... practice run

 

[HennieL]

Very cool, nice shop.

Thanks Madjack

 

[awake]

Thanks, Hennie - interesting to see the "official" recommendation, though I take Baron's point to heart.

Unless your boring bar is extraordinarily stout, you will nearly always get some taper if you only bore once. As said above (maybe also by Baron), the key is a spring pass - or even more than one. When it really, really matters, I take two-three spring passes. Note that you need to factor this in to measuring the bore - if you measure a single-pass, dial in your final diameter, and then bore with spring passes, it will wind up over-size. Not that I would know this personally. Ahem.

 

[awake]

Baron, that's a gorgeous fly cut surface!! Thanks for the additional info.

 

[HennieL]

As said above (maybe also by Baron), the key is a spring pass - or even more than one. When it really, really matters, I take two-three spring passes.

I do that too with brass, and mild steel

Perhaps my inclination to "stick to the rules" of limiting overhang, and trying to follow the manufacturers' speed & feed recommendations with normal turning, comes from the fact that up to now I have done a lot of my machining in tool steels such as 5160, 1095, O1 and EN45 (and also quite a bit in stainless steels such as 304 and 316 as well...), and all these steels work harden when your cutter rubs - it is therefore important to take proper depth cuts to stay below the "hardening zone", and to use carbide insert tools.

This is also the case when drilling into these steels - I cannot tell you how many drills I've broken until I learned to just keep on drilling and never stop until you're through - not even for a second to add more cutting oil, even if smoke starts to come out of the hole! This is the reasons why I've changed completely to using only cobalt drills on the larger sizes, and carbide drills on the smaller holes. Of course, bear in mind that my "smaller sizes" go down to 1.3mm drills to make screw holes for pocket knife liners in titanium, and then using 0-80 taps to make the threads...