# Clint's Optimum TU3008 lathe & BV20 mill



## ClintNZ (May 23, 2022)

A thread to share a few pics & experiences with my new machine. It's an Optimum TU3008G lathe, 300mm swing, 700mm between centres (12x28") I also have the BV20 milling attachment bolted on the back. These were bought new from Machinery House in NZ. Being a mostly European & Antipodean brand there isn't quite as much online info around on these machines compared with ones that are common in North America.







The lathe was just the right size to fit in where my old Atlas 10F used to sit but is a pretty massive upgrade in terms of precision machining capability.

The first job before installing the new machine was to reinforce dad's old bench. A big chunk of channel was swapped for beers at a local structural steel workshop then grafted into place.






I discovered that the supplied chip pan is lower at the edges than under the lathe base - designed to go on the optional stand obviously but a problem for putting it flat on a bench. So some 25mm packers were needed, I had nothing that thick in stock but it was an easy job for the local CNC profile cutters. I work in the pulp & paper industry & there are lots of useful engineering supplies & services available close to the mills I visit in nearby Kawerau.






By this stage I had already removed the chuck guard & cutout. I'm not usually so quickly dimissive of safety features but it looked like it would seriously get in the way when using the 4 jaw chuck & the manual recommended lifting from the spindle as seen above which would have definitely bent the chuck guard if left in place.

Then it was on to levelling 'er up with shims & mounting the mill on straight... Thanks to the guys at one of the mills for the loan of the precision level!











At which point I discovered an issue I still need to deal with. The cross slide is tilted down towards the chuck by about 0.13mm over it's width. Not great on a brand new machine.






This is mostly in the saddle ways but also a little in the cross slide. (Pic above shows using the new chuck jaws as paralells) I'll probably get the cross slide top ground to correct for the slope. Machinery house have offered another better saddle but I'm suspicious of how well that would mate with the main bed ways. It was good to strip the saddle anyway as the factory lube under there appeared to be a mix of waste oil & grinding dust. Otherwise it has checked out ok, some minor fettling required here & there but there are a few things I still need to verify like the 2 collar test etc.

It was never worth investing too much in accessories for the old Atlas & I'm starting from zero for milling equipment so the tooling spend has been substantial & ongoing... I did budget for it a bit though. This lathe didn't come with many included extras like steadies, 4 jaw chuck etc, that all had to be bought separately.






Next on the list was modifying the rear splash guard to fit around the mill & adding space for a shelf.






Also made it two piece so it's easily removable, the machine is jammed up against a wall for maximum space efficiency.

My first milling project was a metric drawbar for the mill spindle. Bizarrely for an Asian made, Euro market machine, the drawbar is 1/2" Whitworth. It came with a drill chuck arbor to suit so I got a chuck for that. With the tooling I bought with the machine I got a face mill & asked for an arbor to suit the machine - this was a mistake, should have just gone all metric from the start as now I have to swap the drawbar around for my other MT3 tooling that is all M12x1.75  until I buy another couple of arbors & swap them over.






Second project was to machine down the lathe chuck key which was too big. The supplied 3 jaw chuck seems like a decent piece but the precision didn't extend to the chuck key unfortunately. At least it needed to be 3/8" so I could use a socket set in the meantime. An insert end mill zipped through the hardened key no problem. I got some Aliexpress MT3 collets to use in the mill spindle as that seemed like a good way to keep things rigid & gain some Z travel. One nice thing about this setup is that the mill & the tailstock are MT3 & it came with an MT3 adapter for the MT5 lathe spindle, so the same tooling can slot in anywhere.






Cheers
Clint


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## ClintNZ (May 24, 2022)

Another early job for the machines was to turn down a bolt into a little BSW plug for the drill arbor. 






This was after I got the arbor stuck in the tailstock :-/ Turns out the end of the tailstock screw is just the right size to get jammed in the back of the arbor when you try to extract it. Nice beefy tailstock though with a good amount of travel & the lever lock works well. 

So after a few weeks of getting the workshop organised around the new machines & actually doing a couple of little machining jobs with the new lathe  (which was sooo nice compared with the old Atlas!) It was time to get serious about the mill column alignment & do some more setup. So the back guard & shelves were removed. A precision indicator holder was very accurately fabricated with welder & grinder...






This swept over almost the full 290mm length of the cross slide. The cross slide also has a generous 150mm width which is great to have for milling operations. Cross slide travel is better than average at 180mm but this is restricted in the area of the mill column to 150mm. 

The column is mounted to an adapter with 4 M12 cap screws & another 4 bolt the adapter to the lathe bed. I did my adjustments on the adapter/column interface. After much nudging side to side & 0.15mm of shims at the top the tram both ways was under 0.01mm over 280mm which should be good enough for me. 

Of course on a light machine like this pushing the mill head around by hand about can move the dial about 0.05mm... A good thing about this BV20 milling head is that if I ever decide I need a standalone mill (& work out where to put it) I can just buy the bench mill base which is available separately & bolt it on. I do wonder if having the mill on the lathe gives it a stronger work table than the normal base would be, however you do lose some X-Y travel with it on the lathe. Having the option of X-Y power feed via the lathe has already proved quite useful though.

So with the tram spot on it was time to measure the offset of the mill spindle centreline & lathe spindle centreline. The manual does mention that shimming is likely required to get these both on the same line. I already have a project in mind where this will be useful. I could see it needed about 4mm, used some new milling cutters as gauge rods to measure the difference & also tried a few different size drill bits until they just touched. 3.9mm shim required.






Now I have a mill I can make a 3.9mm shim! Having been told that less shims is always better I thought I'd try also machining a 0.15mm slope into my shim & reduce or eliminate the shim stock that is presently wedging the column back to set the tram. So a 75x100mm shim, 4.05mm at the top & 3.90mm at the base is required. I had already made a rough fixture plate for another job so this was used to hold my shim while I machined it, screwed it down as well as clamped from the sides. First packed up one end to correct for the sloped cross slide, faced one side, then added more shims to bring it all up 0.15mm at the front & did the other side. Much traversing under the dial indicator was done to check as I went. Now I am starting to learn why one of those sine bar things may be useful... Also need  to look out for a big chunk of scrap to make a heavier fixture plate...






This is all pushing the limits of what I am used to with accuracy & it has been interesting to see what the little mill is capable of. I was rapt to get my shim plate within 0.02mm of what I was aiming for & very even side-side. Pretty serviceable finish from the 7 insert 50mm face mill too.

Now that's made I have one more job for the mill then I'll pull it off to fit the shim & also to get my DRO scales installed.

Cheers
Clint


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## matthewsx (May 24, 2022)

Hello and Welcome Clint,

Thanks for posting such a detailed and picture filled account of your new machine. Many of us have had negative experiences with multi-purpose tools so it's good to know that such a beast exists even if it's not available here in the US. You seem to have a very solid grasp of what you want and how to make it happen, I can't wait to see more projects from you.

I enjoyed visiting your country very much a few years ago and hope to get back before too long, was able to sail in Australia but not there so definitely something to look forward to.

Cheers,

Joh


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## jarhead (May 25, 2022)

that is a nice setup!


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## ClintNZ (May 26, 2022)

Thanks guys. Yep, the type of combo lathe/mill machine that many people know would certainly put you off the concept forever! I look at this more as a pretty decent 12" bench lathe with a little milling ability on the side. The mill attachment was $900 on top of the lathe cost, even the cheapest cheesiest mill-drill costs more than that so it seemed worth a try. A setup similar to this was probably the first milling machine I ever saw actually. In my high school metalwork classroom they had a lineup of Emco lathes, maybe 10" machines, one of them had a mill head like this. I learned the very basics on those lathes but never got the chance to use the mill.

The next part of the lathe commissioning is the DRO install. I'll start another thread on this in the Touch DRO section I think. The first part of the DRO install job was to bore a Morse taper socket in a large chunk of steel using mildly dodgy workholding & very dodgy tooling. (I do have larger boring bars on order) It was great to see the lathe spin the big off-centre work at 225rpm without a wobble.






So if you're wondering why I need an MT3 hole to install my DRO, the Optimum lathe & mill come with 10mm* slots milled in ready for stick-on magnetic scale strips that go with their house brand DRO. Makes for a very low profile tidy accurate install. However that unit is both very basic _and _rather expensive so I have opted for Ditron scales & a Touch DRO Android based system. Then when I got the scales I discoved that the groove in the back of the lathe bed (unlike the other grooves which I did actually measure) was *9.85mm & the 10mm scale would not fit. So how to make the groove wider? Maybe use my new boring head somehow... I figure an MT3 toolpost may come in handy somehow anyway... The block is sized to drop onto the compound slide with the hole on centre & also drilled straight to be a heavy duty boring bar holder after some more machining.






Going to go see if this actually works now...

Cheers
Clint


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## Firstram (May 27, 2022)

Great idea!
We need video!!!


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## ClintNZ (Jun 1, 2022)

The bodgy shaper worked quite well. Could do about a 0.05mm DOC. Lots of spring of course - back the tool out before dragging back for the next pass or you WILL break the insert. DAMHIK.






About 6 passes then flipped it around to get at the other end of the groove:






1 Micron Magnetic strip installed & Ditron DMR200 reader head bodged on pending the machining of a tidier mount that integrates the bed wiper holder & a sturdy cover for the read head.






Cross slide scale install now in progress.

Cheers
Clint


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## ClintNZ (Jun 15, 2022)

Cross slide has now been ground to correct for the wonky carriage (thanks Ross Engineering in Kawerau!) & x axis magnetic DRO scales installed:






A cover for the read head will be milled out soon. Next up is installing the QCTP. An old bolt made a stud to adapt the M18x2 hole in the compound to the M16x1.5 nut. First threads on the new lathe!






Some room to refine my very amateur threading technique I think but good enough. With only 3 speeds in the feed/threading gearbox change gears are usually going to need swapping when switching thread pitches on this machine.






Loctited in place. I will drill out the original 4-way tool post to fit on this also, hence the long thread. TouchDRO working great on the new Lenovo M10 tablet, needs an arm mount though.






Cheers
Clint


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## Mitch Alsup (Jun 15, 2022)

I really like that DRO install--neat, clean, flush, nearly hidden,...


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