[MrSharpie]

Hi all,
New member, long time lurker, (blah blah blah the usual).
I've been planning this for a while, years probably, having read a hundred threads on the subject it is clear that that Taig wins hands down in the price range.
However, with the current weak Aussie dollar, and me somehow assuming reasonable shipping costs (in hindsight a stupid mistake), the cost of the Taig is
not for me what it is to you.

Having conversed with a few sellers, the cost of the Taig Shipped to my door is going to be ~$2100AUD. (1500USD)
That's the basic long travel kit, no options, no tooling, no CNC. Though that's in budget, it's not really a great deal.

A new shop within reasonable driving distance has opened up near me selling almost purely Sieg machines.
They have the:
SX1P (fixed Z column) for $800 (rotating column is $100 less but I would rather have the rigidity)
SX2P for $1100 (fixed Z)
SX2.7 (750 watt motor, more rigid looking z, bigger table) for $1450
The X3 is not off the table, ($1860 or $2300 for the SX3L) however I intend to run the machine indoors in an enclosure and the size is more than I foresee myself needing.

I am certainly leaning towards the SX2.7 or SX2.
The machine would be for cnc conversion with ball-screws.
It would be used for small, mostly one off parts, within the table size of the Taig (12x5.5 inch) however more size is always better and I can see myself wanting (not needing) more Y for other projects.
The machine would be working with 95% Aluminium, 4% Steel, 1% wood.
I would like to use a 4th axis in the future.

Accuracy is a big deal to me, speed is not, this is for home, non commercial use.
I have heard of people getting siegs 're-ground' this would be done at a machine shop presumably?

Thoughts? Opinions?
Is the Taig still worth it at that price?

[awerby]

If you buy the CNC-ready Taig, you don't have to have it reground, or strip out the leadscrews and replace them, or fit it with aftermarket motor mounts. You might save money by purchasing it without the spindle motor, though, since it's set up for 60hz electricity. You should be able to find a motor locally that will work with your supplied current.

[compsurge]

What thickness of aluminum? The Taig really isn't for hogging material. I've been using one for a high school robotics team and it just doesn't have the horsepower (1/4 hp supplied) to cut at anything but a slow stead pace at a "low" rpm and slow feed rate. It is a great mill for small work though. The Taig quickly runs out of space.

I would say to also look at the G0704/BF20 equivalent and a CNC conversion. It has a lot of support and comes under many brand labels. There are some comparisons that place it above the SX3 in terms of rigidity and CNC conversion capability as well.


Good luck!

[MrSharpie]

Thanks for the info on the BF20, I had totally written it off as an option as it's only distinguishing feature over the x3 was the tilting head which I figured would make it less (accurate) EDIT: rigid.
How does its accuracy compare to the x3 and Taig? Assuming all have 'zero backlash' ballscrew convetsions? It us sold locally in it's BF-20lv variant for the same price as a standard x3.
I mostly see myself working with half inch alloy plate and not hogging a huge amount of material, though such a big x axis (480mm) in the BF-20 would be great!

[aarggh]

If the BF20 is anywhere near the build quality and performance of the BF16, then in my opinion it must be a beaut machine!

Very rigid and grunty, and exceptional finish.

Don't know where you are but if in Vic Redfox machinery can be a good source if they still sell them.

Applied Machinery in Dandenong also had them from memory.

cheers, Ian

[lsces]

MrSharpie - getting hold of a Taig can be fun even for those of us who sell them
Check out the price for one supplied without the spindle and motor, but include the stepper motor mounts ... and dovetail plate on the head.
I've shipped the Kress spindle to a few Australian Taig owners and they find it much better than having the big motor hanging on the head.
Kress High Speed Spindles
I believe they are available in Australia now which should help keep the cost down and the 1050W unit has more than enough power.

[compsurge]

Your accuracy with a CNC conversion will rely on several things: the tightness and fit of gibs, the ballscrew pitch combined with the motors steps/rotation and any gearing in between, the tool used, tool deflection, table/bench/stand rigidity, machine harmonics, and other factors.

With the gibs, you can remove some table moments by properly setting them up (put a dial indicator on one and then take your hands and turn the table in plane with the saddle and you may see some deflection)

Motor microstepping is not a way to gain accuracy, only smooth the motion.

In any event, the mill you get should serve you well. I would say the Taig will definitely work for a small 1/2" material, but the same money could be wrapped up in the BF-20. If you need to hold 0.001", you may or may not get it with a typical popular ballscrew conversion. The Taig has 0.0005" positioning accuracy based on the leadscrew pitch and 200/steps per stepper motor.

I hope that is helpful. Post any links to machines you are considering as well so we can examine them.

[MrSharpie]

AARGGH,
I went and check it out at Hare and Forbes in Dandenong, their price seems reasonable and it's not to far away, I also checked out AUSEE in Dandenong and saw most of the range of machines sold by Seig, seeing them in the flesh, makes me less inclined to spend my money on one, the quality of the BF20 seemed leagues ahead.

Isces,
The cost of the Taig Mill in Australia is not much different from having one shipped from overseas, is the Kress spindle used in direct drive or do you use a pulley with the standard spindle?

Compsurge,
Assuming all I need is the work-space of the Taig, properly set up gibs, 5mm pitch ball-screws directly driven by DC servos, which would be better? Do you know if the BF20 would be able to achieve the accuracy of the Taig?

I want to be able to hold 0.001" minimum as far as I'm concerned as allot of the projects I want to do involve reasonably high rpm with vibration reduction only surpassed as a priority by efficiency.
Referencing accuracy requirements: Machine Tools: CNC Conversion Accuracy

I suppose I should better look at my goals and what I actually need.
The parts I need to hold very high tolerances on, are all tiny (within 2" x 2" x 3/8") parts, in Aluminium.
I have always planned on getting a Taig lathe as my first machine as the are reasonably priced in Aus, with the milling attachment for small work in case I have something bigger on the CNC mill.
According to Small Lathe Milling with the Taig Milling Slide I should be able to attain the accuracy I want on the milling attachment, Any thoughts on that? I know the workable area is small, regardless,
for my needs, does that combination sound viable? the BF20 for 0.001" on larger parts and Ferrous materials and the Taig for <0.001" small parts?

[aarggh]

Hare and Forbes are great for all the general Chinese/Taiwanese imports, but some of the stuff leaves a little to be desired at times with the finish, usability, or general quality, but as we always get screwed in OZ on pricing and range, it's not like we have a great choice!

It'd be well worth checking out Applied Machinery at 55-61 Nissan Dr, Dandenong, as they have a great range and are good on prices. When I was looking at mills, I went from the Seig, to the Optimum 20/25, then the RF45, before I ended up buying a V1000 knee mill which has proven a great machine, pretty much a HF50/52 from H&F but with an NT40 spindle instead of NT30. I also bought a 330 x 1000 center lathe there, which is just the bee's knee's, I love my lathe! I found their stuff was very similar to H&F, but a little better quality, and better pricing.

The one thing I would caution on, is don't be afraid to look at something larger than what you think you may have a need or use for in the immediate future, better to buy too big, than too small I reckon. The more I thought about what I wanted to do, and how comfortably the machine would do it, the more the smaller stuff just didn't cut it in the long run.

I bought my BF16 from Redfox Machinery for a song, and absolutely love it, it would easily hold the kind of tolerance your talking about. I have mine packed away atm while I work on reno's, but when done I expect to use it almost as much as my large mill for all the really small stuff. Plus the kids will be using it as their own mill!

cheers, Ian

[MrSharpie]

Thanks for the tip on Applied Machinery
Walking around Hare and Forbes was disappointing, the impression I walked away from was that they are the Bunnings of engineering tool, and as much as I love Bunnings, when I'm working at tolerances and not with wood, it wasn't the place to buy tools.
However I may end up buying the Mill itself from them, though I will check out red fox aswell.
I am not as a point in my life where I have a suitable place I know I will still live in in 12 months time, I have every intention of upgrading to larger machines, or at least adding them to my arsenal, when I am no longer renting!

Thanks a lot for the tips on those other stores!

[lsces]

MrSharpie
While the leadscrews on the Taig are 20 tpi, the brass nuts can be adjusted to maintain close tolerance. I have many clients using them for jewellery making and as long as one takes a little time out each month to check backlash and keep the machine clean and moving freely fine work is not a problem. What is more of a problem is the ones who use the same 2" envelope year on year and ware out that section of leadscrew But a replacement set is not expensive, and by moving work around one can keep the ware more even and not build up 'steps' which prevent tightening up the nuts. Taig are now apparently 'lapping in' the leadscrews and nuts on new machines, but not sure that is entirely necessary and it does cause a step on the Y axis which prevents the addition of the extension spacer that gives another 1"/25mm movement on Y, something the lress spindle makes possible.
Yes the Kress spindle is direct drive. It uses it's own collets due to the high speeds involved, but the 5k to 25K range on the 1050-1 is normally fine for most jobs. I have clients putting 6mm cutters through heavy steel!
The Taig controllers are only half stepping unipolar and so give 1/8" step size. Something difficult to achieve with a ball screw, but we fit them with Chinese bipolar and set them for quarter stepping. The jewellery clients that we have updated have been able to see a difference in the quality of finish, so while quarter stepping does not produce 'even' 1/16" steps, it does produce a more even edge to curves. There was a comment about micro-stepping not adding to accuracy only smoothness of movement, and one can see at 1/8 stepping that rather than getting 1/32" steps one perhaps gets 1/16" plus three smaller ones and I think the jury is out if is any better than 1/4 stepping.
For fine work one needs small step sizes and while the backlash needs to be kept tight it' can be controlled.

[MrSharpie]

The lack of Y on the Taig was my one worry, another 25mm and I'm sold!
Is there much runout in the Kress spindle?
I'm worried this might be a stupid question, but given I'll be working in metric, will there be introduced in accuracy due to the thread pitch? It make sense in my head I've just never read it anywhere.
I wasn't really looking at a ready made Taig CNC machine as a ball screw conversion would be considerably harder?

[lsces]

Kress has very low runout. Needs it given the speed especially when turning a 40mm cutter, but don't recommend them on the Taig But I can't find the datasheet with that bit on ... I think it's a label on the box but I don't have one on the shelf to look.
I'm running metric drawings, but don't ask me what 1/16" is in mm's ...
The point is that ball screw conversion will quarter your accuracy unless you add another gearing layer. The supplied lead screw is more than adaquate, and when it becomes a problem to maintain low backlash then a new set of screws is a lot less than one ball screw.

[awerby]

Yes, a ball screw conversion would be considerably harder, and more expensive than the rest of the mill, if you got good ones. Many have talked about putting ball screws on these mills, but hardly anyone has actually done it. The expense is one factor, and the lack of room for the nuts is another.

There's no problem with working in metric using the supplied 20 threads per inch screws; the computer does the conversion automatically. You just have to set the units per revolution accurately in the first place.

[compsurge]

I can't see the Taig really benefitting from ballscrews. The leadscrew movement is sufficient for the size of the machine. The backlash can be adjusted with the brass nuts and I think that you'll find the Taig will work well for the size object you will be machining. You'll run out of horsepower from the Taig-supplied spindle motor long before you need the feed rate that requires ballscrews.

Accuracy has to do with more than just positioning accuracy. Tool deflection, machine vibration, temperature, backlash, among other factors all contribute. If you need 0.001" accuracy, the ball screw conversion on a BF20 may get you right there. The typical C7 eBay sourced ballscrew from linearmotionbearings2008 is a 5mm lead (5mm/200 steps per revolution = 0.025mm or 0.00098" /step). Temperature can play a huge part as well. If you are machining your part when it is hot out in the shop, you may find that the part is ever-so-slightly undersized when in operation in a cool environment (At this point, we are talking likely <0.001" variation, but this is still a factor). This also does not include any ballscrew error (they have an error per set distance per the spec). You can get double nuts for the ballscrews to take out any backlash that exists.

In any case, holding 0.001" for all dimensions will be possible, but not as simple as the specs may indicate.

[handlewanker]

Hi all.....has anyone considered building their own from the ground up, or is that too labour or time intensive?

I'm currently in the market waiting for a Chinese mill import to arrive.....long story......and in the meantime decided to start building a moving table bridge mill or fixed gantry type, from steel tubing all fully welded etc.

The work envelope is 300mm X 250mm with 130mm max height.......small by many standards, but that is what I needed to have and it's specifically designed to be able to machine steel.

To keep it short, the build so far just has cost approx. $150 just for the tubing, and that is enough for 2 machines........bought purely from the economics of buying full length material cut to size ...... the build is on another thread, currently on the back burner due to reno work etc and the anticipated arrival at last of the import mill.

I thought I'd mention the build as it still requires machine work to retrofit a buy in mill to make it suitable for CNC work, and anyone with some welding skills can arrive at a basic structure that only needs some machining to accept linear rails and ball screw mounts etc.
Ian.

[dharmic]

Did you have a look at the H&F's Optimum imports while you were there? Allegedly from Germany and they had one I seriously considered for a retrofit, seemed to be a slightly bigger build volume than most desktops and reasonably well set up - but that was only on the web.

[aarggh]

Did you have a look at the H&F's Optimum imports while you were there? Allegedly from Germany and they had one I seriously considered for a retrofit, seemed to be a slightly bigger build volume than most desktops and reasonably well set up - but that was only on the web.

I have seen some people bag the Optimum's, which I take with a grain of salt as it seems a percentage of forum members exist solely to run down suppliers, but generally from what I've seen in forums and units in stock at suppliers, they seem to be really well designed units. My BF16 is an Optimum, and the quality and performance is nothing short of superb! The only reason I didn't end up with a larger Optimum for my main machine is because I went for a much larger mill overall.

I've heard German designed and Chinese built, for whatever that's worth as almost everything is made in China these days, but I'd highly recommend them based on what I've seen in person and online.

cheers, Ian

[MrSharpie]

Isces,
Sticking with the lead screws will save me a bunch of money, especially given it means I can buy a cnc read Taig mill (should I go that route), your tip on the Kress spindle is also a great help!

Awerby,
My understanding was that the steps in a stepper motor is a set amount per revolution, wouldn't that mean I would be microstepping to get metric results?

Compsurge.
I don't need to hold those kind of tolerances on all dimensions, if I do it would only be on small parts, I just want to be able to on the machine when I need to.

Handlewanker
I had considered a ground up build before this thread, the thought process being, why pay for leadscrews on the taig/bf20 when I want ballscrews, why pay so much for shipping when the cost of shipping would probably cover materials.
I was thinking of using an EG T-slot build, I will do the calculations on rigidity later and post the results.
Anyone else think this is a viable option?

dharmic
The bf20 and bf16 were the mills I went to check out at H&F, the quality seemed really good especially in contrast to the seig built machines,

I guess I can certainly say Ballscrews for the Taig are off the table, more money for other accessories.

[lsces]

Awerby,
My understanding was that the steps in a stepper motor is a set amount per revolution, wouldn't that mean I would be microstepping to get metric results?

1/16" step using quarter stepping gives 0.0015875mm ... yes it's a funny step size, but it's small enough to be in the noise of all the other factors such as backlash and vibration.
A 4mm ball screw will give you a nice round 0.05mm per step with the same drive, which may well be fine for the work you are doing, but produces a surface texture that is visible with the naked eye when trying to machine curved surfaces for say the round end of a train buffer, or the mould for a cuff link. While some will say 0.05mm steps are more than enough, or one goes to 1/10 stepping for others the smaller more stable step size is essential, and the backlash can be held less than the bigger step size.
One size does not fit all?