Sieg X1L CNC Conversion

[Doug]

Ok I am getting seriously miffed now, the mill is becomming quite useful and very accurate but is showing its weakness very vividly. That is that is is very "floppy" and about as rigid a a wet lettice. So what to do?
I have a few options.
Option 1
throw it away (convert it back to a manual mill and sell it) replace it with a slightly bigger Sieg X2P mill
this has a small benefit of the bottom x-y table is identical to mine so its a bolt on with the already made CNC parts the column is bigger and stiffer
the down sides are i need to remake the z axis ballscrew and spindle intergration plus need to re tool as its an R8 spindle
Option 2
wait a few years till i have enough spare cash to buy one of these and convert it to CNC Sieg X3
Option 3
look at stiffining the machine I already have this one is the most varied option as it can be anything from this (which is a full new build frame base) to this which is a simple stiffining plate mod.

[andyhigham]

I would go for the X3. You can recoup some of the cost by selling your X1 as a fully functioning CNC mill. I would personally go for R8 tooling

[Doug]

Aug 28, 2015 14:18:14 GMT andyhigham said:

I would go for the X3. You can recoup some of the cost by selling your X1 as a fully functioning CNC mill. I would personally go for R8 tooling

the X3 is a beast, i have just had one at work and i am currently "preping it" which in plain english for getting it cleaned down and removing copious amounts of cast iron swaf from the grease. I dont really want to sell the X1 as a working CNC as i would have to buy all the equipment again (PC, screen, interface card, powersupplies, drives etc.etc.) it can go back as a manual mill though as i havent messed with it too much.
if i went with that option i would have to do option 3 as well so i could live with it till i got the funds together. £1500 is quite a bit of cash when the most i have ever spent on tooling in one go is £375.
the worry with getting the X2P one is that i am unsure if it is big enough/ stiff enough to make a big diferance. which is why its a really hard call to make.

[jem]

I like option 3, but I would go for heavy channel rather than welded up square tube, it is much stiffer and you only need to weld the base to the upright. By the same token I like to put a piece of channel under my Myford, 200 by 7 mm works a treat.

Jem

[Doug]

Ok some figures of the problem I have put a clock on the spindle to the table and I can rock it with a couple of Kilos of force it moves 200um (100 each way) and returns to centre I then put the clock on the base of the column to check my gibs are tight and with the same amount of force hardly any movement. 

And the column itself it's not exactly massive,

however I think ridding myself of the horrible swing connection should sort the base right out. Till I can afford an X3, rude not to really.

[RGR 60130]

I'd still recommend a Denford Triac PC. They sure as he** don't bend and have a good working envelope. If you can find one with a fully enclosed cabinet and coolant so much the better.

Reg

[Roger]

Maybe the link doesn't do it justice, but the Sieg3 still looks a bit 'toy like' to me. I think you could convert a decent sized manual mill reasonably cheaply. I've seen a Denford Triac and they're nowhere near as robust as a manual mill. I don't know why all these CNC machines are so flimsy. The bottom line is, you can't have too much stiffness, even mine could use to be more manly at times and I'd love a Bridgeport if I had room.
There's no harm in beefing up your mill if you can do it cheaply enough. I certainly wouldn't convert it back to manual, you'll be a lot more for it as a CNC machine.

[Doug]

Aug 29, 2015 7:48:51 GMT Roger said:

Maybe the link doesn't do it justice, but the Sieg3 still looks a bit 'toy like' to me. I think you could convert a decent sized manual mill reasonably cheaply. I've seen a Denford Triac and they're nowhere near as robust as a manual mill. I don't know why all these CNC machines are so flimsy. The bottom line is, you can't have too much stiffness, even mine could use to be more manly at times and I'd love a Bridgeport if I had room.
There's no harm in beefing up your mill if you can do it cheaply enough. I certainly wouldn't convert it back to manual, you'll be a lot more for it as a CNC machine.

The sieg x3 looks pretty good so far I will report on how good it really is after I have hammered it for six months it's about half the size of a Bridgeport I got an x3 mainly because if I had a Bridgeport it would get used by other departments so at least I get to try it in anger as a manual mill at work before I decide if I want to buy one for home CNC use.
The mounting of the column is very poor on my mill so I am going to build a new base photos and details to follow

[Roger]

It certainly sounds worth beefing up your existing mill, there's nothing to lose and everything to gain. It will be interesting to see how stiff the Sieg3 is, there doesn't seem to be much metal in that style of construction, and the spindle doesn't look that big.
Before you spend your hard earned cash, you're more than welcome to come over and take some big cuts on mine, I'd lay pretty big odds on it being a lot stiffer. You don't have to pay much money so get something similar, I'd be surprised if a Sieg3 was cheaper.

[Doug]

I haven't had chance to cut on the x3 yet as I still have it in bits but I will use it to make my X1 column bracket and give it a good thrashing.
anyway on to said bracket ;


This is the standard bracket which swings the head don't need that function so I am going to remove the lot and replace it with this

Once welded together and the column bolted up with some sturdy bolts it should be quite a bit stiffer with the added side fish plates which will also bolt through the column I gain a small increase in the throat height too.

[Doug]

Aug 28, 2015 17:48:02 GMT RGR 60130 said:

I'd still recommend a Denford Triac PC. They sure as he** don't bend and have a good working envelope. If you can find one with a fully enclosed cabinet and coolant so much the better.

Reg

I had a look at the range of Denford machines they do a nice little machine with a mini ISO taper and tool changer now that would be a handy machine.

[jem]

That's more like it, a good bit of channel and a weld or too,

Jem likes it

[Roger]

Hi Doug,
Although a tool changer sounds like a useful thing to have, I don't think it's of much value for the sort of work you're likely to do.

[Doug]

Aug 30, 2015 17:10:29 GMT Roger said:

Hi Doug,
Although a tool changer sounds like a useful thing to have, I don't think it's of much value for the sort of work you're likely to do.

Honestly I hope your right but so far my programs have been epically long if it works better with a stiffened column then the programs should end up a lot shorter and I can hang around a bit more while it does its thing. most opp's I have done so far need at least two/three tools eg the last crank took 6mm rough end mill, 6mm fine end mill, 2.1mm carbide slot drill, centre drill,1.7mm drill bit to make the part so it could have all been done in one program without any stops with a TC.

[Roger]

Hi Doug,
I hear what you're saying, but there's only one toolchange in hours of running when you swap from roughing to finishing. So long as you've got some idea when that's going to happen, you can be there to change it over. The hole drilling and little program to do the pockets only take a few minutes to complete and you'd spend longer than that setting the tools up to run from a toolchanger. If you had 20 to do then it might be a different story. I can honestly say that I've never had a job where I thought it would be an advantage to have a tool changer. Maybe that's because I've got the Easychange system, but even so, there's not a lot of toolchanging going on if the cycle times are long.

Hopefully the column stiffening will help a lot. If you made it out of big rolled hollow box section, you could fill it with concrete too, that makes a huge difference. We used that on a CNC machine we designed and it transformed the stiffness of the frame.

[andyhigham]

Filling with concrete will also help damp any resonance

[Doug]

I may fill it with casting resin while I am playing with it, it makes sense. Really easy to do too  .

[uuu]

I could put in a word for the Emco PC mill 50. It's only tiny, but it has a one-piece iron casting forming the bed and column. Generously braced with zig-zag webs. A proper three-phase spindle motor, and BT30 taper tooling.

Wilf

[vulcanbomber]

Have you tried plunge Milling on there Doug?

[Roger]

I wonder if you're still using too high RPM, try halving that with the same feedrate and see if that helps.