A “many Pictures Few Words” Sieg Super X2plus Mill Cnc Conversion

petcnc

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A. Mill description

Sieg SXL2 Plus is the common X2 Hi Torque Solid Column Mini Mill, sold worldwide with many variations and under many different names. Different companies sell their variation with their brand name. In my case the SXL2Plus has the 500 Watt (0.67 hp) brushless spindle drive motor, a 3MT spindle but instead of the regular X2 mill table it has the extra long table from the X1 mill.
SIEG_SX2L1.jpg
The Sieg SXL2 Plus mill

1st.jpg
My mill

The company that sells it over here in Europe is ARC Eurotrade (I have no association with them) and the main reason I bought it was the extra long table and the powerful motor.

After the long journey of making modifications in order to make it a precision tool (mainly tramming without shims http://www.hobby-machinist.com/posts/268607/ adding bearings to X&Y feed screws and reducing backlash to Z fine feed mechanism) I decided to convert it to CNC.


B. CNC JOURNEY


My initial research lead me to categorize the CNC journey into 4 main categories

1. acquiring the necessary parts
2. make the necessary parts and modifications
3. test and verify the system
4. fit the parts to the mill


As the mill is used mainly for hobby, I tried to keep the costs as low as possible without sacrificing quality and functionality of the whole project.


B1. Parts & costs

I ordered in the last 24 months the following parts:

EUR 45 1x TB6560 controller that proved to be an adventure by itself to make it work as it should (read the full story here http://www.hobby-machinist.com/threads/retrofitting-the-famous-tb6560-cnc-board.34352/).

EUR 63.00 3x NEMA23 stepper motors 57BYGH56-401B (12.6Kgcm 1.8Degre 4Leads 56mm)
EUR 32.68 1x L500mm CNC SFU1204 BallScrew with Single Ballnut End Machined STS (for X axis)
EUR 22.27 1x anti backlash ballscrew 1605-350mm-C7 (for Z axis)
EUR 23.95 1x anti backlash ballscrew 1605-300mm-C7 with end machined (For Y axis)
EUR 1.59 10Pcs 18mm x 10mm x 5.5mm Silver Tone Metal Ball Thrust Bearing
EUR 10.79 8P 4 Pin Male & Female Diameter 16mm Wire Panel Connector GX16-4 Socket Plug AR (to connect the motors to the controller board)
EUR 8.11 PY4: 3x mm PITCH HTD TIMING BELT PULLEY
EUR 28.00 3mm HTD® Timing Belts 6 mm Width (2 belts 285 mm Length + 2 belts 267 mm Length) ( £ 19.03 About € 28)

EUR 3.26 1pcs 3A Analog Panel AMP Current Meter Ammeter Gauge 85C1 0-3A AK (for the power supply unit)
EUR 1.39 1pcs RED LED Panel Meter Digital Voltmeter DC 0-99.9V new (for the power supply unit)
EUR 7.11 4x IC TOSHIBA ZIP-25 TB6560AHQ (to repair the broken controller board)

TOTAL COST € 247,15

TB6560 Board.png
The TB6560 board

Ballscrews1.jpg
One of the ballscrews (Y)

Bearings.png
X&Y bearings

motors.JPG
NEMA23 stepper motors 57BYGH56-401B

Motor pulley.JPG
Motor pulleys

timing belts.JPG
Belts

Voltmeter.JPG
Voltmeter

Ammmeter.JPG
Ammeter

...To be continued...
 

petcnc

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B2. Z AXIS PREPARATION


COLLECTING IMPLEMENTATION IDEAS


I thought that X and Y axes are pretty easy to prepare for CNC (I was WRONG) so I decided to start with Z axis. For that reason I started seeking ideas on easy and reliable ways to convert it.

First idea from several kits: Z ballscrew on the right side of the head
Z Side ideas.JPG
I did not like the idea of a ballscrew hanging next to column though, plus the mill seemed to me “out of balance”.


Using the existing fine feed mechanism was not a good option either due to the massive backlash the fine feed had.
Z Using existing Fine feed idea.JPG
Using the existing fine feed mechanism idea


Next idea from Hoss: ballscrew between head and column
Z Hoss Idea.JPG
I liked the idea but I had a small problem: Hoss had the mill with the old thin & tall motor that leaves plenty of space between motor and column. My hi torque motor is too close to the column to apply this approach.
Z No space for Hoss idea.JPG
So I was looking for a different approach... then I noticed the large hole of the hollow column...

A large hole to use for Z ball screw.JPG
many people use the column hole to place in it the air spring when they convert the mill from torsion spring to air spring.

I have no intention to change the stock torsion spring for an air spring
Z Keep spring mech.JPG
The stock torsion spring mechanism.


Moreover with this design of the ballsrew inside the column, the ball screw will be protected from debris...


So back to the drawing board... Making blueprints for the implementation.

Z axis mounting.jpg
The motor will be installed on the top of the column and drive the ballscrew through a timing pulley. The stepper motor and pulley mechanism will be secured on 3 aluminum plates bolted on the top of the column.


..... to be continued...
 

petcnc

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FROM Z BLUEPRINTS TO IMPLEMENTATION


installation of the timing pulley and the ball nut needed some work around as In my design the ball nut would be rotating driving the ballscrew up and down and the ball screw will be connected to the head driving it up and down.

Z axis mounting nut.jpg
My design of the ballscrew implementation


To achieve the above implementation I needed to machine threads on the ballnut in order to screw a security nut at the bottom of it.


As you can imagine the ballnut is made of HARD STEEL. Too hard for the tools of my little lathe to be able to make threads on it. Using conventional threading tools (with inserts) I barely managed to scratch the surface of the ballnut on my 7X12 lathe.


So I was seeking a better tool for the job...


Some head scratching later, I managed to thread it using my dremel tool and a disk instead of a conventional threading tool on the lathe (the full story here http://www.hobby-machinist.com/posts/260477/).

Z nut before.JPG
Ballnut before threading

Z nut after.JPG
Ballnut after threading

Z nut threading.JPG
Threading procedure.

Z nut Security nut.JPG
“Security nut for ballnut

Z nut with security nut.JPG
ballnut with security nut on it.

Next I prepared the column to screw the supporting plates on it

Z column top preparation.JPG
Drilling and tapping the column

Z column plates fit.JPG
Column with plates on it

... To be continued...
 

JimDawson

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Great problem solving!! I like it.
 

petcnc

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CONSTRUCTION OF THE TIMING PULLEY.


The problem with a conversion of my mill was that I did not have access to another mill in order to machine parts for the conversion. So the mill needed to be used manually to make the parts. This necessity lead me to design the conversion in a way that the mill could be used manually during the conversion especially for the Z axis.

To make the 72 groove pulley I started by cutting a round aluminum part

Z cutting pulley.JPG
HARD work!!!

Then, calculated the dimensions
X&Y Pulleys distance.jpg
Dimensions calculator.

And machined the pulley...
Z making pulley.JPG
Machining the grooves


I followed the “one pass” procedure as I was not sure that I could avoid mistakes making several passes. I used a “special tool” for the job made from a “concrete nail” as we call them over here (a nail designed to penetrate concrete).
Z pulley cutter.JPG
My “special tool” in action


Pulleys ready
Z & X pulleys.JPG
Z (72) and X (36) pulleys. Some minor mistakes in calculating rotation angles during construction left a few grooves wounded.


Testing the pulleys with the belts.
Z Testing belt fit.JPG
Seems ok!

Testing the motor fit
Z testing motor distance.JPG
Looks ok as well!

Z ballscrew closup.JPG
Column with plates, timing pulley and ballscrew in place.

... To be continued...
 

petcnc

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CONNECTING THE HEAD TO BALLSCREW.


My initial thought was to make a “crane like” construction to connect head with ballscrew as I have seen it in some CNC kits.

Z My initial Idea.png
After sketching it I hated it so I looked for something less bulky and more “elegant”.

Looking in my scrap bin I noticed some long engine rods that connect engine head to engine body...
Z engine rods for head.JPG
They were exactly what I was looking for.

The only problem was that they are custom made for the particular engine and they were threaded in an uncommon 9X1.5 mm.

If I use it I had to make some 9X1.5 nuts for them...

A few cuts and grinding later I had the tap ready.

Z 9mm tap.JPG
And with the tap I made some nuts for the rods
Z 9mm nuts.JPG

Next the Rods were cut to length and threaded at other end
Z rods ready.JPG

Then they were connected to the head. On the fine-feed mechanism at the right side.
Z Fine feed with rod on mill.JPG

on a custom made plate at the left side of the head
Z left side rod connection to head.JPG

Finally both rods and ball screw fitted on the mill
Z ball screw & rods fit.JPG

They look a bit strange as they nearly touch the ceiling at full up position
Z ballscrew & rods up to the ceiling.JPG

Next I prepared the ball screw end for rod connection
Z screw end transform.JPG

and connection of rods and ballscrew through an aluminum block
Z screw & rods connection.JPG

And the motor in its place as well

Z screw rods & motor.JPG

A close-up of the final assembly.
Z screw rods & motor2.JPG

That concludes the Z axis.
I will upload next the X & Y axes.

Thank you for reading this

Petros
 
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Outstanding Job.
*G*
 

petcnc

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really nice work
Steve
Thank you for your kind words Steve! Your posts were (are) great inspiration for me.
I have already adopted your saying "The way I do it".
There is so much truth in this!
There is always another way of doing things, but everyone of us chooses the way that suits him better.
Thanks again!

Petros
 

petcnc

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SIEG Super X2PLUS mill CNC conversion

X AXIS


After finishing Z axis I started the X conversion that I initially thought it would be a straightforward procedure. I could not have been more wrong on that matter!

As I stated in the beginning of this presentation my mill has the X1 extra long table that, for some reason unknown to me leaves too small space between the table and it’s base.

I started measurements by making an “oil printout” on paper to record all measurements. That works like this: you apply used oil on the (flat) surface you wish to print and then you touch the surface with a clean white paper. Next you measure and write all measurements on the paper and if you want to transfer it to the computer you either scan or photograph the printout. As simple as that!

X OIL printout.jpg
The “oil printout” of the left side of my mill table.


In my mill the printout revealed a problem that took a lot of head scratching to solve it.

The distance between the underside of the table and its base (the top of the Y moving part, is there a name for that?) was just 19.5 mm (that’s 0.768 inches)!

X stock nut.JPG
A photo of the left side of the table (stock nut is 45x18mm)
X right side1.JPG
A photo of the right side of the table


Removing the table to investigate what modifications are needed

X Left side.JPG
Left side without the table

X right side.JPG
Right side without the table.

X & Y drawings.jpg
All drawings of X & Y to seek possible solutions on the drawing table.


FACTS

I could not find a ballscrew with a nut that small without braking the bank! The matter needed a different approach! I did not like to machine the base (I did not have access to another mill either) so I was looking and looking for solutions to similar problems in the internet.

Stock screw is 12 mm thick
X stock screw.JPG
X stock screw

For some reason there are very few CNC conversions of X1 mills published and most of the conversions I found use the stock screws for X and Y. There was no light from this source!

Finally I decided to tackle the problem in a non conventional way: If there is no space for the ball nut under the table, kick it out of there.

After Transferring all measures to the drawing board I figured out the solution details:

X nut out.jpg
The idea: place X ballnut at the edge of Y moving part

Naturally putting the ballnut there was not a straightforward task. Some modification was needed.

The easy part was to cut the ballnut top using my disk grinder.
X ballnut mod.jpg

As right side is machined 3mm to make some space for the screw I could do the same on the left side in a way that the ball nut fits.

Lowering idea.JPG

The difficult part was to grind the surface under the ballnut (the red area, see next sketch) to make space for the ballnut.

X nut out drawings.jpg
So material from the area marked in red at the above sketch was removed. That was not an easy task using just hand tools (I managed mainly with help from my little dremel).

X ballnut out of Y.JPG
The ballnut under the table bolted at the edge of Y moving plate


The result: The ball nut fits in the gap and has a clearance of 0.5 mm from (as you can see it almost touches) the underside of the table.
X ballnut clearance.JPG
... to be continued...
 
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petcnc

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CONSTRUCTING THE BEARING SUPPORT BLOCK

After solving the hard part of the X conversion the rest was more or less straightforward.

I needed an aluminum block to support the other side of the ballscrew.
Aluminum block.jpg
The blue prints of the block


I did not have square aluminum block but I have round ones so I had to plan how to extract the square out of the round part
Block details.jpg
Extracting the square out of the round
Extract the square.jpg

After boring the bearing pockets the block was bolted into position
block into position.JPG

Until the whole conversion finishes, I need to use the mill. A handle at the X ballscrew worked just fine. I had to remember though that the ball screw had a 4mm pitch not 2mm as the stock screws had.
A handle for manual use.JPG
... to be continued...
 

petcnc

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PREPARING THE STEPPER SUPPORT BLOCKS.


I borrowed the idea of using aluminum profiles for the steppers and I looked around for raw material.

X Y Aluminium Motor implementation idea.jpg
The idea...

Making the motor support

An old aluminum door frame, with 3mm thickness walls, provided plenty of raw material for the support units.
Raw material for the support unit.JPG

Some preparation and planning needed though...
Stepper support.JPG

For boring (as I don’t have a boring head) I had to improvise using an old tile drilling tool
boring.JPG


Machining with a tile cutter.JPG
Tile cutter worked ok as a boring head, although it was a pain to adjust it to bore the required size!
As There was no need for precision boring here, the tool performed flawlessly!


Finally All X Parts In place!

X Final Front.JPG
X view from above

X Final Side.JPG
X side view

X Final Under.JPG
X view from below

That concludes the X Axle


Thank you for reading


Petros
 

ariscats

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Impressive job.Waiting for the finish.Απιθανο φιλε,μπραβο.
Ariscats
 

petcnc

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Impressive job.Waiting for the finish.Απιθανο φιλε,μπραβο.
Ariscats
Thank you my friend. There are two more parts to publish. Y axis and the electronics (power supply, controller etc.) I will publish it in the next few days.
I strongly believe that we should share our knowledge. That's te reason I am part of this community. Ευχαριστώ για τα καλά σου λόγια.

Petros
 
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petcnc

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SIEG Super X2PLUS mill CNC conversion

Y AXIS


After finishing Z and X axes I started the Y conversion. Here there was enough space to fit a 1605 ballscrew with some minor modifications to support the ball nut.


Ballnut before modifications
SFK001.jpg

After "treatment" with my angle grinder
Ballnut transformations.JPG

Testing the ballscrew on the mill base
in base.JPG

Some careful machining of the base needed to fit the ballnut.
Machining mill base.JPG
After hand-machining mill base using hacksaw and dremel, Ballnut fits nicely.
Ballscrew test fit.JPG

Some right angle steel constructed to secure the nut to the mill base
Ballnut supports.JPG

They made to fit nicely both to the base and ballnut.
Ballnut support.JPG

Now ballscrew is bolted to the mill base
Ballscrew in place.JPG


... to be continued...
 

petcnc

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Y BEARING SUPPORT BLOCK CONSTRUCTION


After fixing the Y ballnut to base I needed an aluminum block to support the ballscrew to the front of Y and connect it to the stepper motor.

I did not have square aluminum block but I had a 40mm round one so I had to plan how to extract the rectangle out of the round part.

BlockCuts.jpg
Extracting the rectangle out of the round

Y block.JPG
 

petcnc

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PREPARING THE STEPPER SUPPORT BLOCK

As in X axis I used 3mm aluminum profile.

Stepper support.jpg

As boring head I also used the tile cutter
bored with tile cutter.JPG

The stepper motor in Y axis fitted to the back of the aluminum block
Stepper fitted.JPG

This way the front of the mill is “clear” without protruding parts
Clear front.JPG

Y view from below. You can see the bearing support block and the ballnut
Stepper from below.JPG


That concludes the Y Axis


Thank you for reading


Petros
 

Konine

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Sorry for kicking this old post, but i am very impressed by it. You did a magnificent job. The idea with the ball screw mounted to the side is very good, and will be copied by me :)
I am curious: how did you bore the holes for the thrust bearings? How did you line up the screws with mounting Blocks ?
And is the mill running? How is it?
Thanx
 

petcnc

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Thank you for your kind words Konine!

Do you have tha same X2 model? (SXL2Plus)

I had to put ballnut outside the table as it was impossible to fit it under the table.

Of course I could have bought a very small ballscrew-ball nut but it would have cost "an arm an a leg" as they say.
Sorry I did not mention the boring of the thrust bearing holes before.

I made it on the lathe as I did it with the original blocks when I added bearings when Ibought the mill

faceplate.jpg

I centered the block on the lathe and bore the hole at he front

bearing block.jpg

And at the back

I did the work to the new blocks using the same setting.
I suppose I could have done it with a boring head on the mill but I do not have a boring head...

Lining up the screws with the mounting blocks was easy (but not very professional).
I measured the stock block...

blueprints.jpg

Then I transfered all measurements to the new block (Top & bottom right to the next sketch)

Cuts.jpg


Finally I made the supporting holes (the ones that secure the block to the table) a little wider as to make micro adjustments.

The mill is running like a charm, although I used a controller that needed plenty of conversions to work as it should
see http://www.hobby-machinist.com/threads/retrofitting-the-famous-tb6560-cnc-board.34352/

Good luck with your conversion!
If you need any help I'm happy to assist

Petros

ps
Write a name, to address to you properly.
 

DMLCV

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This is great, I am doing a x2 upgrade on my HF mill and it was very helpful to see what you have done.
 

Nordle

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Hey, really nice work here. I'm going to order a SX2P from arc too in near future. Can you tell me what size ballscrews did you use for X and Y, cause i'd like to order them now from Aliexpress. Takes some serious time to ship...
I planed to use SFU1605, but not sure about lenght:
250mm and 400mm cause thats the nearest to the stock screws?
I like the idea of how you mounted the ballnut to the outside of the table, but do i need a longer ballscrew then?
And if i use a little longer on the Y-axis, do i get more Y-travel (head wouldn't be in the travel center anymore)?
Sorry for hijacking, but this is the best X2 conversion thread i could find.

Cheers Matthias
 

petcnc

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Hey Matthias,
I'm surprised you asking that, as all the info are in section B1 Parts & Cost.
...
EUR 32.68 1x L500mm CNC SFU1204 BallScrew with Single Ballnut End Machined STS (for X axis)
EUR 22.27 1x anti backlash ballscrew 1605-350mm-C7 (for Z axis)
EUR 23.95 1x anti backlash ballscrew 1605-300mm-C7 with end machined (For Y axis)
...
For X you need 500mm 1204 ballscrew not 1605! as the screw and nut are considerably thicker and will not fit there!

For any axes X,Y,Z, you cannot get more travel than the one specified by the designers! Not without any major modifications!!!

Read it through and if you have any questions I will be happy to help!

Petros
 
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Nordle

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Hello Petros, thanks for you reply

I should have read twice, i wrote this from my smartphone @work and had multiple threads open. So maybe i was a bit confused.

Thanx for your advise but it seems to me this guy link used 1605 on all 3 axes.
Are there any disadvantages in 1204 sized ballscrews. I somehow like the idea of using them for all axes, cause 4mm pitch, and 400steps per turn, won't be an advantage i think but somehow i like the fact. Then on the other side, bigger is better most of the time.

And for the extended travel, I only tought about few (5-15) mm's nothing big or fancy.

So 500mm for X and 350mm for Y. Why are they so different from the stock screws?
X stock 370mm screw lenght and 420mm overall
Y stock 225mm screw lenght and 275mm overall
 

petcnc

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Hello Matthias,

1. The guy you mention above, did a very nice job but with MAJOR modifications. As I have said I did not have acess to another mill at that time and I kept the modifications to a minimum. If you have acess to another mill you can always choose that approach. My thought was that if I fail I could always put back the original screws and have my mill operational again.

2. There are no dissadvantages in 1204 ballscrews. Your software settings will take care of the pitch difference. You will not even notice that two of the ballscrews have 5mm pitch and the 3rd has 4mm pitch. The only difference is in thickness! 1204 fits under there nicely, while 1605 needs a lot of material to be removed.
If bigger was better all the time, everyone would drive a truck instead of a car ;)

3. If you extend the travel and the table moves beyond the end position, I think there will be less area in contact with the gibs, making the mill less beefy. I have calculated the legth while Y was fully retracted (in) and chose the ballscrew length.

4. The differences in lengths between original screws and ballscrews arise from the nut position. The nut is not in the middle of the table anymore but at a different position (even at the edge). On the other hand the machine will use the legth of the ballscrew needed for the travel distance. If there are a couple of cm unused in X or Z axes you can always use your angle grinder and cut it off. If you use a longer Y ballscrew it will not fit under the base as the column restricts it or it will not allow full retraction of the table towards Y axis. You might need to remove material from the column base that is not a wise desicion.

I hope I helped
Petros
 

Nordle

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Thanx again for enlighten me, yo help alot:)
Is your X-screw standing out for aprox 1/3 of his lenght on one side of the table then? Can i see a picture from your mill where i can see the whole assembled machine?

I don't like the idea of cutting my ballscrews, i have a lathe but almost zero experience on it, and i read they are hard. And they need to go into a bearing somehow?
 

petcnc

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My pleasure to help,

The ballscrews do not stand out of the table by 1/3 of the length. The X ballscrew is about 2 cm longer and is standing out 2 cm.

Xout.jpg

I take advantage of that to move the table 2cm extra towards X+ as you can see to the next photo (the ballnut is exposed because of that extra travel)

Advantage.jpg

The ball screws do not move independently they always move in reference to the table as they are connected to it and move with it.

See the next two photos one with the table all the way to X-- and the other with the table all the way to X+

Xlefts.jpg

Xrights.jpg
To make it clear I have uploaded a video showing all the movement of the X axis from left to right.


Same for the Y axis. See the video showing Y to retract all the way


I hope its more clear now and I hope you excuse the mess around the mill :oops:

Petros
 
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