Did not gain much progress over the weekend.
The Turn-Over party didn't happen, as I need to attend to other matter.
Even so, I could keep myself from foundering the build... just to show how addictive this build is.

Assembled the rails on the gantry. did not have time to level & align properly yet.
Attachment 8491

That hammer is about the right size. :)

Oh yes, 3 lb. sledge hammer, the real McCoy, feels invincible when I hold one ;)

A good size for demolition work :)

Don't leave home without it :)

I spend some time to visualize the whole process of aligning & levelling of MM. It gets a little fuzzy what should go on & whiich is the datumn.

Here is how I plan to get on with it. please do not hesitate to beat me up for mistakes.:o

1) flip the table, adjust the leveling feet to level up the main beams with carpenter spirit level + Al rectangle hollow section tube.
2) install only one side of the x-rail, shim the angle to get height level out using a spirit level + Al rectangle tube.
**question, should I also check if the Angle is perpendical to the horizon plane?
3) straighten the rail with my Al rectangle tube as edge guide. eye ball for light through gaps.
4) install the other x-rails,
5) level the height of second rail.
*Q, should I level the 2nd rail to the 1st using or should I use water tube level method?
6) While setting the 2nd rail straight, align it to parallel with the 1st rail.
7) Seat the Gantry on the x-rail, get all 4 wheel seated on the rail.
*Q, should I level up the top surface of the tubes to horizontal plane?
8) install Y-rails & align as X-Rails to horizontal plane.
9) install Z-slide.
10) align the Z-slide by cutting & shim the spindle square to the milled surface.
11) setting the x & y square. (very well described by Gerald in one of the post, will follow to the dot.)


Thanks in advance.

1) Use the spirit level on top of the main beams only. After adjusting the feet, put the level away - don't confuse yourself by using it during the shimming. (No need for later water-tube either - put your alu in y-direction across main beams in beginning only)

At step number 2), Install both rails using G-clamps only and follow instructions on drawing 10 10 300 D. Do not try and drill holes for only one rail at a time - your rack might not fit on the other side!
** check that angle base (where rack mounts) is horizontal - don't worry about vertical.

3) my eyeball would not be good enough - slide a feeler gauge in between.

4) remember gauge rod mentioned drawing 10 10 300 D

5)*Q only check second rail for straightness - do not worry about level because you already levelled main beam in 1).

Thanks Gerald,
Will visualise through the process as many times as I could before I attempt the assembly tomorrow.

BTW, no football team will come to turn the table over, I got hold of a forklift & we will turn it tomorrow. I don't foresee much photo as there will only be 2 of us working on it, the driver & me...

This is a triva question for the experienced, I don't have any shim but some soft drink cans. should I buy some brass shim & what thickness should I buy?

Soft-drink cans make great shims. We also used some 0.6mm and 1.0mm scrap tin plate. Don't waste money on brass for this dry, non-corroding application.

Thanks Gerald, I also found an straight cut aviation snippet & 1/4" & 3/8" hollow punch at the bottom of my junk pile, should come handy for shim making from soft drink cans.

We use strips of shim about 10mm wide and 50mm long. We put them on each side of the screw, sometimes only one side of the screw. We do not put the screw through the shim - that will be very hard work!

Autobody shims are good also.

They come in a lot of different sizes.

Finally got the table in proper position.
Attachment 8518
Couldn't resist to dry fit everything up...
Attachment 8517
I have to confess to another blunder I made..

I drilled all the hole on all the rails before welding (x-rail beam & y-rail beam)...

For the Y rails, no serious damage as I managed to get the V-wheel to seat almost completely on the rails just need a few more shims to get them seat down nicely.,

Not quite so lucky with X-axis, distance between the 2 inner wall of x-rails is ~13mm shorter then the guide rod length... From rough measurement, the rails are fairly parallel but will carry out more elaborate measurement tomorrow. Will adding washers on the wheels do the damage control or should I go the long way by drill bigger holes or slots on the rails?

After staring at the table & rail for a while. I realised it would be best to re-do all the hole & tap...

As you realise, you cannot simple move the wheels under the gantry. (The rack will be too far from the motor.)

Slow down a bit Ken, and think if you can maybe shorten the gantry......? I don't think that is so difficult.

You can also move the rails a little bit (10mm) in the x-direction to find clean space to re-drill and tap.

this is the shape I intended to make with hole punchif it is call for. Also, handy for making washer shim for the roller.

Gerald, didn't see your post earlier...

I wish I could build slower but I do have another job commitment coming up by the end of the month... Just want to clear the major portion before that. I can go slow on the tuning bits later as I foresee I'll can only affort 1~3 hours each day for this. Worst yet... I wasted a few days to turn the table over....

Just wanna make sure work don't get in the way of fun:)

Back to my blunder...
I would op for the re-drilling, I don't have the confident to rework the gantry with good end result welding skill & facility is limited hack I don't even have confident that I can the chop the gantry square enough...

I just checked before this & clearing the tap holes on the beam as you mentioned is definitely possible.

I can use the holes on the rails to mark on the beam by turning a exact size drill in reverse, then remove the rail & drill + tap the beam.

OR I can drill fresh holes all together by drilling pilot hole through the rail & beam while they are clamp in the streighten position then enlarge the holes & tap.

What size are the holes in your rail now?

I drilled with dia.9mm drill bit but my veneer caliper tells me they are 8.8~8.9mm

Then I wouldn't drill new holes in the rails.
Clamp both rails down at the new correct location (within 1mm), start a 8.5mm drill pilot in each hole (cutting normal direction - not reverse), remove rails, drill beams 7mm (or even 7.2 if thick material), tap beams 8mm, enlarge holes in rails to 12mm for a little adjustment.

Can I drill 9mm through holes, bolt through with bolt & nut?

I only have 7 F-clamps that are big enough for the job. they are only enough to line up half of a rail. I'm thinking of lining the rail, bolt down, remove clamps for the other half of lining up.

EDIT,
Can't do. the nut won't clear the channel web... :(

Of course you can use bolt & nut. But then the tuning (shimming) becomes a pain because you need both hands to tighten each screw. Those screws are going to be tightened/loosened lots of times.

I went on drilling new hole on the beam using the rail as template, finished drill & tap on on beam, almost done drilling on the 2nd beam now... should get this over before midnight...

Viola, got the rail & beam holes drilled & tapped.
On dry fit, they look straight to my eye for now.
Attachment 8528Attachment 8529

I think I can safely stow most of my power tools away from here on...

Its been exhausting 1.5 months since steel fabrication started & I'm very happy with the result, exhausted but very happy...

Need to take a break to fulfill my family responsibilities in preparation for the forthcoming Chinese New Year which happens to fall on Sunday the Valentine's day this year (or Spring Festivals shared by the Jap, Koreans & other orientals.) will have a week long festive break before I resume work & fun...

Looking good`n`straight, Ken. Happy weekend!:)

Claus, thanks for the kind words.

Its been 4 days since I left my baby MM for our Chinese New Year celebration & I'm suffering from severe MM withdrawal syndrome....

Ken, I sent you a mail, did you get it?

Jan, Sorry, no mail in my box.

Found some time to play today.
I read somewhere in the forum that 0.01" is the number to aim for but 0.254 is a quarter of a mm so naturally I attempt tighter tolerance just for the sake of it.
Using a 10' long straight-ish Alum rectangular profile as straight edge. and plenty soft drink cans for shim
In no time got the height within .25mm, then I proceed to 0.2mm took a little more time & 0.15mm is do-able, 0.1mm it starts to get difficult, can only get ~80% of the rail to get within this range & 0.05mm looks almost impossible.
I wish to know what is the "enuf" rail height tolerance?

Ken,

enuf depends on what you are planning to do with your machine.
If you are just cutting, then hight is much less of importance then when you do 3D carving.

If you do 3D carving, then it depends on if you are making big items or small items.
For woodworking for me it sounds like anything below <0.2mm is enuf, somebody else might need something more accurate. But don't forget there is sandpaper ;)


Ries

Ries,
Thanks for the heads up.
I should also list down my requirements, will definitely do carving eventually, will use mostly on sheet plywood, mdf, plastics, soft metal such as Alum & brass, but most probably for ornamental work & normal precision work, don't expect to machining space shuttle components ;)

Wonder what the others did.

Ken,

IMHO the following is important:
1) Constant height over small distances rails shouldn't jump and look bumpy.
2) Sturdy en reliable gantry, Y car and Z-plate, if you push/pull anything the only you should see moving is the spring a tiny bit, nothing should feel loose.
3) Good router/spindle (own experience).

You see, if you make a ornamental, then nobody will see that the left side is 0.2mm higher or lower then the right side, given that left and right is reasonable distance apart and given the nature of a ornamental this is something that the human eye will not see.

You would only see un-even machine results if something has bumps, height differences on the rail over small distances.
And even then, the gantry is so large then even a 0.2mm bump on once side will result in the middle of the work table roughly 0.1mm difference.

What I did notice is that low speed performance of the motors are important and that you need to set good CV settings in EMC or Mach3. In EMC it's G64 P0.1 that gives me a smooth ride for cutting my MDF.
If you don't set your CV settings proper for the job, then you can get chatter, in the beginning my machine started to resonate a lot because of wrong CV setting. You will notice it, it will behave shoky.

Ries

From what I have now, I can foresee that the gantry & rail gerald design will be more the stiff enoug, surely I don't have to worry about that. Thanks again gerald.
IMHO, judging from the way MM rails are align, it is surprisingly undemanding! Only one rail is align on x & y plane, then the parallel rail is set only by the guide rod... which from my experience could give nice +/-0.3mm accuracy (parallelism of the rails) at best... & there is inaccuracy in the edge grinding process which I presume to be +/-0.2mm at best... It is really mind boggling :eek:
Your post on your CV setting caught my keen attention, will pay extra effort on the when my MM make dust.

Found enough time & patient to alignment just one x-rail today.

Introduce the fishing line guide & getting closer alignment is possible. Managed to bring all the height within 0.1mm which translate into +/-50 micron. Couldn't get any close as my coke can shim is 0.1mm thk implementing fishing line method.

I us 0.5mm fishing line so the rail straigtness won't be better the +/-0.25mm. I guesstimate at about +/-0.3mm

I know its closer then necessary, BUT ... just couldn't resist getting them closer while I'm at it... :D

##PS, Did took some pix but doesn't show much at that size level....

孔子日: 有朋自远方来, 不亦乐乎

(Confucius said : with visiting friend from a great distance, the joy is unmeasurable.)

Attachment 8742

Picked Jan De Ruyter from his hotel about 2:30pm, brought him around Pasar Rd where I found most of my electrical & electronics stuff. Gave him a whirl wind tour around my neighboring ultra light industry village in Klang, then proceed to my lair. When the heat got too much of us, we went off to a cafe for a long chat then finished off with a long chat over diner in a local eating den.

Its been a pleasure having him.

Thanks Ken, I really enjoyed the visit and the company. Being on the hop all the time is certainly tiring and spending time in KL this time was indeed a pleasure. Visiting the normal tourist attraction never gives you a good indication of how people life in a county, so the tour of the industrial area was very interesting. Amazing what people can do with so little. The bak kut teh was delicious!

One thing the visit proved to me that I should get a certain part of my anatomy in gear and just do it.

I really appreciate the effort you went to and would like to extend an invitation to you (and all the other MechMaters) to visit South Africa.

Ken, you should have taken Jan for a steamboat! :D

Hell Jan, going to Malaysia to see a MM is a bit extreme....Brakpan is not THAT far from PETORIA....oooo sorry, I talk like my son that study in Pretoria...:D

I would if the weather is not as hot. Jan was sweat through by just sitting there... He'll sure lose a few kg if he go through the steamboat threatment :)

Jan, I enjoy having you around very much, & am glad you enjoyed the Bah Kut Teh. Working on the MM in near physical solidarity is tough mentally, don't think I would had came this far without this forum & your visit sure fuel some new drives.
I would love to visit SA in the near future, but I would like to do that when you start work on your MM, remember what we discussed? Holding the MM parts you already purchase is equivalent to holding inventory. Build it & you may generate some revenue...
Before I forget, thanks for the Elephant Liquer, BTW, what is the best way to enjoy the Elephant liqueur?
Cheers

Amarula

(the date of birth question is because of legislation preventing promotion of alchohol to under-18's)

Kobus, it was a choice, a Brakpan burger or Klang Bah Kut Teh. BTW
1) Is there any truth in the rumour they are going to make Boksburg, Nigel and Brakpan one town? What will the name be? That will determine if I will venture going there.
2) I have a job for you, I need a dibbler for seedling trays. Can you help?

Gerald: tonight I'll go steamboating! So many choices around here!

Ken: The way to enjoy Amarula? Without the elephant. Either neat as an after dinner liqueur or with ice.