Stell frame cnc 1500X1000. Adjustable table your opinion please

It has been more than 1 1/2 year that i did any progress
Many issues delay and postpone my work
So it is time to restart
One of the big problems that i had was the steel flatness
I had to have them milled. i didnt have the means to do it (not a mill neather a lathe)
After some research i enter a machinery shop. He told me "i don’t have the means to do what you want, but i know someone not professional who can do what you want"
So i meet Kosta. A 65 years old person who is not a professional machinist. He loves machining but as he has another job, he works only Saturdays as a hobby. I cant describe what i saw. The working place was clear as a surgery. No sign of steel chip. The man is perfectionist. Everything more than 2-3/100mm is not acceptable. I think he did better job than a pro. He loves machining.
Conclusion he help me by milling the pieces and he didn’t want to take any money
The x axis plates where zero level on a surface grinder.
This is the result


Attachment 18269Attachment 18270
Also the Gantry plate need to be milled both sides
As his surface grinder (500X200) wasn’t that big he work the piece on the milling machine


Attachment 18271Attachment 18272
Z axis also need to be milled both sides
Attachment 18273Attachment 18274

Last piece the gantry
1180 mm long 280mm wide. Kostas didn't have such big milling table
Attachment 18275
So i ask a friend of mine who is wood machine constructor to mill the gantry. I went today. He had a 6000mmX1000mm planer ( i don’t know if my word is correct )
He told me that next Thusday it will be ready. I will attach photos of the big machine
Mean while i work on leveling the X axis. It is the point where i stop 1 1/2 year ago
I want to avoid using epoxy. Specially now that i have the x axis plates perfectly milled so i could easier check level between rails
Very painful job. It is very important to find the higher spot and start from that spot, else you have to go on from the beginning


Attachment 18276Attachment 18277

I will keep you informed
Thanks for your time
Feel alive now that i restart

Looking like a great machine, keep going and good luck !

.Me

Loads of steel going in, nice:)

Kostas looks like a perfectionist, hard to find in a commercial shop when time is money.

Hi every body
Wednesday morning I went to a friend of mine who is a wood processing machine constructor, one of the few that manage to survive in the Greek economic environment.

Attachment 18342
http://www.nikolaidismachines.com/index.php?lang=el

Previous week I gave him my cnc gantry in order to put it in the planer (a 6 metres one), in order to mill it and make a datum surface for the the hiwin rails.

Attachment 18343Attachment 18344Attachment 18345
It is possible that the frame (1900mmX1200mm) can be handled from that planer so i have it milled for the x axis rails

This is the Result
Attachment 18346Attachment 18347
Dial indicator has been used for zeroing the piece
Attachment 18348Attachment 18350
After milling the gantry I had to do the drilling and taping
My friend in order to help put the gantry in a drilling and taping mill (the blue color machine 3-4 meters long) so that I could have the threading in a more precise way (other than drilling and taping with hand). This was one of my big nightmares ( how to drill and tap nearly 40 holes on 14mm steel).
He took me no money for that job. I would like to thank him.
First the machine spot the holes
Attachment 18349
Then Drill and tap
Attachment 18351


Even after milling the surface is not 100% flat against straight edge
I wouldn’t expect zero level accuracy from a 6 meters long machine
When i put the straight edge against the surface, i can see the light pass through but the 0,02mm filler cant pass . So we are talking aboutan error smaller than 0,02mm.
In order to get the best result i will shim the y axis rails. I remember Deans' word many times. How right he is ? He told me " Vagelis even after epoxy method or milling, it is possible that shims will be need in some spots". I don’t want to use the epoxy method, as i think that shimming is more challenging and of course more difficult.
I will be glad to hear every comment

Here is a video of that day
https://youtu.be/4VUnQhaaJIE

Vagelis

Some small progress
Last days I have been working on the gantry
As I said even if the gantry has be milled in a six meters planer, there were some small errors that could be corrected with a couple of aluminum foil.
I don’t know if everybody who had some part milled or use the epoxy method has a true flat surface or i am the only one
Even if the error wasn’t so big, i decided to be as accurate as i can with the means that i have (a 1200mm straight edge) and make the rail as flat as possible. I decide to use aluminum foil shims. i have one basic principle in my construction. As this is my first build i want to make secure steps with so that it won’t be needed to come back again. I think that every small error become large as the progress is going on. That is why I use shims even if i had the gantry milled. To be honest the most useful work after having the gantry milled, wasn’t the leveling process but the milling and taping process.

Attachment 18376
The planer mill 3mm so that there is a datum face for the master rail
Attachment 18377

The other rail will be adjusted for paralelsim by following the master
Attachment 18378
I put the rails temporary to get an idea about how it will look like
Attachment 18379Attachment 18380Attachment 18381


After shimming the master rail i tighten it to the datum face
Attachment 18382
Some pictures from the z axis that follows
Attachment 18383
Tommorrow i will start adjusting the slave rail according the master

Vagelis

Looking good Vagelis keep it moving along.. .:toot:

Pwpw Vaggeli, I had no idea there were such factories in mainland Greece. Do you know if they recondition machines too, or just make their own?

Yes there were such factories but very few.
I think my friend should be one of the last constructor at that scale here in Macedonia-Greece who manage to survive
As you mention they recondition second hand machines.

Hi
As I have told I had my gantry milled on a 6 meter planer
The result wasn’t perfect so I had to shim the rails(at some spots) in order to be straight( no light pass) against straight edge.
I had the last three days trying to shim the rails and I think that the result is acceptable
After shimming I try to attach the y axis steel plate (that moves left right)
My question is how tight should be moved. I know that the hiwin carriages have some preload in order to be more accurate.
I made some tests
I use a zero flat ( from surface grinder) steel plate that will be used for my x axis.
I connect to this plate two carriages and put it on the y axis rails
By using a kitchen scale I measure 700gr force for the plate to move
I did the same with the y axis plate( that has been milled in a mill and it is nearly 3 times havier). It needs 2,7 kgr force to move it.
I made a video that show the two plates
First I move the x axis plate (that will be used in x axis), and then the y axis plate
I would like to ask if what you see and what you hear is normal for hiwin carriages
Also if there is any suggestion for grease for the hiwin carriages

P.S amplify your headspeakers
Here is the video

https://youtu.be/yQ5P9gRsEY0


Thanks for your time
Vagelis

That sounds a little dry - do they have any grease in the carriages??

2.7kg also sounds tight - if this is a truck on two parallel rails, i would slacken the screws on one rail, fit the carriage/plate etc and the gently tighten the screws as you slide the carriage assembly along. Also the same for the screws holding the carriages to the plate - slacken and tighten them with the assembly in position. This allows all alignment stresses to be released hopefully.

Still sounds like it needs grease though, my HiWin stuff was very quiet.

Quote:

---

Originally Posted by Davek0974

That sounds a little dry - do they have any grease in the carriages??

2.7kg also sounds tight - if this is a truck on two parallel rails, i would slacken the screws on one rail, fit the carriage/plate etc and the gently tighten the screws as you slide the carriage assembly along. Also the same for the screws holding the carriages to the plate - slacken and tighten them with the assembly in position. This allows all alignment stresses to be released hopefully.

Still sounds like it needs grease though, my HiWin stuff was very quiet.

---

Yes you are correct, I haven’t put any grease yet
Is there any special type of grease for these carriages, or a general purpose grease can do the job?

Quote:

---

Originally Posted by ba99297

Yes you are correct, I haven’t put any grease yet
Is there any special type of grease for these carriages, or a general purpose grease can do the job?

---

A general purpose Lithium 2 grease will do just fine:

http://uploads.tapatalk-cdn.com/2016...3ae9dd03e0.jpg

Quote:

---

A Premium quality mineral oil, lithium thickened lubricating grease suitable for general purpose applications in plain and anti-friction bearings.

Conforms to leading bearing manufacturers specifications for general purpose industrial and automotive grease.

---

.Me

Hello everybody and happy new year
I reastart my project that has been stoped for more than 6 months
I finally epoxy level X axis and i will do the same with the y axis (the gantry) as the milling of the gantry wasnt as good as i expected
I will apply two layers of epoxy 4mm each.

Many off you may wonder why i go with two layers of 4mm instead of one layer 5mm.
To be honest this is the second try of epoxy level the gantry
The first try went wrong
It wasn’t the resign as i had no problem with the x axis leveling
The reason off the first fail was this

Attachment 20271
After having the gantry milled there was a 3mm groove for the master rail.
At the first epoxy try the groove had been covered with epoxy so the epoxy had 5mm thickness above the groove and 2mm thickness next to the grove. i don’t know if i am understood.
So at the second try i choose to cast two layers. The first one will cover the groove and cover the 3mm gap and the second one will be layed on a flat surface.
Today morning i start with the first layer
First i put the gantry lay on the x axis blocks as x axis is perfectly leveled after the epoxy method


Attachment 20255
I zero my dial gauge in order to level the gantry parallel to X axis.
The 1.9 degrees tilt that the gauge show is a permanent error after an accident


Attachment 20254

In order to achieve perfect level tuning i use some screws as jacks
Attachment 20256
Attachment 20259
I knew that i couldnt have zero level at every point of the gantry as the gantry is not true flat. I was trying for an average zero level.
Attachment 20261

All the previous night i use an electric heater to rise the temperature to 20-21 celcious
Attachment 20263
Today morning i start creating the dome
Attachment 20264
I use both mdf and foam
Attachment 20265

Attachment 20267
Here is the epoxy i use

Attachment 20268
More than 10 hours working time
300 mpas viscosity
Pot life 29 hours (70 ml at 23c)
and here is the data sheet
http://www.resoltech.com/IMG/pdf/DS_...21.07.2016.pdf

Attachment 20269
Price 36 euros
Attachment 20270

Attachment 20272Attachment 20273

Thanks for your time
Will be glad to read your comments

Vagelis

48 hours at 20 co after casting the first epoxy layer (4mm thick) is sticky and starts hardening.
Today morning 8-1-2017 I apply the second layer (also 4mm thick)
Things seem to be ok.
The epoxy is transparent and clear as glass
After full curing I will upload photos.
Mean while (until the epoxy hardens) I will start working on Z axis

Vagelis

Make sure you let it cure for at least 10 days if you have made a sample mould then when you try and bend the epoxy it should snap like glass and not bend.

Not sure why you need 8mm thick?

Quote:

---

Originally Posted by Clive S

Not sure why you need 8mm thick?

---

Thanks for your answer Clive
I know that 5mm thick is enough but as i said,"...After having the gantry milled (a process that went wrong) there was a 3mm deep groove for the master rail.
Attachment 20313
At the first epoxy try the groove had been covered with epoxy so the epoxy had 5mm thickness above the groove and 2mm thickness next to the grove. So this uneven surface may cause the failure of the first try. That is why I decided to go with two layers casts. The first one will cover the big error so that the second one will do the level job better. I don’t remember where, but I had read that in some way the epoxy follows the initial surface and corrects a big part of the surface error, but not all the error.
That is why i choose to cast two layers (4mm each).

Sorry I did not read your previous post properly. I take it that you are using the epoxy to level two rails up if so you need a moat between them
Attachment 20314Attachment 20315

Quote:

---

if so you need a moat between them

---

If you see the photos that i upload, i already have made two moats, at the edges of the gantry
Attachment 20316
They are the white extensions left and right of the gantry
It is like a cyrcle. All the epoxy surface (underneath the rails and the moats) are 50mm wide
Thanks Clive

Yet another bloody post i spend reading for it to hang dead lol, How did it go for you in the end?

Big restart after 4 year
This is the second BIG RESTART on a project from 2014. I hope that this will be the last restart
Glad to be back to mycncuk. I have this project running since 2014.
In my last post back to 2017 I was “epoxy leveling” the gantry
Epoxy correct most of the error BUT checking the carriages with straight edge I found out that the rails are twisted (I don’t know if my English are correct). So shims should be used.
I wander if everyone that uses epoxy method ever check the machine against straight edge?

It was a painful process but I learned a lot about shimming
Some photos of my progress till now
Attachment 29291
Attachment 29292
Attachment 29293

Just to remember some basic specs of the machine
Cutting Size 750X1200
Ballscrews x,y axis 2010 z axis 1605
Gearing 1(motor):2(ballscrew)
At first I was planning using three motors (one each axis X,Y,Z) so I bought a set of three Yaskawa servo motors 400 watt, one of them with brake. After many suggestions and advices I finally bought another 200watt Yaskawa for Z so I have
2 X400 watt for x axis (long)
1X400watt (the one with the brake) for Y
1X200 watt for Z
Here is a picture of the motors
Attachment 29294

My main concern is if 200 watt servo with 1:2 gearing and 1605 ballscrew is enough to handle z axis that is nearly 25-30 kgr (assuming that gearing and ballscrew pitch will 4X the torque of the motor)
Last days i work on attaching the ballscrews so I can mount the motors and see what pulleys and belts I have to order (htd5 15mm wide). Are the Chinese ebay pulleys ok? Do you have any reliable supplier. Do I have something to be carefull. Here is my last progress
Attachment 29295
Attachment 29296
Attachment 29297
Attachment 29298

So i repeat my questions
#1 Is 200watt servo enough for z axis
#2 Pulleys and belts.a) What to be carefull about, b) reliable supplier

Thanks for your time
Vagelis

Looking good my friend and welcome back.

To answer your questions then 200W servo will be more than enough to handle 30Kg.

Regards the belts then can't help with suppliers as I buy mine from a local supplier. Most good bearing and engineering suppliers will stock or get you good quality belts and pulleys.

look forward to seeing it move.