Stell frame cnc 1500X1000. Adjustable table your opinion please

Looks like your motors are rated for 400W @ 3000rpm, so 1.27Nm. If you calculate for 15T pulleys on the motors and 30T on the ballscrews using the following specifications:

Mass of axis in kg: [x y z]=[25 25 20] (X-axis mass halved as two motors)
Cutting force in N: [x y z]=[50 50 250]
Acceleration in m/s^2: [x y z]=[2 2 2] (changing this makes a big difference)
Ballscrews: [x y z]= RM2010
Ballscrew length in m: [x y z]=[1.5 1 0.35]

Yields the following:

Feedrate in m/min: [x y z]=[15.0 15.0 7.50]
Inertia in g-m^2: [x y z]=[0.12 0.11 0.07]
Torque in Nm: [x y z]=[0.38 0.34 0.29] (X torque 0.80Nm if gantry mass=0)
Inertia ratios: [x y z]=[3.65 3.18 2.00]

If you instead used 20:60T pulleys on all axes:

Feedrate in m/min: [x y z]=[10.0 10.0 5.00]
Inertia in g-m^2: [x y z]=[0.24 0.23 0.22]
Torque in Nm: [x y z]=[1.03 1.00 0.97]
Inertia ratios: [x y z]=[7.24 7.03 6.50]

So as you can see, even though at a glance you may think changing the ratio would put less load on the motors, you'd actually more than double the torque requirement by using such large pulleys and at the same time get a lower feedrate. This is because most of the torque goes into accelerating the pulleys and ballscrews, so just to illustrate the point about the gantry mass, here's what happens if you use 15:30T and increase the mass of the gantry to something silly like 1000kg:

Mass of axis in kg: [x y z]=[500 250 250] (X-axis mass halved as two motors)

Feedrate in m/min: [x y z]=[15.0 15.0 7.50]
Inertia in g-m^2: [x y z]=[0.42 0.22 0.09]
Torque in Nm: [x y z]=[1.23 0.65 0.37]
Inertia ratios: [x y z]=[12.73 6.53 2.86]


etc...

In other words, your motors are a jot bigger than necessary!

[References:
http://www.nskamericas.com/cps/rde/x...ive_Torque.pdf
ttp://www.hiwin.com/pdf/bs/ballscrews.pdf]

What Jonathan says, but if you are laser cutting the parts then other than cost you could still go for the cutouts but it sounds like it would be more for the looks than any practical reason.
I could not see how the belts would be tensioned from the motor to the pulley. I used 10mm steel for brackets and it's surprising how springy it is, I don't think you should used anything thinner.

Here it is Eddy. If you can see, i have straight slot that will allow the motor movement, in order to tension the belt


Attachment 11974 Attachment 11975

Quote:

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Originally Posted by Jonathan

Forget all the cutouts on the gantry which have been included to reduce its mass. The servos you have a plenty powerful enough to move achieve the required dynamic performance for a gantry several times heavier than what you have designed. If you continue with your plan to use 100mm diameter pulleys then the inertia of just one of those pulleys will be more than the equivalent inertia of all three axes! Decide on the rapid feedrate you want, work out what drive ratio is required, select pulleys, then check that the servo motors are capable of driving it with the required acceleration. It is very simple to calculate, so don't compromise the performance of the system by using very large pulleys when they're almost certainly not required. If you're not sure how to work it out then let me know and I'll show you.

In answer to your direct questions:

1. Depends what you want to do with it, but you seem to be in the right ball park.
2. The consequences of using a lower thickness and having to replace it are far worse than the small increase in cost to use 10mm, so unless you're prepared to calculate it just stick with the thickest you're happy to pay for (presumably 10mm).
3. It looks a bit risky to me - the tolerances on the parts would have to be very good for them to fit together properly.

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I second that. The plates will distort not matter what you do. Use 10mm simple solid plates. Dont be afraid for the weight. When everything aligned and smooth, the gantry will slide with astonishing to you ease.

How you came up with such big pulleys? Another thing to point you is to make sure the pulleys are from Aluminum, cause last time i ordered pulleys from belting online assuming they were aluminum they send me steel pulleys. So ask and make sure before buying.

Quote:

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Originally Posted by silyavski

Dont be afraid for the weight. When everything aligned and smooth, the gantry will slide with astonishing to you ease.

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This is correct, when I first assembled my gantry it was easier to slide it with me sitting on top of it.

Quote:

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Originally Posted by silyavski

How you came up with such big pulleys? Another thing to point you is to make sure the pulleys are from Aluminum, cause last time i ordered pulleys from belting online assuming they were aluminum they send me steel pulleys. So ask and make sure before buying.

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Yes they sent me steel pulleys but that's what I wanted.

As for the pulleys i have to say that my initial planning was to use 2:1 gearing but if i saw that 3:1 would be better, i want to have the room for the new pulley. So i use such big pulley in my plans just to be sure that future changes to the gear ratio will not need gantry rebuild. Other than the pulleys do you see something wrong or something that could be correted

Thank

Vagelis

Quote:

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Originally Posted by ba99297

Other than the pulleys do you see something wrong or something that could be corrected

Thank

Vagelis

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Can you show pictures of the back of the gantry?

Quote:

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Originally Posted by ba99297

As for the pulleys i have to say that my initial planning was to use 2:1 gearing but if i saw that 3:1 would be better, i want to have the room for the new pulley. So i use such big pulley in my plans just to be sure that future changes to the gear ratio will not need gantry rebuild. Other than the pulleys do you see something wrong or something that could be correted

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Maybe if you had enough adjustment on the motor bracket, it would allow you to use the same belt for all size pulleys. I tried to keep all belts the same size so no need to keep lots of spares, I ended up with two sizes.

Silyavski at the previews page ia have some photos. Here i upload some new

Attachment 11981Attachment 11982Attachment 11983Attachment 11984

Eddy as i am not an expert i have the opinion that it is better to keep the belt as short as possible.

You could mount the X motors inside the frame like I did, it stops the machine being wider than it needs to be and leaves room for the cable chain.

Thanks so far for your opinion and for your advices. I have one main question.
You told me not be afraid of the gantry weight. Not to try to lighten the steel pieces as weight is not such a big problem. I want to ask then why many people try to build the gantries with aluminum that it is lighter than steel and aslo more expensive. Why many people try to make their gantries as light as possible without of course having compromises with stiffness. Finally why nearly every Z axis is made from alluminum and not ftrom steel. In my project i think that with or without the offcuts, the difference in weight will be nearly 20 kgr. If that mass isnt important and have small impact to the performance of the machine, then i have no reason to laser cut the parts the way i show before as the cost for lasercutting is not small.

Thanks again

Vagelis

Quote:

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I want to ask then why many people try to build the gantries with aluminum that it is lighter than steel and also more expensive.

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Because aluminum is much easier to work with for most people.

Quote:

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Why many people try to make their gantries as light as possible without of course having compromises with stiffness.

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Because they don't know any better.

Quote:

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Finally why nearly every Z axis is made from aluminum and not from steel.

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Again, aluminum is usually much easier to work with. You can cut it with woodworking tools, or even very lightweight cnc routers if you take your time. Steel requires different tools, or you need to pay someone to do the work.

The Z axis is one place where lighter weight is helpful. But I think ease of fabrication is still the main reason aluminum is used.

I have to admit I did not know the answer to Vagelis' questions but now Gerry has replied I agree with what he says but don't know if that's the full story. I found the Hiwin blocks seemed to move easier with more weight applied so maybe mass and preload of the bearings work together ?

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I found the Hiwin blocks seemed to move easier with more weight applied so maybe mass and preload of the bearings work together ?

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When bearings have a high preload, they will have a "stiction" force that needs to be overcome before they move. Adding weight makes this "stiction" appear less. Unless you have high preload bearings on a lightweight machine, this issue is more "perceived" than actual.

While it's certainly possible to build a gantry that's too heavy, it's rather unlikely. Especially with a servo powered machine. If you keep the gantry weight under 125-150Kg, you should be fine.

After so many months of studding the cnc world, i finally realize that that the myth about lightweight gantries ( that i had in mind ) bites the dust. I am talking about my machine and not for every cnc. Thanks to Deans advices and thanks to Jonathan calculator, i see that 20-30 and even more kgr at the gantry weight doesn’t affect torque needs of the motors. I understood that the most torque will be needed to move pulleys and ballscrew than the gantry that slides on the carriages. Also Syliavsky Eddy, and Ger21 mention that. Thank you every one. After that i will make some changes to Y axis and then go on with the Z axis. So far my gantry weights about 65-70 kgr( without the motors ballscrews of y axis and without the Z axis that need to be designed.
A last photo of the gantry
Attachment 12010


Vagelis

Hi Vagelis,

Sorry I've not been replying to your emails or thread but I've been very busy. I've just today managed to open the file you sent me so have a better idea and can see it's mostly what you posted here.

As I told you before and now others have also confirmed for you that Gantry weight is not such a big issue with Servo's so won't go further on about this.! . . What I want to point out thou is that your complicted Jigsaw puzzle won't really stop the steel from warping while welding.
10mm plate needs serious heat to weld even with Tig and you will experience some warping and for this reason I suggest you design the gantry so it can be welded up completely then important surfaces machined after it as stablised.
Because of your welded and fixed ridged gantry design then you have less areas of adjustment so it becomes important surfaces are machined true and parallel.

I think I've said this before but really for cutting wood then this design is massive overkill unless your planning on attaching a high powered spindle cutting deep and fast 12hrs a day.!
I know your thinking to cut Aluminium with the machine but even then the gantry will be strong enough for light/medium duty work. If you want deep depth's of cut and high quality finish then the size of the machine and Gantry router design will be more the limiting factor not just the Gantry design or strength.

End of the Day you CANNOT have the perfect all round machine at this size so My advise Again is to build it to be the very best it can be for the Purpose you intend to use it for most.! . . . . . . I would rather have a machine that is excellent at one thing than just average at anything and you will only have one or the other.!!

Dean you are right. I am trying to make an all purpuse machine. In my country they said "you can not carry two watermelons under one armpit". That is what i am trying to do BUT as i am going to spend money for a machine, i am trying to achieve the best value for money project. Every day because of asking i find out things that help me avoiding mistakes. I will go on with z axis and come back. If anybody see something that should be mentioned, I will be glad to hear it. Meanwhile if you have any supplier for belts and pulleys tell me. The main problem with me ( among others ) is that I have no lathe or mill for some main machining, so I am trying to avoid that cost by sketching laser cut steel puzzles. As I see it is difficult to avoid machining. Next week I will take my plans and make a research about milling cost. Thank you so far for your help


Vagelis

Here is some progress.
Ganty side plates 10mm steel. Doyou think i need a second side plate each side?
Gantry body 210mm height, made from two tubes 120X60X4 ( up down) and 1 tube 80X80X4 (middle) welded together
All gantry will be welded and then apply epoxy in order to have bottom side carriages in the same level
Z axis from 20mm aluminium and some parts from 10mm steel.
Y axis upside carriages at 400mm distance
Y axis bottom side carriages at 250mm distance
Z axis travel 200mm
Spindle plate 200mm wide

On Friday i will confirm my order to Chai for ballscrews dimensions leave 50mm for pulley attach and easy alignment
I will be glad to hear any advice or comment
Thank you for your time

Attachment 12284Attachment 12285Attachment 12286Attachment 12287Attachment 12288Attachment 12289Attachment 12289Attachment 12290Attachment 12291Attachment 12292Attachment 12293Attachment 12294Attachment 12295Attachment 12296Attachment 12297

Have you thought how you will access the mounting bolts on the Z rail blocks (4.jpg) it looks like the Y rails blocks will restrict them. On another point it seems like you are use angle iron for the rail blocks (Y) are you sure that they will be at true right angles and that the inside edge is flat and parallel to the outside edge. ..Clive

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Originally Posted by Clive S

On another point it seems like you are use angle iron for the rail blocks (Y) are you sure that they will be at true right angles and that the inside edge is flat and parallel to the outside edge. ..Clive

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Aluminium angle is a lot more accurate than steel so maybe you could use a thicker section aluminium angle instead.
Do you need the full Z travel ? if not I would move the Z Hiwin blocks further apart.
Also now is the time to work out where your cable drag chain (energy chain) will sit, you'll need three lengths of the stuff and will need to know the lengths, bend radius, internal dimensions.

Looks like it's coming together nicely.

Quote:

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Originally Posted by Clive S

Have you thought how you will access the mounting bolts on the Z rail blocks (4.jpg) it looks like the Y rails blocks will restrict them. On another point it seems like you are use angle iron for the rail blocks (Y) are you sure that they will be at true right angles and that the inside edge is flat and parallel to the outside edge. ..Clive

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Yes this will be an issue according to these plans but the above plans are only for giving a general idea about the machine. Specific issues ( as the one that you have mentioned ) i think will be solved with small conversions. As for the iron angles the most possible scenario is to have them perfectly milled or use aluminium angles that are more accurate.

Quote:

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Originally Posted by EddyCurrent

Aluminium angle is a lot more accurate than steel so maybe you could use a thicker section aluminium angle instead.
Do you need the full Z travel ? if not I would move the Z Hiwin blocks further apart.
Also now is the time to work out where your cable drag chain (energy chain) will sit, you'll need three lengths of the stuff and will need to know the lengths, bend radius, internal dimensions.

Looks like it's coming together nicely.

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According the plans z axis rails are 400mm the ballscrew (full length ) 501mm carriages distance (outer side 200mm) . That will give z axis a full travel of 200mm. May be ( if that will make the construction better) i will put the carriages at 250mm distance and reduce the full travel to 150mm.

Question 1
The above conversion worth the effort ?


Question 2
Also I would like to say that I choose to put the Y axis ballscrew at the front of the gantry in order to have the ballscrew as close as possible to Z axis and at the same time having the ballscrew exposed to the off cuts of the spindle.
Is that correct ?

Question 3
Do you think I will need a second side plate at both edges?


Thanks for your time

Quote:

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Originally Posted by ba99297

Question 1
The above conversion worth the effort ?

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Maybe you could put some figures in the stiffness calculator and find out, http://www.mycncuk.com/forums/linear...html#post15791

Quote:

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Question 2
Also I would like to say that I choose to put the Y axis ballscrew at the front of the gantry in order to have the ballscrew as close as possible to Z axis and at the same time having the ballscrew exposed to the off cuts of the spindle.
Is that correct ?

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My machine has the ball screw at the back and so far I have noticed no problems.
Some people put a plate over the front with a slot for the ball nut bracket, you could fit these to the slot, Toolstation > Ironmongery > Draught Excluders > Heavy Duty Brush Strip
or keep it like it is and use two of these to keep swarf out Machine Bellows - Arc Euro Trade

Quote:

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Question 3
Do you think I will need a second side plate at both edges?

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I would hope it is strong enough as you have it now with one plate but again maybe you could try putting it into the stiffness calculator.

Roughly in order of priority...(i.e. in order of how much I expect these changes will impact the overall stiffness of the machine:

1. The thin plates the linear bearings are mounted on are definitely weak points.
2. Keep the Y-ballscrew where it is - it's well positioned. Moving the ballscrew to prevent exposure to swarf is totally the wrong priority - just guard it if necessary.
3. The spacing of the bearings on the Z-axis is a bit low - bear in mind the deflection of the linear guide system is proportional to that bearing spacing squared, so every little helps.
4. Try to compact the Z-axis to reduce overhang - by making cutouts in the plates you should be able to avoid putting the rails on spacer strips.
5. The Z-ballscrew could be made shorter if you want, but it doesn't really matter.

You only need the adjustment slots for mounting the X-axis linear bearings to the gantry at one side - on the other side you could use normal holes and mill a reference edge for the bearings to rest against. That will help slightly with getting things square. It's also a good tactic for the other axes - particularly Z in your design.

Quote:

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Originally Posted by Jonathan

Roughly in order of priority...(i.e. in order of how much I expect these changes will impact the overall stiffness of the machine:

1. The thin plates the linear bearings are mounted on are definitely weak points.

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Jonathan when you say "The thin plates the linear bearings are mounted on " you mean the carriages of X axis of Y axis or both X and Y axis?
The "thin plates" of X axis supposed to be 10mm iron. What thickness is suitable ?

Quote:

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Originally Posted by Jonathan

The spacing of the bearings on the Z-axis is a bit low - bear in mind the deflection of the linear guide system is proportional to that bearing spacing squared, so every little helps.

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I suppose you mean to increase the distance between the 2 lower and the two upper carriages and that will reduce the Z axis travel

Should i need a second side plate?


Thanks
Vagelis

After Deans sujestion i put the y axis rails at the front
Attachment 12341Attachment 12342Attachment 12343Attachment 12344Attachment 12345Attachment 12346Attachment 12347Attachment 12348Attachment 12349Attachment 12350
The clearance from the table to the spindle collet is 115mm

Thanks for your time

We've established that the weight of the gantry is not something to be concerned about, so no need for those cutouts between the Y-axis bearings. It'll be stronger if you leave it as a rectangular plate.

Jonathan i agree with you but i must leave at least one small cutout in order to be able to work with the ball screw and also in order to pass the ballnut . How thick plate(steel) plate should i use? At he above plans the plate is 10mm. Also i want to say that i put the ballscrew near the bottom of the gantry and not at the middle, in order to have the ballnut as close to the collet as possible. Is that correct?

Hi guys.
I come back with some final questions before I go on with my machine.
Next week the hiwin profiled rails and carriages will arrive so I will have in my hands all the pieces so I can laser cut the steel and aluminum plates, and the box section tubes.
First I want to say that the machine frame will be made from 80X80X4 steel tubes.
Here is a general overview of the machine

Attachment 12672Attachment 12673Attachment 12674




I I wont use a movable cutting surface as I first had in mind. The cutting surface and the clamping system will look like this.

Attachment 12675

On the 80X80X4 steel tubes I will weld 80X40X3 vertical pieces and between them 40X40 tslot aluminum profile. On the 80X40X3 steel tube, 19mm plywood will be bolted. If there is any comment I will be glad to hear it.


Now regards the gantry it will be made from 2 80X80X4 tubes(in the middle ) and 2 120X60X4 tubes (up and down) welded together like this. At the back side of the gantry all the tubes wont be in the same plane. The 80X80 tubes will exceed 2cm to make space for the ball nut mount flange.

Attachment 12676

The ganty will be welded and then bolted straight to the hiwin carriages ( after I apply epoxy at the bottom side of the gantry ).


And now I come with my questions.
The clearance (after Deans suggestion ) from the lower point of Z to the cutting surface is 180mm. The travel of Z is nearly 130mm. When z axis is at its lowest point the situation is this




Attachment 12677


That means 6mm from spindle choke to the cutting surface.



When z axis is at its higher point the situation is this
Attachment 12678

That means 136mm from spindle choke to the cutting surface.


Is that Ok?This is very critical for the machine construction as any mistake here will need frame reconstruction. Generally is there rule about what is the distance from the choke to the cutting surface when Z is at its lower point.?


Finally i want to ask about resonane. Is it better to use these red plates


Attachment 12679




Or it is better to use a 80X80 tube to connect vertialy left upper side of the frame with the rights upper side of the frame

Attachment 12683

Thanks for your time and i will be glad to hear any suggestion

Vagelis

Hi, I don't think it is a good idea to weld the hiwin carriages if that is really what you mean .G.

Quote:

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Originally Posted by GEOFFREY

Hi, I don't think it is a good idea to weld the hiwin carriages if that is really what you mean .G.

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You are right. By mistake i wrote "weld". I meant bolted. Thanks for the correction. I have already correct the mistake

Hi Vagelis,
I answered some of your questions in my build thread. here is what i think for the other ones.

Quote:

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Originally Posted by ba99297

I I wont use a movable cutting surface as I first had in mind. The cutting surface and the clamping system will look like this.

Attachment 12675

On the 80X80X4 steel tubes I will weld 80X40X3 vertical pieces and between them 40X40 tslot aluminum profile. On the 80X40X3 steel tube, 19mm plywood will be bolted. If there is any comment I will be glad to hear it.

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Your solution seems very nice, man i like it. May be will implement it in my next build. But the plywood thing i don't like. Will constantly need resurfacing if you make precision stuff.
better would be some scrap plastic sheets from doors or whatever found at the Junk yard. And on top-sacrificial layer of expanded PVC plastic sheet. Quite cheap.

Quote:

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Originally Posted by ba99297

Now regards the gantry it will be made from 2 80X80X4 tubes(in the middle ) and 2 120X60X4 tubes (up and down) welded together like this. At the back side of the gantry all the tubes wont be in the same plane. The 80X80 tubes will exceed 2cm to make space for the ball nut mount flange.

Attachment 12676

The ganty will be welded and then bolted straight to the hiwin carriages ( after I apply epoxy at the bottom side of the gantry ).


And now I come with my questions.
The clearance (after Deans suggestion ) from the lower point of Z to the cutting surface is 180mm. The travel of Z is nearly 130mm. When z axis is at its lowest point the situation is this




Attachment 12677


That means 6mm from spindle choke to the cutting surface.



When z axis is at its higher point the situation is this
Attachment 12678

That means 136mm from spindle choke to the cutting surface.


Is that Ok?This is very critical for the machine construction as any mistake here will need frame reconstruction. Generally is there rule about what is the distance from the choke to the cutting surface when Z is at its lower point.?

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What spindle /KW?/ will you be using at the end? That make protruding things longer or shorter.
Also have in mind usual 1/8 bit is 10-30mm long, usual 1/4 bit is 20-40mm long, the piece that is not in the collet i mean.

Quote:

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Originally Posted by ba99297

Finally i want to ask about resonane. Is it better to use these red plates


Attachment 12679

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This is best i believe:

Attachment 12688

Quote:

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Originally Posted by ba99297

Or it is better to use a 80X80 tube to connect vertialy left upper side of the frame with the rights upper side of the frame

Attachment 12683

Thanks for your time and i will be glad to hear any suggestion

Vagelis

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What about doing longer than your table stuff?

Quote:

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Originally Posted by silyavski

What spindle /KW?/ will you be using at the end? That make protruding things longer or shorter.

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I will use a 2,2 kw water cooled spindle

Quote:

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Originally Posted by silyavski

What about doing longer than your table stuff?

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To be honest i dont undertand what you mean. Doing longer what? The braces that the rails will be attached?

Quote:

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Originally Posted by ba99297

I will use a 2,2 kw water cooled spindle



To be honest i dont undertand what you mean. Doing longer what? The braces that the rails will be attached?

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Longer than your bed material. The angle plate will allow material to pass. A soldered profile beam could not allow longer material.

Example: Say you are making a 3m long sign. You can do it working on one half, them moving the other half in the work area.

Hi guys
Guest what?Today i start building
Here is my progress


It is too late now that i am writing
I will continue tomorrow


Thanks for your help




Vagelis

I edit the post in order to explain the photos
First of all i didnt get 6m long pieces. In order to lower the cost i choose for the lower base of the machine to go with pieces that a friend had.
http://www.mycncuk.com/attachment.ph...1&d=1405549128
Too rust but not as bad as it looks


Then i had to cut them. Good for me my friend has a big steel saw so it was easy
http://www.mycncuk.com/attachment.ph...1&d=1405549473


Bak to my home i start to make my "floor welding bench" by laying two 3,3m long pieces of steel.


http://www.mycncuk.com/attachment.ph...1&d=1405549549

I dry the rods in the oven
And i start by making the two big pieces 1,9m long as my machine has 1,9 length
The steel box section that i get from my friend pieces are 1,5 long so i had to weld them in order to make the 1,9m long that is the bigger piece.

http://www.mycncuk.com/attachment.ph...1&d=1405550187

Then i level my floor welding bench and i start
http://www.mycncuk.com/attachment.ph...1&d=1405550839

First i make the rectangular piece off the table try to keep everything square. Then i add the foot an the diagonal pieces

http://www.mycncuk.com/attachment.ph...1&d=1405551110

As i had read many times here in the forum i try to start with spot welding and not with big welding joints in order to avoid distortion. Firtsly that was easy but that make me think that the construction will have no distortion.
That was a mistake
After i finished the table ( lower part ) i realize while checking with an aluminium profile ( that supposed to be straight ) that the table has distortion issues
The following photo shows the aluminium profile when i check the diagonal from one corner to the oposite
http://www.mycncuk.com/attachment.ph...1&d=1405551334
It seems that the aluminium profile has 7mm distance from the table.
I use a jack in order to corect the bending but with no big success
Attachment 12828

Good for me i reaslize that the problem is at the midle of the table, as the 4 corner( lets name them 1 2 3 4) are all at the same level. I use a digital level. First i messure τηε gadient between corners 1-2 and i zero the level. Then i continue by messuring the relative gradient f between corners 2-3, 3-4, and the diagonals 1-3, 2-4. All the messurement show 0.0 gradient. Also 0.0 relative gradient i messure between the front and the back beam. That i s good as i can correct any mistake at the next steps (weld the upper 1,9m long beams where the rails will rest) before i apply epoxy.
Now i am waiting for the 6m long beams to contruct the rest of the table

Attachment 12829

The big problem till now is the weight of the table.
I can hardly turn it upside down
Tomorrow i will put a winch on the ceiling in order to deal with the weight that will be more than 300kgr ( without the gantry)

Thanks for your time

Vagelis

Looking good. Once you have the frame finished the build moves along quite quickly provided you keep it going. Try to order your materials in advance because it felt like I spent a lot of time waiting for things to arrive in the post.

Hi everybody
This is the table so far ( the piece in the middle with be removed a little bit)

Attachment 12866Attachment 12867

This is how it will be
Attachment 12868Attachment 12869Attachment 12870


Two questions

#1 If you see the the top right photo you will see that i dont make a full welding pass just 3 spot ( edges and at the middle ) in order not to produce too much heat. Is that ok or should i weld all the way?

# 2 Do you think that more diagonal support will be needed and where?


Thank for your time

Vagelis

Quote:

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Originally Posted by ba99297

Two questions

#1 If you see the the top right photo you will see that i dont make a full welding pass just 3 spot ( edges and at the middle ) in order not to produce too much heat. Is that ok or should i weld all the way?

# 2 Do you think that more diagonal support will be needed and where?


Thank for your time

Vagelis

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Hi Vagelis,

#1 I believe what is below the gantry and the gantry itself should be fully welded. Anyways later you will epoxy it for leveling. I spot welded only the Z which seemed strong enough/on my build i mean/

# 2 To me it seems there would be no need, especially with your monstrous table bed

#2 I think you could do with some triangulation horizontally to stop twisting but apart room that it's looking good!

silyavski thanks for your comments. I dont forget your help so far.
Thanks.
You have inspired me many time with your work and your suggestions

Quote:

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Originally Posted by njhussey

#2 I think you could do with some triangulation horizontally to stop twisting but apart room that it's looking good!

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When you say horizontally you mean at the corners of the table?


Vagelis

Quote:

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Originally Posted by ba99297

When you say horizontally you mean at the corners of the table?


Vagelis

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Yes that's it, on the inside corners...