NordicCNC's build log

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Originally Posted by NordicCnc

Those block are used to increase the gantry clearance. I want to build machine out of aluminium profiles and the 200x80 profile for the Y-axis sides are not high enough.

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Ok, in that context I understand. It's just in most designs I've seen there is simply a gap there... The desired height achieved by where on the gantry sides you bolt the cross-section (the main bit of profile that forms the gantry).
So in your design, the gantry cross section is supported by being both bolted to the side plates and also by sitting on other pieces of extrusion? Are the blocks underneath connected to the cross-section or does the cross-section simply sit atop them?

Cheers

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Originally Posted by JAZZCNC

Ok well I'll answer this question seen as he's mostly following my design.!

It always makes me smile when I see comments like these because while the physics shows that what you are saying is the ideal location the reality is that it makes no difference to the machine and how it works.

To prove this point I'm going to give you a challenge.! . . . Industry demands the highest cut quality and performance, so logic dictates that they would follow the physics and optimum location very closely.?

So go find me a machine from the major manufacturers that place the spindle smack between the bearings.! . . . If you find one then I guarantee you'll have seen ten before it that don't.!! . .. In fact, you'll be lucky if you find any with spindle inside the bearings.!

You all need to stop worrying about the physics and virtual world so much and get building so you can realize just how little if at all, these affect a real-world machine.!


To answer you directly Joe, then to place the gantry further back to bring spindle into line with bearings would actually weaken the machine not make it stronger. To do what you suggest without getting into complex gantry side designs means using plates for gantry sides that can flex side to side and introduce vibrations at the tool.
I can tell you from building many different designs of router that the design he's using is the best possibly way to build a router without getting silly about.
Mike is correct in that having longer distance between the bearings is good but thats a trade off between travel and foot print of the machine. In the grand scheme again it makes very little difference.

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Is it any wonder that us mere novices get totally confused by all this, as there seems to be loads of conflicting advice floating around in the ether and I'm not talking about just on here.

So there I was working on some supposed designs... Linear rails on back of spindle mount, carriages on z axis, and trying to have a design that keeps the spindle as close to the bearings as possible... Now I find out all that is unnecessary, or not as necessary as I'd been led to believe. But as you've given this design the seal of approval then I guess I'll just try and make mine more like this one, only smaller.

Cheers

Quote:

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Originally Posted by joe.ninety

Ok, in that context I understand. It's just in most designs I've seen there is simply a gap there... The desired height achieved by where on the gantry sides you bolt the cross-section (the main bit of profile that forms the gantry).
So in your design, the gantry cross section is supported by being both bolted to the side plates and also by sitting on other pieces of extrusion? Are the blocks underneath connected to the cross-section or does the cross-section simply sit atop them?

Cheers

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Yes, L-shape bolted together to the gantry sides. Screw clearance holes in the lower profile, threading into t-nuts in the upper profile. I also intend to use aluminium plates and shim them in the t-slot, to act as guides/stopper so that the gantry profiles doesn't move. The blocks underneath the L-shape also have holes and mounts to the lower profile.

Actually I am extremely glad that you commented on the design. It made me realize that I could further increase the stiffness while not compromising gantry clearance significantly!

I've now removed the 60mm high profiles from the gantry sides. Instead I've replaced the 20mm thick blocks underneath, with 40mm blocks. These are going to be machined so that the Z-axis can pass above the blocks. This effectively decreased height the gantry sides by 40mm, less parts, increase simplicity & accuracy while making the gantry stiffer.

Attachment 27883 Attachment 27884 Attachment 27885

However this means that I need to modify the table to compensate for the lost 40mm clearance.

In the current base frame, I've used 120x80 profiles bolted into the sides, consisting of 200x80 profiles. I have 2 alternatives I think:
1. Replace the 120x80 with 120x60 to gain 20mm clearance. Now I've only lost 20mm clearance.
2. Move the 120x80 underneath the 200x80 profiles (+40mm clearance) and bolt from the bottom. Add 20mm item profiles (wide version) as a "T-slot bed" (+/-0mm clearance).

I think I will go with option 2, which will make the bed stiffer also! The budget allows for it anyway.

Might be worth considering how you'll access some of these bolts.

Take for instance the front bearings on the gantry - does the rail being longer than needed foul adjusting those bolts? Does the servo on the back prevent access to the rear ones?

If you're trying to adjust the machine for gantry squareness, and you have to remove the servo between adjustments, that is going to get old fast.

I'm sure someone will be along shortly to tell you not to worry and to ignore this advice it'll all be fine... but hey, worth a thought.

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Originally Posted by AndyUK

Might be worth considering how you'll access some of these bolts.

Take for instance the front bearings on the gantry - does the rail being longer than needed foul adjusting those bolts?

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The rails are not longer than needed. The X-axis can travel all the way to the end actually. The clearance between the rail and the block is 30mm, so I am quite sure there will be enough room. I need to double check this.

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Originally Posted by AndyUK

Does the servo on the back prevent access to the rear ones?

If you're trying to adjust the machine for gantry squareness, and you have to remove the servo between adjustments, that is going to get old fast.

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I will have to look into this as well, hehe.

Thank you for the heads up!

Hi nordic
Why dont you consider doing bed insted of 200x80 similar what robocnc on youtube did?

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Originally Posted by Scustom

Hi nordic
Why dont you consider doing bed insted of 200x80 similar what robocnc on youtube did?

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Hello! I am using 200x80 because it is very stiff. I could of course do it as you describe but I would be sacrificing stiffness. The base frame stiffness is key to a good machine! I also want to keep the part count as low as possible.

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Quote:

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Originally Posted by joe.ninety

Is it any wonder that us mere novices get totally confused by all this, as there seems to be loads of conflicting advice floating around in the ether and I'm not talking about just on here.

So there I was working on some supposed designs... Linear rails on back of spindle mount, carriages on z axis, and trying to have a design that keeps the spindle as close to the bearings as possible... Now I find out all that is unnecessary, or not as necessary as I'd been led to believe. But as you've given this design the seal of approval then I guess I'll just try and make mine more like this one, only smaller.

Cheers

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Joe It's not really fair to hi-jack Nordics thread so let's do it on yours or start another asking this question if you want some guidance and I'll gladly come along and explain the differences etc.

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Originally Posted by JAZZCNC

Joe It's not really fair to hi-jack Nordics thread so let's do it on yours or start another asking this question if you want some guidance and I'll gladly come along and explain the differences etc.

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Sorry, that was never my intention. But in my defense, that was more of a statement of a bit of frustration than a question relating to my own design.

All my questions on this thread have, I think, been aimed at Nordic and his design. I will however be more mindful in the future.

Cheers

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Originally Posted by joe.ninety

Sorry, that was never my intention. But in my defense, that was more of a statement of a bit of frustration than a question relating to my own design.

All my questions on this thread have, I think, been aimed at Nordic and his design. I will however be more mindful in the future.

Cheers

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Hey Joe,

Please don't worry about that. You are free to continue asking any questions you want in my build log. JAZZ was only being polite, since I have not mentioned anything about it. But now I have, so feel free to ask anything!

Also thanks to your questions about the bearing blocks and the standing profiles, I've come up with a much better design I think. I will post more about that later.

Okay I now have a dilemma.

The price difference between 400W and 750W Delta servo motors are only about 100€ each, so total of 400€ price difference. This means that I would get 2 times the torque if deciding to go for 750W servos. Anyway are there any possible drawbacks with these huge servos other than more space requirement and somewhat more expensive? Larger pulley diameters would be needed due to 19mm shafts instead of 14mm shafts.

Also would 400W servos have enough torque to spin 2020 ballscrew with a 2:1 ratio? That would give me a speed of 30m/min. Same case with 750W servos, but those would for sure have enough if not too much available torque.

Also do I need that kind of speed for anything? Machine working area is approx 1200x1000mm anyway. Perhaps 15m/min (achieved with 2010 ballscrews) would be more than enough.

I need help. Please advise! :witless::witless:

Some info that might be useful:

• Z-axis weight: 27kg (1605 ballscrew, 2:1 ratio)
• X-axis weight: 60kg (2020 or 2010 ballscrew, 2:1 ratio)
• Y-axis weight (gantry): 120kg (dual motor drive, 2020 or 2010 ballscrew, 2:1 ratio)

400W with a 2:1 on 10mm pitch will be fine. The ratio will double the torque and Like you say you won't need more than 15mtr/min, in fact, you could go 3:1 or 2.5:1 and still have plenty of speed.

Save the money and put the 400 into better ball screws.!

Quote:

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Originally Posted by JAZZCNC

400W with a 2:1 on 10mm pitch will be fine. The ratio will double the torque and Like you say you won't need more than 15mtr/min, in fact, you could go 3:1 or 2.5:1 and still have plenty of speed.

Save the money and put the 400 into better ball screws.!

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Thanks JAZZ. I am now waiting for a quote from DMM Technology for 400W servo motors. Their servo motors looks really good and the manual/software as well!

The ballscrews that I was planning to get arw C7 rolled ballscrews from BSTmotion. I guess the next step would be either:
1. C7 rolled, with double ballnut
2. C5 ground, with single ballnut
3. C5 ground, with double ballnut

I think that Fred doesn't offer C5 ballscrews so I am mot sure where to buy those from!

Edit: I looked into it and I will probable have a go at double ballnuts. I may need to increase the ballscrew lengths to maintain the same working area, but it will be well worth!

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Quote:

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Originally Posted by NordicCnc

Thanks JAZZ. I am now waiting for a quote from DMM Technology for 400W servo motors. Their servo motors looks really good and the manual/software as well!

The ballscrews that I was planning to get arw C7 rolled ballscrews from BSTmotion. I guess the next step would be either:
1. C7 rolled, with double ballnut
2. C5 ground, with single ballnut
3. C5 ground, with double ballnut

I think that Fred doesn't offer C5 ballscrews so I am mot sure where to buy those from!

Edit: I looked into it and I will probable have a go at double ballnuts. I may need to increase the ballscrew lengths to maintain the same working area, but it will be well worth!

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Never used DMM but I've heard good and bad things so who knows, you just have to try then make up your own mind.!

Ask fred about C5 because I've had C5 from him before and I think he even has or can get Ground screws in shorter lengths. Unless they have stopped supplying them.?

You have to stop at some point because you can go on for ever choosing better quality or performance parts, each upgrade usually affects some other area which then needs upgrading to match else it's pointless. The better machine isn't the one with a few high spec parts, the one that uses lower spec parts that are evenly matched will be the more balanced machine and overall usually work best. . . . Remember machine is only as good as it's weakest link, upgrade one area the rest becomes weak.!!

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Originally Posted by JAZZCNC

Never used DMM but I've heard good and bad things so who knows, you just have to try then make up your own mind.!

Ask fred about C5 because I've had C5 from him before and I think he even has or can get Ground screws in shorter lengths. Unless they have stopped supplying them.?

You have to stop at some point because you can go on for ever choosing better quality or performance parts, each upgrade usually affects some other area which then needs upgrading to match else it's pointless. The better machine isn't the one with a few high spec parts, the one that uses lower spec parts that are evenly matched will be the more balanced machine and overall usually work best. . . . Remember machine is only as good as it's weakest link, upgrade one area the rest becomes weak.!!

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Can you specify some of the bad things? But, yes I will most lilely go for these anyway. Many have used them with great success. The manual and software is really good (not chinglish!) There must be bad things about the Delta servos also.

Fred can supply C5 ballscrews but it will be TBI brand and expensive (about 2.5x more expensive)!

This I have noticed, haha. I have saved every iteration of the machine design. I am up to v11 now..



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Quote:

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Originally Posted by NordicCnc

Can you specify some of the bad things? But, yes I will most lilely go for these anyway. Many have used them with great success. The manual and software is really good (not chinglish!) There must be bad things about the Delta servos also.

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It's been a while but it mostly related to the encoder's output from the drives when using with a controller that can fully close the loop. There were some timing issues that caused problems between controller and drive. But that was some time ago so they will have probably resolved that issue by now but I've seen all kinds of little things and conflicts on various forums etc.
But like you say Delta and other manufacturers do have there own issues as well and it's how they are resolved that matters most, DMM are very good in this respect I believe,

Does anyone know what size cable drag chain is preferred? I am thinking about 25x77mm: https://www.aliexpress.com/item/5300...264066ec24hVi7

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Originally Posted by NordicCnc

Does anyone know what size cable drag chain is preferred? I am thinking about 25x77mm: https://www.aliexpress.com/item/5300...264066ec24hVi7

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Depends on the amount and size of your cables! I measured the diameter of each, approximated them as square boxes, and then calculated the internal area needed. Then you want to fill to about 60%.

Short update to show the final design. NO MORE CHANGES! :nevreness: Started ordering parts today, I am excited.

Attachment 27991 Attachment 27992

Not sure if the frame and/or table needs more bracing. Please give me some advice!

I know I said no more changes but I was wrong. I modified the frame and bed quite a bit. All parts are now ordered and the first parts will be arriving in the beginning of next week. The bed will be adjustable in height to allow for higher work parts if ever needed. This is a safety measure so that I don't regret the design. Table will be adjusted with scissor lifts and should be quite easy to realign. I will also add some triangle bracing to the frame, which are not shown in the pictures. These will be made of steel.

Oh and by the way, budget of 8000€ was not enough, which I expected anyway. It will be closer to 10000€. I am still happy!

Also JAZZ was right in the beginning of the build log about the total weight. It will be over 400kg once everything is assembled.

https://uploads.tapatalk-cdn.com/202...debfa80a76.jpghttps://uploads.tapatalk-cdn.com/202...f3f42b55a8.jpghttps://uploads.tapatalk-cdn.com/202...c64a88e1f6.jpg

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What kind of signal wires are recommended between the controller and AC servo drives? Would ethernet cables be good? Also do they need to be shielded?

Cat5 or Cat6?

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Most AC servos have manufacturer made cables between the motor and drive.

Are you taking about within the control box? Or outside?

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Originally Posted by pippin88

Most AC servos have manufacturer made cables between the motor and drive.

Are you taking about within the control box? Or outside?

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Yes, within the control box between the ESS breakout board and the servo drives.

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Quote:

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Originally Posted by NordicCnc

What kind of signal wires are recommended between the controller and AC servo drives? Would ethernet cables be good? Also do they need to be shielded?

Cat5 or Cat6?

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Cat5 or 6 will work provided it's shielded and you ground one end of the shield at the star point.

Hi,

from #111 "Perhaps I could change the design and use only 1 servo motor on the Y-axis with belt drive connected to both sides. This in turn will not allow for squaring the gantry with motion controller but I think i can get it square any way."

I am face to the same question and first thought is doubling motor + driver + home switch is a costly option compare to 1 motor + belt drive... Have you develop the track of 1 motor for the both Y with belt drive ? Could you advice buildLog of thread that discuss this point ?
Regards

Quote:

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Originally Posted by Gustave

Hi,

from #111 "Perhaps I could change the design and use only 1 servo motor on the Y-axis with belt drive connected to both sides. This in turn will not allow for squaring the gantry with motion controller but I think i can get it square any way."

I am face to the same question and first thought is doubling motor + driver + home switch is a costly option compare to 1 motor + belt drive... Have you develop the track of 1 motor for the both Y with belt drive ? Could you advice buildLog of thread that discuss this point ?
Regards

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No I didn't go for that. I did alrady buy the components fpr dual drive Y-axis and they are being shipped currently. I never looked into the design either. I bet it could work, but perhaps it is not ideal in my case for a 1200mm gantry!

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Status update.

I have ordered all parts and have now received linear rails and ballscrews from BST automation. Stuff looks high quality, but to my unpleasant surprise I ahbe received 2005 ballscrews instead of the requested and quoted 2010 ballscrews... Looks like I will only be getting 7.5m/min rapids now...

I will try to sort this out with Fred, but my expectations are not high. I am not sure how it works with returning the parts. I already paid extremely expensive shipping (due to current world situation) and rip off custom clearance.. Feelings are not the greaterst right now, downgrading from 15m/min to 7.5m/min.

As mentioned earlier in the build log, I will be using servos rated at 3000rpm, with a 2:1 ratio to limit ballscrew rpm to 1500. As I said, I have also already ordered belts and pulleys for that gearing. Fuck. Rant over.

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Are you sure there aren't just two threads on the screws? I initially thought the same thing, then realised if I follow one helix it goes 10mm in one rotation.

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Originally Posted by AndyUK

Are you sure there aren't just two threads on the screws? I initially thought the same thing, then realised if I follow one helix it goes 10mm in one rotation.

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Not sure but I quickly measured from one high point on the thread to the next. I neez to check again tomorrow since I already left the garage. I hope you are right though!

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No they will be correct, they are twin start screws. If you look carefully at the end you will see multiple threads, but it's easy to check just rotate the ballnut and measure how far it moves.

It's a common mistake.

The reason they use this method is it gives higher torque and lessens the depth required and keeps the screw stronger.

Quote:

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Originally Posted by JAZZCNC

No they will be correct, they are twin start screws. If you look carefully at the end you will see multiple threads, but it's easy to check just rotate the ballnut and measure how far it moves.

It's a common mistake.

The reason they use this method is it gives higher torque and lessens the depth required and keeps the screw stronger.

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Omg I will be so happy when confirming this. I believe you and Andy. It really sucked out all my energy when measuring today. Now I have hope again!

I have also received following parts:
- 4x DMM 400w servo motors and drives. One is with a brake.
- ATC spindle from Jianken, 3.2kW with BT30 interface, sunfar E550 VFD, Waterpump and 100mm spindle bracket.
- Aluminium tooling plates from Germany.
- Ethernet SmoothStepper combined with MB3 breakout board.
- 1000mm straight edge DIN 874/2 and 300x200 square DIN875/1 from Helios Preisser.
- 20mm linear rails, 1605 and 2010 ballscrews, cable dragchains from BSTmotion.

I am still waiting for aluminium profiles and HTD pulleys.

I will post some pictures soon to show you guys all the hardware.

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Quote:

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Originally Posted by NordicCnc

Omg I will be so happy when confirming this. I believe you and Andy. It really sucked out all my energy when measuring today. Now I have hope again

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99.9999% Sure they will be correct. I did exactly the same first time I came across them so yes I know that feeling you felt.!:dejection:

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Originally Posted by Kered

Can someone of yous enlighten me as to why nobody uses them

Derek

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You'll see some diagonals in welded steel frames but I suspect with aluminium it's the practicality as you sugest. If the profile manufacturers made the fittings for it and the builders bought the saws for it then you'd see nothing else.

Any recommendations on building your electronics enclosure yourself versus buying one? I am struggling to find one that I think will be large enough for any sensible price. I want to fit everything in the sam enclose, which includes:

(3 phase 400V mains)
- AC line reactor
- Mains filter
- E550 Sunfar VFD
- 4x Dyn4 drives
- 1A schaffner filters for each drive
- MB3 breakout board
- 1 or 2 24VDC power supplys
- Mains circuit breaker
- Contactor for E-stop circuit
- Relay for E-stop circuit
- Circuit breakers for each independent phase (insteaf of regular fuses)
- Terminals

It starts to seem like I would nees atleast a cabinet sized 800x600x250mm. I figure welding my out of sheet metal would be cheapest.

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I can assure you that 800x600 is too small :)
This is what I have and everything is cramped inside.

I bought mine from rs-online, price seemed reasonable.

My next build I'm going to look at using small extrusion for a enclsoure frame, then one can make it any size one wants.

I dithered for ages about this, feels like they should be cheaper.

In the end I went for a Tempa Pano EKO, which enabled me to have a glass front. From memory, the non-glass version, 800x600x300 was about £115, with glass circa £130.

http://www.tempapano.com/en/eko/

Is it overkill? Yeah. Is it nice? Uh-huh.

Space wise, I think its about right... theres plenty of room left in mine, and allowed lots of space for airflow and future expansion. But, honestly, I'm not using most of the depth and its all about how you want to package it. I could probably have fitted the same components in 500x500 or less. Have a look on my log for a reminder of how full up my cabinet is, page 9 post #87 has a photo.

Alternatively, I also looked at used server racks, which seemed like a viable option.

Quote:

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Originally Posted by NordicCnc

Any recommendations on building your electronics enclosure yourself versus buying one? I am struggling to find one that I think will be large enough for any sensible price. I want to fit everything in the sam enclose, which includes:

(3 phase 400V mains)
- AC line reactor
- Mains filter
- E550 Sunfar VFD
- 4x Dyn4 drives
- 1A schaffner filters for each drive
- MB3 breakout board
- 1 or 2 24VDC power supplys
- Mains circuit breaker
- Contactor for E-stop circuit
- Relay for E-stop circuit
- Circuit breakers for each independent phase (insteaf of regular fuses)
- Terminals

It starts to seem like I would nees atleast a cabinet sized 800x600x250mm. I figure welding my out of sheet metal would be cheapest.

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Don't buy anything until you have everything electrical and lay it out on the bench. Servo drives require a lot more space than steppers for cooling purposes and just physically larger anyway. Also think about fitting fans and the Air flow when placing drives etc.

Given that your mostly using extrusion then I'd use aluminium panels and some small extrusion and build the control box into the lower frame if possible.

Talk about keeping us in suspenders,??? . . . . Was the pitch wrong.?

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Originally Posted by JAZZCNC

Talk about keeping us in suspenders,??? . . . . Was the pitch wrong.?

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Sorry, the pitch was of course correct! Thanks for having me double check, I dont think I've realized unless until the build was finished!

About building the enclosure into lower frame with aluminium plates is a good idea. I have a large 2mm aluminium sheet lying around that I could use. For the next step I will lay out the electrical components in 3D and make a wiring diagram to ensure I have accounted for everything.

I've seen that atleast both DMM and Sunfar recommends either mains filter or both mains filter and line reactor for the mains power supply. I have seen people here using line filters but I haven't come across anyone using line reactors yet. Is that really as necessary as the manufacturers are claiming it to be?

Also mounting the electrical enclosure directly to the frame (made of aluminium) would it be a problem since it would basically be in direct contact with the machine frame? I mean that would be a direct earth connection for the enclosure. I am not too into electronics (yet)!

Thanks everyone for your good and helpful advice!

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