Purchasing new parts for new build.

[samsagaz]

Hi guys, i want to purchase a few parts from BST AUTOMATION. I purchased a few years ago some linear guides like
18545
but read bad things about it for aluminium machining :)

I want to build an machine with rigid Y axis and move just X table (think that is easy to get rigid machine with small X and big fixed Y).

Want routing surface of 600/800mm Y and maybe 300/400mm X.

Want some small machine because want high rigidity at least for make parts for bigger machine.

Want to route at least aluminium/copper.

Will be OK purchase HGR25 ones ? if purchase HGR35 will get the same result?

I have a lot of questions but will start with this one :)

PS: have two 16 (600mm) and two 25mm diameter balls crews (1000mmL) at home

[lucan07]

Its possible to route aluminium with these I have hgr20 on my build around same size as you plan ( http://www.mycncuk.com/threads/9678-Aluminium-Framed-Router ) , and cut aluminium regularly without problems, the general advice I am sure will be go for more expensive square rails which are indeed better at a price, when I sell up and move and get a proper workshop I may well build second machine and use top materials but for first build I am happy with performance of these and the price.

[Clive S]

I have a lot of questions but will start with this one :)

PS: have two 16 (600mm) and two 25mm diameter balls crews (1000mmL) at home
But what is the question?

20mm rails will be more than enough for a machine the size you are building.

[mekanik]

Hi Samsagas
Welcome to the forum
As Clive sail 20mm Hiwin rails more than adequate.
Under no circumstances purchase any electrical kit, get a design knocked up, show it to the lads and they will give you advise on the best option for motors and drives.
Good luck with your build
Regards
Mike

[samsagaz]

i already have the motors, and drivers, ball screw, spindles :(

will try to draw some design to get recommendations from you guys!

[samsagaz]

so 20mm is more than enough, great! can purchase long ones then to use more of my ballscrew.

Btw, when is needed 25, 35, 45mm ones? exist some kind of relation table?

[Clive S]

so 20mm is more than enough, great! can purchase long ones then to use more of my ballscrew.

Btw, when is needed 25, 35, 45mm ones? exist some kind of relation table?
Not sure what you mean with the above but in order to get some good advise you need to put some sort of drawing up and it also will be good practise for later when you what to start making things etc

[routercnc]

25mm + rails would be for industrial machining centres where they are chasing max stiffness high throughput and long hours. But the cost goes up with the bigger sizes and the money would be better spent on the other parts to keep it all in balance.

[samsagaz]

i already start the draws! i really liked designs like Silyavski design https://www.youtube.com/watch?v=C9hTLN1CydU (low profile and moving grantry) or fixed gantry like https://www.youtube.com/watch?v=K9UA9ZRFwWU

These are very good machines i think, and maybe impossible to make for myself but will try to draw something :D

I will use welded construction materials like IPN and UPN ones.

will try to draw two designs to see wich recommend me

[Clive S]

or fixed gantry like https://www.youtube.com/watch?v=K9UA9ZRFwWU
That and the series (3 vids) are probably the best I have seen in a long while. Thanks

[samsagaz]

yeah, incredible right? and very well recorded too!

[Norgmonster]

Hi,

I'm new to the forum and in the planing stages of my own cnc router. I'm planing to start with a 2' x 4' cutting bed and use materials that will allow me to upgrade it to a 4' x 8' when i have the space. To do this i'll use 3" x 6" aluminum profile, rack and pinion rail attached to the stepper motors with a drive belt (except for the z axis) and other materials that can be extended or deconstructed. The design is based in part on "Joe's design" (seen being made hear)

https://www.youtube.com/watch?v=5ThZws-858M

It being an American video and being based in the UK I have found most of the equivalent parts except for the X and Y motor mounts that link to the rack and pinion rail.

All in all i think i have the design sorted out "in my head" and will start to drew it up in CAD asap.

First of all i would like to ask if anyone has come across this design and what they think of it?

And second, what is the best hardware to buy for something that will be enlarged in the future (NEMA 34 N.m. 11.2 stepper motor, stepper motor Drivers and so on).

[samsagaz]

what about the ballscrew diameter? how its calculated? i have 2 x 1300mm length 25mm diameter and 2 x 1000mm but 16mm diameter (1605 i think that is the model).

will be the 16mm very small for the Y Axis? im thinking abt purchase 20mm Hiwin rails as you guys recommend me maybe 2 x 1000mm to get close to 800 mm of travel.


As i have 1300mmm i need to cut it and will waste like 400mm :(


cut the 16mm will be better for me, because can use the UPN that i purchased today and think that will not fit the 20mm rails + 25mm ballscrew because have just 160mm width.

[Clive S]

Samsagaz UPN!!! I think you are going to waste a lot of money if you don't get a drawing together before buying parts. In my opinion the 25mm screws are over the top. Generally on a machine of this size 1610 for x and y and 1605 for z might be a better choice. Good luck with the build.

[Norgmonster]

For my 4' x 8' table I'm planing to use Nema 34 motors with around 12Nm for the x and y axis. Is it overkill to use the same for the Z axis (planing for any future upgrades) or should i go for a nema 23 with around 4Nm?

The motors will be driven by rack and pinion.

What would be the best digital stepper drivers, breakout board and power supplies?

[Clive S]

For my 4' x 8' table I'm planing to use Nema 34 motors with around 12Nm for the x and y axis. Is it overkill to use the same for the Z axis (planing for any future upgrades) or should i go for a nema 23 with around 4Nm?

The motors will be driven by rack and pinion.

What would be the best digital stepper drivers, breakout board and power supplies?
Hi and welcome to the forum. First it might be better to start your own thread and then all the questions will be together. I have seen the vid link you posted and although the machine looks nice it won't be that accurate the gantry is too high and the feed rate looks very slow for cutting MDF. Have a read through some of the build logs. and decide what you want to use the machine for.

Don't buy any stuff until you have it drawn up in cad and are happy with the design. An 8 x 4 machine not designed correctly is a bit like digging a big hole in the workshop floor and filling it with hard earned dosh.:apologetic:

Good luck with the build.

[Norgmonster]

Hi Clive S,

Thanks for replying. I can start my own thread but i thought this was a general thread for people asking about parts.

I know the gantry on that design is to high and i have already dismissed most of it. The guy in the video was living my dream and that's why i liked it :-).

I plan to use proper HGR25 Rails and carriages and the gantry will be much closer but I need the z axis to have about 200mm of travel.

I hope to cut wood, plastics polystyrene, sheet metal.

As I'm designing I also want to work out a shopping list and prices so i know what i can afford.

Any advice on hardware like drivers would be appreciated.

[mekanik]

Samsagas/Norgmaster
Hi Guys
If you both get a design drawn up you will get a more meaningful response to your questions.
Norgmaster
You need to start your own thread.
Regards
Mike

[samsagaz]

Samsagas/Norgmaster
Hi Guys
If you both get a design drawn up you will get a more meaningful response to your questions.
Norgmaster
You need to start your own thread.
Regards
Mike


Well my first idea was something like this for Y fixed gantry...

185841858518586

i can reinforce the tower welding a plate in diagonal and can reinforce the back of the UPN too welding it too.

if close the structure can fill with sand or similar to get more weight.

i dont want high Z Axis, think that 70-80mm travel will be enough.

Its my old Z Axis idea, i want to avoid welding the parts and use an UPN as show in first image

18587

Sorry for my english

[Clive S]

My first observation is that you have to be able to build it and assemble the parts have you thought how you would bolt the bearing blocks to the z plate (I think the blocks are to close together). This is why you should draw it out to see these problems.

[lucan07]

With a short a travel required on the Z axis I followed some advice on here and virtually did away with the gantry sides and mounted rails on top of a pair of 6x2" box sections which resulted in a very solid gantry with little effort.
http://www.mycncuk.com/attachment.php?attachmentid=18337&d=1461873328

[samsagaz]

updated Z Axis
1858818589

[samsagaz]

With a short a travel required on the Z axis I followed some advice on here and virtually did away with the gantry sides and mounted rails on top of a pair of 6x2" box sections which resulted in a very solid gantry with little effort.
http://www.mycncuk.com/attachment.php?attachmentid=18337&d=1461873328

ok, will check that.. i was drawing while you post that :)

Its your machine? Looks an strong and nice design because dont weld anyhing, wich is the post? is your machine?

[Clive S]

updated Z Axis
1858818589Can you see the red rail blocks how are you going to drill the mounting holes they appear to be in the edge of the steel

[JAZZCNC]

Samgaz:

Channel isn't very stiff and certainly not flat. Welding in braces etc will cause heat and twist etc. So unless you intend machining the Gantry flat and true then I'd suggets you look at better materials that won't need stiffening by welding.

Your Z axis idea with Channel is disaster waiting to bite you. Like Clive mentions the practical side of bolting etc means it won't work but again Channel just isn't flat enough or good enough. Z axis IS THE MOST IMPORTANT part of the machine.

25mm ballscrews are too large for machine this size and will actually lower the performance and increase the costs in ways you haven't realised yet.
The extra interia of the Screw and Ballnut means you'll need motors with higher torque. This will mean using Nema 34 Motors.
Nema 34 motors spin much slower than smaller nema 23 motors for the same amount of voltage. So this means you need higher voltage to get the same or similar RPM.
In practise this means using drives which offer much higher voltage capabilty. While 60-70Vdc will be fine for nema 23 it will cripple performance of nema 34 and the Larger the motor size the worse it will get. So often larger Nema 34 Motors use drives that run at mains voltage levels.

If you try to run tham at same voltage would nema 23 then your RPM will be so slow the machine is crippled.

NorgMonster: This also applies to you and it's the only comment for you I'm making on this thread so start your own if haven't already.

It's common mistake that Bigger is better and offers upgradabilty. It DOESNT. What it does is Cost more and lowers performance.
Nema 23 motor matched with correct size and Pitch ballscrew run with correct voltage on decent quality drive will run rings around and cost much less than Nema 34 motor running on wrong voltage and connected to large ballscrew.

In your case Norgmonster with R&P then you'll probably need nema 34 motors because of the much lower efficiency of R&P. But again if you don't correctly size and match components then peformance will suffer and money will be wasted.
R&P machine requires careful thought towards pinion size and Reduction ratio used along with Motor/Drive/voltage selection.

Both of you are going about this all wrong and you will Both end up wasting money, time and probably resutling in less than great machine unless you STOP buying without knowing what's required and Design the machine before starting. Fag packet drawings while ok for some things just make this CNC building a disater waiting to happen unless you have plenty of experience which you two clearly don't.!!

Stop, take Step back look and learn then design. Then look again before buying any thing.!! . . . If in doubt ask.!!

[samsagaz]

Yes i understand you, i can move a 10mm to the center each rail and can drill it without problem. Z Axis UPN are 21cm width, so have some space to drill the holes.


Can you see the red rail blocks how are you going to drill the mounting holes they appear to be in the edge of the steel

[lucan07]

ok, will check that.. i was drawing while you post that :)

Its your machine? Looks an strong and nice design because dont weld anyhing, wich is the post? is your machine?

It did turn out a strong build and have been happy with rigidity and weight so far a few things I would change if starting again, hindsights a wonderful thing, but as I have no previous experience in any sort of metal work apart from bolting some lightweight frames together a lot of the changes would be things learned during the build.
http://www.mycncuk.com/threads/9678-Aluminium-Framed-Router

[samsagaz]

Samgaz:

Channel isn't very stiff and certainly not flat. Welding in braces etc will cause heat and twist etc. So unless you intend machining the Gantry flat and true then I'd suggets you look at better materials that won't need stiffening by welding.

Your Z axis idea with Channel is disaster waiting to bite you. Like Clive mentions the practical side of bolting etc means it won't work but again Channel just isn't flat enough or good enough. Z axis IS THE MOST IMPORTANT part of the machine.

25mm ballscrews are too large for machine this size and will actually lower the performance and increase the costs in ways you haven't realised yet.
The extra interia of the Screw and Ballnut means you'll need motors with higher torque. This will mean using Nema 34 Motors.
Nema 34 motors spin much slower than smaller nema 23 motors for the same amount of voltage. So this means you need higher voltage to get the same or similar RPM.
In practise this means using drives which offer much higher voltage capabilty. While 60-70Vdc will be fine for nema 23 it will cripple performance of nema 34 and the Larger the motor size the worse it will get. So often larger Nema 34 Motors use drives that run at mains voltage levels.

If you try to run tham at same voltage would nema 23 then your RPM will be so slow the machine is crippled.

NorgMonster: This also applies to you and it's the only comment for you I'm making on this thread so start your own if haven't already.

It's common mistake that Bigger is better and offers upgradabilty. It DOESNT. What it does is Cost more and lowers performance.
Nema 23 motor matched with correct size and Pitch ballscrew run with correct voltage on decent quality drive will run rings around and cost much less than Nema 34 motor running on wrong voltage and connected to large ballscrew.

In your case Norgmonster with R&P then you'll probably need nema 34 motors because of the much lower efficiency of R&P. But again if you don't correctly size and match components then peformance will suffer and money will be wasted.
R&P machine requires careful thought towards pinion size and Reduction ratio used along with Motor/Drive/voltage selection.

Both of you are going about this all wrong and you will Both end up wasting money, time and probably resutling in less than great machine unless you STOP buying without knowing what's required and Design the machine before starting. Fag packet drawings while ok for some things just make this CNC building a disater waiting to happen unless you have plenty of experience which you two clearly don't.!!

Stop, take Step back look and learn then design. Then look again before buying any thing.!! . . . If in doubt ask.!!

Thanks for take time to write so much! Really appreciate your words/help.

I Already have nema 23 motors and drivers :/ im 99% sure that they support some high voltaje. I already made the mistake that purchase a lot of stuff a few years ago, will try to make it better now and follow your advices before waste more money :/

Maybe copy the design from other guys?

I really want to use some of the pieces that already have, but if not possible is OK, i want an stiff machine, dont want tooo much precision, but of course if more precise better.

[mekanik]

Samsagas
Do as instructed by jazz, take some time to read the build logs all the way through, then read them again. the forum contains priceless knowledge you just have ingest it.
Good luck
Mike

[JAZZCNC]

I Already have nema 23 motors and drivers :/ im 99% sure that they support some high voltaje. I already made the mistake that purchase a lot of stuff a few years ago, will try to make it better now and follow your advices before waste more money :/

I'd doubt they'll be more than 80Vdc drives. Which means Max voltage you'll be able to run motors is 70-75Vdc and that's not enough for large nema 34 motor. Your motors are nema 23 which for 25mm ballscrew are not strong enough. I'd also wager if bought from Ebay/china they are high inductance motors which lowers performance.



i want an stiff machine, dont want tooo much precision, but of course if more precise better.

Well if you want real stiffness and precision then dispite what's been said by Lucan07 then I suggest you forget using round rail and buy some profiled linear rails. It's ok for router but when comes to stiffness and precision it sucks compared to Profiled rails and don't let anyone tell you different.

[samsagaz]

I'd doubt they'll be more than 80Vdc drives. Which means Max voltage you'll be able to run motors is 70-75Vdc and that's not enough for large nema 34 motor. Your motors are nema 23 which for 25mm ballscrew are not strong enough. I'd also wager if bought from Ebay/china they are high inductance motors which lowers performance.




Well if you want real stiffness and precision then dispite what's been said by Lucan07 then I suggest you forget using round rail and buy some profiled linear rails. It's ok for router but when comes to stiffness and precision it sucks compared to Profiled rails and don't let anyone tell you different.


yes i will purchase Hiwin Linear rails like the one that i draw in my bad design :)

[samsagaz]

Samsagas
Do as instructed by jazz, take some time to read the build logs all the way through, then read them again. the forum contains priceless knowledge you just have ingest it.
Good luck
Mike

Ok, will try to find some good log that dont use welding :/

[samsagaz]

Guys, some log to recommend me?

As you see im looking for something useful, i was thinking abt use UPN because are not hard to find in Argentina at normal prices (i pay 18USD for 1 meter of used UPN 160mm yesterday).
Companies that cut aluminium and steel with water/plasma/laser are very expensive, but looks like i will need to pay for that service.

I get the idea of use UPN because its used in some of the vids that i post, but of course they guys have good welding equipment and mill the welded surfaces to fix deformations.

Im a little lost now... EPOXY very expensive, machining very expensive.....

[samsagaz]

Two months ago i asked for 1m2 of 10mm aluminium plate and cost 625USD i think thats its too much for my build. so searching alternatives.

Found the Drivers that i talked about a few post ago. Leadshine AM882 manual say that support 80V max, looks like its the only stuff that purchased that can use in the machine

[samsagaz]

Guys, what about IPN? not good to use it ? i can use the rails in top/bottom or at side. To level it i can use epoxy. I was checking IPN and looks like IPN280 have 10mm center wall thickness. I can bolt the IPN easy to side towers

Btw UPN and IPN are bad because the welding or exist other problem?

lx (7590cm4) of IPN280 are good, but ly (394cm4) dont looks very good

btw the UPN that i use to draw the first image was just lx (925 cm4) and ly(96cm4)

[Clive S]

Found the Drivers that i talked about a few post ago. Leadshine AM882 manual say that support 80V max, looks like its the only stuff that purchased that can use in the machine
The Am882 are good drives but don't run them at the max voltage as Jazzcnc has said 70V is good.

In post #13 you said you have 1605 ball screws you can use those OK.

Start leaning some CAD Can you get Sketchup or Fusion360 and get a drawing made to start?

[lucan07]

UPN or IPN and angles are not recomended from what I gather because while they have good strength they have a tendancy to twist or deform more than closed box section. As in your video of the fixed gantry machine www.youtube.com/watch?v=K9UA9ZRFwWU (https://www.youtube.com/watch?v=K9UA9ZRFwWU) UPN when used tends to be closed forming box section for strength.

[samsagaz]

The Am882 are good drives but don't run them at the max voltage as Jazzcnc has said 70V is good.

In post #13 you said you have 1605 ball screws you can use those OK.

Start leaning some CAD Can you get Sketchup or Fusion360 and get a drawing made to start?


Clive, used sketchup to draw the images that i post. Still searching for complete design/log to get more ideas, at least now skip to use IPN/UPN

[samsagaz]

UPN or IPN and angles are not recomended from what I gather because while they have good strength they have a tendancy to twist or deform more than closed box section. As in your video of the fixed gantry machine www.youtube.com/watch?v=K9UA9ZRFwWU (https://www.youtube.com/watch?v=K9UA9ZRFwWU) UPN when used tends to be closed forming box section for strength.

One (Maybe stupid) question, when the guy on the video add a plate to the UPN to get more strength gantry, they get a lot of deformations, so they mill the piece for a flat surface right? Epoxy will be useful too for flat surface too?

[Clive S]

One (Maybe stupid) question, when the guy on the video add a plate to the UPN to get more strength gantry, they get a lot of deformations, so they mill the piece for a flat surface right? Epoxy will be useful too for flat surface too?Yes. There are quite a few epoxy posts on here if you do a search for them.

[lucan07]

Epoxy is used to self level on many builds to get flat surface to mount rails. You need to complete design and get some comments there are knowledgeable and experienced people on here that will advise of any known pitfalls with your design. The fixed gantry was an excellent design but he was obviously a skilled welder with a well equipped shop, I noted when he ground the gantry and thought it would be possible to some degree of accuracy with a large grinding wheel and mounting gantry on a pair rails and carts temporarily fixed & levelled to allow feeding in a similar manner. With my build and my limited equipment it was a case of the best I could do with the resources I had available so I converted a micro mill first.

[samsagaz]

well, all the draws that i made really sux, cant show anythin yet :/ can someone recommend me some design that are strong enough?