Ar last!!! Started my Gantry 3-Axis CNC Build

The day has come and I have finally started my 3-axis Gantry router build. I've been lurking on the forum for too long now and its time to do this. Firstly thanks to all the forum members who have contributed to the design - Jazz, John & HiltonSteve who inspired me with his build all those years ago. Attached are some 3d renderings and pics of stuff. Currently doing lots of drilling holes and counterboring in ali strip and plate for the bolts etc.
Basic machine specs are:

3-axis 1100 x 700 x 300 ballscrews.
SBR20 on X SBR16 on Y & 7
Frame from 80x40mm heavy and intermediate extrusions (2.8 and 4kg/m)
Plate - Gantry sides 20mm cast plate 5083
Z axis - Tooling plate cast 5083
Frame Ends 15mm plate 6060

3.1Nm Steppers CNC Kit 1 from Zapp

Photos taken in a unit my neighbour has - did'nt trust the runout on my pillar drill with M8 clearance drill.

Watch this space for more pics as build progresses

Mikehttp://www.mycncuk.com/attachment.ph...id=14043&stc=1http://www.mycncuk.com/attachment.ph...id=14044&stc=1http://www.mycncuk.com/attachment.ph...id=14045&stc=1http://www.mycncuk.com/attachment.ph...id=14047&stc=1

looks like you have it all worked out, and plenty of space & a kettle!!. Keep the pictures coming..

Should be a nice little build that. Looking forward to seeing it come together, keep us posted.

Nice little wood cutting machine. Don't forget the energy chains. You might just fit one under the X rail on a shelf bolted to the extrusion.
With the single ballscrew on X try to cut jobs on the centre line of the machine to reduce racking.

Quote:

---

Originally Posted by routercnc

Nice little wood cutting machine. Don't forget the energy chains. You might just fit one under the X rail on a shelf bolted to the extrusion.
With the single ballscrew on X try to cut jobs on the centre line of the machine to reduce racking.

---

Nah there will be no problem cutting off centre in wood with this design at this size. I've built several know using almost identical design (probably because mikey copied most of my router design. . Lol) and they don't flex while cutting woods, even hard woods.

That said I wouldn't use single screw for cutting aluminium or really deep DOC cuts in hardwoods as then there is potential for some racking.

There is just enough room for energy chains between profiles but needs certain size. It also doesn't need a shelf as nearly half the chain can be supported or bolted to the profile and the remainder easily handles the weight of cables etc.

Quote:

---

Originally Posted by JAZZCNC

Nah there will be no problem cutting off centre in wood with this design at this size. I've built several know using almost identical design (probably because mikey copied most of my router design. . Lol) and they don't flex while cutting woods, even hard woods. .

---

Hi Jazz - I merely took the good advice that you offered !!!

Once the machine is up and running (and doing some useful work) I will upgrade to twin belt-driven ball screws.

I admit that the energy chains location is a bit of an afterthought....

Thanks
Mike

Quote:

---

Originally Posted by MikeyC38

Hi Jazz - I merely took the good advice that you offered !!!

---

So you saying you haven't copied anything from the L shape profile gantry Gantry or the offset drop Z axis Layout or the profile base with aluminium end plates I use.?. .:hopelessness: . . .Ok.!!!!

If thats the case then sure you must have accounted for the gotcha's that I see and encountered.!!

Quote:

---

Originally Posted by JAZZCNC

So you saying you haven't copied anything from the L shape profile gantry Gantry or the offset drop Z axis Layout or the profile base with aluminium end plates I use.?. .:hopelessness: . . .Ok.!!!!

If thats the case then sure you must have accounted for the gotcha's that I see and encountered.!!

---

Hi Jazz

I have to ashamedly say "yes" but good design and good principles are always worth following!

regards
Mike

Quote:

---

Originally Posted by MikeyC38

Hi Jazz

I have to ashamedly say "yes" but good design and good principles are always worth following!

regards
Mike

---

No problem and it's fine by me. If didn't like it copied I wouldn't let it out in the public domain.

Hi Guys
Sorry to be so tardy with postings and updates but I have been working on this. One of the things you discover when building a CNC from extrustions is the amount of drilling and thread tapping you have to do! Thanks to my neighbour who is a retired tool maker, he advised that I use spiral taps and these are brilliant when used in an electric drill! My top tip of the day! Attached are some photos of progress. You can see how the L-shaped Y axis inspired by Jazz was done. I have recently completed the drilling of the "thickner plates" which are used to mount the round supported rails because the material in the extrusions is too thin to directly mount the rails. Also I now need to clear out my garage so that I have space to assemble and check the machine!


http://www.mycncuk.com/attachment.ph...id=14541&stc=1http://www.mycncuk.com/attachment.ph...id=14549&stc=1http://www.mycncuk.com/attachment.ph...id=14548&stc=1http://www.mycncuk.com/attachment.ph...id=14547&stc=1http://www.mycncuk.com/attachment.ph...id=14546&stc=1http://www.mycncuk.com/attachment.ph...id=14545&stc=1http://www.mycncuk.com/attachment.ph...id=14544&stc=1http://www.mycncuk.com/attachment.ph...id=14543&stc=1http://www.mycncuk.com/attachment.ph...id=14542&stc=1http://www.mycncuk.com/attachment.ph...id=14550&stc=1

Hi Guys
Making somewhat slow progress on this but the attached pics show the gantry trial assembled. Runs really nicely on the supported round rails and I detect no binding anywhere! However I have invested in a pack of steel shim material because I expect that stuff will need it to get everything square and nice! The biggest step now is to get the plate holding the z-axis stepper manufactured. Hoping that the local FE college will help here as I don't have a milling machine :upset:http://www.mycncuk.com/attachment.ph...id=15698&stc=1http://www.mycncuk.com/attachment.ph...id=15699&stc=1

Also does anybody have or make some clamps for the 80mm water cooled spindle? I thought Jonathan was making these at some stage but can't raise him via the forum?

Any tips on what lubricant to use on the supported round rails? I will be using Mobilux EP2 for the ball screws (via the ball nut)

Regards
Mike

Looking good Mike!! I've used a 50mm round linear rail bearing housing (bought it from Zapp) which can be picked out quite cheaply on ebay. Jyst take out the circling holding the bearing in and press put the bearing, cut through one side and when you tighten it down it clamps the spindle....

http://images.tapatalk-cdn.com/15/07...a01577b4ff.jpg

Quote:

---

Originally Posted by njhussey

Looking good Mike!! I've used a 50mm round linear rail bearing housing (bought it from Zapp) which can be picked out quite cheaply on ebay. Jyst take out the circling holding the bearing in and press put the bearing, cut through one side and when you tighten it down it clamps the spindle....

http://images.tapatalk-cdn.com/15/07...a01577b4ff.jpg

---

Thanks nj for the tip. Trying to keep the gantry weight down as it will approach 30kg when fully loaded with spindle z-axis and rails.

You could always cut a couple of slivers off it at either end to keep the bolt holes??

If I had my router finished (nearly!!!!!!!) Then I'd cut you some but as it is you might be waiting a few weeks yet.....

I've got a Nema 23 driving my Z axis up and down and ive got a 40mm plate dangling out front, Nema 23 on the Y axis and they're set at 10m/min rapids at the moment and they handle it fine....mind you I've a 8Nm Nema 34 on the X axis [emoji6]

Also I managed to get my garage cleared ( well sort of!) To continue the build. The mc will weigh around 100kg when completed so I needed a hefty table. Thanks to my neighbour Martin who custom welded a table for me!

looking good.. keep the pictures coming... both of the machine.. and the tidy workshop :D

Congratulations on nearing the end of your build and setup. I'm hoping to get the machine moving under computer control by September and fine tuned and ready for real work by the end of the year...

Some more pictures of the build. I've been ill since September 2015 and thus made no progress until March 2016. But the Z axis is in place and moves nicely in the Y axis!

BTW does anybody know if SBRUU linear bearings have to be lubricated? and if so, with what type of lubricant and how frequently?

Thanks Everyone for the help and inspiration so far!

Mike

Quote:

---

Some more pictures of the build. I've been ill since September 2015 and thus made no progress until March 2016. But the Z axis is in place and moves nicely in the Y axis!

---

Glad to hear you are getting back to good health and able to start back on the machine again.:applouse:

Its looking good and seems to be nearly there have you started on the electronic etc?

Quote:

---

Originally Posted by MikeyC38

BTW does anybody know if SBRUU linear bearings have to be lubricated? and if so, with what type of lubricant and how frequently?

Thanks Everyone for the help and inspiration so far!

Mike

---

Mike, Yes they do. Should have some grease nipples...(hehe) on the side. I like to use moly bearing grease for high load applications, this is commonly known as CVjoint grease too. Do not go crazy though so you can at least make an attempt to keep the rails clean of dust/grease gunk. Frequency depends on use, gut feel indication would be 1/month for occasional use, 1/week for heavy use.

R's

Quote:

---

Originally Posted by komatias

Mike, Yes they do. Should have some grease nipples...(hehe) on the side. I like to use moly bearing grease for high load applications, this is commonly known as CVjoint grease too. Do not go crazy though so you can at least make an attempt to keep the rails clean of dust/grease gunk. Frequency depends on use, gut feel indication would be 1/month for occasional use, 1/week for heavy use.

R's

---

I'm not sure about SBR16UU type blocks having grease nipples. External features on the sides of these always look like grub screws to hold the bearing in place. I've not re-greased mine and they've been running fine for years. Where possible I think you would have to slide the relevant axis off the rails to smear some grease onto the balls and that involves quite a strip down. It wouldn't hurt to give them a very light smear of moly grease before assembly:
Attachment 18393

But Hiwin style blocks do have them and you can grease them if you can get to them, but you are not using that type:
Attachment 18394

Quote:

---

Originally Posted by routercnc

I'm not sure about SBR16UU type blocks having grease nipples. External features on the sides of these always look like grub screws to hold the bearing in place. I've not re-greased mine and they've been running fine for years.

---

No they don't have them :(, the side grub is for taking out any slop allowing you to preload them just right on the TBR units, they also have a locating grub in the top that I think is for locating the bearing unit it's self.

I thought about engineering up oil lines on too each housing, that would allow the oil to drip directly on to the top of the rail as it passes in to the bearing unit, though I thought for the effort it's probably not much of a job just to oil the rails as you need to manually...

.Me

Thanks Lee, Routernc and Komatias

I've not been able to find any info on the web about lubricating these SBRXXUU linear slide bearings. So I might just have to grease / oil the rails (lightly) I guess. I found a useful source for the ballscrew grease (Mobilux EP2) ( here) and much cheaper than Ma*Di* who charge £12 for a 50ml syringe! The tech support guy at Simply Bearings is making enquiries for me , so if I get a reply I'll post it here.

I hope to start on the electronics soon - within the next 3 weeks, so more questions and photos to come. Thanks to Jazz for posting a solution for the safety circuit and the use of proximity switches for homing. Now I understand how to wire the emergency stop system!

My bearings are the SBR16UU and I did put grease nipples on side and grease them with the gun mine had no grub on the side only on top side was open, if Lee is correct I may have made an error but the grease certainly arrived where expected, having removed Z axis at one point for adjustment bearings were nicely coated and operation has certainly been slightly quieter since application, at extremes of travel a minor grease line appears at wipes max reach is apparent. I did have some paperwork with the two boxes of chinese bearings recieved in chinese so not read but picture showed top grub for loading bearing and side had grease gun aligned hence my judgement to add nipples and grease. Would be interesting to hear any thoughts if I can find paper recieved with mine will scan and add here, although it may well have been recycled as being of little use.

Quote:

---

Originally Posted by MikeyC38

Thanks Lee, Routernc and Komatias

I've not been able to find any info on the web about lubricating these SBRXXUU linear slide bearings. So I might just have to grease / oil the rails (lightly) I guess. I found a useful source for the ballscrew grease (Mobilux EP2) ( here) and much cheaper than Ma*Di* who charge £12 for a 50ml syringe! The tech support guy at Simply Bearings is making enquiries for me , so if I get a reply I'll post it here.

I hope to start on the electronics soon - within the next 3 weeks, so more questions and photos to come. Thanks to Jazz for posting a solution for the safety circuit and the use of proximity switches for homing. Now I understand how to wire the emergency stop system!

---

Just get yourself some lithium 2 grease and that will be fine, it's cheap as well.

Just consider the bearings glorified skate bearings because that's all they are really, so don't require anything specialised unless you really want to make the effort, grease will last longer than oil but obviously it gets gummy once contaminated and so on, but again the wipers on these units do quite a good job at keeping the raceways clear of foreign bodies.

I could be wrong on the side grubscrew being there for greasing, they may have improved the design or something but all the open type bearing cages I've handled were closed on the casing, I'll have a look shortly on the TBR I've got here and take some pics but I'm confident on those being closed...

Edit: Just looked at the EP2 you linked, it says "is a premium quality multi-purpose, lithium-base NLGI No 2 grease".

The stuff I can get is a multipurpose NLGI lithium 2 grease but it's only £3.50 a tube and doesn't have a major brand name to inflate the price:

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.

---

Can send you a tube if you want, I've been using it for everything and for years with np.

.Me

Thanks Lee for the comment. From my research a lot of ball screw manufacturers recommend the Mobilux EP2 for their ball nuts @ 0.8-1.0ml per 10mm of ball screw diameter, so that's the only reason why I'm choosing it. However £3.50 is much cheaper so I'll have a look around for alternatives as you have suggested. For my 1605 screws this works out to around 1.5ml per ball nut per axis. The SBR16UU and SBR20UU have a side screw but I believe this is for adjustment / pre-loading as you have already said.

See my edit above ^^

Hi Lee.

I'll contact you via PM

Thanks
Mike

Had a look for my bearings documentation but could not find picture but did find this one online from same supplier same as picture which was on leaflet which got recycled except for being open bearing for supported rail. As it goes the fact that they all used to be sealed helps me, I have removed nipples on Z axis can always pop one in annualy to grease them again, but they got in the way a little as I hadn't allowed for them.

Quote:

---

Originally Posted by MikeyC38

Some more pictures of the build. I've been ill since September 2015 and thus made no progress until March 2016. But the Z axis is in place and moves nicely in the Y axis!

BTW does anybody know if SBRUU linear bearings have to be lubricated? and if so, with what type of lubricant and how frequently?

Thanks Everyone for the help and inspiration so far!

Mike

---

I have done the initial stages of the electronics build and the stepper motors have be attached to the machine. I have a video of it working (albeit at a modest 1m/min) until I've done the following:

1) Limit Switches
2) E-Stop connected to relay to cut power and signal Mach 3 (rather than signal Mach3 first)
3) Proximity home switches

Again thanks to Dean for posting a great schematic of how to do a 24V dc e-stop system. What would we newbies do without your help (and ). And to Lee for the steer on grease for the ballscrews.
Expect to have above done by mid october so I can start doing the tramming etc.

In the interim I posted another picture with the spindle mounted (just to show that I am making progress!)
Attachment 19249Attachment 19250

Wish me luck boys!

Quote:

---

Wish me luck boys!

---

It's coming along nicely Mike keep up the good work looks like you will have a nice machine

Thanks Clive for your kind comments.

I've uploaded a YouTube video here showing the gantry moving in all axes at a magnificent speed of 1 metre/min!

Now that I've worked out how soft limits and emulated home switches work, I'll post a video of it working with a piece of real G-Code doing air cuts at this stage.

Hi, I have a quick question how are you finding having one Y axis with the cut quality you are getting, i am at the stage now where i am thinking for the first machine i will keep it at one for now, so i don't need to worry about belts driving two ballscrews etc. If you had your time again would you use Two steppers / or belts or do you find having a single Y axis drive centered is working for you?

Kind Regards
Sherpa

Quote:

---

Originally Posted by Sherpa

Hi, I have a quick question how are you finding having one Y axis with the cut quality you are getting, i am at the stage now where i am thinking for the first machine i will keep it at one for now, so i don't need to worry about belts driving two ballscrews etc. If you had your time again would you use Two steppers / or belts or do you find having a single Y axis drive centered is working for you?

Kind Regards
Sherpa

---

It all depends what you want to cut with the machine and how wide it is how it is built etc.. There are pro's and con's using one or two motors that has been debated many times on here.

Quote:

---

Originally Posted by Sherpa

Hi, I have a quick question how are you finding having one Y axis with the cut quality you are getting, i am at the stage now where i am thinking for the first machine i will keep it at one for now, so i don't need to worry about belts driving two ballscrews etc. If you had your time again would you use Two steppers / or belts or do you find having a single Y axis drive centered is working for you?

Kind Regards
Sherpa

---

Which to use or how well one works over the other moslty depends on the width of machine and like Clive mentions what your cutting.
The cut off point for me is anything wider than 600mm cut will bennifit from twin screws/belts. 600-400mm is open to usage to which is best. Less >=400 then single screw is fine unless mostly cutting Non ferrous metals then I'd go twin every time.

Quote:

---

Originally Posted by Sherpa

Hi, I have a quick question how are you finding having one Y axis with the cut quality you are getting, i am at the stage now where i am thinking for the first machine i will keep it at one for now, so i don't need to worry about belts driving two ballscrews etc. If you had your time again would you use Two steppers / or belts or do you find having a single Y axis drive centered is working for you?

Kind Regards
Sherpa

---

Hi Sherpa
I don't know about the cut quality yet -still fiddling with basic calibration and wanting to fit Jazzcnc's relay based e-stop system before really "going" for it. There may be some racking issues but if I cut in the centre of the board, this should reduce it. I guess if (or most probably when!) I do this again , then twin 1610 ballscrews, belt driven (avoids problem of twin steppers de-synchronising but I don't want to start a flame war here!!!) 68v stepper drivers and a different design for the gantry and precision profiled rails. But I'll wait and see how I get on with this one. It's taken me long enough to get to this stage!!!

I have to admit I'm impressed with the current stiffness of the gantry but cutting will be the true test.

Regards
Mike

Quote:

---

Originally Posted by MikeyC38

Thanks Clive for your kind comments.

I've uploaded a YouTube video here showing the gantry moving in all axes at a magnificent speed of 1 metre/min!

Now that I've worked out how soft limits and emulated home switches work, I'll post a video of it working with a piece of real G-Code doing air cuts at this stage.

---

I've uploaded another YouTube video here running g-code for the first time. Programmed random rapid movements in the XY plane of up to 4500 mm/min. Now got the cable chains installed but had to unsolder all the stepper motor connections to fit the cable chain! doh!

Almost there Mike sounds nice as well, keep up the good work.

Have some more footage posted on YouTube here

Have temporarily given up trying to get my proximity switches to work :-( so using soft limits for now.

Question: I now have to tram the spindle head. I have a dial micrometer and a sheet of 10mm plate glass. Do I need to level the glass in absolute terms, then tram against the glass or just tram against the glass so that the spindle is correctly aligned relative to the glass?

Advice appreciated.

Thanks
Mike

That one:

Quote:

---

Originally Posted by MikeyC38

or just tram against the glass so that the spindle is correctly aligned relative to the glass?

---

Looking forward to seeing how this machine performs Mike, it's very similar to mine.