How Would You Upgrade An Old Ox CNC Build Into A Serious Machine?

[Boyan Silyavski]

Was looking at some HGR20-1000’s in the BST automation store for my side rails... but for the life of me I can’t figure out the differences between the different carriage options.

I’m also wondering if adding a better cross piece between the gantry uprights is going to reduce twisting and for mounting the linear rails. I’m definitely going to ditch the C-Beam linear actuator because although it stiffened up the Z axis compared to the original one, it’s currently pushing the spindle too far from the gantry for my liking and is wasting X axis travel (my gantry is the Y axis... yeah, I know... I’m weird lol).

I said it in other thread : I buy from these guys https://es.aliexpress.com/store/822038 12 and 15 size. Have not bought from them 20 size , but their rails are very good quality and price. Custom size also, contact them. make sure to buy the long carriages.

BST is good for original HIWIN but last time i checked / 2 years ago/ the Chinese rails they were selling were not very good. While the ones from the link above are top notch

Dont rush discarding the C beam. Take a look at my design for a DTG printer base using that C beam and said linear rails+some 3d printed elements:



This is 12 size Hiwin square, which would happily move 0.8kw spindle. I would say even 2kw spindle if 3 blocks.

But this is not my point. Maybe 15 size and use the C beam like a L shaped gantry. I have never tried it but that's the fun of it, you can figure it out for yourself.

[Kitwn]

I said it in other thread : I buy from these guys https://es.aliexpress.com/store/822038 12 and 15 size. Have not bought from them 20 size , but their rails are very good quality and price. Custom size also, contact them. make sure to buy the long carriages.

Boyan,
I notice that both BST and your recommended supplier Hong Yi sell both the 'miniature' MGN15 size rails and the larger HGR15 (same size as Hi-Win). The overall height from the base of the rail to the top of the carriage is only 16mm for the miniature compared to 28 for the standard size. Strangely enough the larger size works out slightly cheaper from Hong Yi for the 400mm set I'm looking at for my planned Z-axis upgrade. 15mm seems to be the largest size available in the miniature range and the smallest in the standard sizes so this is the only size where the confusion might occur.

I'd advise anyone looking at 15mm rails to check exactly what you're buying. No doubt the miniature size has practical advantages for some projects but it is not as robust as the standard size for heavy load applications. Those initials make all the difference!

[Boyan Silyavski]

Boyan,
I notice that both BST and your recommended supplier Hong Yi sell both the 'miniature' MGN15 size rails and the larger HGR15 (same size as Hi-Win). The overall height from the base of the rail to the top of the carriage is only 16mm for the miniature compared to 28 for the standard size. Strangely enough the larger size works out slightly cheaper from Hong Yi for the 400mm set I'm looking at for my planned Z-axis upgrade. 15mm seems to be the largest size available in the miniature range and the smallest in the standard sizes so this is the only size where the confusion might occur.

I'd advise anyone looking at 15mm rails to check exactly what you're buying. No doubt the miniature size has practical advantages for some projects but it is not as robust as the standard size for heavy load applications. Those initials make all the difference!

Thats why i laugh when someone says here on forum, he will buy the stuff and figure it out later. I make 3d model of what i make, then piece by piece simulate the assembly and still so normally a mistake or 2 happens.

I say : Figure it out earlier, buy rails and screws. Receive them. Check what is received. Then compare to drawing and continue the build.

[NeoMorph]

I said it in other thread : I buy from these guys https://es.aliexpress.com/store/822038 12 and 15 size. Have not bought from them 20 size , but their rails are very good quality and price. Custom size also, contact them. make sure to buy the long carriages.

BST is good for original HIWIN but last time i checked / 2 years ago/ the Chinese rails they were selling were not very good. While the ones from the link above are top notch

Dont rush discarding the C beam. Take a look at my design for a DTG printer base using that C beam and said linear rails+some 3d printed elements:



This is 12 size Hiwin square, which would happily move 0.8kw spindle. I would say even 2kw spindle if 3 blocks.

But this is not my point. Maybe 15 size and use the C beam like a L shaped gantry. I have never tried it but that's the fun of it, you can figure it out for yourself.

One thing I’m thinking of building is an engraver for spherical objects. I bought an Eggbot yonks ago to check out engraving on a sphere but it’s still in its box.

What I need to engrave for a long term project of mine is two hollow hemispheres. They are part of an Apollo navigation system.



The reason the hemispheres are hollow is because there are motors and sensors INSIDE them. There is a central disc with an axle going through the middle of it and a hemisphere on either side giving the appearance of a sphere. The disc then has axle point top and bottom and it then mounted in a C clamp and that is powered too... then the C clamp is rotated to give the third access.

I worked out all the control circuitry but the one thing that is holding me up is engraving the hemispheres. Both of them are half black and half white making it even harder.

Anyhoo, my point is I think a heavier guage Eggbot might do the trick... emphasis on the “mighty.

[JAZZCNC]

Was looking at some HGR20-1000’s in the BST automation store for my side rails... but for the life of me I can’t figure out the differences between the different carriage options.

There is only few differences HGR is the rail followed by the rail width then length. HGR20-L1500
HGH20CA is Narrow carriage
HGW20CA is wide flanged carriage.

Hi-win do offer other types with different heights and preloads etc but most of what you see for sale in China are common preload and carriage heights.

[JAZZCNC]

Give me the dimensions of the machine ie: Profile lengths for X and Y axis and I'll see what I have kicking around that could possibly send your way. I've got several second-hand but in good condition linear rails and also some new 15mm Hi-win bearings floating around. I've also got a few ballscrews floating about.

How is the gantry made up it's hard to see from that picture and I've seen them build these things several ways, plus you said you'd upgraded it. Just trying to determine if it's strong enough and best layout for rails. etc.

Regards the Z axis and C section profile and it sticking out a little far then I wouldn't worry too much because if you change to linear rails then the gantry end plates will probably need changing so you can design them so the gantry is offset back a little to reclaim the lost travel.

Give us better pics of the machine from different angles so can see better how to beef it up.

[Doddy]

... and honestly 0.8kw spindle is enough for it. Anyways the spindle is a good buy, could be moved on a new machine

I think one of the common design considerations for a 2.2kW water-cooled spindle is not so much the mechanical power, but more the ER20 collet size (20mm tool shank dia) afforded by the larger body. 0.8kW tend to top out at ER11 - which covers a 1/4" shank but not much more.

[NeoMorph]

I think one of the common design considerations for a 2.2kW water-cooled spindle is not so much the mechanical power, but more the ER20 collet size (20mm tool shank dia) afforded by the larger body. 0.8kW tend to top out at ER11 - which covers a 1/4" shank but not much more.

Yeah... when I wanted other sized collets for my Dewalt router I had to order them from the states and got hammered with import duties... just because I wanted 3mm, 4mm, 6mm and 8mm collets to give me some flexibility... and then I ordered the wrong 6mm collet so had to reorder as just returning the wrong one to the states costed more than actually buying another one.

At least I will be able to buy ER20 collet sets in the UK.

[Neale]

For a Z axis the larger rails can even be an advantage. Increases the plate spacing for a typical Z axis design which makes it easier to fit the ballscrew and nut between the plates. Even then, I had to machine some recesses for the ballnut on my own machine. Extra stiffness was a bonus! Depends on your Z design, of course, but worth thinking about.

[Kitwn]

For a Z axis the larger rails can even be an advantage. Increases the plate spacing for a typical Z axis design which makes it easier to fit the ballscrew and nut between the plates. Even then, I had to machine some recesses for the ballnut on my own machine. Extra stiffness was a bonus! Depends on your Z design, of course, but worth thinking about.

I'm not sure I'd want the 15mm miniature version on any router machine. A laser cutter, 3D printer or plasma maybe but not something with cutting forces to resist. Not with the full size version costing the same anyway.

I can see the advantage of using 20mm or larger on the Z to increase the plate spacing. By sheer luck my own 20mm fully supported round rails and 1610 ballscrews fit perfectly between two flat plates which makes things easier. Not that I'm using that as a reason to recommend round rails!