sgspenceley published a new build:

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Thank you this was a lot of 3D modeling, but mathematically accurate and fully parametric so when parts arrive from China I can check the dimensions and the model will update and adjust automatically!
Now I'm working on the rack and pinion version, which I'm going to nick name the "Extra Strong OX" using the same extrusion as your Strong OX..

 

Thank you flo. Greeting to Munich, I have spent many fun trips here, working with BMW.
Can you send me a link for the square bar you are suggesting?
Funny I just finished a regular OX, and decided to upgrade to this design thinking it was a lot better!

Gerald I was thinking about using some solid bar to provide the require spacer.

 

Thank you for the bearing information. I'm not sure if this idea goes beyond my budget. Quick research shows $300 VS $140. But you are 100% correct $140 is more expensive if does not work. So I'm going to try the Y axis first.

Gerald I tried putting the rack in between the rails and could not find a solution I was happy with. So played with the idea of bolting a rail to the top to strengthen the Y by creating an additional beam.

Plus is also helps keep dust & chips from failing on the linear bearings.

 

Ricks gear box post is a very interesting read.

I have decided to buy one ball screw for the Z axis to see what the quality is like. $70 for the set looks reasonable.
http://www.ebay.ca/itm/1pcs-antibac...755?pt=LH_DefaultDomain_0&hash=item46109e45e3

So I designed a Z ball screw axis VS the 5 start acme thread which I designed earlier.

 

Next I worked on the main beam design again. I thought if I take the two original 20 * 60 X axis beams and then add two new 20 * 80 extrusions, I could create a very strong box section.

Basically I have two 20*80 extrusions horizontally, two 20 * 60 extrusion vertically, in addition to the plate than supports the linear bearings.

My CNCRouterParts nuts arrived Saturday, so I'm going to try this approach first, before going to the expense of ball screws on the X & Y!
Today produced an accurate 3D CAD model of the anti-backlash nut, so I could work out the correct positions of the X axis & Y brackets.

 

My first set of X axis linear bearings arrived from China, quality is very good.
Now they are in "hand" SBR16 are a good size for the X, Y, & Z axis. Bearings are very nicely made with go good dust shields. Amazing quality for $86 for two rails and 4 bearings...
I would not go down to the SBR12 because the circulating ball bearings will be too small for my taste... If I was building a machine with a long Y axis I would consider SBR20's on a production quality machine.

Shafts are both very straight, one of the mounting blocks has a "slight" twist along its length, but this will be removed when bolted down.

With all four bearing surfaces on the two rails I think these will produce a very smooth and strong X axis.

I purchased from solarjean, packaged arrived very fast from China via DHL about 14 days, free shipping, expertly packaged with great care!
http://stores.ebay.ca/enjoylife?_trksid=p2047675.l2563

 

Thank you shali85, when this build is all complete and tested we will be offering custom plates on Geralds new area51 web site... http://area51cncparts.com/

 

Hi Gray
Two 600mm, case hardened round shafts, 16mm diameter, two 600mm mounting shafts and four bearings was $86 US, free shipping.
Here in Canada I was charged $20 CDN tax... No getting around that if the parcel is flagged by customs!

I'm going to mount these on a 1/4" or 3/8" aluminum plate and then mount that to the beam.

I will now order the linear bearings for the Y & Z axis...

 

I agree Gray this is why I only ordered one set!
I looked locally and they wanted $760 for what looks like the same product SBR16's. So I thought I would try the gamble!
This seller really packaged well and no issues with quality...

 

Thank you JustinTime. I agree items that go through the post office if it's below $300 I typically don't get charged HST, with the Free shipping from China I cannot really complain about the surcharge. The only annoying part is the HST was $6 and the processing fee from DHL was $16... A deliver time of around 2 weeks from China was really great.

 

Thank you Neil for your kind words.
Your build & Geralds inspired this version along with looking at a friend's big production machine. It became obvious that little mods would never give me the machine I really need for my custom sim racing projects.

When you consider I need to re-engineer the OX Y axis gantry plates, I need a longer Y extrusion, new end plates it's basically a brand new build.

So I have decided to go all out and sell my original Aluminium OX which is all complete and running with belts and ideal for hobby work. I have no regrets building the original it was fun & great learning experience. I originally wanted a machine to cut carbon fiber sheet and my plan was to continue using a 3rd party to cut aluminum. But have decided it would be better to cut both parts in-house.

From a X axis, design perspective. I needed a tall vertical surface to mount the linear bearings on, so a 80*20 was logical, knowing this would flex I thought adding three 60*20 horizontal would be enough, then I decided to make a box section. Two vertical 80*20's & three 60*20's all bolted together. I'm also investigating a large single extrusion from a small CNC company in Pittsburgh.

I use SolidWorks & Photoworks for designing, it's a really excellent solution but expensive. For most of my career I worked for a company called Alias Research developing 3D surface modeling for the automotive (Autostudio) & entertainment industry (Maya). It was lots of fun in the 90's and early 2000's until Autodesk purchased the company.

I must admit I'm considering commercializing the design once it's proven itself. Gerald will be cutting the first prototype plates for me once all the additional parts arrive.

Thank you Neil...

 

Thank you for the links, I would consider the 3" x 6" nothing smaller in width. Ideally I would like 4" * 6" extrusion.

I use SolidWorks 2014 premium.

Agree the urge to build again is really strong, because it lots of fun designing and engineering. I have been having loads of fun & spending far too many hours in SolidWorks playing with design concepts...

The original Ox is a wonderful tastier CNC project targeted at a specific group of people. Of that group a small number will want a much stronger & more precise version. You and Gerald both proved you can mod the design to go to the next level. I'm hoping to go one step beyond that and I don't mind learning from but ignoring the original design constraints. Such as wheels that run in a V-slot.

I have a friend how purchased CNCRouterParts Pro series machine with steel wheels, who recently switched his machine to linear bearings in the hope to make the machine more robust... I'm now so pleased I did not buy this machine!

The Ox route has been far more fun!