Ox max build with mods

Hi there, here is some pics of my open build ox max 1500 x 1500 router build. Now I'm no expert, in fact this is the first router I have built and also my first post here, but I would like to show you some of the modifications and decisions I made during the build, and welcome feedback and suggestions.

The build so far: vacuum table not yet fitted.



Purchased from robocutters.co.uk

Firstly I decided to make the stand out of wood over using Ali profiles as I felt it would be more rigid and plus a lot cheaper. the stand out of 80 x 40 pine and cost around £50 to make. Very pleased with the outcome, is super rigid and not too heavy. I will be adding a few more braces through the middle of stand to help support bed.

As you can see i have not used any profiles through the middle of the frame, as i cannot see that it would add any benefit to the rigidity, as all the rigidity is in the stand. plus dropping a tight square vacuum table inside the frame will work to the same effect i feel. personally if i were trying to strengthen the frame using profiles i would want them at 45 degree angles.. the two profiles supplied with the kit as cross braces i really dont think would strengthen a frame of this size, maybe 4 or more might. but i would strongly recommend fixing to a rigid stand instead, plus save yourself the added expense.



Modifications:

The first modification I made was to the z gantry lead screw bottom plate, the cad model I received with the kit showed the two bottom plates doubled up to make a single plate with the flanged bearing for lead screw placed in from the top, however I found that the bearing would try to ride its way up the lead screw when turned anti-clockwise.

To stop this i sandwiched the flanged bearing in-between the two plates and spaced the plates with 1mm shims where any bolts go through.

This has fixed the issue and also has added protection from dust.



The next modification I made was to the y gantry plates. I was informed that having a plate either side of the profiles was more rigid than using both plates on just one side... So obviously no argument there however this would mean the y axis profiles still bolting to only one plate, which made no sense to me. So I made a cutout so the profiles could continue through the inner plate to bolt to the outer plate, and used brackets to secure the profiles to the inner plate.

Cutting the slot in the steel plate was, how can I put this politely, a *****. However the outcome I feel is well worth the effort and made the whole axis a lot more rigid.



The next big decision I had to make was where to locate the motor drivers and breakout board. Having scoured forums for a solution I noticed many people have placed theirs on the back of the y gantry. This for me didn't really appeal as I felt it would be more open to getting damaged and added extra weight to the x axis.

I next started looking at off the shelf enclosures and didn't find anything suitable.. So having spent days without coming up with a solution, I noticed that the extra long bolts I had used in the assembly of the y gantry assembly that were needed to space the plates either side of the profiles had a good excess length that would be ideal to bolt a housing to. But then still the issue of finding a housing.. So rather desperate by this point.. Then it hit me.. It didn't need to be a complete housing.. Just a cover. So with some rapid silicone I simply stuck the heat sinks of the drivers to the outside of one the gantry plates. And stuck the breakout board across two of the heat sinks.

With a fair bit of pressure squeezing any excess silicone out between the plate and heat sinks seems to have made a very good bond. And having the electronics there have made running just two cable carriers, one along the x axis and another along the side to the power supply, very neat and easy.



wiring needs tidying still and needs a cover with a fan. I intend to make from acrylic sheet at some point.

So that's where I am at, like I say I'm a complete novice to cnc so my modifications were made only to satisfy my own thoughts and we're not in any way approved, so avid builders please comment, and anyone thinking of copying my mods please view the comments first.

Thanks for reading.

Jon.

Software:
Mach 3 r3
Autodesk inventor hsm pro 2015
Inventor cam 2015

 

Thanks..

Also something that occurred to me today I feel to be important but haven't seen to been mentioned, is the importance of a common ground between Pc, drivers, bb, psu, drain wires, and frame. And screening of home switch wires. Grounding PC case to the psu ground to avoid a ground loop.

Although, and feel free to comment, I may be exaggerating slightly but have noticed a fair amount of noise when connecting ungrounded frame to an oscilloscope with motors running.. Is it possible at a peak in current from say resistance on any of the motors possible to send a charge back into one of the coils? I'm not sure but pretty certain grounding the frame would reduce the possibility.

My missus has named my ox "the time machine" and the "mistress". Sadly I'm noticing why. Lol.

 

Lol that thought had crossed my mind too.

The way I look at is if you were to hang the frame vertically and drop it with two cross supports it would still fold, 3 it would still fold 4 may bounce but still distort. However attach it to a rigid stand, hang and drop the lot. The chances of it still being square will be much higher.

 

Some updates:



My temporary electronics housing until i get a hot strip acrylic bender. with makeshift optical home switch stop made from foam.. works perfecly well and doesnt break if it hits anything plug extension still needs tidying .. :s shhh and will eventually run the usb cable through cable carrier.. thats when i have a spare to cut open to find what kind of wires i will be dealing with as it will need to be cut and rejoined.



Fan, will make a filter to go over fan when i make acrylic version. optical home switch for y (same on on other side for a) in the distance.. bolted to corner bracket.



Vacuum bed, holes still being drilled. (thank god inventor hsm has hole recognition)

unfortunately i didn't take a picture of the middle sheet that makes up the vacuum bed completed but here is it being routed.. not using a flat end mill would have been a good idea but its all i had at the time. just took forever.





Vacuum bed plumbing, standard 40mm waist pipe push fit connectors work a treat. space under table already filling with garage junk grrrr

Also have upgraded to GT3 belts and pinions.. originally i was using gt2 however had belt stretch in first job and constant slipping from under tee nut.
GT3 seems to have eradicated the stretching issue, however still slips under tee nut, so i suggest using 3 tee nut at either end or with the help of robocutters.co.uk,
using colins belt clamps (will post picture later) as single tee nut just isnt up to the job.

 

belt clamps (from [email protected])