Aluminium Profile Type Router - Initial questions

[Doddy]

Admittedly - I just looked at the technical data for the transformers, e.g. https://airlinktransformers.com/prod...ange-cm0750255 ... which you really would think that they'd replicate that most basic of info. Even on the link you provided there's no clear statement as to the phasing of the windings (I've seen better data sheets).

Edit: Actually, I take that back. The link you provide does, in the schematic symbol, give the phase relationship of the tails.

[CNCRY]

So the transformer lives, and nothing exploded/shorted etc! I did a quick reading across the output and its 70V, which is higher than the 65V its rated at. Is that normal with no load applied? The drivers are up to 70VAC and don't wan't to fry them..

Made some progress over the long weekend - if only I had a CNC machine this would be so much easier:)

Reading some of the new threads I've been re-thinking and slightly concerned that the accuracy I'm building too could result in inaccurate final results.
As this is all "by hand" and printing 1:1 scaling, drill holes are perhaps up to 1mm out, I'm using a digital caliper and angle measuring device during the build, but check as much as possible
There is some slight adjustment by the hole sizing on everything - how much can the software make up for sub mm "corrections"
Maybe overthinking it - but also don't want to end up with something not accurate after all the effort.
As I haven't owned a CNC machine before I don't know what accuracy I'd like, but for example if I could produce something like the Aztec calendar I'd be happy..

Some photos of current build.





Thanks

[AndyUK]

Reading some of the new threads I've been re-thinking and slightly concerned that the accuracy I'm building too could result in inaccurate final results.
As this is all "by hand" and printing 1:1 scaling, drill holes are perhaps up to 1mm out, I'm using a digital caliper and angle measuring device during the build, but check as much as possible
There is some slight adjustment by the hole sizing on everything - how much can the software make up for sub mm "corrections"
Maybe overthinking it - but also don't want to end up with something not accurate after all the effort.
As I haven't owned a CNC machine before I don't know what accuracy I'd like, but for example if I could produce something like the Aztec calendar I'd be happy..

First off, looks like some great progress in the photos, well done!

Regards the by hand - quite a few of us have used this method to good results. Yes, sometimes you cock it up, but just be slow and methodical double checking measurements.

No idea of your experience so lets ensure we hit all bases; make sure to centre punch well (optical if possible - the press type I also like), and let the drill bit align to that punch mark (if you clamp too tightly aligned slightly off, the bit won't happily sit in the punch crater). Use the drill press as much as possible (but check its square to the plate in both directions). If you're not using printouts, use marking dye. Set your digital calipers to the value from a reference surface, lock them off, then use them to scribe the line. When using a steel rule, never use the end for final marking (its a bit variable), always align to markings on both sides (e.g. to measure 10cm I'd align the 1cm mark and the 11cm.) - Now check using the end on the first mark!

If you come to fit components together and the holes are a bit out, you can always identify troublesome ones and widen only those. An M5 clearance hole already gives you 0.5mm of wiggle room, a 6mm hole isn't going to be the end of the world. Worst case is you have to make it again (oh no!) or remake it using the CNC later.

Regards accuracy - mostly to do with how you align the linear rails and screws. Use a dial gauge and get everything running smoothly and true to a reference surface. In your case this is mostly on ali extrusion or cast ali plate, so the height of the rail shouldn't be a massive issue - shim slightly if required, and you'll have plenty of left-right wiggle on the extrusion T slot. Your main problem will be aligning the two sides of the long axis so the rails sit at the same height. You won't go too far wrong if things move smoothly. Avoid software corrections as much as possible - the main one is the steps-per-unit, which shouldn't be too far from the calculated value (if it is very different, somethings probably lose).

[JAZZCNC]

Reading some of the new threads I've been re-thinking and slightly concerned that the accuracy I'm building too could result in inaccurate final results.
As this is all "by hand" and printing 1:1 scaling, drill holes are perhaps up to 1mm out, I'm using a digital caliper and angle measuring device during the build, but check as much as possible
There is some slight adjustment by the hole sizing on everything - how much can the software make up for sub mm "corrections"
Maybe overthinking it - but also don't want to end up with something not accurate after all the effort.
As I haven't owned a CNC machine before I don't know what accuracy I'd like, but for example if I could produce something like the Aztec calendar I'd be happy..

Don't stress over it and it's perfectly possible to build an accurate machine that will easily cut the Aztec calendar by using hand tools, most of the builds on this forum are built solely using hand tools or a large percentage.

Accuracy comes from the setting up and alignment etc. Remember Adjustment, Adjustment Adjustment so slightly oversize holes can help here.

[CNCRY]

Thanks everyone for the replies , no way I'd get throug h the build without the help here !
So I think the best option is going to be new transformer, with the cost of the drives at risk, and fact I'd prefer the simplest approach !
So to be 100% here, 60v or 55v to be safer if supply varies to high side . Will I lose much power @ 55V? And stick with 750VA?
Will PM you about other transformer if interested jazz.

[Clive S]

Thanks everyone for the replies , no way I'd get throug h the build without the help here !
So I think the best option is going to be new transformer, with the cost of the drives at risk, and fact I'd prefer the simplest approach !
So to be 100% here, 60v or 55v to be safer if supply varies to high side . Will I lose much power @ 55V? And stick with 750VA?
Will PM you about other transformer if interested jazz.

Personally I would go with 60V and 625Va or even 500Va

[Andrewg]

Watching thread with interest, as admire how you have got stuck in and learning as you go. I am trying to get a clear plan and design before spending a penny......so happy to learn from your journey.

No help on electricals, but back to printer paper plans. I use this all the time for woodworking templates. You want a spray can of 3M '77' good for temporary and permanent bonding light weight materials.

Keep going and keep sharing gotchas!

[CNCRY]

Watching thread with interest, as admire how you have got stuck in and learning as you go. I am trying to get a clear plan and design before spending a penny......so happy to learn from your journey.

No help on electricals, but back to printer paper plans. I use this all the time for woodworking templates. You want a spray can of 3M '77' good for temporary and permanent bonding light weight materials.

Keep going and keep sharing gotchas!

Thanks Andrew - I researched lots before starting but I find its easier to get started and "fix" some variables in the design otherwise I was going round in circles thinking and changing ideas. Probably means I will have a few gotcha's but hoping not too many! the help on this forum is great also, and helping me get a machine built which was just a pipe dream 6 months ago.

[Doddy]

Will I lose much power @ 55V? And stick with 750VA?

As I understand it (and I might misunderstand the theory) you're not losing power, as such, but top-end speed/torque. But listen to Clive.

[CNCRY]

Gantry Sides done - need to counterbore the M12 bolts slightly but waiting on a 13mm drillbit for clearance hole..


Ended up ordering a new 60V output transformer. Fingers crossed I'll also have the closed-loop steppers and drives turning up in next few days. :)
Lichuan 5.5Nm - LCDA86H+LC60H2127 > https://www.aliexpress.com/item/3279...44bf3421SaYv5O

I'm thinking about cable management, its probably been a bit of an afterthought so far, but I'm thinking having it in my hands will be easier to "visualise". From other post's I'm thinking something like https://www.ebay.co.uk/itm/R38-18mm-...K/163618534489 or will that be underkill?
I'd have 2 x 8mm coolant pipes (and 1 air TBC), 1.5mm CY for spindle, Z and Y motors, encoder cable? Y and Z limits.

Also trying to find the right pulleys for Y and Z - planning on 15mm HTD5 (10mm bore) in 1:1 ratio - but how many teeth do people go for?