My CNC Router Build Adventure

I'm really bored with this, tables for 1450rpm motors which actually state on them that higher speed motors will take less current don't help at all.

Fact is that many people are happily using these spindles from 13A sockets in the UK. For your information a standard UK 13A socket is on a 2.5sq mm ring main - effective 5mm - from a 32A breaker.

Pippin has written on this thread that his is working fine on his Aussie 10A outlet, countless others are doing the same.

Add in the fact that they're probably 2200 "Chinese Watts" and you have even more headroom.

I'll waste no more time on your claims that a 13A supply can just about manage 1000W and will pop breakers - it doesn't happen in theory or the real world, only on Planet Mac.

I'm out.

Quote:

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Originally Posted by Zorbit

I'm really bored with this, tables for 1450rpm motors which actually state on them that higher speed motors will take less current don't help at all.
I'm out.

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You are out, you have been out to lunch the whole time. :)

The Motor ratings, where just to show that even your basic Math was in correct, for the most basic of AC motor's, this showed that your calculation's where incorrect.

Yes any AC motor can have a different FLA rating, it just depends on the windings and Rotor size, but the basic AC 3 Phase motors do not deviate very much in there Amp rating.

A VFD Drive's output is V/H ratio and is 100%, The Bus voltage for 220v supply is 340v, not much more to it, there is no Power Factor or square root involved in this calculation, every VFD that use's a 6 pulse bridge rectifier, which is most work this way.

Almost all manufacturers use other components manufactured by other companies. there is nothing special about a VFD Drive or the brand name, some have better quality requirement's and a price to go for that quality. they all work the same.

You should not post what someone else has posted some where, if you have not seen it and checked it, you don't know if it is factual or not.

You posted this link and it tell a different story. and the troubles he had running on a low Amp circuit :) your own post contradicts everything you have been posting. which 90% is incorrect information.:rolleyes:
https://www.model-engineer.co.uk/for...?th=128681&p=3

Quote:

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Originally Posted by mactec54

You are out, you have been out to lunch the whole time. :)

The Motor ratings, where just to show that even your basic Math was in correct, for the most basic of AC motor's, this showed that your calculation's where incorrect.

Yes any AC motor can have a different FLA rating, it just depends on the windings and Rotor size, but the basic AC 3 Phase motors do not deviate very much in there Amp rating.

A VFD Drive's output is V/H ratio and is 100%, The Bus voltage for 220v supply is 340v, not much more to it, there is no Power Factor or square root involved in this calculation, every VFD that use's a 6 pulse bridge rectifier, which is most work this way.

Almost all manufacturers use other components manufactured by other companies. there is nothing special about a VFD Drive or the brand name, some have better quality requirement's and a price to go for that quality. they all work the same.

You should not post what someone else has posted some where, if you have not seen it and checked it, you don't know if it is factual or not.

You posted this link and it tell a different story. and the troubles he had running on a low Amp circuit :) your own post contradicts everything you have been posting. which 90% is incorrect information.:rolleyes:
https://www.model-engineer.co.uk/for...?th=128681&p=3

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I know that common sense isn't your first language, but until now at least your English has been reasonably legible - sadly you've lost me now, not even Google could make sense of that lot.

If you are referring to the motor current chart you posted then we can see that they refer to motor efficiency, which implies that the 3hp motor they list is actually outputting 3hp and the input power is correspondingly higher. The common 2.2kw spindle motors I have seen do not quote efficiency, so it's reasonable to assume that they are quoting input power, especially since some of them ( like the one I linked to earlier in the thread ) claim to draw only 6 amps.

We don't of course know the genuine specs of these spindles, and the Chinese are notorious for overstating their capabilities, hence the term "Chinese Watts", but what we do know is that many of these spindle / VFD combinations have been installed and used on household power with no problems at all. It's a popular size in the UK because it runs fine on our standard socket outlets, despite your claim that our 13A outlets will just about run a 1000w spindle and will pop the breakers under any load. Pippin has written that his is running fine on an Aussie outlet - tell him his isn't working.

Now, I really am bored with this now. If you wish to pursue it why not start a thread about it, ask if anybody has measured how much current their 2200w / VFD combo is actually taking.

Start the thread with this one.....

Quote:

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Originally Posted by mactec54

So to supply a VFD Drive output to have 2400W the input would have to be, 1.73 times more. this is what I have said from the beginning. Which would be without any safety factor required by code.

The input to the VFD Drive will need 4128Watts to have an output of 2400Watts. this is very basic Single Phase to 3 Phase requirement.

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Quote:

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Originally Posted by Zorbit

We don't of course know the genuine specs of these spindles, and the Chinese are notorious for overstating their capabilities, hence the term "Chinese Watts", but what we do know is that many of these spindle / VFD combinations have been installed and used on household power with no problems at all. It's a popular size in the UK because it runs fine on our standard socket outlets, despite your claim that our 13A outlets will just about run a 1000w spindle and will pop the breakers under any load. Pippin has written that his is running fine on an Aussie outlet - tell him his isn't working.

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Are well we do know what these spindle spec's are, because I have them, and know what they need to run them, so enough of your arm chair Bs, you have no experience with these spindle motors. so why are you posting, what other people say, and then repost it, incorrectly. (nuts)

Quote:

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Originally Posted by Zorbit

Now, I really am bored with this now. If you wish to pursue it why not start a thread about it, ask if anybody has measured how much current their 2200w / VFD combo is actually taking.

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Yes I have measured what current these 2.2Kw 400Hz 220v 10A spindles use to get there full power, and have tested other size spindles also, my last test was with the motor pulling 10Amps out, and the input was just over 18Amps in, so almost the same as the calculated number. :wave:

I also have repaired many of these spindles, Plus rebuilt some with different Bearing configuration's, to be used for metal cutting.

There are some threads already, that have some of these spindle power requirement's, this is not something new. :)

You keep talking about Pippin, he said that he is using a 16A breaker so is very close to what my tests are at 18A to get full current draw of 10 amps for the quality spindles, an Australian outlet can have a 10A / 15A / 20A / all the way up to 32A for a single Phase supply, so I'm not sure what there problem is, when they can have the correct size Breaker and cable to do the job. :)

So if Pippin's spindle is one of the lower quality units, which most likely it is, it will have a lower Amp rating, that is why he can run it on his 16A circuit, it just won't have as much cutting power as the better quality spindles, which have the higher Amp rating. :)

You can't use a regular meter, to measure the output of a VFD Drive, some of the quality Fluke meters can read the output, any regular meter will either read incorrect or fail completely.

Hi everyone,

Just received a shipping update. My order from BST Motion has arrived in Sydney and cleared customs overnight. The estimated delivery date to my door is Thursday. Woohooo!!! :D

Hi everyone,

My delivery arrived today. Yay!!! I probably won’t get a chance to open the boxes until Saturday so will have to try and be patient until then. I’m eager to inspect what I’ve ordered.

I’ve been thinking about how to setup the rails for the Y axis to be parallel and planar to each other. To do this I would need a reference plane to measure from. If I set up say the left side as the master and reference from it to then set up the right side, it could work but the distance between the walls is too far to accurately reference the right side to the left. Also, the way the walls are constructed, there is no guarantee that the top plate of the wall where the rail will be mounted will be perfectly flat. I’ve read other build threads where the top of the walls are levelled with a self levelling epoxy with a temporary bridge between the left and right side to ensure both sides will be in the same plane but I don’t really want to mount the rails on top of epoxy. What if I use self levelling epoxy on the bed (the yellow part in the attached image)? That would then give me a reference plane I can measure from using a height gauge. Theoretically, if the self levelling works right, then moving the height gauge adjacent to each wall along the y axis, I should be able to accurately adjust the rail height so they are both flat and planar to each other. Did my explanation make sense and would that be an acceptable way to set the rails in the same plane? The wall top plate will have a reference edge that will hopefully be good enough to make the rail straight.

As for making the right rail parallel to the left master, I was thinking of securing a length of stiff extrusion (I have a few pieces of varying sizes which should be ok) to a carriage on the master rail and just resting the extrusion on top of a carriage on the right rail. I’d attach a DTI to the extrusion on the right side indicating off the edge of the right rail and sliding the carriages along the length of the rail adjusting as I went. Would that work or is there a better/easier way?
Feedback welcome.

PS: I found an interesting thread at mycncuk where a USB camera and a laser were used to measure deflection along a line and also to a certain extent, measure variations within a plane. It used readily available parts which many people may already have. I’m thinking of trying it out as an experiment. I’m keeping an open mind. Later in the thread they talked about using a string line (thin music wire or stainless steel fishing line) and a USB microscope. The software calculates the centreline of the wire by detecting the edges and halving the distance between them and calculated deviation by how many pixels the line moves on the camera image sensor. If you are interested in reading the thread, here is the link:
DIY Laser levelling using webcam and laser level

Morning Jayne - I'd stay away from the "self levelling epoxy" concept. To truly self level, epoxy needs to be at least 5mm prefer over 6mm thick. This means you create a soft foundation for the rails as most epoxies are in the 3-4GPa modulus range. It has to be that thick to get around surface tension, viscosity and whats called "thin coating" cure issues. Thin coats cure in zones and as these heat up (expand) and chill (shrink) they "crawl" making surface wrinkles. Your best bet is to make a "lap" and lap the master side. This identifies the lows which you can work the surface down to. Or use an epoxy filler to fill the lows and continue lapping until you get a flat surface. Work both sides at once and try to bring them into best agreement. Fill lows, remove highs, average it out as best as poss... Peter

If your brother has a machinist level this will be useful for shooting across from the master to the secondary rail. Or buy one on line or local. To get the secondary rail parallel to the master I use the gantry or a stiff extrusion to hold the cars. I set the master as level and straight as poss then use the "link" to work down the second rail. Nipping as I go. Then you can remove/loosen the car say from the second and use a dial guage to check its runout relative to the "link". You can also buy geometric laser systems, cheapest I can find is about $35000USD... for the job.

Hi Peter,

I wanted to avoid using self levelling epoxy for the rail beds for the reasons you mentioned. That is why I considered using the method in the machine bed instead. I was planning to use a sacrificial spoil board (is that the correct term?) in tip of the machine base. If I use self levelling epoxy on the base, the sacrificial board would be attached on top of the epoxy. I figured the low modulus epoxy layer wouldn’t be an issue on the bed since the sacrificial layer will be MDF.

My main concern is getting the two Y rails in the same plane. The gantry is about 1 metre across and I’m not sure how to accurately project the plane of the master rail across to the slave rail. If the machine bed is used as a reference plane, that spans the full width and length of the machine so problem solved, provided I can get a good pour.

Is the method you described good for aligning the rails in the same plane or only for getting them parallel to one another? I was planning to set the slave rail parallel to the master in a similar way to what you described. My brother has a machinist level but it’s not long enough to span across the two rails. I think it’s only about 300mm long.

Hi Jayne - No need to level the base with epoxy. You set up the spoil board then using the router you plane the board flat. This brings the board into correct plane with the machine. Use the machinist level and a straight extrusion or steel section to project across the master and second. Flip the extrusion and check both ways. This will establish the rails as "level" or planar. You can also use 2 tight stringlines across opposing rail ends to establish there is no "wind" in the rails (twist). The lines should touch each other in the middle. As you build the base use the machinist level to level every step of the way. True the level as well and be patient for the bubble to settle. Takes a long time vs a builders level. If you use the machinist level regularly on everything it will be worthwhile. You can set up rough with a good builders level so you can move through the first fitup fast (to establish everything is in order and identify issues, then fix) then come back and use the machinist level for second fit and final levelling.. Peter

first fit - establish everything is in order and only nip bolts. Fix identified probs. Move along quickly so you get everything fitted and working
second fit - work from bottom up, levelling snugging up and truing. Intent is to get everything true
third fit - full torque everything and fine tune. By now you will understand the machine enough to have lunch together...

so in short get the wall rails level and parallel, then the Z axis orthogonal then you can plane the spoil board to the machine. The hardest thing I've found is getting the gantry at 90degs to the wall rails. I do this with large squares and eventually by marking large squares under machine control with the machine and adjusting the gantry to correct square.

I have a good extrusion that I use. I remove two opposing screws from the wall rails and screw the extrusion across the walls. I then use squares to square this to the rails. Then set the gantry rails to this via dial gauges or calipers.

another reason not to use epoxy for your bed is that when you move the machine its level will be upset and become incorrect. So then you have to re-plane the spoil board anyway. I do not use a large spoil board. If I do a job that requires flatness I install a suitable spoil board for the job and plane it prior to doing the job. If you are doing large flat sheet work often that requires flatness vs just profiling then a large level spoil board is important.

Hi Peter,

Thank you for the detailed explanation. I got the general gist of what you said but not sure I follow it exactly without a real life machine in front of me. I’m sure it will all become very clear once I start building. Like you said, after going through the process a couple times, Carlos and I will be in a steady relationship having lunch together. Lol

Hi Jayne - I think there are photos of this process in the Brevis-HD thread :) Peter

I wasn’t really happy with the Z motor mount. The plate it attaches to doesn’t seem rigid enough without any additional bracing so I thought I’d try one of those HM12-57 cast aluminium brackets from AliExpress (see attachment) as an all in one solution for the motor mount and fixed end support bearing. The floating end of the ballscrew will still connect to the BF end support bearing that came with the ballscrew. Only issue is I’m not confident the dimensions given for these brackets are reliable due to variations from seller to seller, which means I can’t accurately model the part to check if it will work. I’m also uncertain if the bearing rotating axis in the bracket will be in line with the bearing axis at the floating end of the screw. So I ordered the bracket and waiting for it to arrive from China so I can measure it before proceeding any further with the Z axis fine tuning. Plenty of other work to do in the meantime.

That's a cool find... I wish I had know about those when rebuilding my Z I'd have picked one up.

Adam,

Hi Jayne - was going to use these on Frankie. Would like to know if they are same dims as steel ones. Here's the ones i get from BST... Peter

https://www.aliexpress.com/item/3295...531e2b20hxt0Gr

This is the one I bought

AU $13.37 40? Off | Stepping servo motor seat screw support seat bearing HM12-60motor fixed seat integrated bracket support for NEMA34 NEMA 24
https://a.aliexpress.com/_mPJdQBM

Peter, one of the vendors I was looking at mentions in their ad that the aluminium and steel brackets have different dimensions but I don’t remember which gender that was. If you search for HM12-57 you will get lots of hits from lots of vendors. I just went with the cheapest. (HM12 is for 16mm ballscrews, and HM15 would be for 20mm and the 57 refers to 57mm for a Nema 23). I also found between vendors, the dime signs listed vary for what looks to be identical items so not sure how reliable those dimensions are which is why I just ordered one to measure myself. Will let you know more when it gets here.

Hi Jayne - The alloy ones are half the price of the steel ones and lighter so attractive. Will be good to know dims... Ta Peter

Hi Peter,

The stepper motor mount arrived today. It's cast aluminium and looks to be reasonable quality, especially for the price. I purchased the "HM12 for NEMA 23 C5" from this link https://www.aliexpress.com/item/4001...65024c4dhObNt0

I took a bunch of measurements, see attached images. The item I received looks slightly different from the images in the ad and the dimensions don't seem to line up with what is quoted. I suspect they source these items from different places and may look different from batch to batch. The measurements I took are mostly rounded to the nearest 0.5mm using a cheap digital calliper. The mounting holes for the motor come pre tapped with what looks to be an M4 thread (I don't currently have any M4 screws to try). Let me know if you need any other measurements. Hope this helps.

Thanks Jayne - Looks good. Will compare dims to catalogue dims. You have a great Xmas and hope Santa treats you right. I assume you've been good this year!? :) Seasons Greetings, make happiness Peter

Thank you Peter. Hope you and your family have a great Christmas too.