Building My First CNC Router, Looking for Advice & Other Info

[Desertboy]

Hi I had KJN cut and drill my frame (With counterboring) which is a little cheaper than using the corners but also stronger. They will do it to your cad model, you could still use corners as well for extra strength.

Cost me £35 +vat for 18 holes with counterboring.

I already had the corners I did it for strength, I used m12 50mm A2 socket bolts.





A top tip if you do what I did make sure you get some corners then use them to get the extrusion straight before putting the bolt in when it's tight you can remove the corner and reuse.

Also 9045 extrusion takes M12!!!

[AlexDoran]

I'm sorry to inform you that the fourth axis on the controller is only rotational and can't be slaved. Have been drooling over it myself but have to go another way as I'm using 2 motors for my X axis. Boyan runs it with two drivers on the same signal but because of that he lost the ability to home separately.

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I see, i also had this answer in another thread, a couple of the guys thought that it should be fine as long as there are no major crashes and i have a method for adjusting the gantry to be tram.

Hi I had KJN cut and drill my frame (With counterboring) which is a little cheaper than using the corners but also stronger. They will do it to your cad model, you could still use corners as well for extra strength.

Cost me £35 +vat for 18 holes with counterboring.

I already had the corners I did it for strength, I used m12 50mm A2 socket bolts.





A top tip if you do what I did make sure you get some corners then use them to get the extrusion straight before putting the bolt in when it's tight you can remove the corner and reuse.

Also 9045 extrusion takes M12!!!

That's a good shout, i will be buying my Extrusion from KJN too, i have used them in the past! Are brackets alone not rigid enough do you think?

Thanks

Alex

[Desertboy]

I see, i also had this answer in another thread, a couple of the guys thought that it should be fine as long as there are no major crashes and i have a method for adjusting the gantry to be tram.



That's a good shout, i will be buying my Extrusion from KJN too, i have used them in the past! Are brackets alone not rigid enough do you think?

Thanks

Alex

Brackets are strong enough but bolts are stronger, cheaper and alignment is easier of course. Seemed to me a no brainer but you need to use 2 brackets with 4 T nuts to keep the beams straight whilst you bolt them tight then remove the corners.

What are you intending to use as a bed?

[AlexDoran]

I agree with you, how did you go about organising the counter boring? Can they also thread the ends of the Extrusion?

For the machines main function (Routing the 1mm Interdens), i will simply use 18mm MR MDF, and use strips of double sided tape to hold the sheet and keep the cutout items in place after they are separated from the main sheet.

I will also drill the MDF and fit a grid of threaded nuts to use standard clamps / buy a machine vise for machining components we hope to make out of aluminium / bakelight / acetel.

Our larger CMS machines use vacuum pods, sometimes these suffer a nasty end if they happen to meet with a cutter :( I have machined them before on the smaller of the machines but i find it difficult to get repeat-ability in the jig i made to machine them. It will be much easier on this machine. The largest of the pods are 80mm Thick Phenolic Plywood so it will be a good challenge, i think i have enough Z Travel.

Here are some pics of the 2 Bigger Machines and an example of the Vacuum Pods. The Larger Through feed machine has a 3200 x 2000mm workable area (depending on which tool your using in the Horizontal / Arbitor A Axis), It has a 16 Space Carousel Tool Changer. It has a "5th Axis" which actually only controls the mobile vacuum pod row.

The smaller machine has 2600 x 1300mm workable area, 1 Horizontal / Arbitor Head - 8 Head Revolver (8 Motors Fitted with Tools, very fast tool change, mass production suited).

Both machines use an OSAI Controller, programs are generated from a CAM Package called DDX PowerCam - I write C Based Programs for Component Files, we use an Access Database where the guys in the office can build different Door Configurations (We make timber fire doors), Access exports a text file of parameters, PowerCam reads the text file and builds the CAM File autonomously, no manual drawing is ever done.









Thanks

Alex

[Desertboy]

I holed the extrusion cad model then emailed them the model as a .stp but you're using solidworks which they do so you can send them a solidworks file. Make sure the holes are the correct size lol, should be 13mm I think but check this they can tell you if you ring them.

As for counterboring just tell them to counterbore every hole on 1 side with the correct size head but again they will know this is a pretty standard operation. There's no need to model the counterboring.

Make sure your hole size is correct! I can measure the correct bolts with a vernier calliper but will have to wait till tomorrow.

You are using 9045 and 4545 extrusion? If so you will have the same issue I have if using BK12/BF12 ballscrew mounts the hole distance is 45mm between the tracks and the hole distance for the mounts is 46mm.

My Y axis I'm having custom mounts made for the gantry I'm just going to wangle the mounts into T nuts but did consider custom T nuts offset by 0.5mm. I still might have them made.

[AlexDoran]

Ok i will ping them an email and ask how best to send to them, My extrusions are only 40x40 & 40x80, i have drawn up mounts that bolt to the Extrusion and then take the BK & BF15 supports. I will 3D Print these first to check how well they work, then have them machined or attempt to machine myself.

I THINK the 40x40 & 40x80 will take an M10 Bolt? Im not sure and im also not very clued up on the tolerances i should be putting on any the holes i have on the Build, at the moment through holes i have just allowed 0.5mm tolerance for the bolts to slide through - too much or too little?

I would have to check that through bolting into the extrusion would not interfere with the mounts for the bearing supports at either end of the X Axis, if so i will just have to use brackets.





Thanks

Alex

PS Any build log for yours?

[Desertboy]

If you have to send the extrusion I would google and find a supplier closer to you they will almost certainly be able to cut and drill the same as KJN but without the cost of sending the extrusion. I thought you would buy the extrusion from KJN not already have it. I'm lucky I live down the road from them so it was easy to get everything sorted.

Country has many extrusion providers I would look for somewhere you can drive to to drop off otherwise it will be expensive with postage.

KJN are in Leicester, I am very happy with the quality of their work. BUT make sure you have everything specified first correctly because it will be expensive to correct later! I had an issue but I sorted it if I didn't live 5 mins down the road it would have been a big problem.

Click my sig, the budget went up a lot lol from when it started but we're getting there and I ditched the supported rail and belt drive for Hiwin's and ballscrews so was going to cost lol.

Any supplier of this extrusion will be able to cut, drill, counterbore and tap.

If you do want to send via post try myparceldelivery.com you can send 30kg's for just over a £10