It looked to me like the ball screw was binding up in the same spot every revolution and then it ran well for the rest of the revolution, so maybe there's an alignment issue.

@routercnc9517

6 ай бұрын

I think that was part of it. But I’ve just found the real reason, and managed to sort it out. Watch out for the next upload!

All trial and error mate looking great tho

@routercnc9517

6 ай бұрын

I usually run the calculations to get the spec right but I only needed 1Nm to move the knee but it’s not working out. More options to think about.

Check if lifting the table with your hand helps, if so, install a counterweight, e.g. more powerful engine

@routercnc9517

6 ай бұрын

Thanks I’ll try that and see how close it is to lifting the table. More power is on the way, I need to lift the table and hopefully auto drill. I have thought about a counterweight but space is limited. Hopefully have this sorted before the next video! Thanks

@routercnc9517

6 ай бұрын

Ok I checked it. If I push reasonably hard the stepper can lift it without stalling. But I’m leaning over and pressing the button so it’s a bit awkward to do to gauge how much effort is required. It means it needs a bit more power to at least lift it.

More space and worse stiffness. Is it a good deal? You won't get good milling results with that Z-carriage

@routercnc9517

6 ай бұрын

It's OK. This is only a drilling machine, not a milling machine. Only vertical forces.

@lr2147

6 ай бұрын

@@routercnc9517 ahh, I see

@routercnc9517

6 ай бұрын

Ok, also torque from drilling but I think the carriages will be ok for that. I guess we will see!

Okay but if it can barely lift the table, you can say goodbye to drilling with that thing. Even with the 3Nm and 48v. The rated torque of steppers is only a holding torque, once you move the torque drop off is abysmal. Imo, get an AC servo with a brake. Maybe increase the power transmission since the servo can go up to 3k rpm. You can get decent quality ones for under 250£ with the controller included. As I've told you before, your Arduino is not going to cut it, especially not with servo controllers, those usually "micro-step" starting at 10k pulses per revolution. The ones I got peak at 8Nm and are barely bigger than a Nema23, but the have a 18mm shaft, so can actually deliver serious torque. All up to you, but if you stay with a stepper, I doubt you'll ever be able to quickly auto cnc drill with this thing without stalling or having to go in painfully slow pecking cycles. So at that point you might as well go back to using a geared DC motor.

@routercnc9517

6 ай бұрын

I think you are right. I usually do calculations for this sort of thing to get the spec right but since it looked like I only needed 1Nm of torque to start lifting I thought it would be OK. So it is either go with 48V and 3Nm and just use it to lift the knee (and I think the arduino will still work here), go to a simple DC motor (and just lift), or go all in with a servo and get all the functions. Although I would need a better step source as you say. The other option is a counterweight but space is tight at the back. I could go hhe cheap route and see if I really miss the extra functions. The other thing I’ve not tested is the holding power when drilling which might be too much. Again braked servo, or counter balance are options. Decisions, decisions . . .

@nils1953

6 ай бұрын

@@routercnc9517 Since you've already got everything mounted and purchased, try out the bigger motor and 48v, if that can lift the table for simple positioning without drilling, just try it out. Unless you've got projects in mind that would benefit from a fully CNC drilling machine, just use it as is and if you outgrow it you can always sink more money into it..$D I think holding torque should be fine, but I don't know how smooth your ballscrews are.

You can put your two supplies in series to see if voltage make a difference, I kinda doubt it at that low speed. if leave the screws on the ball nut slightly does it have some radial movement?, it kind sounds like things are binding in some places but not others. Since you don't need speed you could easily increase the force with a smaller pulley on the motor, just needs a different belt or bigger idler

@routercnc9517

6 ай бұрын

I did think about linking the power supplies but didn’t want to damage anything. Anyway the 48V supply arrived today and it was a bit better but still stalled. I checked my records for the stepper and it is only 1.8Nm. I’ve got a 3Nm stepper and smaller pulley on order which combined should give about x3 the torque. Also looking at a gas strut and looks like one might just fit behind the table. Got one on order at 500N to play with (table weighs about 45kg all up). Might be a while before the next video!

@routercnc9517

6 ай бұрын

Yes also ballscrew is slightly bent, and I think the drive pulley bearing is rubbing on one of the races against the housing. It all needs finessing to reduce the drag on the motor.

On My mill I put a round 12v 90mm led ring light, I could have got away with 70mm but to stop any shadows when using an ER32 collet chuck I went slightly larger, works great. If you drill out the rivets on the way cover and put them back on straight without the 180º twist it should be long enough, the rivets will show though, as its a wear item screws or rivet nuts would aid replacement rather than drilling out rivets every time. The lift motor seams out of line some how as it spins and slows down to a stop every revolution in the same place. All in all your drill press is better built than my small factory made milling machine, nice job. What`s the next project?

@routercnc9517

6 ай бұрын

Hi Derek. Yes I thought about those ring lights, was worried about shadows. The goose neck lights arrived yesterday, hopefully they will be OK. I could fit the bellows straight but the curved section helps them fold up. Maybe I’ll try it straight and see how it goes. The ballscrew is very slightly bent, as they typically are. If I had a hydraulic press I’d straighten it as it was about £50 to have the last one straightened. I think with more Volts and probably a 3Nm motor this will work. Wait for the next instalment. . .thanks for the comments

@incubatork

6 ай бұрын

@@routercnc9517 I did it as with a single light always got shadows one side or the other, now nothing at all, I think there are 28 leds around the ring with a diffuser on top so you don`t get the bright bit where the led is and it gives you 360º very uniformly, how long it will last no idea so I got 2.

@routercnc9517

6 ай бұрын

Ok I’ll see how I get on with the ones I’ve bought and if no good then I’ll look at the ring LEDs Thanks

Hi. Please, do you have a link for the DRO showed at 16:25 ?

@routercnc9517

6 ай бұрын

It was from Machine-DRO and I bought it at a trade show years ago Their website shows this model which is similar www.machine-dro.co.uk/digital-readouts-display-and-encoders/m-sure-ms-272-100-digital-linear-scale-metric-imperial-measuring-micrometer-100mm-4-inch-ms-272-series The rest of the parts I custom designed and made. Thanks

@IceCreams62

6 ай бұрын

@@routercnc9517 Thanks a lot, very appreciate 🙂

good stuff, but too much talking the same that was said in previous videos.

@routercnc9517

6 ай бұрын

Ok thanks for the feedback. I do spend a few hours editing them down and I sometimes loose track of what I have included. But I’ll try not to do that as it annoys me too on other videos. Thanks.