[peteeng]

Yep lots to learn - Peter plus if you want to be very helpful mud maps of the preferred wiring would be great. Electronics is not my thing but I muddle through.

[joeavaerage]

Hi,
yes, no trouble I can help with that.

It rather sounds like the Nighthawk controller is just exposing its 'computer level' outputs to the external world. Such outputs need often to be amplified as a minimum and
very often they should be protected against shorts or over voltage from external sources. You really don't want a small or even extremely brief mistake made while you are
wiring your machine to damage your controller. That is the role of the breakout board, it should amplify/buffer signals and provide some protection to the controller while having
screw terminals or plugs to connect to real world hardware.

For example I made my own breakout board, see pic attached. The small green board is the Ethernet SmoothStepper (upside down), the motion controller, plugged directly into the breakout board.
The first board is for LEDs, so each and every input or output has an LED to indicate its status for diagnostic purposes. The lower board has the buffer amplifiers and level translators, a relay for the spindle, a PWM
circuit again for the spindle, an electromagnetic brake output and all the required inputs. Each servo has its own plug, with all the appropriate inputs and outputs to each servo brought together.
The servo Step/Direction outputs are differential.

No point in getting too carried away yet, there is a lot of water to flow under the bridge before you even get servos, let alone start making a breakout board to best suit them.

Craig

[peteeng]

Hi All - I have Commander/Nighthawk running on my small router/laser. Has been painless so far. Will be good to get up the learning curve on this device before I get Lanky built... So much easier then the usual mass of devices and wires!! Plus it has a built in E stop and start go!! Peter

[peteeng]

Morning All - I have been mucking around with the "arrange" function in fusion. Basic nesting really. Plus I have decided to leave the middle of the machine bed open so it forms a pit. The pit or well sides will be deeper to create aprons so edge work can be done (tenons, dovetails, box joints etc) I also want to make the front of the machine an apron, but I'm not sure how far the spindle will come forward yet. Next phase of design is the walls. Peter

[peteeng]

Morning All & Sundry - This mornings job was to rebuild Lanky12 into Lanky No13 V5. The main thing was to correctly establish sub assemblies and get ride of all the smoke and mirror parts in No12. I'm finding Fusion to be quite flexible and it tracks most of the changes if you start shunting parts around inside of its data base. Other CAD programs are very sensitive to where you place things and how you relate things, otherwise models go AWOL real quick. Now its rebuilt I can move onto the walls and gantry... I need the well to make the trunnion for Epoch!! My laundry faucet has cracked so I have to put on my plumbers hat and go fix it... Peter

[peteeng]

Evening All - I have worked through the aprons, bases and bits and rationalised the parts. I've moved onto the walls and now to the gantry. The walls look a little thin so I may taper them to give them better proportions. I'll sleep on that thought. Maybe because of the pit I won't have to make the Z as high.... Some ZZZZs may sort that out. Peter

[peteeng]

Morning All - I have =fixed the wall and worked thru the model again to get rid of niggles. I checked the parts are the correct material via creating a dwg. I also do this via the simulation tab as it has a tabled materials list in the browser. In the dwg I can check the total weight by adding a weight text. But I can't get this to format in Kg only g's which is annoying. I shall request an extra line for total weight in the parts list... Getting happier with the design... Now to add up the bits and figure out how many sheets of ply I need... I want to start building this week... Peter

Re Nighthawk - their new version has 5V control outputs...

[peteeng]

Evening all - Lanky has moved along nicely. Now to rebuild the alibre cad models into fusion models and optimise the height of the walls/gantry and ZA axis bits. Peter

[peteeng]

Hi - I have been investigating the gantry design. Steel, aluminium, plywood laminates etc. There is a 200x50mm rectangular section in AL that is interesting. I did some numbers scaling up Scoots gantry to Lanky size. Scoots is basically 100x100x3mm by 1.6m long steel. To make the same rigidity gantry over 2.5m in steel it would need to be 155x155x3mm in AL it would be 180x180x6mm square. With my rails on top design the gantry height has to be small, otherwise the Z axes becomes long and inefficient. So next is to do some modelling to figure out structurally which material to use. Plus I have to look at the wall, gantry and Z axis stack heights to figure the best way fwd. I may have to put the rails on the front of the gantry if it becomes too high.

The steel section weighs 14kg/m the AL section weighs 11kg/m so not a big delta in weight. maybe just grow up Scoots laser cut and bent design to suit. Peter

[peteeng]

Hi All - I have been running some trade studies on the gantry. In Fusion I found the laminated beam to be remarkably stiff so did some hand calcs and ran the same model in Simsolid and found its wrong in Fusion. So I have sent a note and the model to Fusion support for comment. The images attached have the laminates as the same material as the beam, they are all MDF. The laminated beam is the same size as the monolith beam 130x130mm yet the laminate deflects 0.034mm vs the mono at 3.04mm which agrees with the hand calc. I'll keep you informed. Peter

[peteeng]

Hi All & Multifarious - I have been learning about joints, alignments and motion in Fusion 360. I think I'm over most of the hurdles now with it. F360 is still odd in how the browser, timeline and various information is spread over all of these vs in one place. But I suppose the logic will dawn on me one day. I have rebuilt the Z axis assembly and I've nearly got the saddle sorted. So close to final. I have also done some adhesive tests on the formply and I don't think I'll use it when it has to be bonded. It didnlt bind very well. last time I did it the film tore off. I'll keep testing. The formply is the cheapest stiffest solution. Peter

https://www.facebook.com/ScootCNC/vi...95161256633697

[peteeng]

Morning All -Topic: Fusion and contacts - I have received word from support and they have indicated to use "offset bonded" connections not bonded in this situation. I have run a couple of models and yep that works. The explanation I received about the offset bonds having more degrees of freedom included in the contact didn't make sense as this would seem to increase stiffness (not increase compliance as the models need) , but Hey it worked so all good. I think my takeaway is to use offset bonds for all connections into the future... Peter

[peteeng]

Hi All - Now I'm thru that hump (bonded vs offset bonded) I can get serious with the gantry design. The images show Scoots gantry (short one 100x100x3) the equivalent Lanky in steel (155x155x3 steel) and the laminated one. MDF core (E4.5 GPa) and 3mm aluminium skins (136x136 solid) . I want to use 6mm skins so will update the model now I have reliable answers. The laminated gantry is stiffer then the others. I shall also use plywood which is stiffer again. My aim is to make the gantry as shallow as possible ie least depth. The "skins" will be made from extrusions which are 160x6mm flat bar... I use 3mm steel because that is available in galvanised so no painting needed.... Peter

edit - The laminated gantry is much better then the steel ones now to optimise it...

[peteeng]

Morning All - My deflection target is less then 200um up/down and fwd/aft as this is Scoots nominal deflection at 1000N. Plus I want the beam depth to be under 150mm. The current design is 136mm so that's great. But the up/dwn is just over 200um and it uses 3mm plate. So I think I'll use the 6mm top and bottom and 3mm in the middle. I now have to figure out utility of the extrusion. It comes in 4m lengths so there will be leftovers to use on the machine somehow.... Happy to move fwd now the F360 contacts are sorted. I'm confident the laminate deflections are correct. Peter

The cores are from 25mm plywood by the way.

[peteeng]

Morning All - Just - I have been fretting about gluing the formply. The phenolic film is designed to be non stick. I did some tests a while ago with epoxy and a melamine glue. This resulted in the film being torn off with both so the melamine glue was used as its one part and easy to use. I set up another test with gorilla glue and titebond. I cleaned the film with acetone and edge glued. The result was that it did not bond, came off under very small load. So I abraded the surface with P80 grit and redid the test. The film and the first veneer were torn off so can't ask for more than that. The Gorilla glue joint came off under more load... So clean abrade and glue is the mantra... I spent a lot of time looking at alternative plywood's. They are more expensive, less stiff as they are softwoods and I'd have to coat them with resin... So formply it is. So happy to go fwd now. I must have abraded the first tests, didn't remember clearly what I did... Peter

[peteeng]

Morning all - Lanky CAD is nearly complete. I have rebuilt the saddle and Z axis in Fusion and they slide!! Now to sort the Z working height in relation to the walls and gantry. Then its time for a bottom up review. Peter

[peteeng]

Hi All - Lanky's GA! - Today I drew (or F360 drew) the first General Arrangement (GA) of Lanky. GA's are a big milestone in a project. Its the first time the big picture can be looked at closely. These days with digital manufacture the emphasis on drawings has decreased a bit. But they still are and will remain the principle device to transmit manufacturing information. It is said Leonardo De Vinci invented technical drawings, maybe the Chinese did it way before that but until we can embed tolerances and design intent into 3D models we will have to use drawings. Being a draughtsperson was a profession once; I worked for a few companies as a detailing draughty while I was at Uni. Drawings I see in workshops these days leave a lot to be desired in clarity and intent. Times change, so onward to a review and to part drawings and part ordering and building. I need to decide on Z axis height and how it sits wit the gantry and bed heights...Peter

[peteeng]

Hi All - I've been detailing the gantry and decided to make it hollow. Then I realised I had some aluminium tube I could put in there. The weight of the ply removed is more then the aluminium put in. So I modelled a simple version to see how much it made a difference. Its enough to put it into the design for now. Peter

The left model is the al tube alone with 1000N on it, the middle is the ply/al gantry and the RHS is the gantry without the tube.

[pippin88]

Looks good in theory but impractical to make

No alu tube - can use long rectangular sheets laminated on face

Alu tube in the middle - heaps and heaps of squares with a hole cut in middle laminated
Hard to clamp
More cutting
More waste
How are you going to end up with a straight and flat gantry?

[peteeng]

Hi Pippin - I have no problem making it. But I agree is it worth making it? As I said it's there for now (to think about) Having trouble understanding why Fusion moves supposed rigid assemblies around. I find having the timeline, browser and other bits in separate places to be confusing and non sensical. In alibre if you right clicked on a part all info about constraints, dims, properties was all at hand & easily changeable. Its a struggle once you define stuff to go back and change it or find it. Fusion seems to leave debris and sketches and bits & bobs all over the shop....

Anyone have a good video on joints, the timeline and the browser use in F360? or the intended workflow to use? The videos I find are fine for 3 parts but when you have 10 subassemblies and various other parts its a **** fight...

I'm working through the makability issues now. eg I selected an AL 160x6 flat bar out of a catalogue then found out that they don't have it and they don't have it in 150x6 either. The 150x3 and 150x12 is there, thought I was close but the horizon just ran away from me again....... Peter