Design & Build of Frankenrouter

[peteeng]

Hi All- Frankies controller arrived today so now I can start laying out the electronics. Its an all in one simple box solution that I've used on Brevis machines. My only complaint is that is a 24V solution. But it works well.... I originally got them from stepperonline but they stopped stocking this sort of thing. Took a while to find another supplier. Layout will be similar to Brevis3 image.... but the wiring will be a bit neater. That machine got its wiring reworked a couple of times and got a bit untidy.

https://www.oyostepper.com/ prompt delivery and well boxed. Peter

[peteeng]

Hi All - Well Frankie has languished on its project bench and has started gathering dust from the mud left over from the flood. But I have been doing some DOC and speed tests on Brevis and have hit a small issue with the 10mm belt being a bit springy at a particular speed. Slow Ok 1000mm/min springy (typical speed around curves) fast 4000mm/min OK. I intended using the 10mm belt on Franki as I have 10mm pulleys and belts left over. But Frankie is a bigger machine and a springy belt would be a disaster on it. So I'm thinking big belt or use screws? On the BrevisNo1 I've decided to upgrade the 10mm belt to 20mm to see what happens. On Scoot proto I had 16mm belts and never saw this issue and it was much bigger then Brevis. I've also done a test cast of aluminium powder and epoxy for machining tests.... Now I'm getting back to normal after the flood my projects are warming up again... Peter

[peteeng]

Hi All - Been involved in a thread about motion control that has sorted a couple of things in my mind. I think Frankenrouter will run with a TinyG controller. Reading up on this now. Any commentary about a TinyG would be appreciated. The alternative is Linuxcnc... Reading up on both. Peter

[rodw]

I think linuxcnc would be a far more capable platform than a TinyG and you will have no limits on what features you can add to your machines into the future. Eg Tool changers etc.
Look for an old corporate Dell 780 or similar (Dell or HP) with a parallel port and install the standard Linuxcnc V 2.8 Buster ISO. I've never used a parallel port with Linuxcnc but plenty do.

If you really want space saving you could consider running Linuxcnc on a Raspberry Pi.
There are also some compact Celeron based Industrial PC's but they will need external ethernet hardware like a Mesa 7i76e which are in very short supply due to global chip shortages.

I've attached a pic of my Linuxcnc PC that runs my plasma cutter. Its a Celeron J1900 Fanless PC from AliExpress with 2 serial ports (for RS485 spindles etc), Wifi and 2 ethernet ports and controls a Mesa 776e. The table has 36 m/min rapids and 5 m/s/s acceleration with stepper motors so these little PC's do the job!

On my Mill (a new project). I use a (unfortunately) now obsolete Odroid H2+ J1415 Celeron PC board that fits in the palm of your hand. It is running ethercat drives just for a bit of fun. The spindle VFD is controled by modbus RS485.

I also bought an i3 All in One PC with touch screen the other day for $120 from FB marketplace which is perfect for ethernet hardware based on initial testing.

[peteeng]

Hi Rodw - But linuxcnc uses trapizoidal vel profiles. S curve is on its to do list but no action there. Tiny G has amazing velocity & Accel profiles. Currently exploring both. Plus I want to grow up to a 6 axis robot that seems to push towards linuxcnc.... Peter

[rodw]

Hi Rodw - But linuxcnc uses trapizoidal vel profiles. S curve is on its to do list but no action there. Tiny G has amazing velocity & Accel profiles. Currently exploring both. Plus I want to grow up to a 6 axis robot that seems to push towards linuxcnc.... Peter

I don't think Frankie will really miss jerk limited velocity travel with light weight design and smaller motors so not much inertia. There is some work on jerk limited planning happening. I think one enabler has just been achieved as I think the motion planner is now a replaceable module (As is the homing module - which I am playing with to enable internal homing of CIA402 ethercat drives where home sensors can be connected to the drive, not Linuxcnc.)

Linuxcnc supports 9 axes but you may also want to look at ROS for robots. I know Tormach used some of it with their robot.

[rodw]

I might also mention that TinyG does not do tool path compensation so compensating for tool wear is not possible. I think Lcnc will have a much greater feature set in its Gcode in general

[peteeng]

Hi Rodw - I have looked at the motion planner and yes we could write one for Lcnc. My intern would be up for that. But TinyG has many years of development (as has Lcnc) and its performance is V good. Frankie if done the way I'm thinking at the moment will move very quickly over 30m/min so jerk is an issue. Would use it for mould making and final cuts although light are fast to get the many miles of tool path done. I'll keep reading - Thanks for the ROS idea looks great. Peter

[peteeng]

Hi Rodw - I was reading some stuff on the TinyG forum and one person copied the TinyG MC code into the Linuxcnc MC code. Not sure how that goes with copyright. But it is open source. Frankie has taken a turn. I have an order for a Scoot-S3 so will be ordering 3 sets of machine base parts. So I have decided Frankie will use up one of those sets. I may aim at a fibreglass or CSA gantry... Will rethink now that has turned up. Base parts will be here in 5 weeks so Frankie will be in build soon. Peter

[benwrite1]

Hello everyone, I am ben, and as a graphic designer employed with consulting structural engineers at adelaide. I am very happy due to the high information available here related to my profession.

[peteeng]

Evening All - Stay away I've been RATed with Covid. Grumpy head for a couple of days but now over it. Ordered the machine base today so Frankie will be in build soon!! Have to start making decisions on the belting and gantry material.... I nearly ordered a TinyG but after reading how to get all the front end talking to each other decided it would be good to play with but above my usual clients frustration level. So stay with UCCNC and the OYO box for now as they are in stock.... Plus Elons box arrived today was an easy install, all computers talked to it first up and the phones as well. 10x faster then copper... Peter

[mactec54]

I might also mention that TinyG does not do tool path compensation so compensating for tool wear is not possible. I think Lcnc will have a much greater feature set in its Gcode in general

Cutter comp is not needed for most hobby users, so this is a non-issue. cutter comp is good to have if you have reground cutters or undersize cutters, once you have made a cut with a cutter you will know it's size, and then can compensate in your cam program to cut the right size, so cutter comp is not needed.

[peteeng]

Hi you motley G201.1 lot - I ordered the machine base parts and the confirmation says they will be ready for pick up in 2 weeks So better organise a solid bench for it. I have been keen to make an aluminium bench, as usually I build plywood benches. Will also cruise through the thrift shops tomorrow in case there's something suitable in town... Peter

[peteeng]

Evening all - have been thinking thru Frankenrouter and decided on a direction. The gantry will be aluminium mdf or ply laminate, the saddle will be carbon fibre and the base will not be the Scoot-S3 base but plywood and smaller. I've decided to make the gantry as big as I can on Scoot and that will determine the size of the machine. Since its intended use is surfboard fins (at the moment) it does not need to be as big as Scoot-S3. I can't machine the gantry on the Scoot-S3 in one op as its too long and I don't want to do it in a two ops. Peter

[peteeng]

Evening all - Have put some CAD time into the design. Since its going to a surfboard fin shaper I'm calling this FinMaker. Happy with the overall design. Have to think about the Z axis - do I use the square rails or go wit the round? This will come out in the wash in a few sleeps. Peter

[peteeng]

Evening all and Sundry - I have decided to use the square rails on the Z axis as one of the design rules is to use parts I have so that's it. I have started working through the assemblies figuring out where bolts go and moving parts to allow bolt access. Plus adjusting rail lengths and ballscrew lengths to suit travel and bolt access. The usual juggling act. But its coming along. The 1200x1200mm footprint is a good size. I usually make it wide enough for a sheet but maybe this is a good entry level size. Next step would be to make the machine base in fibreglass/UHPC.... If so it maybe a good base for Milli the Mill. Would be 20mm thick for router and 40mm thick for mill.... Gantry travel 750mm, easy to do this in the mould. I think I've found a good spindle for Milli as well. See attached. Peter

[mactec54]

Evening all and Sundry - I have decided to use the square rails on the Z axis as one of the design rules is to use parts I have so that's it. I have started working through the assemblies figuring out where bolts go and moving parts to allow bolt access. Plus adjusting rail lengths and ballscrew lengths to suit travel and bolt access. The usual juggling act. But its coming along. The 1200x1200mm footprint is a good size. I usually make it wide enough for a sheet but maybe this is a good entry level size. Next step would be to make the machine base in fibreglass/UHPC.... If so it maybe a good base for Milli the Mill. Would be 20mm thick for router and 40mm thick for mill.... Gantry travel 750mm, easy to do this in the mould. I think I've found a good spindle for Milli as well. See attached. Peter

Just a heads up those spindles you have a listed are not worth looking at, if you want something in this size and RPM look at a AC servo motor and Drive they are cheaper and will do a better job, or just used a regular high speed spindle 6000RPM to 24000RPM 1.5Kw work well on single phase supply

[peteeng]

Hi Mactec - Thks for the thought. Its easy to use a 24k spindle but its too fast for many steel jobs. I do see that many people are using high speed spindles in steel these days perhaps its just getting the feed speed up to get the correct chip thickness.... Peter

[peteeng]

Evening All - Been working through FinMaker adjusting rail lengths, putting in screw holes. Making sure screws have top clearance and access etc. Now to check the top and bottom height of the Z axis to maximise its opportunities. May think about an apron... suitable for a rotary. The big picture is drawn, now onto the details. Peter

[peteeng]

Hi All - I think I'll call the machine Ockah rather than FinMaker. FinMaker is a bit specific if it ends up being a production machine. I sent out a RFQ to BST for the motion parts today and start making the machine base parts tomorrow. There's movement at the station. Peter