08-03-2015 Kit CNC Router for Makers & Fabbers
I’ve always been interested in automated machines and have designed a few for various companies over the years. A long time ago I was a project engineer for ASEA and programmed welding robots. Several of my recent projects required the use of cnc routers and having also just hand shaped a daggerboard (read lots of sweet and work) put me back onto the task of designing a personal CNC router. Seems there are a few small kit routers out there but they are all too small for amateur boat builders. I’ve also been toying with the idea of offering a rudder and foil design/build side to CarbonWorks so the router would be needed. One client is interested in building a foiling 50ft catamaran! So Scoot came about, I started 4 weeks ago and cycled several concepts. The aim is too get a sturdy learner type router together. I’ve had to research the electronics and steppers etc to find out what works and what is available.
Version 2 of Scoot (2400x600x150mm machining area). This one had a good bearing arrangement but this produced a clumsy motor mount area. Plus the V-groove bearings where frightfully expensive. Even having V groove rims machined put the price over the budget. Its the little things like pulleys, belts, belt clamps and things that blow out the cost. Seems the big extrusions, laser cutting and folded parts are quite cheap.
Version 4 integrated the motor mount and the main bearing elements much better but doubled the amount of bearings so I’ve had to use a cheaper bearing. I’ve stayed away from welding as then I’d have to have parts re-machined. So its bolted connections mainly. But I used to do a lot of aluminium brazing which worked well on heavy sections but was a bit tricky on thin sections. So I’ve started looking at aluminium soldering. This solves the distortion problem and will do the job nicely. By soldering the connections they will be stiff and light vs lots of bolts and nuts. I’m waiting on some special flux from the USA to continue my soldering trials.
Version 5C captures most of the features and aims of the scope. I’ve had a few quotes on the bits and it seems to be in budget. Busy getting the construction and parts dwgs together to send out for final quotes this week. So the mechanicals are nearly set…
The other side of the project is the electronics. I’ve had to suss out motors, motor controllers, power supplies and the software to drive the motors. Seems Mach3 is highly regarded so I’m starting there. As I use Rhino and Geomagic it seems Rhinocam is the answer for the G code stuff. I’m using an old computer I had nearly thrown out as its motherboard lost its connection to the LAN but that is fine for this application. So I’m building a prototyping board for the electronics. I’d like to get the controllers etc into the computer box but seems this is unlikely as the controller uses a parallel port and the parts are mixture of surface mount and panel mount so its complicated. So in summary I’m nearly at the running stage (Ha Ha added 27-3-15). One objective of the design is to have a variable Z height. So instead of having the longitudinal bearings along the bed they are integrated high. So if you need a 300mm Z we just use longer “legs” from the bed to the rails. Once I get Scoot running and form an opinion of the machine I’d like to offer it as a kit in various stages from individual parts to various build levels.
I’ve bought a little Mikita variable speed router for Scoot. Has a nice long barrel and is smooth and quiet running.
The other area of interest is 3D printing so I have found a few printer heads to use on Scoot as well. I’m also talking to a guy in the USA about water jet cutters, so there are a few variations to explore. (6-4-2015 I think water is out after a few chats, I’ll leave that to the water jet experts)
Anyone interested in this type of machine just let me know and I’ll quote once I’m in production! I already have a) a rudder and keel for a friends timber boat to do b) machine timber parts for a long john timber bike c) rebuild the dagger boards I’ve done recently so I can use a better foil section and make the plugs for a 50ft cat 20% lift foils. So I’m a busy boy!!
21-03-2015 Building the proto electrics board at the moment. Have to decide on the control software (probably Mach4) as I have a 64 bit machine. Then I’ll be able to spin the motors!! That will be a great milestone.
22-03-2015 – More and more wiring. Got the first motor wired in today. Pick up some controller software tomorrow then I can do a test run!! The little DB-9 plugs are fiddly. Mucked up the first one, so need to buy a new one. I’m using an 18 gauge wire for the bigger motors and the terminals are for 22 gauge. So its a bit tight. Decided to use 22g to a terminal strip then 18g from there. Hopefully can get some work finished tomorrow morning so I can complete the prototype wire up tomorrow afternoon.
23-03-2015 – CarbonWorks jobs have taken a bit more time than expected, but I did wire in the motors. In the morning spent a bit of time with a client who makes carbon car parts. He has a new time trial car to do and we’d like to do the moulds all via CNC pattern makers in Adelaide. Also had a look at Mach4 and WINpc-NC USB. WINnc runs a cloth cutter at the clients factory. Its a 32bit system and I’d rather run a 64bit. Still need a CAM system though. Looked at many, seems VisualCAM is a good solution. Have downloaded their free FreeMILL and had a play. It works very easily. Now to download the visual mill trial so I can see if my wiring works!!
27-03-15 The soldering idea has become difficult. Because its not a commonly done process the local suppliers don’t stock the right flux. I ordered some through a local auto parts supplier and they rang back a week later saying they can’t get it because of minimum order sizes etc. Then I placed an order with a welding company for a particular product (even told them where to get it and it was in stock) but they ordered a different product from a different supplier! So it took 2 weeks to get here and its wrong. So I’ll have to plead with the distributor to break their minimum order rule or I’ll have to order from the USA. Probably easier to order from the states then bang my head here!! or I go back to the nuts and bolts approach… Hmmm….
06-04-2015 Ready to turn on!
Now its wired up and checked. Need to get drivers and Mack4 organised for software check!! Cleaned up the workspace ready for bringing the computer and proto-board together! Order some bearings, pulleys and small parts tomorrow so now in countdown mode for mechanical parts. Did a quick review of the parts yesterday and now will finalise parts for manufacture. I’ve sorted the aluminium soldering and have done a couple of good trials so all is well there (but later trials were poor). I got the flux through Blackwoods a big industrial supplier so supply is stable. I’ve started rationalising the layout of the electrics so I can get it neatly into the shelf I’ve designed for the router. I’ve soldered 5000 and 6000 series alloys so material choice is not limited.
Shelf for computer, screen, keyboard, electronics and a few bits and bobs. Next one I’ll use a laptop and save heaps of space! Have to start thinking about the wiring and how to allow it to move around. Usually use a cable chain but I want to hang it from a central arm for this one. Peter
1-05-2015 Been let down in the soldering department. Has been difficult and the solder supplier hasn’t been able to help. So I tracked down some brazing materials I used to use for aluminium bicycle frames and Viola! Its what I want.
Now I will convert the bolted connections to brazed ones and I’ll get back to the design I wanted. Yippee…
20-8-2015 Been a while for an update!
Been busy with commercial projects but now have spent time working through the parts and establishing a manufacturing drawing stack. Stack now done, so all the fits and tolerances are done. Hole alignments checked and shes ready to go for quotes. I think the Y axis bearing arrangement needs to change (too many bits) and I’m really keen to make my own bearing units. Next time around!! Need to get this one running. I had another inquiry for a daggerboard build today! Its tempting to scale up but I’ve decided to keep it at one sheet size for the first one. This includes the footprint of the control “box”. Next unit will make much longer so can do big boards.
13-10-2015 – There’s been some twists and turns since the last update. The quotes came in and the total cost went way over budget. Once I changed from laser cut parts to cnc machined parts the cost went sky high. So I’ve done a total review and established how to get what I want. The bearings have been a big issue in terms of cost, number and their flow on effects. So I spent some time looking for alternatives. I even built some fibreglass bushes that are very good but as its a development issue I decided not to go this way. Coupled with this I found some very good and cheap V groove bearings in the USA that are a game changer for the Platform. So these are on a plane somewhere right now coming from sunny California to the equally sunny Gold Coast.
I also found a construction extrusion that I thought maybe the go, but upon building two complete CAD platforms from it realised that it is too big a compromise in the main design areas. So I went back to basics and over viewed the project, picked the best bits from the 8 versions I now have and built No9…
Scoot CNC Platform No9 CAD animation
At least the electronics and the box have moved along and are now real! So its time to get the pulleys and belts to finalise the drive details. These have been a problem sourcing. I’m not using the small GT2 type belts as I want something that is stiffer and will scale up. I eventually found 16mm belting & pulleys in Perth. So it will be a small International build! So I’m up to detailing No9 for costing and this should be it!
13-10-2015 – Finalising some of the details for Scoot’s rails. Here’s a screen shot of the FEA comparing a 100x25x3mm channel to the standoff solution. The standoff deflects 0.3mm while the channel deflects 8mm. So using the 50x50x3 as a rail is a good thing!
I was going to use aluminium for the standoffs (as per the FEA model) but will use steel as its 3x stiffer. Have to paint the steel however but I can use safety orange or something spectacular like stripped paint. Perhaps Masters has some poka dot paint as well?? Cheers Peter S
24-10-2015 Big ticket day today!! Got the electrical board mounted and 240V to the monitor and the computer. Switched it on and there were no sparks or smoke just the pleasant little green light that says the driver is happy and the Windows XP flag. So I’m happy, need to move onto the software now and get things talking to the motors.
Motor board with happy green LED showing. Been a long journey nearly there!! How excitment as my wife’s English students used to say! Soon I’ll be able to participate in the Digital Fabber experience!
13-03-2016 – Been a hectic few months with nearly zero progress on Scoot. My commercial projects have run riot over the last few months and so slow progress on the router. But one of the commercial projects pushed me down the path of commercial linear bearings and these have been remarkable. So I’m going to rejig around linear rails and carriages. They are slightly more expensive then my rail and carriage design but they have no adjustment, no internal clearance huge capacity etc etc. A commercially available unit for a function is always a better choice then reinventing the wheel I feel. Plus I have re thought the direction of the bed and by making it transverse a whole sheet of plywood can be slide in and cut vs riping down sheets to get it in. In fact you can then use the router to ripe sheets if you want so I’m rejigging the router nearly from the ground up. Development projects are like this sometimes. You need to go around the loops several times to find the right starting point! I also note that its been a year since I started this project. Time flies when your having FUN? Are we having fun yet?
22-04-2016 – Redesign nearly done. Need to finalise Z columns and then can do some FE on the sections to check sizes. Was going to use a drive screw for the Z axis but also wanted to keep the drives the same to lower the part count. This one will have the belt drive.
01-05-2016 – Been burning some midnight oil to accelerate Scoots progress. Have reduced the part count, bolt count and boiled it down to about the right spot.
Now time to do the drawing stack and finish detailing. Check all the holes match and are spec’ed etc. Decide on whether to do it in stainless steel or mild steel and powder coated. Seems the price difference isn’t much. I’ve changed one end so it can do edge machining. Running some models to look for structure improvements. Found a small spot on one of the braces that could be improved. I’m super happy with the gantry to column connection. Last thing to check is the Z axis assembly. See the video below for the gantry FEA.
Now need to review the CAM side of the project and get it organised. Much closer to sawdust this week!!
13-05-2016 – Reviewing the z axis stiffness and found it to be a bit wobbly. 1.2mm deflection at 30kgf is too big. So will improve the metalwork in this area. Following is a AVI of the Z axis deflecting when it is at its longest. Currently I have 250mm Z travel.
05-06-2016 – Been working through the fits and holes. So the drawing stack is complete and it goes for quotes this week. I’ve bought the CAM system which is VisualCAM. They ran a end of month special and dropped the price from $1600USD to $999USD so jumped on it! last structural decisions to make were the gantry size (75x75mm or 100x100mm) and the column detail. Sorted the column detail. see video here.
28-06-2016 – Some late changes due to chasing better stiffness and a review of the philosophy of the build. I’ve always intended the Gantry to be an aluminium extrusion. But this leads to problem of how to get nuts inside to connect the rail. So I decided to use a threaded backing bar. Threaded holes are expensive and its preferable to use nuts. Plus with aluminium I need to buy a length and then I have enough gantries for 4 machines. The idea with lean is to be able to make balanced units. If I was making 4 units at a time this would be OK. Then I decided to look at folding the gantry vs the extrusion and this put the cat amongst the pigeons! But It opened a possibility to remove the 22 threaded holes and allow me to tailor the stiffness of the gantry so the face can be thick and the rest can be 1.2mm S304. So the outcome is that the gantry is 3x stiffer, uses 3 parts less and can be ordered from the same place as I get the rest of the bits vs the extrusion comes from down south. So I’m detailing that out. I’ve decided to call this one Scoot α or Scoot Alpha. I’m sure Beta will have lots of mods as well!
20-11-2016 – I’ve been putting stuff into the carbon-works blog but today I made the router bed by laminating 2x15mm ply sheets together. Last week I also ordered all the mechanical components so will be able to assemble the machine in 2 weeks time. Been over a year of thinking and sourcing with a few gaps due to life in general. But its nearly here…
29-01-2017 – It’s come along way in the last few weeks. Have completed first fit and identified how to make assembly logic easier. Have checked the parts and talked to the supplier to improve these in future and after adjusting a couple of holes will do second fit and install the wiring.
Will add a couple of holes to allow easy key access to the gantry bearing bolts. These are deep in the machine and currently if the bolts have to be checked or tightened it would mean nearly the whole machine has to be pulled apart to get at them. But some holes in the gantry web will fix that. Scoot does not look like any of my original sketches, but I now feel it’s a commercial grade product. I’m also developing the construction manual and hopefully will sell some soon!!
Steel belted timing belt. Always clamp when drilling guys and girls!!
Tuesday 07-02-2017 – Router does first cuts!! But they are manual cuts. I had an interesting job to do and I was about to take it out to a CNC guy but had the brainwave to use the router in “manual” mode to see what happens. So I set the part up and used it like a radial arm saw. I locked off the X axis and moved the gantry by hand to do the long cuts. Then locked off the Y axis to do the cross cut (not shown ). What I learned was the trimmer needs more support then the one band clamp does. I had thought this but decided to under do things and come up vs overdoing things and not being able to back down.
Now I run my hand trimmer round the edges with a fillet tool and its done. Turns out the plastic doesn’t like being sanded so I sharpened my scraper and finished it by scraping. Came up a treat.
Next week I concentrate on the wiring and the Z balancing mechanism.
21-02-2017 – Z balancing – I have added a gas strut to the assembly so this is the last mechanical thing to do. I’ve decide to add a form-ply bracket to the top of the Z axis as I can do this easily and it will add some timber “charm” to the machine. So it’s back to wiring and its getting closer to making sawdust.
22-02-2017 – A good friend and my safety and QC observer dropped in to do some work on our trimaran yesterday. He was looking at the trimmer bracket and was intrigued with the silver soldering of the stainless steel so I said I’d show him how to do it. So I upgraded the bracket to two superclamps as planned. Its now really stiff. Very happy. Back to more wiring.
27-02-2017 - completed the Z axis balancer came out quite well and I included the wiring box on it. Will have to figure out its ascend and descend rate so it can be programmed without stressing the motor. The strut has a damper system so the velocity is nearly constant. Addition turns out gas struts have quite a big tolerance on their pressure and are usually biased on the strong side. The 150N strut I bought for instance was in fact measured at 210N. So I took some scales along to the strut shop and went through their stock and found a slack one that had the right strength for equalising. This worked a treat at 110N and did not stress the motor as it compressed the strut.
Onto installing the A axis and the final wiring. Need some glands and better wiring clamps to tidy it up a bit. A trip to Bunnings is in order.
Bunnings aftermath: – found some nice cable holders that are zip ties with a screw hole for fixturing. Works a treat very snug and much cheaper then P clips or alternatives.
11-03-2017 – Well I’ve turned on the power and the motors have locked which means they are wired correctly. The computer I intended to use had a small hiccup so I took it to the computer tech and they reinstalled Win7. I started thru the Mach3 checklist but couldn’t get the driver to work???? Turns out Mach3 will only run on a 32 bit machine (& yes mines now 64 bit) so now I have to make the decision to A) buy a motion controller and run Mach4 $188AUD B) get a 32bit OS put onto my computer $$?? perhaps a backward step C) Buy a second hand 32 bit computer $10 upwards and run Mach3…. D) use an old laptop we have and buy a motion controller $188AUD but laptops don’t work apparently need to investigate… The learning continues. I was hoping to have it moving this weekend HmmmpppFFF!!
13-3-2017 – Been sorting the electrons on Scoot. I had picked Mach3 as the CNC Controller but my machine was checked by a tech and he upgraded it to 64 bit so M3 won’t work on it. So I decided M3 was technically at its end so M4 would be the go. But M4 needs a motion controller so had to research these. Decided on a UC100 and the same company has a CNC Controller called UCCNC and it looks good so I’m getting these. This should be the last hurdle to getting Scoot to move!!
30-03-2017 - Last two weeks I have loaded UC-CNC and jogged Scoot around but the Gecko G540 driver faulted occasionally, then permanently as I tuned some of the motor parameters. Spoke to Gecko and they sent back a check list. Then UCCNC wouldn’t store profiles so I had to re-enter the parameters each time I opened it. Spoke to the UC distributor and he gave me a checklist to work through as well. I loaded the software onto my office machine and it worked fine. I also loaded it onto a old laptop and it worked fine so I swapped out the desktop for the laptop and its a beautiful thing! So the software issues are resolved. This clarified the hardware issues to the driver fault, it could only be a current overload so I put current limit resistors on the drives (even though Gecko says they are not needed in this case) and bingo everything feel into place!! Now I can jog scoot around, up and down and it feels & moves like it should. I have sped up the axes to a good clip and adjusted the accelerations. Now need to tune the motors and make some dust!! Been a long time coming. Just passed two years in the project….
Addition 3-4-2017 – All was still not good and it did fault again. This time Gecko said that they have had this issue with users that have 4 high amperage motors in this router format. The current clipping circuit is a bit eager to go into fault and they have modified this circuit in the motherboard recently to reduce its gain (sensitivity). They are happy to send me a MB FOC or here’s instructions on how to modify the motherboard… So I pull the gecko apart, remove a micro capacitor with my wives hair twissors and put it back on line. Perfect, no faults and the Z axis load application is up. Now it’s really good!! Thanks gecko for the help!!
Well Scoot Alpha is nothing like the sketches at the beginning. This blog has been great in documenting the processes. Its been a great project and has taken me down paths that I would not normally tread due to time and commercial restraints. I think it has broadened my skills quite a bit.
I’m moving house in 3 weeks and will not have a shed for a few months. This means Scoot goes into storage or I sell it then rebuild a bigger one in the new shed. So I’ve put Scoot up for sale. See link attached.
9-4-2017 – Scoot cuts under program control for first time!
But it’s an ellipse not a circle! So I have to calibrate the axis better. No big deal to do this. So it’s adjust a bit here and there and speed the cutting up. Soon Scoot can cut its new table and bed.
18-04-17 – Have sorted the calibration and have used the CAM part of UCCNC to cut several different profiles. Used Rhino3D to create the CAD lines, exported these as dxf into UCCNC and then tool pathed using UCCNC. Quite easy. Now need to learn surfacing via Visualcam… getting close to making a test foil!!
23-04-2017 – I’m packing up the shed and house to make the move to NSW. Came across this piece of history. It was the impetus for making Scoot. So now the story has gone full circle.
Just over 2 years ago. 8-3-2015 I started this thought train, blog and task. Now onto Scoot Beta. Through Scoot Alpha have learnt a lot, sorted suppliers and clarified what’s needed for this to be commercialised. More good stuff ahead in a big new shed!
11-05-2017 – Moving house is a big effort! Plus I have all the shed equipment to deal with. Took 3 weeks of sorting, giving away, selling and gifting stuff but we got there. Had over 700 visits to the “for sale” ad and several calls. Scoot was either too big or too small or not strong enough for their work. A few wanted to cut steel which is well above this sort of machines stiffness and cost levels. But no sale. So I have moved Scoot Alpha to a secret laboratory location in Murwillumbah. Staffed by experienced blokes, all wearing white coats and making top secret stuff.
I joined the Murwillumbah Men’s Shed and they have an active cheese board and cutting board program, that pays their rent. So they were really keen to automate their profiling. So Scoot is in active storage there and I go and develop it two days a week. So far I have cut a guitar shaped cheese board, EVA tool insert and some candle holders for members. Two members are quite keen and are learning CAD and using the machine under supervision. Things to do are: design and fit a dust extraction system, fit limit/homing switches and a vacuum table for the boards. I have fitted a grid of thread inserts into the bed which makes holding down things easy. So it’s onto the next machine, what shall it be a big machine or a small one? The feedback from the sales ad is mixed. Everyone wants something different. Guitar makers, electricians mounting plates, signs and art stuff. One machine does not fit all!!
To make the guitar shape I photographed the actual board and imported this image into Rhino3D. I traced around the edge of the image using splines. I also corrected a couple of asymmetries the real one had. Then I exported the splines via dxf to UCCNC. In this process the splines are broken into 1mm lines for the CAM section to deal with. Within UCCNC CAM page I tool pathed the profile and left some ligaments to hold the piece in place while the profile is cut , set up some scrap plywood and cut the shape. John will be happy!! He spends quite a bit of time drilling, sawing and sanding to get to this point!!
10-05-2017 – Yesterday at the shed I played with nesting. Found out I had to use a bounding box on all parts to maintain their correct position on the sheet. So after test running the NC code I had to re export parts with a bounding box. After making clamps and checking the sheet fits, quite tight, it’s the biggest profile that can be cut in one go on Scoot, then solving the issue with coding (it had a duplicate line in the file that was a confusion to the toolpathing) It’s now set to cut this saturday.
23-05-2017 – And here is the real cut.
Need to figure out the chip load for the cutters. Scoot likes to move fast, the faster it moves the more steady it is, it seems. I’ve read up on chip loads and its cutting at quite a bit less then some toolmakers recommend. But the trend is that faster is better. Generally using a 6mm cutter at 1500mm/min. For a chip load of 0.3mm which seems to come up in a few charts this means that the tool speed should be 10000rpm. I’ve been running at 30000rpm so maybe need to slow it down a bit. Will do some test runs tomorrow.
07-06-2017 – Today’s mission was to cut a Ukulele shaped cheese board for a friend at the Mens Shed. Last week I had trouble importing large dxfs into my old notebook computer. Was taking over an hour to do something that took 3mins on my desktop. Since I have just moved house and now visit clients on the Gold Coast it’s been on the list to get a serious laptop so my programs are mobile and this notebooks slowness made me go out and order the new laptop. So today is its first run on the machine. I had a couple of glitches with the new config copying everything across but then it feel together and I got some sawdust flying.
David had not used sanders or trimmers or machinery really so I walked him through the finishing steps so he did some of each of them. He can tell his daughter he has made some of it at least!!
Now the requests are finished I’ll get onto the vacuum pad and designing the improvements for Scoot. Scoot Alpha is to become Scoot Beta, Z axis to be a bit stiffer and maybe a bit higher. I have nearly glued the letterbox together and I have the hinges. So it’s painting time in the next couple of days for that project. Next project is to make a test V foil for a friend. Been watching the Americas Cup with its twists and turns and pitch poles!!>>>>
14-06-2017 – Made a mirror from a nice piece of Camphor Laurel today. Its for my great nephew on the request of my wife. Leonie saw a piece of timber at the recent timber and machinery show and bought it. Then she decided it should be a mirror. So today I made the mirror and also did a precision check on Scoot.
Scoot did better then 0.1mm repeatability on the X and Y axes which I’m very happy with for this system. Because the system is micro-stepped it seems every two repeats it is very accurate (comes back to within 0.005mm of start) and then on the first cycle it’s about 0.05mm+. So I’m happy to say it’s definitely within 0.1mm of the programmed co-ordinate.
The mirror was fun, hardest bit was deciding where the mirror should go visually. I recalibrated the axes and checked the mirror would fit. Now the axes are quite accurate. Now have to get the hanging hardware for the mirror. We deliver it this weekend, pressures on!!