Okay here we go with a Solsylva CNC table build. Since there seems to be rather a lot of overlap between the two forums, and one tends to lead to the other, some of you may recognise my good self from this project!
Firstly I want to congratulate David on an excellent set of plans, which are well worth the money in my opinion. Shipping to the UK isn’t so bad either! I’m actually fairly well into the build now, but want to start the build log from scratch just in case I am missing any of the finer points. BTW the plans are in imperial, which means there’s a little head scratching and conversion to do, however it’s actually quite straightforward and in some ways make aspects of the build easier. For example, the bearings are actually metric in the first instance, so are a good match for M8 threaded rod. That said, aluminium section is still sold in imperial measures.
I’m not going to divulge much information about dimensions and specifics of the build – go buy the plans if you want to know! I have however shrunk both the width and length of the table slightly so that the finished beast will fit in my car (which is a pretty average UK saloon)
UK SUPPLIER LIST TO DATE
Timber: Mostly 18mm and 24mm birch ply recycled from the skip at work (thank you employer….) For thicker sections I have laminated two 18mm pieces to give 36mm. We have a couple of big saws which are a Godsend for this.
Aluminium angle and threaded rod: Metal Supermarkets (Park Royal branch)
Aluminium channel: 13mm*10mm*1mm, available at B&Q. This size worked best for me, unfortunately Metal Supermarkets don’t stock it.
Rails: 25mm and 19mm chrome steel tube from Travis Perkins. B&Q actually stock the same range, but of course charge more for it. This is the stuff used for towel rails, wardrobe hangers etc
Bearings: Bought off eBay months ago, the complete set was about £15 I think
Steppers and drive: Xylotex 269oz 3 axis kit, bought in the USA. Unfortunately they don’t currently ship to the UK.
Belts and pulleys: Not really found much, so probably have to bite the bullet and import from USA
First things first I converted everything into metric and knocked up a CAD model to check everything fits. In particular since the drivebelt is only available in certain lengths, I needed to be sure my reduced width will work OK.
A further change I have made from the original plans is to install the x-axis stepper at the rear of the machine rather than the front. Functionally I don’t think it will make a difference, and will keep it out of the way a little better.
In addition to the build, which doesn’t deviate much from the plans really, I have designed this base for the machine. Since the finished thing is farily large, I wanted a unit which could be stored upright, and also have wheels.
So the X-axis stepper will be behind the rear panel, which doubles as the base when stored vertically. Other features of the design included cutouts for carry handles, and also a section at the front of the machine where the router can be withdrawn without having to disassemble the Z-axis gantry. The two sets of four holes at the top of the rear panel are for castors, also salvaged from the work skip.
Looking at the base from the rear, the castors are attached to the four baseplates shown, and the motor will be installed in the middle, connected via a drivebelt to the x-axis leadscrews on each side of the machine. In addition, I have included two cutouts for cooling fans.
Looking underneath the table, I have built two enclosures into the base, both featuring an intake fan and exhaust holes. These will probably be covered in aluminium or similar, not shown currently. The purple blocks are the fans, and the red blocks are the electronics. The high voltage components (i.e. the 240v-24v PSU) will be on the RHS of this image, and the stepper controller on the LHS. This makes it nearest to the Y-stepper which is also on the LHS of this view. The angled wood sections will, I hope, help direct the airflow through the compartments.
At the front of the machine there is a further ‘enclosure’ which I may use for some form of control panel, featuring jog buttons and so on. That’s probably one for the future though!
So that’s the current plan, a few initial questions, particularly re the table design:
- In principle is it a good idea to mount the electronics in the same unit? I don’t know what levels of vibration I might get.
- From anyone’s experience, would the Xylotex PSU need to be cooled by a fan? I know the stepper motor driver does. The kit comes with just the one fan, but it’s intended that the two are in the same box I imagine.
- Does my COG look reasonable?! The lower wheels are under the main table, and the upper wheels are more or less in line with the Y-gantry.
- Moving onto the Z-axis, the two side panels are specified as tempered hardboard. I’m not sure where to get that – does anyone have experience with using plastics for this? There’s a whole wealth of products out there (Nylon, Polycarbonate etc) and even after reading all the blurb I don’t feel much wiser!
- I’ve got a few ideas for some electronics, but that can wait for now. In particular I want to eliminate connectors and so on from the stepper hookups, so these connections are as robust (soldered probably) as possible. Can’t be doing with frying the drive board!
I have no idea what this will weigh, but in know that in addition to the birch ply (which is quite weighty) all the little bits and pieces add up to, well quite a lot!
Any comments/ ideas gratefully received at this stage! I have actually built and painted some of the bits already, but that can wait for a future (and shorter) post
I think you'll really enjoy this build. I know I did. I can answer two of your questions:
1) Yes, you should plan to use a fan on the PSU, especially if you plan on mounting it in a cabinet of some sort that will restrict air flow. I built a rack to power two CPU fans so that one blows over my PSU and the other over the HobbyCNC breakout board.
2) I used 1/4" ABS plastic for the carraige sides and all the motor mounts. In fact, I used a smaller cnc to make these parts as my real world "homework" to learn about cnc. Drilling pilot holes and cutting out the oval hole (on one of the sides for access to the Z-axis leadnut to make adjusts) with a cnc was a whole lot better than I could have done by hand. I even learned how to make a pocket on the textured side of the ABS so that the stepper motor would mate cleanly.
David's plans are well written and allow for lots of modifications, but still allow for adjusts for those us with less than perfect machining/construction as in my case. The end result is I can cut to about 0.003" accuracy.
Yes I am enjoying the build - I've actually built most of the components already and am just waiting to put everything together. Will post some photos in a few days. I am fortunate to own a drill press which is pretty much essential for the build IMO, plus have access the a panel saw at work which is awesome. So hopefully I can get things pretty accurate. I got the y-axis bearings tried out this weekend and the movement is lovely and smooth.
Re the motor mounts, I was thinking about making some tempoarary wood ones, then using the machine to make some parts for itself, much like you have done.
Anyone any views on the vibration issue, i.e. is it smart to mount the electronics to the machine in some way? I want to minimise the number of connections i.e. none between the steppers and driver board, to reduce risk of damage to the drivers.
What vibration are you concerned about? From the router or from the steppers? Both?
I used the recommended Porter Cable router and don't really find all the much vibration due to it. There is enough mass in the table to dampen it out. The two all-thread lead screws for the x-axis do a fair amount of vibration when doing a rapids move (depending on where it is on the x-axis) but I believe this is because I have to re-adjust the bearings which I neglected to do after tramming. I plan on doing this after I get my current project completed. Most likely I'll be able to increase the rapids speed and reduce vibration simultaneously after doing so.
I'm not sure I understand your concern over this issue. I wouldn't attached any electronics to the cnc at all. My BOB and PSU are housed in an old PC cabinet, remote from the CNC. I soldered the wires from the steppers to the cables running back to the BOB. I also used e-chain to keep everything clean and orderly. I don't think there is any chance to accidently disconnect a stepper while running to fry a driver chip.
I may not be understanding what you are concerned about. If so, my apologies.
Yes I don't know what to expect really, but it sounds like as you say since the machine is fairly beafy then the issue probably isn't so bad so I've not got much to worry about. If I go ahead with my base then my unit will be really solid! I guess I like the idea of having everything in a self-contained unit, but that's not absolutely essential. I think I'll go with that for now and see how things work out. I'll be buying a second fan in the next day or two so I can cool both my compartments (to be) effectively.
Out of interest, have you implemented any kind of relay control for the router power connection? I have seen some driver circuits and like the idea of having this functionality.
No, I haven't tried that yet. I'm using Mach3. And I'm not sure how I be able to do it without a VFD. So instead I using a manual variable speed control that I picked up from Harbor Freight. I find that I run pretty much at the same speed for what I'm cutting.
I highly recommend the auto-zero feature that Mach3 supports. It sure speeds things up. It's pretty simple and I'll have to search for the links on CNCZone if you're interested.
Any of you UK-based builders managed to source long leadnuts? Based on DIN standard, the normal length for a M8 coupler seems to be 24mm. I'd like something a little longer - any ideas? I don't have a lathe so making one is not an option.
A few initial photos to prove that something is actually happening! Actually there's a good chunk more than this complete, but the paint is drying currently!
First up here's the completed y-gantry. This is made of 2 sheets of laminated 18mm birch ply, so is pretty solid!
The bearing trucks are complete and work beautifully:
Test fitting the y-bearings...
and the z-bearings...
Good news is I now have most of my parts, just waiting on a couple of pulleys to be shipped over from the USA (can't find a European supplier)
The Xylotex 269oz stepper motors
Next up I am working on the Z-axis. I haven't chosen a router yet - I am wondering what the best options available in the UK are? There's a few which I have been looking at for this, bearing in mind I probably want to use a trim router, but I am conscious that I don't want something too underpowered.
Have you thought about Hitachi? I'm in love with the brand for small power tools. I've been using the plunge base version of this router for 2 years. Whisper quite as far as routers are concerned.
That Hitachi looks good - the only problem is I haven't found a UK version on the Internet, i.e. I want a 240V 50Hz version rather than having to rely on a converter.
Thanks anyway - let me know if you spot one It also looks like the motor may be hard to mount to the spindle plate, but I guess I'd need to see one in the flesh to be sure.
This week I have mostly been working on the Z-axis, around the day job. Here it is almost complete, though I haven't built the spindle plate yet. In the end I decided on 10mm MDF for the sides - it seems fairly rigid for now. Also I figured I could bond this better with PVA wood glue, whereas I might struggle to glue a HDPE sheet, which was my original idea.
Fitting the hardware to the front and back. I'll be cutting down the M5 bolts which hold the four bearing assemblies to this component - other than that all tensioning rods are cut to length.
Finally I test-fitted the assembly to the completed y-axis gantry. It works beautifully for now
The x-axis bearings are completed, including the angled brackets
The y-axis motor mount is complete and bolted to the gantry. These are made of 10mm MDF for now, though I might go for some HDPE versions made by the machine once it's in action. One tip not mentioned in the build manual (and this applies to all motor mounts) is to drill through both parts simultaneously to ensure the holes line up
The Z-axis is painted
And finally, the Z-axis motor mount (also 10mm MDF) had been installed
I was at the hardware store and couldn't resist these domed nuts, which give a nice finish to the Z-axis (and are a little kinder on the pinkies I imagine. I also trimmed all the bolts to length with the trusty angle grinder, so these fixings should all now be final. I might need to tweak things slightly when the machine is assembled, but for now the alignment seems pretty good (by eye)
I trimmed the router spindle plate down to size and installed it. No problems here either on the movement - lovely and smooth In the case of my machine, it ended up 43mm wide. Now all I need to do is go and buy a router.... Actually we have two of the models at work which I am considering, so I might 'borrow' one of those to see how it works out. I haven't drilled any holes yet for attaching said machine. I'll think about painting this when I get the router mounting figured, but no huge rush here.
Finally I have been thinking about cabling up the motors. I am considering using Van Damme starquad cable, normally used for balanced audio connections. Perks of this is it is intentionally really flexible, and also is shielded so that might help things. Another perk is I could permanently borrow a few metres from work. I have read that I should connect the shield to 0v, but leave the shields unconnected at the motors. My only concern is whether this cable will be able to handle the current. The conductors are slightly more lightweight than the wires connected to the motors, but not by much to be honest. What do people think? See this photo for comparisson - motor wires are on the left.
The cables will be soldered together then covered in heatshrink to insulate. Then all I need to do is work out which wire is which - there are conveniently two white and two blue cables! eek
My HDPE sheet arrived today, so I have built all of the bearing assemblies here. This stuff is great to work with - I can see why it's a favourite for cutting using CNC machines as well. I've got an adjustable drill bit so I managed to get the bearing holes a really tight fit, i.e. they had to be hammered in gently. This means I can probably do without any screws to hold them in place
The sheet is 10mm thick, bearings are 7mm high so I drilled the holes to that depth. That leaves a bonus 3mm of material to support the thrust load.
Next up on the build I think I really need to crack the base unit (own design - not on plans) This will help to keep the final machine in rigid and hopefully make it easier to tune.
Leadnuts have been made today. The couplers I found were 24mm long, so I have managed to get the M4 connecting bolts 16mm apart. I was hoping to find something a little longer, but didn't have much luck there. Hopefully these will be OK as a starting point...
The bolt screw heads are temporary, and will be removed once I know how long I want the threads to be.
Here's work in progress on the main chassis - in fact not too far off done now. The base is a large sheet of 18mm birch ply. I have four 90mm pieces running the length of the board, plus there will be a couple of cross-members to give extra rigidity. I've also made a couple of carry handles at the front, since I know already the complete machine is going to weigh rather a lot!
BTW this photo shows the base upside down!
The back is ready to be attached to the work table. When stored in an upright position, this component doubles as a base. The four groups of four holes are for some large castors which I have (thank you work skip ), the two large round holes are the cooling fans for the two electronics compartments, and the large rectangle just off-center is for the control panel. This won't be seen since there will be an aluminium plate in front of it, so it isn't my most beautiful piece of work. To the left of this is a vertical narrow hole, which will house the parallel D-sub connector.
Behind the control panel goes a regular UK double socket mains box - one of those metal things which usually get built into walls.
There's a few tiny changes to my design since my initial plans I published, but nothing too radical.
The base has at last been assembled - it seems really flat and rigid for now, so lets hope it actually is! I can always true it with the router when the machine is finished.
I permanently borrowed these castors from the work skip many months ago, knowing they would come in useful one day If my calcs are correct, there SHOULD be enough clearance to mount the x-axis stepper under the unit so so that it's shaft clears the ground when stored upright like this.
I need to build the enclosures for the electronics on the LHS and RHS here. They will enclose the purposely large air intake holes each side. Also I need to think about how I am going to cable the motors and limit switches around the machine.
Resting the unit on it's base, as it will be used when operational. I might treat the whole base to a coat of paint, or maybe wood varnish. I haven't decided yet...
The back panel has cutouts for my two cooling fans, also I have a control panel which will cover the rectangular cutout.
Finally I test-fitted the frame, and the good news it it fits. Phew!
Next steps is to bolt these two components together through the base into the legs, and also from the rear beam through the rear plate.
Richster's Solsylva dual leadscrew build
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Go with the Trend because of the variable speed.
