Floor

Built the floor on Sunday, Started by laying out the welded frame on the floor as a work surface and guide for laying out all the pieces.

img_2908

From there it was a  case of cutting all the price framing to the right length and then putting the pocket holes in the ends of the cross members.

img_2909

img_2910

Once that was complete the side rails were clamped into position on the welded frame and one side of each of the cross members was glued and screwed into the side rail before applying glue to the other ends of the cross members and then applying the other side rail.

img_2911

I’d decided that at the rear of the caravan at least I wanted another line of framing down the centreline of the trailer. This is to provide something to screw some parts of the kitchen into. I decided given there was wood left over that this may as well run the length of the floor and so pieces were cut, drilled, glued and screwed into place.

img_2912

Next step was to attach one side of the plywood paneling to the floor. Luckily one sheet was able to cover the floor from side to side after reducing the width of the caravan by 50 odd mm a few weekends ago and so it was only a case of cutting the length to size, applying glue to the frame and then dropping the plywood on. Clamps held these two pieces in together  whilst it was tacked with brad nails prior to being flipped and having weight applied to the centre.

img_2913

Polystyrene was then cut to fit in the gaps before the same process with the plywood panelling was undertaken again to put the top panel on the floor. Much weight was applied to give a strong bond.

img_2917

img_2918

To finish the floor I just need to run a router with a flush trim bit around to smooth out the edges and then job done.

 

Welded frame and Oak bowl

Over the weekend the frame for the teardrop was welded up, big thanks to Dave for teaching / showing me how to weld this and to Matt for putting up with us welding up the frame when we should have been working on fixing his car…

img_2850

The frame had to be rotated around a few times to get all the welds complete, initially it was tacked upside down after which all accessible welds were complete.

After that it was flipped and the top was welded (note these welds will need to be ground flush for the wooden floor to sit flat)

img_2851

When complete this was loaded back onto the trailer (pretty good two man lift) and transported home where the welds were ground flush with an angle grinder and flappy sanding disc.

img_2853

Weld pre grinding

img_2852

and then post grinding

img_2854

The other project for the weekend was the turning of an Oak bowl. A number of months ago a large tree was removed at my parents place, I managed to save a few sections for turning and also cut one of the larger sections into slabs (still to see how this weathers).

The sections destined for turning had their ends coated with wax to help prevent them from splitting from drying out too quickly. Walking past one of them over the weekend I noticed that some of the wax had started to crack and not wanting the wood to start splitting I decided that it needed to be turned.

I still don’t have the ideal setup for turning bowls, OK for spindle work but the swing over the bed is less than ideal and moving parts from the outside end of the tailstock to the inside is a bit of a pain.

Rough turning was completed on the outside at a fairly low-speed, this is where having the three-phase motor really comes in handy.

img_2857

At this point the bowl as just screwed really well onto a faceplate.

img_2856

After the outer shape was complete an attachment point for the chuck was cut into the bottom before the blank was shifted to the inboard side for hollowing out.

img_2859

img_2858

Some sanding is still required and I’d like to make the walls a little bit thinner if possible but once again the current lathe setup isn’t conducive to turning bowls, there is only a limited amount of room on the far side of the lathe before hitting the wall which makes it hard to get a bowl gouge in.

Given this was the first turning completed in a while all the chisels were in a bit of a state and so required touching up. Previously I had the Teknatool Nova jig mounted on the bench grinder but to be honest found it less than ideal.

According to the instruction manual for 8 inch grinders you are supposed to mount the jig on a raised block. The issue then was that the jigs slide didn’t fit under the grinding wheel and so there was only a limited range that the slide could move in and out. Another minor annoyance was the method of locking off the slide, basically a small rod inserted through another shorter threaded rod with two small rubber caps (designed to but not really) stopping the rod from sliding out of the threaded piece (picture below missing the rubber caps).

Screen Shot 2017-02-13 at 7.59.32 AM.png

In practice I found that the rubber caps would fall off and then the smaller rod would constantly slide out of the bottom part when tightening and then roll around the floor. I also found that once you had used the grinder for a while a deposit of ground material would build up on the slide which would then drastically increase the friction between the slide and clamp when moving it in and out.

I also found had a few issues with the top part of the jig. The cast section never seemed to slide that well on the stamped / folded plate (tried oil, grease, silicon spray, graphite powder), also it was slightly annoying to have to disassemble the top section to swap between sharpening with the cast section and sharpening with the guide arm.

Screen Shot 2017-02-13 at 8.02.51 AM.png

My version didn’t have the black thumbscrews but rather a threaded rod with a 90 degree bend on one end and then on the other a wing nut. Also the angle indicator pieces further down were always a bit of a pain to fit back in. The red folded piece was about 5mm narrower than the silver piece and so had to be pulled out whilst you tried to fit it, all in all a bit too fiddly considering how often it needed to come on and off.

All these things made me look around at other options and in doing so came across the Woodcut Tru-Grind system, very similar to the Teknatool but with a few differences.

  1. Slide does not need to be mounted on a block for 8 inch grinders.
  2. Slide system seems to lock off better (lever at the side as opposed to clamp on top.
  3. Guide arm part has notches which positively locate it at 10 odd fixed angles.
  4. Has two cups allowing you to locate the support arm at two different locations on the arm.

This was fitted to the grinder last night and is looking promising so far, the geometry of the system seems to fit the 8 inch grinder better making it easier to get the correct angle when grinding.

I haven’t sworn off the Teknatool jig yet but for the moment will use the Woodcut one and see how it performs for a bit.

Both of these jigs have one minor issue however and it’s definitely scraping the bottom of the barrel but it would be nice if the markings on the slides were engraved or stamped as the printed labels options that both systems use don’t last long at all.

Frame and Initial parts sourcing

So a Teardrop Caravan has been something that I’ve been keen to build for a couple of years. The motivation for the project always seems to be strongest after Eastercamp but then again there is nothing like spending a week in a tent working long hours to motivate one to find a better accommodation solution. I was talking to my brother-in-law recently whilst on holiday and he was interested in building one as well so we decided to finally give it a go.

Many long hours on the internet were spent researching the subject; what laws do you need to comply with in NZ when building a caravan, what is the best size and shape, do you go fibreglass or wood finish etc. The TNTTT.com website provided a wealth of information but I have to say the jackpot was discovering this site http://teardropbuilder.com. Contained within is an entire wealth of information as well as generously provided full construction plans and a Sketchup Model. Well worth checking out regardless of whether you are wanting to build your own or not.

As mentioned in the previous post the main hurdle to be overcome in NZ is the sourcing of a couple of the critical parts, namely the galley hinge and the side doors. The rest although perhaps in different sizes (metric vs imperial) are achievable.

Galley Hinge

There are a few main approaches that people seem to take here which fall into the following categories.

  1. Aluminium extruded hinge. (Hurricane Hinge)
  2. Piano Hinge with some form of weatherproof covering
  3. Rubber “Centaflex” hinge

I looked at all three options and rules out option two pretty quickly. Whilst I have no question that it is possible to waterproof these hinges I didn’t want to run the risk of stuffing around trying to waterproof it and then have to constantly keep an eye on it to make sure it’s not leaking

Option 3 turned out to be one option easily available in NZ from these guys http://www.mainlandfasteners.co.nz/2390/Plastic. The price I got back was reasonable at around $90 so definitely an option however it was hard to put aside the suspicions I had regarding the longevity of the rubber hinge material.

Option 1 turned out to be the option I went with however. One particular post on the TNTTT forum indicated that Grant Whipp based in the US shipped these hinges internationally. An email reply from Grant however advised that unfortunately (for me but not so much for him) he had retired. He was kind enough to pass me onto TCTeardrops.com in Wisconsin who make some pretty gnarly d including some off road models. Carol here was amazing and in short order a 5 foot section of hurricane hinge was on its way to New Zealand for pretty much the same price as the option 3. Highly reccomended dropping them a line if you too are after hinges.

Door

The door was the other option that was proving hard to source. Many hours were spent searching the internet for a workable option. From what I read online it seemed that about 50% of builders built their own door, the other 50% ordered one that was premade.

Once again waterproofing concerns were pushing me towards a premade option, the build your own approach used a number of extruded aluminium profiles and foam / rubber strips that all needed to be fitted around a plywood door section before being fitted to the body. Given the weather that you get here often in NZ I didn’t want to arrive at the campsite to find that rain had snuck in around the door edges on whilst in transit and that the mattress was soaked. The pre made option consisted of an insulated door and frame with little opening window, fly screen and inner trim strip. Basically cut the hole in the wall, screw the door in and then fit the trim. The only issue was sourcing in NZ.

One final option I looked into was marine hatches but the issue here was a) finding something large enough and b) something that had the locks on the outside.

Vintage Technologies seemed to be the go for pre made doors, any search on Google, Amazon or eBay returned his products so I contact them asking for a price to ship a couple to NZ. The price that came back for the doors was good but the shipping was an eye watering $550 USD.

Unfortunately NZ Post’s YouShop service has a maximum size that they ship, playing around with the shipping calculator revealed that the doors were only a couple of inches too large for them to carry however the price was significantly lower than $550 USD. The search then swapped to one of freight forwarders of which there were many. I settled on MyUS in the end, they had a simple calculator on their website to estimate shipping as well as a number of different service options and so after an account was set up with them a trial door was ordered from Amazon.

This arrived at MyUS this morning and should be shipped out in the next couple of days, just getting them to confirm that the correct door has been sent by Amazon, white on the inside, black on the outside and Insulated. Will provide an update on both the quality of the door and the MyUS service when the door arrives.

Frame

The steel for the frame arrived last week. This was purchased off Trademe from a seller MagellenImports based in Hederson. Big plus was that for $45 they would deliver it straight to your door, a big win when dealing with 6m lengths that weighed all up about 100kg.

img_2837

In short order this was cut to length and after a mornings work the ends of the C section had been notched to slot together prior to welding.

img_2845

One final fitup and the parts were stacked until the chance came to weld them up (or so I thought)

img_2843

The next day I was looking over the plans with a few friends and we came to the realisation that the frame was going to be too big to fit the locally available materials.

The widest sheet of plywood that I am locally able to obtain is 1530mm or approx 60 1/4 inches. Looking at the roof details from the plans we see that the roof overlaps the walls and so the widest that the trailer could ever be is 1530mm. (Images from http://teardropbuilder.com)

top

Looking now at the bottom we can see that from the outside of the wall to the outside of the trailer frame (point A) there is 1/8th of an inch of exterior skin and then 1/2 of an inch of wall which given that we have this on both sides, means that the trailer frame has to be 1 and 1/4 inches narrower than the roof.Bottom.jpg

The plans called for the trailer frame to be 60 inches from one outside side to the other and so this was the sizing that we worked to when cutting the frame steel but when you then add to that the thickness of the walls you end up with a complete teardrop width of 61 and 1/4 inches, about an inch wider than the available plywood…

Long story short, the next day steel was being cut again, to make sure that there were no issues about an inch and a half was removed from the width, this should now give a total teardrop width smaller than the plywood sheeting available locally.

To be honest I expected that something like this would happen at some point given that I’m using imperial plans in a metric world and that there are going to be regional differences when it comes to material sizing, I just didn’t expected it this early in the piece.

Next step will be doing the first weld up of the frame, the final weld will include the drawbar and the mounting points for the leaf springs which will probably happen close to the end of the build when to allow the trailer to be balanced. Ill have to come up with a way of making the top of the trailer detachable from the welded frame but don’t anticipate this being too much of an issue.

I have emerged…

So its been just over two years since the last post and to be honest its not been a case of nothing to write about, rather a case of little time to spend writing up blog posts.

Whats been happening? 

  1. Moved house
  2. Had to build and move into shed at new house
  3. Landscaped back garden
  4. Finished ML7 repaint and assembly
  5. Assembled new 3 Phase drive systems for both ML7 and ML8
  6. Started on drill press restoration (still in parts)
  7. Started on Home Automation project using openHAB (excellent software)
  8. Put finishing touches on Arcade Machine
  9. Decommissioned Shopping Trolley 😦
  10. Started recondition of planer and table saw attachments for ML8

Why have I emerged now?

Well its time to catch up on some of these things. Expect a few posts hopefully in quickish succession. These will probably be image heavy in place of large swaths of text.

What projects are on the horizon?

A Teardrop Trailer build. This is currently in the investigative and sourcing phase. Being located in NZ makes a few of the parts hard to find (read doors and rear galley hinge). There doesn’t seem to be a huge amount of information on the internet re where to get these parts when based in NZ so successful or otherwise ill make sure to post the results in the hope it may help other NZ builders.

Consider this the first update

Built a bookshelf over the weekend with Vicks. A couple of years ago we purchased some old Rimu skirting board off TradeMe, this had been pulled out of a school somewhere.

Initially this was covered on one side with white paint and had a curved radius on the top edge and so the first steps were dispatching the radius with a table saw and removing the face / cleaning up the front face with an electric plane.

After that it was a case of cutting out the wood too damaged to use and then after confirming that we had enough, cutting the wood to size.

Four shelves were then clamped together and had braces glued and screwed to the bottom of them (these braces are at each end and then behind the legs in the middle in the below picture)

IMG_2835.JPG

The end sections had their ends glued to form a plank section and clamped (no braces on these) before assembling the outer frame and then mounting the two internal shelves.

The 8 legs were the final pieces put on, for some reason these were the only parts of the build where the wood wanted to split when sinking the screw heads in so these all had to be countersunk first.

Final step will be applying a couple of coats of light stain before moving into position which should happen this weekend.

On the whole it was a relatively painless process, there was additional work in preparing the boards which wouldn’t be required if the wood was purchased new but then again I don’t think there’s any way we would have got the wood new for the price we paid.

There’s still some sections left over so it looks like a matching coffee table may also be in the future.

Until next time.

 

 

 

Largest post thus far and Happy New Year!

So this is the fifth attempt in getting this update online, if it’s not project progress that makes it outdated at time of almost posting its flaming Microsoft Word crashing when it tries to auto-save. I was going to use the excuse that with starting a new job there hasn’t been enough time to actually get stuck into any serious project work but that would be a bit of a lie. The truth is that the motivation to type out the update has grown less and less as the amount that needed to be updated grew and grew.

In the last update on the arcade machine the second controller panel had just been painted and was drying before the buttons were added and it was installed in the machine. A couple of days later this was done and the buttons were then wired up. One of the modifications that I made to the original design was the inclusion of a M8 threaded behind the front of the player controls, this helped to pull the wooden sides together tight against the metal panel.

IMG_1022

This was a bit of a mission if I’m completely hones as I underestimated the length that the rearmost wire extended off the back of one of the joystick micro switches and ended up munching it pretty good when drilling one of the holes. This then meant that the control panel had to be removed which required the removal of the green trim and a bit of repainting of the wooden sides with the panel was reinstalled.

All that aside once both panels were installed and tested it was time to install the green acrylic behind the panel which will eventually be backlight. I had hoped to find some semi opaque green acrylic that allowed some light to show through but didn’t allow you to see inside the machine but all that I could find on TradeMe was green tinted acrylic. To solve this issue I doubled it up with a sheet of semi opaque white plastic similar to that used on lightboxes.

IMG_1024

The first one of these went in pretty easily with the help of some 3D printed brackets

IMG_1025

The second however fell victim to the old measure twice / drill once curse which then required the purchase of two more pieces of acrylic. The issue that I then faced was that the plastic was delivered approx. 1mm undersize which would have meant that light from inside the machine would spill through the gap left at the side. After stuffing around for a while with black tape and paper I settled on a 2 layer high 3D printed strip which fits perfectly down the side of the acrylic and is invisible enough.

IMG_1023

The final modification that I made to the electronics was the hack of a remote control to turn on and off the stereo and change the input / volume when the cabinet is closed. One of the annoying things about the car stereo is that every time the power is cut and then restored the radio defaults to a powered off state. Secondly when you then turn the stereo back on it’s on the wrong input. I didn’t want to really open up the side of the arcade machine every time I turned it on to turn on the stereo, change the input and set the volume. To solve this I cracked open the remote that came with the stereo and wired it up to several relays which were then connected to one of the nRF24L01 nodes that I’ve been experimenting with.IMG_1028IMG_1030

As a result you are then able to “press” the buttons on the remote wirelessly using a computer / another node to turn on the stereo, switch the input and turn the volume up and down.

A piece of glass for the table top has now been sourced and cut to shape and is ready for install. First the wooden section of the top needs to be cleaned after sitting in the garage for a number of months and have its final coat of paint applied.

Last time on the mower I’d just installed the replacement petrol tap and gasket between the cylinder head and the exhaust with the next steps being the reinstall of the blade, wheels and the handle. This has all been completed with the lawnmower being used to mow lawns with good result several times since, it’s already beginning to collect a few scratches in the paint.

IMG_1034IMG_1032 IMG_1033

I didn’t go really go too far with the restoration of the wheels as they’ll soon be removed to convert it into a lawn robot, the height adjustment lever and rods received a clean and the removal of the old paint as its likely they will remain. I did have doubt around the mower running at the correct RPM but a test with a cheap TradeMe tachometer has confirmed that it’s within specification. I still do need to check however that the spring that acts on the governor is set right to allow the engine to respond correctly when the RPM drops as a result of long grass etc. For the moment this project is going to be classed as closed.

I’ve also been playing around recently with some of the WS2811 LEDS that are everywhere these days. The amount of information and libraries that have been written to interface with these makes it extremely easy to connect them to a computer, cell phone or lighting console which has resulted in people making some absolutely mind-blowing art pieces. The first step for me however was ordering a number of different strips and rings for the local supplier to play around with but after coming up with an interesting project using the 12 LED rings I was left with a 1m long strip that I wasn’t really using…

One of the first world problems that I have at the moment is that there is no light switch next to the bed to turn on and off the main lights in the room. This means that there’s always a disagreement over who’s going to be the person that has to turn off the lights and then make their way across the room in the dark. To solve this the 1m strip was attached using the 3M tape provided to the bed end was connected to a Arduino clone and Bluetooth to serial module which was mounted on the side of the bed end in a 3D printed case.

IMG_1035

An app was then whipped up using the ever useful MIT AppInventor software which allows you to control the strip with an Android phone.

Screenshot_2015-01-04-17-57-13

When opened, the app immediately tries to connect to the Bluetooth module and then presents the user with buttons to select either the left hand side, the right hand side or the entire strip. Four sliders then allow you to set the Red, Green and Blue channels or all three at once using the white slider.

IMG_1038 IMG_1039 IMG_1040 IMG_1041 IMG_1042

There is also an “All Off” button to turn all of the LED’s off at once. In all the project only took a night to build and then program. Eventually the plan is to replace the Arduino and Bluetooth module with one of the nRF24L01 nodes to integrate it into the rest of the node network.

The second project that I’ve been working on with these LED’s uses the 12 LED 90 degree sections that can be soldered together to make a 60 LED ring. Quite a convenient number to be honest.

IMG_0984

The first step was soldering the ring together, a flat surface really helps here to make sure that the ring isn’t twisted once soldered together. That being said there is enough give in the three solder joints between each section to straighten it out afterwards. To provide extra bracing to the ring and to eliminate having to use wires as such I built a bracing frame to connect to most of the 5V connections on the back of the ring and then another to connect to the GND points. The GND braces actually sit about 1.5mm further back than the 5V frame and are isolated with small pieces of heat shrink where required. I quite like using bare copper wires when possible for things like this as not only is it reasonably strong but also conducts (duh) and looks quite cool.

Once this was complete the five components (Arduino clone, RTC, capacitor and 2 x resistors) that were going to be used were positioned and then soldered to the bracing frames to mount them and provide the 5V and GND connections. The SDA and SCL connections were then made to the RTC as well as the DIN connection to the first segment on the ring.

IMG_0986

After this it was time for testing. At this point I hadn’t put the power connectors on the clock yet but having a frame that was actually the 5V and GND rails made it extremely easy connect the power supply with the help of a couple of alligator leads. Success LED ring works with the demo sketch on the Arduino. I’d previously used this model RTC on another project and so was able to copy the code that interfaced with the RTC from that which saved some time however when trying to run it on the Arduino for some reason the RTC wasn’t running. Poking around with it mounted achieved little and so it needed to be removed from the frame without damaging either the RTC or the bracing frames. Once complete however temp headers were soldered on and it was tested with several different Arduino models. None worked.

At this point I was thinking that perhaps I’d received a dead model so I started tracing out the connection on the PCB. All were fine. I then replaced the backup battery and ran through them again to find 0V on the battery input pin on the RTC. After confirming that the battery did in fact have charge I had another fiddle and figured that perhaps the positive connection on the battery holder wasn’t making a proper connection. Scratching some of the surface off didn’t solve the problem but shoving a piece of tin foil in did. After testing that the clock was now working properly I replaced the tin foil with a pad / blob of solder and returned the RTC to the clock frame. Note: despite having power applied to the +5V input on the RTC the backup battery appears to need to be present for operation. Who figured?

A wee bit of further programming later and Voila, finished clock. Hours are represented in green, minutes in blue and seconds in red. After 6pm at night the clock display turns off and then turns on again at 6am in the morning.

(Sorry for the vertical video, I know I’m a bad person)

On the lathe a number of parts have been painted and installed to the point that there is one more part needing a second coat to reassemble the headstock. Both the front and back belt guards covering the longer of the two belts have been installed as well as the countershaft, swing arm and V cone pulley. Both of the bearing caps and the back gear eccentric assembly have also been painted. Once all the parts are ready the headstock will then be assembled, after that the next step will be to paint the other belt guard, back gear lever and tumbler gear lever…

IMG_0901 IMG_0902

(Leap forward in time two weeks) Since typing all that out the headstock got its second top coat and was installed on the bed. It was a relief to finally get this done and remove the masking tape that has been on some of these parts for the better part of three months. Now that the weathers warmed up a bit it’s so much easier to get paint to dry which has vastly sped up progress. A few days after the headstock was installed the drip feed oilers were cleaned out and attached to the bearing caps. The backgear eccentric assembly has also been installed and loosely connected to the lever on the outside of the headstock. Once the spindle has been shimmed up and the correct position of the backgear has been determined then the lever will be tightened up onto the backgear eccentric assembly. IMG_0904IMG_0906IMG_0916

Leap forward yet again…. The headstock has now been finished with the spindle installed and shimmed up. The back gear has been positioned and tightened and tested and runs pretty nice. The lathe is at the point where it can be used to an extent again and so as opposed to having to polish the hand wheels in the drill press I’ve been able to do them in a proper chuck without having to mount them on a piece of metal rod to mount them in the drill.

IMG_1020

Unfortunately I discovered some time ago that the same colour paint from the same manufacturer differs depending on whether it has come out of a tin or a spray can. Normally I guess you’d use one or the other however at the start of the project I used a couple of cans on the first few parts before switching to a tin to do the bed. Since then I’ve stayed with the tin as the finish is actually better and it’s a lot more economical. The problem (to me) that this created was that the tailstock was a slightly different shade of grey to the rest of the lathe and due to its position (all the other sprayed parts aren’t readily apparent) a bit of an eyesore. To fix the tailstock was disassembled and wiped down with IPA before receiving a coat of paint from the tin before being reassembled and reinstalled. The oil nipple on the top has also finally been screwed on (small job but never seemed to get done) with the hand wheel for the tailstock receiving two light topcoats.

IMG_1017

When painting the first hand wheel I went with a mask and paint approach, masking off the outer polished section prior to painting the inner. The tailstock hand wheel has a slightly different profile between the polished and painted parts which made the masking attempts less than ideal. In the end I abandoned masking and used model brushes to paint the border between the painted and polished sections. This is probably the same approach that I’ll use for the remaining hand wheel as well.

The tumbler gear assembly has also been painted and reinstalled along with the leadscrew bracket assembly at the headstock end as well as the change wheel quadrant. I know that the bracket assembly is a different colour, this is because it’s new and I can’t bring myself to pull off the factory paint and repaint it in a matching colour. I realise that this may sound hypocritical in light of the tailstock repainting requirement however I’m justifying it as an homage to the original colour.

IMG_1014

The leadscrew has also been reinstalled but is hanging off a section of wire at the tailstock end whilst the bracket at this end receives its coats of paint. This will then be reinstalled with the associated spacers and nuts etc on the leadscrew to the complete this section of the lathe.

IMG_1013 IMG_1019

This has now been done, the bracket install went pretty easily although the top coats were a pain in the butt. Its been stupidly hot here recently and so the paint has been drying too quickly for it to flow out and make a smooth surface. Eventually a passable finish was achieved. The full geartrain was run today for the first time with most pleasing results.

Moving onto the carriage assembly, the topslide has been installed on the topslide base with the gib strip adjusted to remove slop, this has then been installed on the crosslide with the crosslide endplate receiving its first coat of paint two days ago. The carriage proper has been stripped of paint completely and will be cleaned of the protective oil layer, masked and painted probably this weekend.

IMG_1016

For the last couple of weeks the amount of work that still needed to be completed (read repainting) still seemed to be an obscene amount. After making inroads on the carriage however the end seems to be a lot closer somehow. Both the belt guard that sits between the swing arm and spindle and change gear cover still need to be painted however I’m hoping to bead blast these which should speed things up a bit.

The final project that I’ve been working on is the construction of a Shapeoko2 which is mostly complete aside form a number of modifications that are required for the end stops to work properly.

Ive only got three pics of this sorry, one of it in the box,

IMG_0632

one of it out of the box,

IMG_0639

and one with piles of junk gathering on it because my Dremel has crapped itself

IMG_1037

In general the construction of the frame went fairly smoothly and was completed in a couple of nights although tapping all the aluminium extrusion got very old very quickly. From first inspection it looks to be a fairly well designed machine with the following comments.

  1. The screws that attach the gantry to the Y motor mounts could be longer. Compared to the rest of the screws that went into the ends of the aluminium extrusions these were oddly short. This combined with the fact that the holes are tapped into aluminium didn’t offer too much strength (note only in my opinion). I ended up replacing these with longer screws for peace of mind.
  2. Some form of indication as to how to beset attach end stops wouldn’t go amiss. In the end I had to print a number of different brackets (6 in total of 5 different designs) in order to mount all the end stops.
  3. Make the end stops NC by default. This I think would solve a lot of the issues that people have with the end stops triggering from motor noise and would certainly be a lot more fail safe
  4. Someone really needs to have a look at software such as Repetier Host or Pronterface and come up with a solution for the Shapeoko (or if you know of one then let me know please!!)

These last two points have been a real pain in the ass…

Firstly it’s interesting to see the difference in maturity between the PC software for 3D printers and for CNC machines running GRBL. Taking Repetier Host or Pronterface for example you have two pretty polished pieces of software that works with a number of different firmwares and offer a lot of functionality. Looking at similar software but for CRBL based CNC machines the pickings are a lot thinner with it seems to be greater “width” but not as much “depth”. What I mean by this is that it appears that there seem to be a wider range of PC side programs but at the expense of functionality and usability. Issues demonstrated by this approach have been identified as follows

  1. The “$#” ordering of the settings seems to change between the different versions of GRBL with new settings displacing current settings in the numbering plan. This caused issues with a number of programs that had the settings numbering coded into the program which then didn’t match the different versions of GRBL. These programs at time of writing have not been updated yet.
  2. The requirements for a federate to be included in move commands changed within different versions of GRBL as a result the jog functions on some of the software didn’t work.
  3. Not all software provided button access to commands such as “Home” and “Unlock” Whilst I accept that you are able to issue these commands using “$H” and “$X” it seems odd that these were omitted considering how central they are to operation.
  4. No one bit of software seemed to offer good machine jog controls, visualisation and easy access to the settings in GRBL
  5. Half the software had the machine moving in negative space as it moved away from the home positions, the other half had it moving in positive space with no apparent setting in any of the software to change this. I accept that this isn’t functionality provided by the majority of the 3D printing software but at least the approach is consistent.

I think that there is massive potential with GRBL to have a stable low cost platform to run homemade CNC machines off but at the moment this shotgun approach to PC side software hasn’t resulted in the full potential to be realized in my opinion. I’ll keep looking however and update below as this changes.

Secondly the decision to go with NO end stops for the GRBL shield is interesting and seems to cause a lot more issues compared to NC end stops as well as being less fail safe. Numerous blogs, forums and my own experience with NC and NO end stops on 3D printers have indicated a greater number of issues with noise and false triggers with NO end stops over NC end stops so I’m really sure why at the expense of the above the design choice was made to go with the NO option. It seems from what people are having to do to fix the issues with the NO end stops that it would have been a lot easier to have NC ones in the first place.

In my instance I wasn’t able to easily modify the GRBL shield I had to run with NC end stops so I had to resort to adding extra resistors and capacitors to pull-up the end stop properly and remove enough noise from the end stops for the machine to run reliably without the end stops triggering all the time. I haven’t yet run an extended job on the machine yet so it’ll be interesting to see whether these modifications will be enough or whether more work will be required to get it to function properly.

In conclusion with the Shapeoko I kind of get the impressions that it’s less of an “Out of the box” product than it claims to be with some obvious shortfalls in the software and end stop department. Despite that the design works well and has promise. In all, for the price it’s a pretty good option.