General Update

More of just a general update this time, actual caravan progress has been minor as a result of the cold weather. Overnight most nights the temperature is dropping down below the minimum temperature for the Titebond 3 glue and given that the sections being glued at the moment give most of the strength to the structure we want to make sure that everything sets to full strength.

First off, Bandsaw.


This was purchased a couple of months ago for use on the caravan project, specifically for when it came time to cut the ribs for the rear hatch, whilst this could have been done with a jigsaw the benefit of the bandsaw for the price was hard to pass on. When I purchased the saw the seller advised that the motor was potentially too small for the saw as the saw bogged down when cutting. Given that it was a 3/4 hp motor however I couldn’t see this being the case and sure enough all the issue turned out being was a stretched and therefore slipping belt.

This fixed it was time to turn it on for the first time (for me) and make some sawdust. This lasted all of about 30 seconds before the blade jumped off the wheels hitting the front guard giving me a hell of a fright.

Turned out this issue was the tires, they were decently old and made of rubber and with the glue being of similar vintage they had stretched from being spun properly for once and so had caught the blade and thrown it off.

A replacement set of Urethane tires was sourced from Amazon which arrived mid last week and so the process of fitting them began.

First step was to clean up the wheels removing the old glue and rubber, from this…


To this…


After that the tires had to be softened in warm water and dish washing liquid in order to stretch a 12 inch diameter tire onto a 14 inch wheel. 5 minutes at 40 degrees did the trick.


I don’t have any photos of the actual fitting as it required both hands but basically you clamp the tire on at one point and then hold the tire on the wheel a further 90 degrees around in one direction. You then work around the wheel in the other direction levering the tire onto the wheel. The supplier of the tires actually included a special tool for this, a piece of 20mm dowel approx 100mm long with a 100mm nail stuck in one end with some plastic tubing on it. Primitive but exactly what was needed. Once the tire was on I ran this around the wheel (between the tire and the wheel) to even it all out.

Process complete for the top wheel


and then for the bottom wheel


Final job required to get the bandsaw running was to make some new throat plates as the original ones were missing. a few quick measurements resulted in a 3D model which was then printed on the i3. One advantage of using a glass bed is that you get an almost glassy smooth finish on the bottom of the part.


The part is basically two concentric circles (here printed upside down). Only the top circle is actually needed but the bottom step gives extra strength to the part.


Almost mirror finish which will help in work not getting caught on the part.


Part installed and just needing the slot cut in it to make it a true hero clearance insert.


On the Caravan front the only progress has been gluing on one of the side walls. Both the cabinets were removed before everything was masked up (left hand wall being glued here).


The wall was then removed and wax paper installed between the wooden base and the trailer frame. This is to hopefully prevent parts that shouldn’t be glued being glued accidentally.


Decent amounts of polyurethane glue was then added before the wall being reinstalled and screwed to the base with a total of 13 stainless steel screws along the length of the wall. The next job was to reinstall the front cabinet with again a decent amount of glue before spending a further half hour dealing with squeeze out.


In all this seems to have done the trick, giving the wall a shake shows that its stuck pretty well to the floor, hopefully when the rest of the gluing between the cabinets and walls is complete the structure should be solid enough.

Final work recently has been on the ML7. The drip tray still hasn’t been installed because some rider blocks were needed to raise the lathe above the tray sufficiently. These were cut from a length of aluminium stock before being faced and drilled on the ML7.


The lathe was then unbolted from the bench which required the removal of the change gear quadrant, headstock lead screw bracket, tailstock lead screw bracket and finally the lead screw itself. I now need to work out how to lift the lathe off the bench enough to get the tray, blocks and rubber isolating washers all installed before lowering the lathe back down. I suspect this will end up being some overhead gantry contraption to lift the lathe the 100 odd mm required.


Cleaned & Painted Lathe, Mower and what I’m printing now

So after the Lathe had soaked in the tub for a week it was taken out and all the black crud was scrubbed off with some 3M nylon pads whilst spraying it all down with water. After it was lightly dried it was then rubbed down with phosphoric acid, then washed down again before being quickly dried with hair dryers and towels. The end result was this

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The whole thing was then given a good scrub with IPA before a primer coat from the Killrust range was applied. After drying for a couple of days the first top coat was then put on leaving it looking like this.

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There is still one more top coat to go on but I think I’ll wait a couple of weeks to let the current paint dry. Its starting to get colder and more humid here which I suspect isn’t helping with drying times. There’s still a fair amount to do but once the final coat has gone on and its had some time to dry then reassembly can finally begin again. Most of the parts to get the headstock back together have either been painted or are in the process of being painted and should all be finished around the same time. Stay tuned for experiments in handwheel polishing and masking..

Also this last weekend William and I got the first coat of paint on the lawnmower deck. I’d been putting this off for a while because before painting there was still some finishing that needed to be done on the deck. The amount of trauma that this mower has suffered is beyond belief with numerous cracks on top of the deck, a massive split down one side and a fist sized hole in the other. The fist sized hole was pretty much the main repair that needed to be completed, it had already been patched (probably more thoroughly than needed) but in the spirit or over-engineering I also wanted to weld / solder it together.

I found this product on the internet called Durafix that is supposed to allow home users to weld aluminum together with a MAPP torch and no other special equipment. On their website there is a picture of two aluminum cans with their bases attached to each other with the stuff but I’m dubious aye. Admittedly it could be the stuff that the mower deck is made out of but the finished result hasn’t been as solid as I was expecting. On some of the smaller surface cracks I opened into a V groove with a grinder to get better penetration and the Durafix seems to flow into that alright but I’m not sure how strong the bond is. For example it’s quite easy to flick up the edges of any Durafix that has flowed out of the join and across the deck. I guess what I’m saying is the bond between the two materials doesn’t seem to be the same as say solder and copper… Time will tell whether the fixes will hold up I guess but I was hoping for joins that looked a bit more resilient. Just to clarify both the parts were scrubbed with the supplied wire brush and both were hot enough and were able to melt the Durafix without the presence of the MAPP torch.

All that aside we ended up with the following setup to weld the massive hole together,photo 1 (Resized)

Gas ring to add more hotness. End result.

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This was then cleaned off and ground to match a bit better the contours of the surrounding metal. It won’t win any awards but if it holds together then all well and good.

A couple of other minor holes were patched before it had a etch primer sprayed on.

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Before painting

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and after. This will get one more light coat of primer and then the first top coat in the next couple of days.

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On the 3D printer front I’ve got 2 x new projects going. Firstly the parts for a Mini Kossel have started to come off the I3. Getting there slowly and I have the extrusion so just waiting on some hardware from China before frame construction can begin.

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Secondly I’ve started work on a robotic dolly for a small camera using OpenBeam extrusion. From design through to one finished section.

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Stay tuned..















Tabletops, Vases, Voltmeters and Guitar Pedals

Prepare for another multifaceted update

1) Tabletops

Much searching around Auckland for the required 25mm sheet of plywood took a week of unanswered emails, unhelpful sales staff and staff who claim to have stock until you turn up to find that they’re completely out. When calling one store to ask if they had the product in stock one really “helpful” sales guy even replied “If my staff spent all their time running around the store seeing if we have stuff in stock they wouldn’t have time to do their proper jobs”. Considering that the store solely sold plywood and if they had it in stock I would have brought it I’m not exactly sure what the staff was doing that was more important than making a sale. Thanks non named plywood merchant located in Penrose…

All that aside eventually a sheet of plywood was located and then cut into three sections with a blunt handsaw to fit in the back of the car. This then had the outline of the table top drawn and cut out of it. Next step will be cutting out the hole for the LCD and mounting it to the cabinet. Aside from that the control panel braces and a couple of air / speaker vents are all that will be left on the wood working front. After that a final bog and sand before painting.

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2) Vases

I’ve also started to experiment recently with thin wall 3D printed objects to see how well the printer did printing large single extrusion objects. The main concerns that I had were related to the piece glooping down because it didn’t have time to cool or the layers not lining up, which when printing with a .35mm nozzle is quite important. Aside from a few artifacts on one corner the parts printed quite well however, I’m happy enough with the result at the moment although ill probably fiddle with the density of the walls at some point to make them more solid.

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One interesting discovery I did make however was a strange translucent goopy liquid that started leaking out of the hot end after a while of printing. It’s possible to wipe this off before a print and even after 2.5 hours of solid printing it’s not really an issue but I’d still like to work out what is happening. Seeing as it looks similar to the stuff that ends up inside the V2 nozzle between hot end services I’m inclined to believe that it’s either a result of the temperature settings not being quite right and so the filament is doing something weird when melted and separating somehow or the filament has absorbed too much moisture and that is what is separating out when it is heated. As near as I can figure this is leaking out of the hot end where the nozzle threads on and is then oozing out between the nozzle and the heater block.

3) Voltmeters

Over these next two weeks ill need to spend some time preparing the shopping trolley for Eastercamp. Thus far I’ve replaced a button mount that has snapped off with a beefier version and finished off the Lo-Jack code on the GSM and Comms Nanos. Now sending the correct string to a cellphone number will cause the trolley to TXT you back a Google maps link to its position as determined by GPS. At the moment the number to reply to is hard-coded to one cellphone number but the long-term intention is to have it reply to the number that queries it.

Additionally I’ve added a couple of voltmeters in a printed enclosure to the front of the trolley. These are completely separate from all of the rest of the trolley electronics, connected directly to the batteries via a toggle switch to power them on and off. Testing with a multimeter confirms that their reading are accurate.

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(Mount in the middle without screens)

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(and Screens)

Still remaining on the to do list is an investigation in to the throttle code (sometimes the trolley takes off on its own) which I suspect will require the addition / modification of a greater dead spot for All Stop. Sometime next week one final yet to be unveiled cosmetic change specifically for Easter Camp will also be completed.

4) Guitar Pedals

Recently a friend asked me to look into making a cheap copy of a midi controller / guitar pedal to control a Strymon Timeline “some-sort-of-multi-effect-/-looper-pedal?”. The original controller pedal can be brought online for approx $150 US but that is before shipping from the States and any import taxes etc. I’m afraid I don’t have any photos of this project as it was completed in two days but the concept is as follows.

On the top of the pedal there are three foot switches evenly spaced across its width with an LED above each. The left and right LEDs light up with the switch below is pressed whilst the center LED is an RGB one that changes color to indicate the mode that the pedal is in. Pressing the center foot switch cycles through the modes changing the function of the left and right buttons. In each different mode a press and/or hold and/or release of the button sends a MIDI message out the 5 pin DIN port on the back. Pressing and holding the center switch sends a particular message independent of the mode. An Arduino Nano inside is the brains of the lot

The most “fun” part of the project was fiddling around with the differentiation between a press and hold especially considering the foot switches had a lot of bounce that needed to be programmatically taken care of. The basic functions presented by the controller pedal include scrolling through the Strymon presets, controlling the looper record and playback functions, bypassing (something) and controlling the “Tap” input and “Infinite Repeats”. In the end the project was a success however coming in at around half the price (before shipping) of the pedal available online.

Oops, Pics

Ok so I promised pics of the finished I3 a couple of days ago but didn’t manage to get around uploading them what with work and going camping over the weekend. The quality is a bit average but anyway











Finished I3

So the I3 is finished. One more project ticked off the list and officially marked as done, one more project moved from the “when will it be finished and when can I stop worrying about it” box to the “now I just need to keep it going” box. (Pics tomorrow I promise)

First thoughts?

Well the design is pretty good. Although Ive not used the increased z build height yet I can defiantly see how it could be an advantage. Also the more open design over the V2 also looks like it could end up being advantageous. Truth be told thus far Ive only printed three parts on it so not really enough to justify any concrete opinions about its long term performance.

As both printers sit there printing as I write this one thing is apparent however, for all its quirks and failings, for its constant need of attention, maintenance and freshly printed parts I know that my Prusa V2 will be my first 3D printer love. The cables may not be routed as neatly, it may not have the same precision and resolution and it definitely at times pisses me off beyond all belief but as it stands tonight its knocked out 4 going on 5 parts (albeit at a lower resolution) compared to the 2 from the I3.

The ugly duckling is definitely here to stay..

New Reprap

Generally my relationship with NZ Couriers goes something like this. I order an item, they pick up the item, item gets lost several times, travels through Gisborne, I call up, they investigate, I receive item 1 week after shipping despite it only having to travel across town… As such I avoid using their service like the plague and bang my head on me desk repeatedly when I find out that someone has dispatched a part on their service.

Imagine my surprise then when I ordered some Reprap parts from Christchurch and they managed to pick them up on a Monday afternoon and have them at my desk first thing Tuesday morning. I still have no idea how they did it, but anyway I received the following. (and no that is not my real address)

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Next step – Take received parts – Add printed parts

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Mix well

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Let sit overnight

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End result after a weekends work on and off. The Silver and Black theme is purely accidental, it just happened that I had black filament in the printer and that the motors were black but I like it and think ill carry on with it. Printing the parts has been a bit of a pain in the butt this time around, a combination of upgrading both Slic3r and Repetier host means that he V2 needs a bit of fine tuning to get the result back to quality that it was before the upgrade but I think on the whole the upgrade was worth it as the bridges seem to be coming out a lot better. The other change that I needed to make was moving everything across from the Vista boot that I am running for general day-to-day stuff on the computer to the more stable (read not full of crap) Win 7 boot that I use for programming. The reason for this is that the printer was more and more randomly carking out whilst printing which really tears your gruds when there’s 5 minutes left in a 2 hr print.

The intention with this printer is to go with a .35mm nozzle and have a default lower layer height to obtain higher resolution prints on small or technical parts.  In addition to the nozzle the I3 frame seems to be a lot more rigid in both the X/Z axis and the Y/Z axis so this should help get the quality of the output up as well.Ill still keep using the V2 for larger parts to keep the print times down though.

At the moment the 4mm to 5mm couplers are on order as well as the lm8uu bearings so ill fit those when the arrive and complete the next step of construction. Until then it’s going to be a case of tweaking the V2 to try to get the output quality back to where it as and printing the remainder of the parts.

As a closing pic have a look at the inside of a mobility scooter gearbox.

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