NickJ

A stainless pot from the junk store on a gas ring outside.

After much thinking and reading through Tomble's efforts I've realised that DIY electroplating is not something I wish to master. The hardware I have is all pretty manky and not really something I wish to invest much into as new bolt kits for the car are available and cheap. And then Parkerising crossed my path... Blast then boil in Phosphoric acid and Manganese Dioxide. While not as durable as zinc plating, it did give me something to mess around with, first of all a trial with Manganese Oxide extracted from Alkaline batteries and acid from Supercheap which came out pretty good. Pre-blast on the left, "Parkerised" on the right. I've now got my hands on real deal Manganese Dioxide and been a bit more careful with prep, the result is a nice dark green/black, more than sufficient for my needs.

Hinges - door, bonnet, boot etc Whats the usual way to prep and paint these? Unsure about sandblasting filling up the pivots with garnet. Just soak in paint stripper? Then the paint rubs off when the hinge is installed, or get them plated/parkerised?

This is gospel.

I have a galaxy a7 tab for off road navigation, in an aliexpress hardcase it handles all the abuse, dropped/rained on etc. screen is quite terrible through the cheap cover which may encourage a better option for you? Had it a few years but was below $400, usb and sd card slots to transfer data.

Coming up to the two year mark, thats two of seven checked off..... The last 6 months i've been hating my job, many small issues just killed my desire to go to the office 5 days a week not to mention overall happiness on weekends when I should be relaxing, taking a pretty big leap I handed in my resignation and looked for new adventure. In that regard I kind of lucked out, the new job has pretty much every tool a resto needs, most of which I can access after hours no worries, taking full advantage i've spent the last month dragging suspension bits through the blasting cabinet and spray booth slowly getting through the pile. Three weeks worth, slow but momentum. And this week's trolley brings up the balance of large bits. As for the shell, it hasn't escaped my motivation either, in the weeks between jobs I knocked off the underbody rust and stripped the remainder down to bare metal, I had planned to do more, but the spring winds and rain had better ideas. Then the last few weekends have gifted warm weather with unheard of low winds so two coats of epoxy and a pretty heavy layer of underbody have been applied, can't stress enough how incredibly happy for the rotisserie at this stage, what a mess! No real finished pics, but here is one halfway: I have picked up some paint for the suspension bits, current plan is to roll black underbody, charcoal suspension bits so its not all black underneath. (works in my head......) Colour is the same as used on the MK64 calipers I restored some years ago, a dark metallic grey Will it be ready to roll this summer? tbh i'm too scared to check the timeline, but will soldier on with that plan in mind.

Solder has its place, if you use solder in a high vibration environment the key to long life to also provide support/strain relief, the reason here is the solder wicks up the copper forming a defined change in rigidity, the copper will bend at near zero radius at this point and eventually fail, this is often inside the insulation and a right pain to trouble shoot. A crimp designed for this environment will have a bellmouth type exit which increases the bending radius reducing the work hardening effect above, even better is they have the electrical connection and secondary mechanical connection to the entire conductor and insulation. Adding solder to this type of crimp can easily negate the mechanical connection if done carelessly. Most important is to use the appropriate crimping tool for the crimp, ratchet style crimpers (when set up correctly) allow repeatable termination that plier style will never match. While the plastic type have a place, I personally detest them on the whole as they are bulky and don't allow visual inspection of the completed crimp, may as well twist the wires with masking tape. /triggered

Solder in a crimp connector? Some parts of the internet claim you will die of syphilis for such activities

Didn't @ajg193 make a steam lawnmower?

Bit of a Barry fix innit? There is corrosion allowance in the tank design based on whatever standard it is built to, so not really a big issue if you keep on top of draining and retire the tank when expired as written in the manual.....

0.9 is terrible for panel work, you need way more heat than 0.6 to get a decent weld which puts you right on the edge of burning through. ER70S6 is standard mig wire spec for steel.

Yeah definitely, while I don't want to spend my weekends shuffling jobs through, if its gunna take up half my shed it needs to be productive.

I use a diamond wheel on my dremel for tungsten if budget is the driver?

Saw that up at ashburton lakes a few years ago, dude driving had a massive smile on his face tackling a gravel road turn around. Looked massively bloated but impressive build for such a small chassis

Mate called asking if he could borrow a jigsaw to knock up some decoys. Jigsaw? Pffft, bring the corflute over.

Good point, i'm still basking in the glory of getting onto a 5 year standing DIY job, I shall remind her of the costs savings at once!

Making stuff! Last weekend I poked a pretty nasty scab The lower part of the frame lifted out in a soggy heap once the glass was out. The usual way to profile the required timber is to run it through a table saw only my table saw doesn't angle the blade and its in storage. But I have a CNC! Step 1) Take a picture Step 2) Draw around it using real measurements to calibrate Step 3) Assign toolpaths And munch So what could have been achieved in 30min actually took most of Sunday, what kicked hard was the clearance of the sub spindles, at full cut depth on the tool, there was barely 1mm clearance on the part, with the tool at full retract I had less than 2mm of travel left, this lead to some dubious manual code changes and many errors as the controller informed me the next move would hit the limit switches. While I have the new profile ready, the window is still boarded up. Also fired some ali through to make spaces for another project, it really showed up the play in the spindle retract mechanism, while its really nice having 3 different clearance heights, I will probably have to fix the spindle to gain more rigidity.

Cheap guns only have one emissivity setting so can vary wildly depending on surface, a cold black item can read higher than hot polished stainless etc. Expensive guns have full emissivity control but you can never be bothered to change it -Hold down 2 buttons in a sequence you can never find the instructions to remember. Easy way to get around this is buy a cheapish option and just place a small square of masking tape on the surface as a target, i've found it to be as accurate as you'd look for in such a device.

Servo tuning time.... So, how does a machine get from A to B? well, in basic terms you say hey, go to this location. In greater detail, imagine you have a tennis ball in your hand and want to get it onto a shelf 10m up, in order to get in nicely, the ball will need to go slightly above and come back down, this is called overshoot, not really a problem until you want to machine an internal corner, that overshoot will eat into the corner and not leave a sharp edge. The ideal path is to just make it onto the shelf and stop. There is an additional problem, in order to perfectly land on the shelf and minimise the overshoot, the max acceleration of the ball will be finite, limiting how quick you can get there. If we add brakes to the ball, then we can throw it much harder, bringing the ball to a stop in just the right place, hit the brakes too hard and you'll need a harder throw, get it just right will minimise input energy which is an obvious goal for machine life etc. For a machine, all these values are fixed in code so in order to find them we can either do really complex maths (which also needs many precise inputs) or we can force an input and look at the raw path it took to get there, iterating on initial acceleration and braking force until the error of reaching the desired position is minimised. -Now before I get much further one can go way further down this path, the above is a simple explanation and my methods are not exact, but get the machine working to a level that the residual error is less than other errors, ie no need to roll in too much glitter. How does the machine know where it is you ask? On the back of the servo motors that drive each axis is a rotary encoder that sends a signal back to the computer informing distance and direction, in this case, 8192 pulses per revolution, or one pulse for ever 2.5 micron of travel. The inputs I will look at are the position error "joint.0.f-error" in halscope, a handy tool in linux cnc to look at raw inputs, this output provides us with a simple calculation of position expected minus position actual, if we adjust the input acceleration and braking forces, we can iterate around to get this to a minimum. Starting values are hard to guess, thankfully I had the factory settings which where actually on the money for a conservative start. Round one, request a 5mm movement: That squiggly line is telling us we're close, but can it get better? Adding some numbers, in real rough terms, P = the initial throw, D = the braking, I = A helping hand to hold you on the shelf FF0, FF1, FF2 are new to me but I was advised to leave I, D and FF0 alone, add small amounts of FF1 and even smaller amounts of FF2 which should get us there quick. Before FF1 and FF2 are added, the value of P was increased until the drive went into oscillation then backed off to stability. After some iteration where I double or half the input and react about that these are the numbers I settled on for the X axis, once the changes are in orders of magnitude I accept good is good, hence round numbers. The result: The output is now scaled 100x larger and the error is now visible in relation to each stepcount coming back from the encoders, if we view the square pulse as 2.5 micron, the overall error is in the order of 0.01mm, on a woodworking machine, no worries. This was then repeated on the Y and Z axis to even better results: Y axis: Z axis was a bit weird, but I also had issues with the pneumatic counterbalance as it adjusted to grease in the raceways for the first time in 20 years, if it shows up in machining I may look at these again, i'm betting its not going to..... All the above tuning took me less than an hour, by far the hardest part was finding the correct inputs for the scope, searching google for information is a nightmare, so many Barries harping on for 45min+ on youtube but not distilling the required 2min of info or reams of data sheets written by software engineers (fuck know what methods they communicate in). Once the inputs were confirmed (Cheers Andrew, again) I could dial in on the signal, getting gain/zoom correct, moving forward.

Really wish half the "Engineers" I come across would spend a week with you (but you don't want this) What you achieve with basic tooling they spend weeks trying to draw with every CNC under the sun at their disposal. Very simple work holding and robust strategies, such a pleasure to read and follow.

Ooh, which model? Pics? Andrew has been a massive help with mine (Author 503) getting me up to speed with linux and the Mesa boards, its all up and running now but I still expect fine tuning on the axis scales as i've only calibrated them with a tape measure.

Nah not me there sorry, but I do have access to machines that build such fun things if you have an overly excessive budget.

I am greatly impressed by your perseverance and those subframe bolts are a thing of beauty!

As per previous post (and my partner's disgust) I have successfully carved the official OSCNC test pattern: This brought forward many answers, firstly the original machine coordinate system puts Z+ as moving down, this is a right pain so needed a swap on both Y and Z axis direction to get everything happy. Also found the air blast works really well at scattering chip around the workshop, once things progress further i'll re-install the vacuum hoods. And not so fun, while cleaning out the X axis pulley housing I found cable ties holding the drive cable plug, uh-oh Seems this has had quite a crash at some stage, busting both plugs, replacement cost hurts but have a pair on the way, really don't need that shorting out. for now its carefully back together with additional zipties until parts arrive. And it turned even worse after that, in an effort to clean up the housing better I pulled the ballscrew out, turns out it should not have been pulled out in one piece, the smaller diameter is meant to go out the other side, this took most of Saturday morning to rectify, but everything is clean and back together. Belt is pretty standard AT-10, pic here for reference if needed.... And to finish on good news, walked the dog past Anton's house this morning for a catch up and he lent me this wee toy Beautiful Soviet era tachometer, this confirmed my speed was out by a factor of 1.2, after some digging, I found LinuxCNC is limiting max speed to 10,000rpm, so far I have no idea why, but have scaled back the output voltage to 8.33V@10,000rpm which when asking for 2500rpm gave 2500 on the dial, awesome

Whats backlash? Spent the day digging further into the greasing issues, pretty sure its now getting everywhere, lots of black gunk spewing out onto the rails and its much, much quieter! still have quite a list to do before full operation, but yeah, could start smashing out cabinets if the will to CAD them existed.