MadModder

Been a while since I updated this thread, but I've been keeping busy.

The printer has been repaired and put back into operation printing out rear axle and suspension parts.  I've ordered and received a bunch of parts and materials that will be needed for the axle modifications.  Two days before Christmas my long lost axles finally showed up, turns out Customs had opened them for inspection and apparently misplaced them.  I contacted the seller, who had already refunded my money, offering to pay for the axles that I had finally received.  On Christmas Eve he told me to forget about it and have a nice Christmas. 

I found out that I am much too digitally inclined to be able to keep track of where the tool bit is on the Sherline, as opposed to where I THINK it is.  So I installed a pair of remote digital readouts on the Sherline.  Hopefully that problem is solved.

Rather than my original fairly complicated plan for shortening the axle shafts, I came up with a simpler one that should give a wannabee machinist like me a better chance of success.  I got some 5mm OD brass tubing with a 1mm wall thickness, which arrived on Saturday.  I'm going to cut a chunk out of the existing axle shafts, turn a 3mm OD stub on the pieces I'm going to reuse, use the brass tubing as a sleeve, and Loctite the parts together.  Now to get back to the axle modifications.
 
Yesterday I cleaned all of the god-awful smelling factory grease off the donor axle parts. I need to make several modifications to the axle shafts and I don't want to be smelling that crap all the time.

I know I need to find some clearance for the spider gears, but how much do I need? I knew that if I backed off the screws holding the ring gear to the spider housing the diff worked as advertised, but how to measure it? My idea was to use the M2 screws that held the spider housing to the ring gear as my indicator. If I count the number of flats as I loosen each screw until I find the sweet spot, that will tell me how far I moved the screw. Turns out that sweet spot is 1-1/2 turns out from tight. An M2 thread has a 0.4mm pitch, so 1-1/2 turns means the head of the bolt moved 0.6mm. I need to take 0.3mm off the back side of the bevel gear on each axle shaft to make things fit right. I think that's right, gonna need to try it and find out.

I also need to shorten each axle by 29-30mm. I'm not sure if that number will be affected by my fix to the spider gear clearance problem. I don't think it will but I need to try it and find out before I start whacking chunks out of the axles.

The part 4:


Celso Ari from Brazil

Yes happy accident :-)

The escapement is certainly operating as it should now , with the extra little push

I'll have you know those crocs went in the washing machine along with my jeans after that job and came out snow white 

Today I sorted out an issue with a land drain that runs under my farmyard. In the recent cold spell we have had an increasingly large 'ice cap' growing in the yard - it got to the stage that visitors children in the holiday cottages were using it for rough skating.


I installed this perforated land drain quite some time ago when we had puddles forming. In the end it actually transpired that the water source was a leaking South East Water main in the road and it was running between layers to this point. The drain cured the problem but then they also repaired the leak!


When I started using my borehole as a source of cooling for my induction furnace it was convenient to draw water from the bore hole, pass it through a heat exchanger and return the slightly warmed water via this land drain some hundreds of feet away to a handy stream. As the bore hole was sightly artesian I arranged that the return pipe also served as an overflow. Now this bore hole was originally used for public water supply but that stopped when they decided that the iron content was too high - BTW it was originally 250 foot deep by 5 foot diameter in 1923 when dug - I've plumbed it to still be over 190 foot deep !


Now I'd always thought that the iron sludge that forms would perhaps block my pipes and I strongly suspected that to be why water was emerging from the course of this land drain and freezing into the ice cap - even several days after the weather has improved we still have a vestigial ice cap !

 

Now I was loathe to use normal drain rods on a perforated drain and instead wanted to high pressure water jet it with a retro-jet that should help to unblock the pipe perforations - I knew that I had one somewhere but not only could I not find it, I knew its pipe was only 25 foot long - OK Amazon what have you to offer?


Well £52 got me this delivered last night:

 

I had to cobble together bits from two pressure washers to end up with a trigger mechanism to start and stop the flow and be close enough to the action - but I got there in the end.


Now when I installed the original land drain I'd terminated it with a rodding eye at the high end so inserted the retro-jet at that point. Perhaps I should explain these things have six backwards facing jets to propel it forwards, and one forward facing to cut through blockages.


At about 15 foot in I come up against something solid - I couldn't get further. Measuring on the ground I was pretty sure that this was where the borehole overflow tee-'d in - blast do I have to dig! Well one last attempt got me though thank goodness to another (but softer) stoppage - working the high pressure hose in an out eventually I heard a fair old flow plummet into the stream. By the time I got to the exit end the flow had diminished considerably but there was a very large patch of very brown silty water going down stream.

 

At this point I wanted maximum flow down the pipe to flush as much out as possible, and of course a pressure washer doesn't create much flow. So I started up the Induction Furnace cooling system that has a flow rate of something like 50 gallons a minute IIRC. Sure enough more silty gunge and had the advantage of slightly reducing the borehole level.


In this image of the bore hole access manhole the green stripey pipe is the pump suction hose that goes down about 15-20 foot to a weighted strainer, and the 32mm MDPE pipe is the flow from the heat exchanger going into the branch in the land drain and thus out to the stream.

 

I left it flowing for some time before packing everything up. This is the retro-jet nozzle:

 


100 foot of high pressure pipe reeled for next time !

 

All together a satisfactory result only needing a brace of Ibuprofen and a hot shower to recover from !