A Milestone of Sorts

Monday morning bright and early off to the body-builder to have the fibreglass skin done.
Finished all the details that are required from the outside (I hope) so clean up and get ready.


























































































Lifted and ready to go . . .























and about an hour later . . .












































































Can't wait now to see the next stage !!

Under The Pump . . .

Well setting a date for someone else to start work on the house certainly (as a friend of mine is prone to comment) "focuses he mind".

Mine started to focus about 2am a couple of days ago.
After spending a couple of days putting in vertical beams everywhere and the roof vent aperture etc. I awoke with the thought that "there is a 60mm flange 3m thick pressed aluminium angle to go all around the top and on each corner riveted every 150mm to the frame and I have built the doors full height with only a 25mm wide face at the top edge. That is not going to work!!"

After a sleepless night I finally got out in the workshop to discover that the doors were about 2000mm high.
They don't need to be that high - tall people can bend a bit to get through.
In fact I have been in quite few buses and in very few of them can I stand upright in most areas.
I think that is why in most of the professionally built versions a roof lift is step one.
Never the less I was able to add a 100m wide architrave at the top of each door and then had to try hard to bump my head going though.
It actually required a little lift up on my toes to manage and I'm 1830mm tall so I think it will be fine.

The motorbike ramp idea I mentioned previously will (I'm sure) turn out fine.
The winch I ePurchased the other day has arrived and looks just fine.
I expected a "Made in China" version (and it may well be) but I cant find a single reference to any Asian country anywhere.
All the standards marks and instructions are in European languages (mainly German) and while compact, which is what was required, looks quite substantial.
All of this made me realise I needed to pay attention to the actual attachment points for all this hardware.
Having a good look made me realise that in fact apart from the new pivot points added the rear was rather flimsy.
I didn't fancy the idea of a 120kg tyre and wheel combination, or two of them even, hanging on the back as it stood.
Actually standing was not a problem - quite small components can support quite large weights - but any movement, particularly a couple or tens of thousands of kilometres of corrugations can break just about anything.
This needed serious attention.
Firstly a beam was needed which could actually stand up to that sort of punishment.
There was some left over 150mm x 50mm x 3mm RHS from the main longitudinal beams which carry the entire house. If that wont do it then the whole structure will collapse anyway.
So a bolt pattern was set out that will support some adapters which penetrate the fibreglass but not allow leaks (more on that another time) and will actually carry the mount for the wheels.
I made a little mistake some time ago when I bought the tyres and wheels and missed out on two good second hand spares and was forced to buy a single brand new spare.
In the hope of maybe later finding another spare (or as a last resort buying one if/when needed) I set out two patterns for carrying one wheel in the middle or two side by side.
As the corner posts were not originally originally intended to carry the load the two inner posts were removed and some new 75mm x 50mm x 3mm posts substituted to transfer the weight down to the lower beam.























This solved the problem of weight and vibration for the wheel mounts but left the upper cross beam a little weak for mounting the necessary pulleys for lifting everything up and down.
Out with the angle grinder again . . .


















Actually it got really frustrating there for a while and I had to go across the road to my neighbour as I no longer own a HACKSAW and an angle grinder just wouldn't quite get to the part I wanted to cut out.
Talk about desperate !!
















A new 75mm x 50mm x 3mm beam was then welded in right across the top, which will incidentally help with the flexing problems as well.


















And a couple of extra pieces with "rivnuts/nutserts" in place and the final struts for panel support added as well.


















That leaves just the intermediate struts below the main beam for later and we're are almost ready to go.

Friends. You Can't Do Without Them. . .

Sometimes . . .

Nearly every day this week involved one or more friends dropping round and chatting for an hour or so.
I keep telling myself that's what it's like when you are "retired".
But I sort of have these plans . . .

Mind you sometimes I welcome the break.
Climbing all over this house part is getting quite strenuous.
I have been putting off doing the roof part because the welder only just reaches to the centre from each side and for the tricky parts I need to lift it on the fork lift.

So . . . DECIDE . . . JUST DO IT !!

This raised the question (which has been sort of running around in my mind anyway because of the gas regulations which require a minimum amount of non-closing venting) as to whether to have a roof vent. Although I am very partial to air conditioning I have this vision of going to sleep with everything closed up (ducted refrigerated air conditioning) and waking up dead due to lack of oxygen!!
It turned out to be convenient because "Sich" also wanted to get some "stuff" for his bus. A pleasant morning but with driving and then coffee which turned into an early lunch (mutual decision) there goes another half-day.

Sich has an all singing all dancing automatic rain sensing self closing satellite controlled whatever type of roof vent for his bus. I thought it was a bit over the top and the price too but it turns out if you want anything but a piece of crap you are going to have to pay about $400 !!
So after looking at quite a few the inevitable "FIAMMA" brand was decided upon.
This is a manual opening and closing type but has a shape which will cause negative pressure when travelling and hopefully keep the dust out (from this point anyway - it may well suck it in elsewhere . . .).
It also provides even when fully closed a labyrinth vent which is completely rainproof and helps to meet the gas regulations.


















Finally back to the roof frames which now have to accommodate fitting this item in.
Again the inevitable "rivnuts" seems like the best idea so they are fitted into a frame made on the bench and then the whole frame offered up to the roof and welded in place.


















And again from underneath.
As you can see this completes the roof main beams and there is only the cross bracing to do.










Finally with all the rest in place there is just a lot of detail work left to be done.
This is from the front.
The large low "window" type opening is just in case.























It aligns with the rear windows on the truck.
Many of the truck mounted motor homes have an access passage between the cab and the house. Although it is not legal to wander around he house while travelling it is generally included as a safety measure. There are apparently some places and situations in which it may be advisable not to exit the house but just to get in the cab and drive away.
In exotic travel situations it is advised to have the camp packed up each night so that it is possible to drive off like for example if somebody is wandering around outside with gun !!
In my case with the tilt cab it makes such an arrangement rather difficult but I have avoided putting any structure in the way just in case I manage to find some windows which can replace the truck cab windows which can be opened for emergencies. In that case I will cut the hole in the house and fit a matching escape hatch. In the mean time it is behind the cab out of the wind so it's lack of strength will not be a big drawback.

After all that climbing around for couple of days my back needed a rest so I decided to finish off the bed control mechanism.
I have managed to build it so far with reasonably readily available car parts so decided to keep with that theme.
While lots of clever electronic bits are available they are not easily sourced in out of the way places. I opted for simple car type relays and switches and analogue controls so if anything goes wrong in all likelihood a simple trip to the local car wrecker will provide replacement parts.
There is a minor complication in this circuit in that both the active and neutral wires need interruption as both need to be reversed to make the motors run backward. Normal car relays are single pole so you need to have two - one for each wire and drive them simultaneously. This leads to double the number of components but at $8.00 each brand new its not too much of a problem.
Until the proper fascia panels for the circuit breakers and indicators and the active and neutral bus bars are fitted I just mocked it up on a piece of plywood to keep it all together.





































It works fine but I was a bit perplexed for a while by some switches which turned OFF when pressed in the desired direction rather than ON . . . seemed a bit strange.
Ended up using a three position switch instead UP - OFF - DOWN seemed logical.
Not visible in the picture is the in line fuse holder.
I couldn't find the fuse rating on the motor vehicle wiring diagram from which I took the wiper motors but I assumed they would be fairly substantial - maybe 15 amps.
Running two in parallel would require probably double.
The relays are rated at 30 amps each so they would be OK so I added a 30 amp fuse to start.
Being an inquisitive sort I wondered what sort of current was actually required. Being too lazy to set up a proper meter I decided a $0.50c fuse would be a cheap way to find out so I started replacing the fuse with 5 amp smaller versions in steps . . . when I got down to 10 amps with everything still running OK I decided to leave it there. . .

Lastly there were the limit switches to stop the movement at each end of the travel so it can just be switched up or down and left ( it takes approximately 75 secs to raise and 60 secs to lower - but if I cant wait that long it's going to have to happen on the floor) and can't be switched in the wrong direction and be over driven and break the mechanism.


















It's going to be a tricky little exercise to find a way to make them inconspicuous.

Well at least it is now convenient to operate.

Tomorrow back to the welding.

The deadline to be ready for covering is rapidly approaching . . .

Good Ideas !!

My neighbour (the one with the boat) was looking at the "house" a couple of days ago and was wondering why I was about to attack the back end of the house with an angle grinder.
I explained that I was about to put in all the reinforcing I thought was necessary to lift up and support my motorbike and spare wheels (which are enormous) on tracks on the back of the house. It was going to require substantial track mounts, winch mounts, pulley mounts, locking clamp mounts etc at the top edge to enable the required platform to be winched up and then secured in place.
My truck does not have a hydraulic PTO fitted (a regretful oversight of the previous owner) or I may well have considered a commercial tailgate lift which would have solved a multitude of problems!
He suggested instead that some sort of arm could perhaps be used.
I rejected the arm as not practical but it did inspire some further thought.
I remembered the folding ramps on the back of low loaders for driving equipment on and off and it occurred to me that a similar arrangement (although mounted sideways) lifted by a winch (see at the end) and pulley system would do the job perfectly and have numerous advantages, not the least of which is the mounting system is all low down in the strongest part of the house. And if I was a "little bit clever" it could be arranged to be swapped left to right for safety in LHD/RHD countries (similar to the doors, one on each side).

Some quick measurements determined that it should all work and the previously purchased tracks and rollers etc. have been relegated to the "next shed door track box".
Some bushes were turned up and welded into some 150 x 50 x 3 RHS which would fit neatly into the back wall and provide the mount shaft for the ramp.
This shows the bush from inside the generator bay (with a dummy pin in place to hold up some aligning beams on the outside).






















Like so :














A shaft was also turned up with a thread on one end which will enable it to be locked firmly in place when mounted in the bush. This will have a pipe sleeve over it to which the ramp will be welded. You cant see the bush from the outside here as the aligning beams cover it all up while the RHS is welded in place.



















All will be revealed as progress continues.

As not much more than 10 days remains until the outside fibreglass goes on as much progress as possible (given the lack of material delivery) has been made with the overall framing.


















Fortunately just at the end of the day the remaining tubing turned up on the truck so full on tomorrow!

I don't know how this is going to work out but I found this on the "NET" the other day. It is marketed in Australia from a mail order house only on the other side of the country and given the price it may well be "foreign junk". (I really did try to find one locally . . .)
But at $160 delivered - you have to at least give it a try !!

It Helps If You Know What You Are Doing . . .

Well it would help if I knew what I was doing!

I had just abut finished welding in all the bits and pieces necessary for all the utilities which needed access to the outside.

Then it dawned on me that given the nature of the cladding, requiring angle trimming on all cutouts, I couldn't space the openings vertically in the manner I had (already) as there was not enough width for the hinge and the trim piece over a strip of fibreglass and ply only 25mm wide which was all I had allowed.

After much head scratching and almost deciding to cut it all out and do that bit again sanity prevailed and I modified it with additional tubing welded into place. It will all be covered with the external cladding from the outside and wall lining from the inside.
If you stood on your head inside the bins you would be able to find the evidence in the space under the shelves - good luck!

So by 5 pm I was about back where I had been at lunch time.























Level 1
The vacuum toilet base in the bottom left corner.
The mounting base has yet to be trimmed to the correct size and the spare holding tank installed alongside.

The water pump needs the same height as the toilet base so it gets installed in the other corner. Not sure what will go in the space left there.

Level 2
The hot water storage tank on the left facing out to the front behind the cab.
Two gas bottles immediately adjacent.
There needs to be a sealed box around the gas bottles which will get built when the walls are put into position.

Level 3
The air conditioner is installed slightly differently as it does not have an opening lid but has a "fixed" fascia which is fully louvred.
In order to protect this a little it has been recessed back into the wall 25mm so there are no protuberances outside the external skin.
There is a space to the left of it which will probably be used as a small cupboard accessed from inside the "bathroom".

Level 4
This will all be cupboards accessed from the bathroom.

Final bit of framing to be welded in around the air conditioner and then the remainder of the wall and roof struts which have been left out for convenience of access during construction.

Then the whole thing will be stripped out and the final finishing treatments for all the bin areas applied before the false floor is fitted.

Now if I could just anticipate some of these construction issues things would go a little faster. . .

Going to Hell in a Handbasket . . .

I was just sitting here doing a bit of this while waiting for a truck to deliver some more steel tubing I need to complete the framing. . .

I've been waiting since WEDNESDAY LAST WEEK !!!

Wait a second . . . the truck has just arrived . . .

I can't believe it !!

The truck didn't have my order on it and the driver does not remember dropping my stuff off anywhere else . . .

They'll try and sort it out tomorrow.
I had less trouble when the world was busy !!

I planned to work over the long-weekend but with no material I decided two days as boat crew was far preferable. Couldn't have wished for better weather but not much work gets done that way.

Failing material for new work I decided that a bit of finishing off was in order so (NOT AGAIN!) the bed frame was stripped out and narrowed by 10mm. It had been annoying me for some time. It was made first and the tracks put in around it and never having done a similar item before I aligned all the wrong things and consequently everything after that was just a little bit off. It came to a head when trying to fit little brackets and springs to the chains ( to provide correct tension to the chains to keep them back in the track and not get grease on you if you lean back against the track) and I could not get a rivnut into the tube as it was right on the edge!!
Narrowing the frame by 10mm fixed all the problems.


















Next was trying to do what I could with the little bit of material on hand.
I was also getting a little annoyed with myself in not being able to arrange the hot water heater, gas bottles, air conditioner etc in the required space without encroaching on the bathroom more than I wanted. The main trouble was the water heater was much longer than all the other items and then had its fittings in the back. A sudden rush of blood and it occurred to me that it was much narrower than it was long and perhaps I could mount it sideways??? This would put the opening just behind the cab which was OK as there was a a vent cover which protruded a little more than I liked anyway and that would put it out of the way. The only problem was I would need to take the whole house off the truck if I needed to get at the hot water system to service it!!
Wait a minute . . . what kind of idiot am I ???
The truck has a tilt cab !!
Just tilt it out of the way . . .
For once something goes right !

So frame up the opening and put in all the rivnuts to screw it down.


















It's difficult to see there but the holes were also drilled right through so that when the skin goes on I will be able to drill pilot holes through from the back without ruining the fibreglass by drilling in the wrong place searching for the rivnuts.

Some additional pieces I found allowed me to also frame up the front of the bin opening for the gas bottles - bearing in mind they need to be separated from everything else and have venting for any leaks - and to start on all the floor bits for the bathroom.


















I'm actually quite happy with how this part is turning out now that I am into it and if the truck turns up first thing tomorrow ( as promised - again ) I will only have the air conditioning to traumatise about then.

Now Where Were We ???

Life is what happens while you are making plans

My old clunker computer is gone and my flash new laptop (used as a desktop most of the time ) is installed with a second screen for added "visual real estate" which makes a big difference being able to have more things visible at the same time.

All my software and licenses are transferred and up to date. Now there's a fun game if you have any Garmin devices, mine include a GPSmap60CSx, nuvii 760 and soon an ex US military hardened laptop running real time navigation software with topographical maps. And that of course doesn't include all the commercial stuff like accounting, office, drawing, photo, iTunes/iPhone/iPod, geocaching etc.
A fun time was had by all !

Tax finished - my part anyway !
The accountant has to do his bit now.
But the first part of tomorrow morning is blown while
we make sure the story is the same for both of us.

Then one of my old customers begged, pleaded, cried and finally won me over when he promised to pay money in order to get a job done. He wanted some parts made for his plastic extrusion machines in a special grade of stainless steel. Like this :


















I didn't really want to do it as it means I have to start up a machine which has been cleaned and parked while I work on the truck "house" and then clean up after so it wont turn into a pile of rust while not being used. Still I promised . . . .
I wouldn't have minded so much except that after working until about 3:30pm, cleaning the machines again and then delivering the parts I got a phone call about 5:00pm . . .

"Hi"

"About those parts you made for me . . ."

"Yes . . ."

"Do you think you could do another set ?"

"It would have been nice if you ordered them all together . . . "

"It's not that. I just tried to modify them slightly and I sort of ruined them . . .
Could I have some more tomorrow morning ????"

"AAARRRGGGHHH !!"

So finally back to the plan . . .

Finally starting to work on the utilities portion of the house.
It occurred to me that with my friends and other buses etc. their initial configuration determines pretty much where things can go. Generally they are fairly "widely" separated.
This can have a few advantages. Most components even when made by the same manufacturer have very different front panels, mountings, fittings, sizes etc..
If you are mounting them away from each other this isn't too bad as generally there is a space somewhere and if necessary a hole is cut in a side panel and the manufacturer's front panel screwed on and nobody notices.
With my arrangement all these things are alongside each other and trying to work out how to arrange the framing is proving to be somewhat problematic.
I have also been talking to a truck body builder who has quoted on fitting an outside skin of fibreglass bonded to plywood with all the corners capped with 3mm aluminium pressed angles sealed and fastned with countersunk rivets.
This will produce a great finish and speed the whole project up a bit - the only drawback is that any and every cut edge has to be finished with a sealer and reinforcing angle - which doesn't necessarily suit mounting any particular item !!
Just another little complication.

In addition the ablutions area needs several changes of floor level to accomodate toilet pedestal and shower base heights.
All in all it's challenging my spatial relationship visualisation abilities.
I know there is a key to it somewhere -
if I just start at this point it will all fall logically into place.

Well we live to dream . . .

Also I can't believe that the manufacturers of these components (for caravan / motorhomes) who know these things are going to be fitted in tight awkward places can manage to place their fastening systems in such difficult and out of the way places !!

So for the moment I have positioned the vaccuum toilet base station, water pump, water heater and gas bottles. I just have to finish the framing around them and I can put the air conditioning above that.

So from the back :























and from the front :























Now if I cn js t learn to tupw on this laptop keybord I';ll be hapy . . .

Mea Culpa Mea Culpa ...

Short weeks, a new computer (I can't believe I used to deal with these things for a living !!) and my accountant telling me I have to finish my 07-08 tax by the beginning of next week all mean that I haven't even been out in the workshop this week !!

I apologise to anyone interested in the lack of progress but I am hoping for a concerted push beginning next week as I realised, from doing my accounts that I bought the truck last July !!!!!!!

I try to convince myself that real work didn't begin until very late in '08 so I am "not doing too bad" but I am a hard person to convince . . .

Still tomorrow a guy who does fibreglass truck bodies professionally is coming to look at my truck to see if he wants to do the covering bit for me . . . that ought to speed things up !!

Christian / Pagan Festivals . . .

Easter Holidays . . .

I learned many years ago never to travel on the roads at Easter.
It's long enough to tempt people to try and go further than they should in the time available. Combined with double demerits : a guaranteed recipe for disaster .

The idea for me is just to do whatever comes into mind without trying to set targets for work to be done etc.. Just do whatever at a relaxed pace : including nothing at all if that appeals on the day.

My neighbour was taking his boat to Rottnest and invited me along to go diving but unfortunately a cold put paid to that.

So it was just pottering work as the mood took me . . .

First thing was to put the second motor I had obtained to work.
The first idea nearly caused a disaster!
I intended to put one motor on each of the primary drive gears. It would require that one motor worked backwards while the other went forwards. Not a real problem as these DC motors can run either way and in fact run one way to raise and the other to lower. I wired them up to do this while they were loose on the bench to make sure it would all work OK.
Not a Problem.
Now bolt them in position and try it . . . lots of blue smoke.
Both from the motors and the following long strings of rude words.
I had completely forgotten that the frame of the motors was part of the circuit and bolting them together made an electrical connection between them so that when I put a +ve cable on one and a -ve cable on the other I had made a dead short!!
Liable to melt things if not stopped quickly.
Fortunately no damage was done and the motors were still usable.
Implement plan "B" !!
Both motors driving on one primary gear in the same direction.

(Sorry about the green cast in all the photos but I had the overhead lights on and I set the camera white balance to match to try and get the colour right but apparently that just makes it worse!!)

The motors are mounted against the back wall between the main beams which is just wasted space anyway. Wiring is very temporary at the moment just using the original car harness as cut out of the wreck.
From the outside - to be sheeted over.















and from the inside of the storage compartment under the floor where it will have a partition between it and the rest of the compartment (to keep things from getting jammed in the gears :) ).


















The next thing on the list was the brackets connecting the chains to the bed frame. They were modified from the original experiment with cords by having a threaded bush welded onto them. All in all not a very pretty solution. So new ones were milled out to a more elegant shape and altered in order to position the chains further back into the tracks so no grease would get onto you if you leaned back against the track. The wire was temporarily holding the other end of the chain before a spring was fitted. (Flash changed the colour cast again!!)























A spring was fitted which showed that a different attachment method was also required here to also position the other half of the chain back into the track as well. So that's now on the to-do list for tomorrow as a different shorter spring will be required and I can't get them until Tuesday.























I also went around and measured each corner of the bed frame from the floor and discovered that I had about 25mm difference between some of the corners. This would have added to the effort required of the motors as it all needs to be "square" to minimize effort. It took about an hour to get all the corners at the same height and with the same tension on all the four chains. Thank goodness I had decided to put in the adjusters.

After all that another load test was in order.


Just a small portion of the run up and down.
It takes 70 sec's for up and 60 sec's for down.
Just about perfect I think but it's too long to stand and hold a switch for the full travel. So the next item will be proper wiring with "UP" and "DOWN" switches and limit switches at the top and bottom to stop it tearing itself apart when you turn on the switch and then get distracted!!

Parked at the top of the "up" allowing for mattress and bedclothes etc.. It will have a timber valence all around to hide everything during the day.


















And with a temporary seat just to make sure that head room is adequate when using the "dining area".























The seats form the main storage areas for outside. One for the generator and one for all the outdoor living necessities like barbeque, small table and a couple of folding seats etc..
The eagle-eyed will notice I have changed sides with the generator as it looked like too much weight was going to one side and I believe the off-side will be better served with the outdoor equipment. Two birds with one stone. Also the floor area under the table between the seats hinges up and gives access to quite a large storage area which is only accessible from in side.


















There is an ingenious moulded hinge (which I am not sure if I have mentioned previously, anyway . . .) made of some miraculous plastic and rubber materials which flexes like crazy, supports good loads and lasts through millions of cycles. I am going to use it outside on all bin doors as it is stylish, waterproof and simple to install. What more could you ask for.




















I'm also going to use it for this lifting floor section as it will be unobtrusive and being impervious will ensure no wet, muddy or sandy materials can get into the storage area from this arrangement. A sample piece is inserted here for spacing calculations. From the "outside" it is quite unobtrusive as it is only about a 2mm protrusion.


















Quite happy with progress for a holiday period :)

KISS (Not the Musical) . . .

From the torque tubes the drive needs to be brought down to a point where it can go horizontally into the centre. The main back cross-beam seemed like a good idea and the easiest way to turn the corner without multiple idlers etc. was to just make a double simplex sprocket and mount it on the cross beam.























All this really does is allow the drive to change direction 90 deg. without idlers.
The simplest way to mount these was turned spigot which goes right through the sprocket and is bolted to the back beam with a washer just as a safety precaution (although its all sort of self-aligning unless something is mounted out of skew).
















The beams here are only 3mm wall thickness which is adequate for the strength required of the structure but is not a lot of metal into which to tap a thread when there is likely to be forces of 50+ kg in two direction sideways.

Enter the "rivnut".


















These are, as the name suggests, a combination rivet and nut.
The ones in the photo here are for 8mm bolts.
An 11mm hole is drilled and the rivnut inserted and then tightened with a special tool


















which causes part of the serrated body to expand and the area immediately behind that to collapse outwards as in a "pop-rivet".
The tool is removed and the rivnut can then have a bolt inserted capable of significant loads.























Of course it's easier if you have one of these.


















But unless you have a lot of use for it the extra mortgage probably makes it not worth while.

So now the system looks like this. The extra small gear at the top between the two black ones is a temporary arrangement merely to take the load off the motor by jamming the two gears together.











About ready for a trial run.
The first run up was a great relief.
Travelled smoothly with just a little motor noise and not much else.
Whhheeeee !!!
Then I thought I better load test it.
It was quite OK for me to climb all over it (and bounce a little) while it was static.
Not that it was ever intended to support anybody's weight while elevated or moving.
It's intended to lower it right down onto the seat units for actual use.
However it will have a cosmetic valence, mattress, bedding etc. all adding weight.
The whole idea is to NOT have to deconstruct the bed during the day!
So some load testing seemed appropriate while in motion.
About 50 kg of additional weight was added and tried again.
The system worked fine but the motor gave indication of being under quite a high load.
After debating whether to pay somewhere between $400 and $800 for a new higher torque motor it occurred to me that I can just add a second motor of exactly the same type and run it in parallel.
It's like carrying a spare and using it all the time just to make sure it's not really needed - if you can see what I mean ???


















The only other issue the loading brought to light was accentuating the slack on the non-working side of the sprockets. If this gets too much it can cause the chain to jump a tooth one one sprocket and all the alignment gets out of whack. Believe me (it did happen at one point) it is a pain to fix !!

So in the spirit of the KISS principle (and throwing out hours of thinking about complex tension adjusters) the simplest possible method I could come up with was an eccentric! Seeing as this all moves quite slowly (about 1 minute for full down to full up) it doesn't have to be super flash.


















Works a treat.

Tomorrow off to the wreckers for another $60 motor and it should all be working well.

Now all I have to resist doing is tearing out the guide rails and modifying them to be bolted in (instead of welded as they are now) so they can then be powdercoated instead of painted.

They would look rather nice then.
(And I could fix that rather scrappy grinding out of the upper section where the pulley had to be relocated).

I just have to keep saying to myself -

"If it ain't broke - don't fix it!"
"If it ain't broke - don't fix it!"
"If it ain't broke - don't fix it!" . . .

Slow and Steady . . .

I think there is a lot more "slow" than "steady" going on for some reason lately.

I'm putting in the hours but when I look at what gets done
I start to wonder if I'm in a "Twilight Zone" where someone
is stealing hours out of my life.

Mind you I have an acquaintance who believes he sees UFOs !!!!
He keeps sending me photos of what looks like blobs of light
in various places which he is convinced are UFOs.
If he disappears some time maybe I'll believe it . . .


To continue :

In order to keep weight down I decided to use a tubular shaft between the bearings on each end of the drive. As it all is supposed to work in synchronisation in order for the bed to stay level the shaft needs to be fairly rigid but there is no point in carrying extra weight. 22 mm OD with a wall thickness of 1.6 mm seemed about right.


















In keeping with the re-embraced KISS principle simple sleeve bearings from acetal were turned and pressed into simple pipe supports.



















These were lined up by use of the shaft itself and tacked into place.
Spins in your fingers . . . luverley !!


















Now of course comes the tricky part :
a single motor has to provide drive to both shafts (one each side)
each turning in the opposite direction.

Having decided that the original motor is not quite strong enough
to lift directly some sort of gearing is needed in order to lift the weight.
While commercial gearboxes etc are readily available
they are not necessarily inexpensive and still don't solve the
problem of two drives in opposite directions.
For example a visiting sales rep the other day suggested using
a "roller door" drive. Absolutely perfect at first glance :
powerful, self programming for limiting rise and fall and provides
the output via a chain.
And only $800 !!!!
Of course not the size chain I elected to use
(only because I hadn't thought of a roller door drive - DUH!).

So after much thought and trepidation and because
I have more time than money to waste at the moment
I decided to build it custom!
Completely ignoring my own rule :
"If you can buy it - don't make it."
Of course on that basis I would just mortgage everything I own
and steal a bit more and buy a UNICAT.

Back to reality . . .

First to provide two drives in opposite rotations :
just put two gears together and the shafts go opposite ways.
I am sure that I have seen little "gearboxes" somewhere that have
one input shaft and two outputs in opposite directions -
but I can't remember where the hell I saw them.
But I used to design and make sprockets and gears recently
so why don't I just make some to do the job.
Unless you have very specific tools and machinery making
things less than a certain size is almost impossible so what I
have dictates the size to a considerable degree.
As it will be built into it's own compartment this is not a very big problem.
For me (and I am sure I mentioned it before) acetal is an amazing product.
Strong, light, easily machinable and slippery, and
I have some left overs that will probably come in handy.
Of course not having done this for a while it took a bit of stirring
of the grey matter (and a computer disaster when I accidentally
destroyed the spreadsheet I created to calculate all the important
dimensions and shapes for sprockets while adapting it to do gears.
But that's another saga !!)
I also originally decided to use aluminium for the drive gear off the motor as a mental lapse caused me to think that that would be the gear with the highest loading.
Of course it is the lowest loading!
That's the whole purpose of the gearing in the first place.


















I'll remake that in acetal tomorrow.
Now it's all set up it will only take 20 minutes.
So the primary part of the drive layout looks like this:


















I still need to get the drive over to the shafts from here by chains so I will also make some chain sprockets which will bolt to each gear to provide the chain drive.
While I was at it I thought I would also put in another level of reduction so another set of sprockets was quickly whipped up to do this.





















They wont be used exactly in this arrangement but it gives the idea.
Yes. I could have used another set of gears but then the mounting of the shafts for the gears becomes problematic in order to provide proper meshing etc. and chains are so much more adaptable in this regard.

This arrangement will allow me to stretch it all out across the back of the "house" in the lower part of the rear wall all out of sight when finished.

Hopefully tomorrow will allow for a test run and another day to get this whole saga over with.

Then on to stuff where it actually looks like progress.

I know this all seems like a huge shemozzle for this part but the lifting bed is an extremely important part of the design in order for the whole house unit to be kept compact enough to go on the truck without modifications and into a sea container for transport.

I just have to keep reminding myself of that basic overriding premise.