I can do it from the side but i think it would be much faster to stradle it and slope it as a go. I've been googling for about a week, issue i'm having is that there all 1200mm buckets and mine is 30 inch which limits cylinder travel quite a bit if i side mount it like most cylinder type tilts, although i see bobcat has a different design where the cylinder is vertical.
30 inch is 762mm, which is rather small for a 1.8t machine, the mud bucket on my 1.6 tonne Kub is 900mm and I have seen excavators in that size with wider mud buckets but they where not as deep as mine.
However with a full load of heavy material in the bucket I have to careful when I swing the machine if the bucket is out a fair way.
This shows the vertical cylinder design
http://www.mascus.co.uk/Constructio...-attachment--42-ditching-bucket/xfycmpvo.html
Perhaps find a wider mud bucket to add tilt function to?
Yes it would be faster to drive the machine into the ditch and work from the bottom of it but if you plan on straddling it sideways, you will be re-positioning the machine a lot and it will be slower than working from the side.
Perhaps you could clarify how you plan on doing the job and some people who have done this sort of thing can advise you on your options. Hard to say unless we know the size of the ditch.
To be honest I cannot see the sense in spending time and money to built a tilt bucket for one job, a job on which you may gain 20-30% efficiency by having a tilt bucket.
I would think that if your machine can reach across the ditch you're best of to work from the top, a 1.8 tonne ex with a 30inch bucket is not likely to tip over, unless you're inexperienced or have to position the machine with one track on the slope of the ditch. If you can easily reach across the ditch, you can use the boom swivel function to clean a fair bit before having to shift the machine.
If you have a quick hitch fitted, you can remove that as well to reduce weight on the boom.