Garden Project - Maths help needed
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slowmotion
Quite dreadful
- Location
- lost somewhere
I really wouldn't use any sort of mechanical guide jig with a hand-held angle grinder or disk cutter. If the disk binds in the cut, you could have a really nasty accident. Freehand cuts with the same tool are a lot safer. Use the blade guard of course.
Seevio
Guru
- Location
- South Glos
Disclaimer: I've come back from the pub so I may be missing something.
Radius (r) 90 inches = 2286mm
Circumference = r x 2 x Pi = 14363mm
If you only have 10 slabs, the minimum inside length of these slabs is 1436.3mm or 1.4363m.
I reckon you're going to need more or bigger slabs.
The pic suggests that 90 inches would be a bit of an exaggeration for the radius but even if it is the diameter, your slabs are too small.
Radius (r) 90 inches = 2286mm
Circumference = r x 2 x Pi = 14363mm
If you only have 10 slabs, the minimum inside length of these slabs is 1436.3mm or 1.4363m.
I reckon you're going to need more or bigger slabs.
The pic suggests that 90 inches would be a bit of an exaggeration for the radius but even if it is the diameter, your slabs are too small.
Two comments.
1. The pond looks lovely as it is. What is the feature - the pond or the fan shape?
2. Once you have decided on the right dimensions could you make some scale models to check they fit? Or could you start with the scale model and scale up from there (could be a lot of guesstimating, I guess!
Hope you enjoy the pond when it's finished.
1. The pond looks lovely as it is. What is the feature - the pond or the fan shape?
2. Once you have decided on the right dimensions could you make some scale models to check they fit? Or could you start with the scale model and scale up from there (could be a lot of guesstimating, I guess!
Hope you enjoy the pond when it's finished.
Profpointy
Legendary Member
a full scale cardboard model is an easy way of banishing cock-ups before taking disc to concrete
Levo-Lon
Guru
Template would be a good idea..for a idea of angle
when ive had a curve to do with rectangular or square slabs i have 2 options i use.
one way is to cut both sides of the slabs..pita job..but allows for a neat 10mm joint which you want rather than a taper..
the other way is to use a brick or block paving to achieve the curve.
its so much easier to get a nice neat mitred cut with a block than a slab.
disc cutter would be fine though id use a block splitter for cutting blocks.
try not to get too hung up on the maths...its all about looking right to the eye...
so cut your slabs or blocks and jiggle it about until it looks right..
once your happy you can then set and point..
Pond looks great btw.. nice job,love the cobblestone path
when ive had a curve to do with rectangular or square slabs i have 2 options i use.
one way is to cut both sides of the slabs..pita job..but allows for a neat 10mm joint which you want rather than a taper..
the other way is to use a brick or block paving to achieve the curve.
its so much easier to get a nice neat mitred cut with a block than a slab.
disc cutter would be fine though id use a block splitter for cutting blocks.
try not to get too hung up on the maths...its all about looking right to the eye...
so cut your slabs or blocks and jiggle it about until it looks right..
once your happy you can then set and point..
Pond looks great btw.. nice job,love the cobblestone path
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biggs682
Touch it up and ride it
- Location
- Northamptonshire
Cant see any frog spawn so that cant be a pond
oh and sorry i cant help with the maths
oh and sorry i cant help with the maths
Levo-Lon
Guru
@User9609..your cutting Q
id use a disc cutter rather than a grinder..strip of wood on the slab held with foot.
then a quick run over with a diamond blade to get the line..then remove wood and cut safely with foot out the way, use a steel toe cap boot with a saw..
if the slabs are very hard you may need to wet cut? Blade may start to bounce and struggle to cut as it gets hot. Good blade will help
id use a disc cutter rather than a grinder..strip of wood on the slab held with foot.
then a quick run over with a diamond blade to get the line..then remove wood and cut safely with foot out the way, use a steel toe cap boot with a saw..
if the slabs are very hard you may need to wet cut? Blade may start to bounce and struggle to cut as it gets hot. Good blade will help
- Location
- Manchester
Put some frog spawn in the back pond and it will be those frogs that will use it next year.
Don't cut the slabs at all. The fan shape you have laid out looks good as it is. Fill the gaps with gravel or plants. Less waste of the slaps, your time and your energy. Less risk of mistakes and injury. Less wear on the tools.
Don't cut the slabs at all. The fan shape you have laid out looks good as it is. Fill the gaps with gravel or plants. Less waste of the slaps, your time and your energy. Less risk of mistakes and injury. Less wear on the tools.
[QUOTE 4210404, member: 9609"]doing it by degrees and establishing an angle is a good way of doing it, never thought of that. I was doing it as a percentage on the grounds that at 0mm out from the center the width would be 0mm and at 3.5m out it would be 448mm therefor everything inbetween would be propositional in a linear sort of way - seems obvious in principle but would feel a bit silly after cutting everything to find out my theory was flawed.[/QUOTE]
You are doing similar triangles, so your numbers are fine. Sometimes its worth getting the angle as well (although all you need is the length ratio - tan) as this would tell you that if you had 10 times as many slabs, you could do the whole circle (and keep yourself very busy).
You are doing similar triangles, so your numbers are fine. Sometimes its worth getting the angle as well (although all you need is the length ratio - tan) as this would tell you that if you had 10 times as many slabs, you could do the whole circle (and keep yourself very busy).
Levo-Lon
Guru
[QUOTE 4210440, member: 9609"]Path is just stone out of the fields, some nice colours and itf free.
These are just 5 slabs that were never originally used (3x2s) pity I started cutting them in half to form a steppy stone type path, and now want to form them into a very small little patio in a fan shape to match the curve of the pond. My big concern is the accuracy of the cuts, I want neat 10mm joins, and if some are 7 mm and others are 12 then it may look very diy. so I am going to have to be very careful and accurate with my cuts, cut easily cut them out of wood to that accuracy, but full thickness paving slabs may be more difficult.
anyway, going to dig the pit out the day, 6 to 7" deep, leaving 3" hard core, the 1½ sharp sand cement then the 2" slab .... does that sound reasonable ?[/QUOTE]
yes that will be fine..
i know what you mean with the joints But if you wet point them with a 3to 1 mix they will be right. As colour will be close...
try a flat trowel finish rather than a pointing iron..again it will look better. Try to finish the mortar edge with a fine line..run the trowel along the joint at a 45° angle or less
a couple of mm looks worse with a soft joint..plus it shows up the exposed cut edge.
These are just 5 slabs that were never originally used (3x2s) pity I started cutting them in half to form a steppy stone type path, and now want to form them into a very small little patio in a fan shape to match the curve of the pond. My big concern is the accuracy of the cuts, I want neat 10mm joins, and if some are 7 mm and others are 12 then it may look very diy. so I am going to have to be very careful and accurate with my cuts, cut easily cut them out of wood to that accuracy, but full thickness paving slabs may be more difficult.
anyway, going to dig the pit out the day, 6 to 7" deep, leaving 3" hard core, the 1½ sharp sand cement then the 2" slab .... does that sound reasonable ?[/QUOTE]
yes that will be fine..
i know what you mean with the joints But if you wet point them with a 3to 1 mix they will be right. As colour will be close...
try a flat trowel finish rather than a pointing iron..again it will look better. Try to finish the mortar edge with a fine line..run the trowel along the joint at a 45° angle or less
a couple of mm looks worse with a soft joint..plus it shows up the exposed cut edge.
twentysix by twentyfive
Clinging on tightly
- Location
- Over the Hill
