Jump to content

Measuring Roof Curve?


Doodlebug

Featured Posts

Hi everyone,



I am almost finished with building the website for my top boxes, but have realised that every boats roof has a different curvature.



I am going to need to get people to measure the curve of the roof, and am trying to think of the easiest but most reliable way for people to measure them. The best way I can think of is to lay either a straight bit of wood, or stretch string so it just touches the top of the arch, and then measure down from the end to the roof, so that I know how large the curve is.



What do people think? It needs to be simple so everyone can do it correctly yet accurate enough so they fit!



Thanks as always,



Doodlebug


Link to comment
Share on other sites

I think the easiest way is to get some ply and hold it across the roof, the put a pencil on a block of wood ensuring that the pencil will go no lower than the bottom of the ply and then run the pencil block across the roof giving a profile on the ply.

 

This, however may not help the mail order business aspect. I wonder if you send out a bit of stiff card for every order it could be done?

Link to comment
Share on other sites

Card was a possible idea, but then I thought its no harder then measuring it. Would I send a pre-cut curve and they adapt it, should I ask them to cut it to the right shape then send it back? Or just mark on with a pencil?

 

Thanks!

Link to comment
Share on other sites

Liverpool shells seem to have the most curvature in the roof amongst the clone boats. There weren't many of my shell built, but you are welcome to the measurement should you need it.

Do your boxes "curve" underneath to fit the roof? I made my top boxes on four short legs/feet to avoid that problem. If I went into production I would make these adjustable.

Link to comment
Share on other sites

Card was a possible idea, but then I thought its no harder then measuring it. Would I send a pre-cut curve and they adapt it, should I ask them to cut it to the right shape then send it back? Or just mark on with a pencil?

 

Thanks!

That's called Spiling and is probably the most accurate method as it will follow any odd humps or depressions.

And old Springers had V profile roof's.

Link to comment
Share on other sites

Hi,

 

Use a technique called scribing. Put two wooden blocks - one each side of the roof and each the same distance from the centre of the roof. Rest a flat piece of thinnish plywood on edge across the blocks (it will need to be about 7 ft long). The side blocks will have to be high enough for the piece of plywood to clear the centre of the roof. With the plywood and blocks held firmly in place look at the gap between the side of the roof and the plywood. Make a small block that is greater than this distance.

Rest it on the roof against the plywood at one side of the roof and carefully slide it from one side of the roof to the other. While sliding the block across the roof use a pencil or felt tip pen on the top of the sliding block and touching the plywood. The shape of the roof will be transferred from the sliding block to the plywood.

 

Good luck

Link to comment
Share on other sites

Yes the boxes actually curve, they don't have a bottom to them for ventilation and water drainage, and sit directly onto the metal surface.

 

Maybe I should give people the option of measuring if they feel confident, and if not, for a pound, I could then send them a black card template which they can cut and mark to size, then send it back and I can then use those as a template?

 

Thanks!

Link to comment
Share on other sites

That's called Spiling and is probably the most accurate method as it will follow any odd humps or depressions.

And old Springers had V profile roof's.

Sorry Doodlebug this reply was meant for Wanted.

Link to comment
Share on other sites

Is it safe to presume that curved roofs have a constant radius curve? If not, your idea of measuring the height difference between the top and the edges wont allow accurate reproduction of the roof shape, so the card idea would be better.

Link to comment
Share on other sites

Is it safe to presume that curved roofs have a constant radius curve? If not, your idea of measuring the height difference between the top and the edges wont allow accurate reproduction of the roof shape, so the card idea would be better.

Exactly. Wanteds Spiling method is the most accurate.

Link to comment
Share on other sites

Yep, a template made as described above is the way to go.

 

We had a curved radiator made for our bay window at home. The fabricators came in, made a card template of the curvature of the bay & worked from that. You should have seen how irregular it was! Still, beautiful job which couldn't have been done any other way.

Edited by Spuds
Link to comment
Share on other sites

 

Hi everyone,

 

I am almost finished with building the website for my top boxes, but have realised that every boats roof has a different curvature.

 

I am going to need to get people to measure the curve of the roof, and am trying to think of the easiest but most reliable way for people to measure them. The best way I can think of is to lay either a straight bit of wood, or stretch string so it just touches the top of the arch, and then measure down from the end to the roof, so that I know how large the curve is.

 

What do people think? It needs to be simple so everyone can do it correctly yet accurate enough so they fit!

 

Thanks as always,

 

Doodlebug

 

 

 

S'pose asking them to digitally photograph the roof section and send it to you, with the actual width, so you can measure the curve is out of the question?

Link to comment
Share on other sites

The digital camera idea is good, but not everyone can do that. My main problem that I see is that to send the card template will cost 2.60 there and then 2.60 back, so is going to raise the price by 5 pounds.

 

Surely narrowboat roofs aren't that badly made that they aren't a smooth curve? Maybe I give an option of either measuring or paying maybe £3 for me to send a template?

 

Thanks, the comments are appreciated!

Link to comment
Share on other sites

The digital camera idea is good, but not everyone can do that. My main problem that I see is that to send the card template will cost 2.60 there and then 2.60 back, so is going to raise the price by 5 pounds.

 

Surely narrowboat roofs aren't that badly made that they aren't a smooth curve? Maybe I give an option of either measuring or paying maybe £3 for me to send a template?

 

Thanks, the comments are appreciated!

 

I would say it depends on the level of quality & accuracy you want your products to be known for. A photo won't be very accurate & a template is the best method of transferring the information you need. Alternatively, I suppose you could approach the major builders & make up your own templates & then all your customer has to do is tell you the name of their builder.

 

Besides, why the need to return the template? Can't you do that when you deliver the finished product or incorporate the price in your delivery charges? You can set up a business response service where you send a label to the customer, maybe with instructions on how to produce the template & package for return to you without the need for them to buy postage, or set up a freepost system thus avoiding producing labels. Or you could simply leave the responsibilty of postage to the customer when they send the template which could be paper to save weight & cost to them.

 

Better still, Richard's post above is your simplest solution. Remember the KISS rule & you won't go wrong, even if you want to produce your boxes with bases that follow the roof curve, there will be a simple way to get the info you need.

 

Good Luck, hope you solve it profitably.

Edited by Spuds
Link to comment
Share on other sites

I think it would be a potential minefield to assume that customers will do this correctly and when it goes wrong it will be your product not their ability to measure the curve. Possibly a generic curve that will fit the majority of roof profiles along with adjustable feet fitted on the inside corners that can be used to level the box off.

Link to comment
Share on other sites

I think you need to establish a common generic design. I work in bespoke manufacturing and know a bit about how to make it work. Trying to produce an exact match for every boat is going to be a commercial nightmare. The cost of errors and reworking will sink you.

Link to comment
Share on other sites

Thanks for all the suggestions,

 

The boxes don't have a base to them, the idea is that the contents sits directly onto the steel, as mentioned for ventilation, so I didn't want to have an extra bit of wood for the base, which will both put the price up, and mean that less can be stored since the wood will bend (Unless I use 25mm ply in which case its going to cost an extra £50.

 

The boxes should fit the roof curve as well as possible, so although maybe small feet that can just raise the boxes by a cm or two may be a good idea, any more and, because the boxes have no bottom it will look wrong.

 

I could fold the template and send it as a large letter, but is there any guarantee that they will cut it correctly?

 

And if they aren't able to measure it themselves then will they be able to cut a template out?

 

Also - I would cut the curve to give a 1cm gap at the very top of the arch, which should allow for any errors. They are 110 by 120ish cm so the tiny errors in the boats build shouldn't be a problem

Link to comment
Share on other sites

 

 

Also - I would cut the curve to give a 1cm gap at the very top of the arch, which should allow for any errors. They are 110 by 120ish cm so the tiny errors in the boats build shouldn't be a problem

Would a 3/8 inch gap in the middle of a curve, that touched at each end, be acceptable on a boat of £50-100,000?

Also the wisdom of having the contents directly on the roof paint.

Sorry to put such a downer on your idea.

A cheaper range of fixed size & shape, with a floor might well work.

Ford Escort rather than Rolls Royce, approach.

 

Bod

Link to comment
Share on other sites

The slight gap is there on purpose, to allow air to enter the boxes and to prevent the edge of the wood sitting directly on the paint, allowing the rain running down the sides of the boxes to settle on the base.

 

Equally the boxes are aimed at those who currently use their roof for storage anyway. - but will keep things a lot dryer, and therefore protect the paint better.

 

I could add in to the design something resembling bed slats, which are laid at the bottom onto the roof, raising the contents off the roof, but I do think that if I make the entire box hover on 4 legs, they will look both like more of an 'add on' than part of the boats design, and that a few bags of coal will cause the underside to bow, making them look cheap.

 

Bear in mind this is to get me through the summer, and not an amazing business plan with room for expansion. If I sell 2 boxes a week I will be more than happy.

 

This is what they look like, I do think if they float on legs it will just look silly.

 

solar.jpg

Link to comment
Share on other sites

Would a 3/8 inch gap in the middle of a curve, that touched at each end, be acceptable on a boat of £50-100,000?

Also the wisdom of having the contents directly on the roof paint.

Sorry to put such a downer on your idea.

A cheaper range of fixed size & shape, with a floor might well work.

Ford Escort rather than Rolls Royce, approach.

 

Bod

 

I would consider offering a slatted bottom, or a curved ply bottom, depending on intended contents, so that the box sits 'off' the roof. Also, if made with a 'generic' curve, maybe supply a plastic (a la double glazed upvc windows) or rubber trims to close the final gap (remember unless you also curve the timbers of the long sides of the box, it will not sit fully on the roof anyway.

 

I *do* like wanted's idea of conveyor feet! The idea of templates, whilst good for many, will fox the ham-fisted bods and will taint your reputation - they will often blame others (look at those folk who cannot build flat-packs - who do they blame for their own shortcomings?) - That said, you can offer the use of a template, at buyers risk, if they would 'prefer' it.

 

ETA Having now seen the post above, I would put conveyor feet 'inboard' so for the main part, will not be seen.

Edited by dave69700
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.