Thread: Eureka Problem - mis measure? and how to fix

Originally Posted by honkongphoie

but if all the panels are measured using the same technique this would make no difference at all, it's only if you start mixing methods you'll run in to problems.

Actually, that's not quite right. If you are marking out 300mm steps, and get one wrong, that error carries through the rest of the hull ie, if you marked out one step at 200, the rest of the boat will be that 100mm step. However, if you set the tape at one end and mark 300, 600, 900 etc, a mistake at one point just gets lost in the crowd because the next one will be at the correct distance.

Regardless of how you set out a grid (or any other set of distances), it's always good practice to measure the overall distance as a check. Similarly, if marking out either side of a centre line, I will mark both sides and then measure the overall distance to make sure they're right.

is it maybe a problem with the lower panels, take a look at the two photos below.

i don't know how to put this down in words but i'll try my best

this one is Martin2121's bow, if you hold a piece of paper parallel to the top panels and in line with the tip of the bilge panels you can see there is a big difference in the angle where the top half and the bottom half meet



now looking at m2c1Iw's bow there is no change in angle and the lower panel just flows into the top panels creating an nice sweeping bow profile



well i did say i didn't know how to put this down hopfully some one will understand what i'm getting at

Are you suggesting that the final point at the top of the bottom panel might be too far forward? You might be right, it's something to check and a possible solution to the problem too.

Richard
ain't it fun fixing other people's problems, so much more enjoyable than trying to sort out our own

Originally Posted by Daddles

Are you suggesting that the final point at the top of the bottom panel might be too far forward? You might be right, it's something to check and a possible solution to the problem too.

yes that's exactly what i'm saying (why couldn't i make it that simple)

Originally Posted by Daddles

ain't it fun fixing other people's problems, so much more enjoyable than trying to sort out our own

it sure is but i'm starting to get withdrawal symptoms from not having by own to sort out

Originally Posted by honkongphoie

it sure is but i'm starting to get withdrawal symptoms from not having by own to sort out

Build a Eureka canoe - cheap, quick and you've already done the trouble shooting

Richard

Originally Posted by Daddles

Build a Eureka canoe - cheap, quick and you've already done the trouble shooting

Richard

the Eureka is already on my wish list but for now i need to put all the money and preparation work towards the scoter

Thanks Mik, I appreciate the help from everyone. I will muck about with it over the next week or so and show what i come up with. I'm positive that it's me who has stuffed up but I'm frustrated by not knowing where.

Originally Posted by Martin2121

I'm positive that it's me who has stuffed up but I'm frustrated by not knowing where.

Oh how well do I know that feeling

Look for the down right screamingly obvious and daft mistakes as well as the subtle. It might be something as simple as a number that's misleading or easy to misread (flaw in the print out, bit of dirt, etc) and the problem with this sort of blue is that you'll keep making it convinced that you're right, so try to find an independent check. Look for other hints too - sometimes when you mark out a curve and run your batten over it and find that one point is out, it's not that point that's incorrect but another point that throws the whole lot out.

Welcome to the subtle joys of boat building ... which is why all good sheds have a moaning chair

Richard

Got it figured! Maybe?

The side panels go 6mm past the last reference line on the join end. I would guess that it was cut off flush with the reference line.

Remember that the photo with the big difference is not quite right either because the join between the side panel and bilge panel had not been stitched up at that point.

The boat was like this.



When it was stitched the difference reduced - we don't have a pic of that though. There does seem to be a tendency for some of the side panels bows to be a few millimetres short - maybe between 0 and 3mm, add the extra 6mm of cutting off the join end and it jumps up to and error of between 6 and 9mm.

Or it would if that is the exact error made.

The only other thing I can think of is that the reference lines themselves were not quite right. But that should average out (with the Eureka only - not any other storerboats) because all the pieces come out of the same sheet. So the bows and butts will average out to pretty well the right lengths - unless there is an error in one of the end reference lines only.

Main point is that it is not critcal and can be worked round in a couple of ways.

Best wishes
Michael

This is a great forum and without it I'd be struggling. I appreciate all the help very much.. Today I made up a sort of stem piece for each end and epoxied them in and the process went well. I'll post a couple of pics when I've finished. It was a worthwhile process cos now I've learned how to mix up the bote cote to the consistency required for when I do the filletting. In todays heat (about 37) the epoxy was really runny and I kept adding powder until the peanut paste stage, whacked it on the stem pieces, taped them on and voila. Didnt go off too quick either. Thanks again to all of you.
Marty.

Pics of stem. I'm in half a mind to make a matching piece for inside the hull to epoxy against the outside stem. Is that overkill or should I just use fibre glass tape for the inside?

Well done, Mik will be along but m2cw glass the inside and ouside seams or put in large fillets on the inside so as there is plenty of glue surface between the stem piece and panels

Howdy,

If the fillet has about 18mm of contact area onto the hull panels it will be fine.

Looks fine in the pics. Continue it down to the end of the stem and it will be fine.

MIK

now i dont feel i have much weight in my reply as im yet to start making my first (im going to build the eureka so when i saw "problem" i thought i might read as i most likely will come across a few of my own), but due to this thinking from the outside it may be a good thing??? (you guys can judge)

but anyway i noticed in the pictures that you have the spreaders attached to the top panels as you are stitching... and you have stitched the ends of the panels together (stems?), when you put the spreaders in the sides bow out and the stems pull in (think of when the sting is drawn out on a bow and arrow, the bow pulls in)

perhaps before you cut try removing the spreaders and have one last stab at stitching again...?

ok so i feel dumb... note to self, check for a page 2 before replying... hahaha

Not as dumb as I feel MiLKey! I don't really know what happened, guess I've just mis-measured something. Anyhow it's turning out o.k. and I'm going to paint the outside so it won't be too obvious. Thanks for the suggestion though.

Marty.