CNC Plywood cutting

[GregHBBR]

Hi Chris,

Chris Waite wrote

But now I remember, Microsoft and Nabble between them couldn't quite cope with the idea that I had uploaded, cancelled, cropped and tried to re-upload the photograph. (Once Nabble has a photo file and its dimensions in its claws, then I can't fiddle with it without cancelling and shutting down the whole system and reopening).

I recall that you do have some unusual problems with Nabble, but what you describe above is an extreme solution. For anyone else this should work:

1. Delete the special tag that represents the previous version of the image/file.
2. Insert/Upload the revised version of the image/file.
3. Click the "Post message" button.

If you have already posted an earlier version of the message with the image/file, then you will have to do an extra initial step of clicking on: More > Edit post.

You certainly, shouldn't need to "cancel, shut down the whole system and reopen".

[John P]

Chris, I suppose you are right about the width accross the oars being a limitation for some inland waterways, but we have in mind the rivers of Europe, many of which are wider as well as longer than any English river. How this will work out I cannot say, maybe it is just a dream, but the possiblities for river cruising around Europe (downstream only) would seem almost endless, certainly more than enough for one lifetime.  

Incidentally, the oars on our sailing dinghy are quite long and rowing up muddy Essex creeks at low water we have quite often been planting both the oarblades in mud rather than water.

I weighed Josephine's rowing boat with a good scales this afternoon. Its at the undercoat stage now, still needs more sanding then topcoat.  All the bolted/screwed on bits are removed for painting but I put them loose in the boat for weighing. The weight is 43kg, the weight predicted by the computer drawing program was 41kg, both without the oars which will add a bit less than another 3kg. I can guess where those extra couple of kilos have come from - I just cant resist adding a bit more epoxy here and there to make sure glass fibre is properly wetted out and everything is well stuck together.  I asked my phone "OK Google, what is the weight of a Mirror dinghy" and the answer came straight back in a second at the most - 45.5kg (without sails, oars, spars and rigging).  Josephines boat is a bit narrower than a Mirror dinghy but also considerably longer and the sliding rowing seat arrangment adds some weight (that could have been made lighter). Our row boat is made from 3mm plywood throughout, I think a Mirror is 4mm, but our boat is sheathed with grp on the outside, I dont think a standard Mirror has sheathing. So I was a bit surprised, and pleased, that it has come out at about the same weight as a Mirror dinghy.

I think the Pedyuloh is a great idea.  I have another thought for human powered boat propulsion that would pull from the bow rather than push from the stern. I might draw it sometime, it would be easier to explain in a drawing than words. But its not a yuloh, nor oars, nor a conventional propeller.

And something my father once asked me (he who had little knowledge of boating) - if you want to make your boat move without having to row why dont you just paint the back of it with water repellant paint?