Gina's Mini Widefield Imaging Observatory

[Gina]

And ordered

[Gina]

The marine ply has just arrived by courier   Probably be marking it out and cutting it up tomorrow - best in daylight

[Gina]

The new design roof for the mini observatory "big build" begins tomorrow

[Tinker1947]

Check every thing twice, have a cuppa tea think about it then do the cutting, it not the end of the world if its wrong, but really feels nice if its right first time. This was my weeks work, made it last November as a flat pack, it went together like a hand in a glove......

[Gina]

Very nice

Had some storm damage to fix this morning - no not the observatory, that's fine.  Had a roof panel blow off and land in my neighbour's field something like 100m away.  Got him to retrieve it for me and it's now back in place and fixed.

As for the mini obsy roof, I'm taking that slowly and carefully.  I don't want to buy another expensive sheet of marine ply

[Davey-T]

Check every thing twice, have a cuppa tea think about it then do the cutting, it not the end of the world if its wrong, but really feels nice if its right first time. This was my weeks work, made it last November as a flat pack, it went together like a hand in a glove......

Very nice, where does the scope go ? 

Dave

[Gina]

Getting ready to start   Table cleared off ready for action and adapter for dust extractor designed, printed and fitted - seems nice and solid   Now having a rest

[Gina]

The previous sketches were just approximate so I've drawn out a revised plywood cutting diagram.  I found there was enough area available to get the sides out of the sheet as well as the ends.  I was going to cut separate pieces of wood but with the marine ply available I might as well make them from that.  Probably make a better job too

Here's the new cutting diagram - screenshot from SketchUp.  I think I'll have the outer layer grain direction up/down the diagram.

[Gina]

This diagram shows possible rough cuts (black lines) but I'm wondering if I might just go straight for routing the rectangles straight from the full sheet.  That wouldn't be very difficult with a fence clamped or screwed to the sheet.

[Gina]

That would give this resulting shape, with these possible cuts.  I want to be sure I get the plan right before starting to cut.

[Tinker1947]

Place the straight edge the router will slide along so should the router drift off the straight edge it drifts into scrape material....don't try to do to deep a cut take 3 or 4 goes.....

[Gina]

Good thinking   The Bosch router has a stepped depth guide which makes it easy the do multiple cuts a bit at a time

[Davey-T]

If you don't have to plunge in then set the depth first, start router away from the edge then feed into the work piece, start at left hand end and go straight through without stopping, good luck.

Thinking about it it may be best to start fresh tomorrow.

Dave

[Gina]

I think I shall do all the cuts with the router as that has a dust extractor which my jigsaw doesn't.

[Davey-T]

Less wear and tear (and dust) if you jigsaw out all the pieces first with a fine tooth blade to avoid too much shattering of the edge leaving about 3/4 of the cutter width then just trim the edges with the router.

What size cutter are you using 1/2" is good you don't want to use anything thin.

Unless you have a professional dust extractor you'll still get plenty of dust flying around so don't forget your mask

Dave

[Gina]

If you don't have to plunge in then set the depth first, start router away from the edge then feed into the work piece, start at left hand end and go straight through without stopping, good luck.

Thinking about it it may be best to start fresh tomorrow.

Dave

Thanks Dave   No plunging necessary so can set depth and then start cutting. 

I shall leave cutting until tomorrow as you suggest but I might mark out the sheet this evening.  Actually, there's still a fair bit to do before I'm completely ready to cut.

[Gina]

Less wear and tear (and dust) if you jigsaw out all the pieces first with a fine tooth blade to avoid too much shattering of the edge leaving about 3/4 of the cutter width then just trim the edges with the router.

What size cutter are you using 1/2" is good you don't want to use anything thin.

Unless you have a professional dust extractor you'll still get plenty of dust flying around so don't forget your mask

Dave

The jigsaw blade teeth are spaced at 3mm.  The machine is a Performance Power 550W which I've had for yonks.  If I have any other blades I don't know where they are

As for router blades, I have the 8mm one that came with the router and I bought 5mm and 6.35mm TC ones.  

I can see the point of cutting out with a jigsaw and trimming up with a router - less material to machine.  Hadn't thought of that

Hmmm...  maybe this needs more thinking about before proceeding

[Gina]

I'm finding difficulty in finding long enough bits to trim two thicknesses of 12mm together other than in small diameters.  However, this Bosch 20mm diameter by 25mm looks alright.  Would 20mm be too big for my job?  I can get this for Monday.

[Tinker1947]

There are many way to cut out the pieces from the one sheet,  having a variety of machine/tools helps,so i would rough them out with a jigsaw, then the straight pieces run them through a table saw, if you don't have a table saw then a straight edge clamped to the work piece so the router will run along in a straight line with a piece of the ply placed so the router cannot dip as it goes along, for the curved pieces a piece of MDF 6mm thick cut to the shape and clamped to the work piece, same again a scrape piece of MDF placed so the router cannot tip but remains flat with a bearing guide following the profile of the curved MDF. i use a headless pinner instead of clamps make for quicker placement removing the pins afterwards. Once the cutting is done clamp the pieces together and go round the edge with a sander. 

[Tinker1947]

i would go with something around 12mm keep the router speed low, if there's any burning slow it down a bit more.....

[Gina]

How about this Draper 10mm x 25mm bit ?

[Davey-T]

Kitchen worktops are 40mm thick and the cutters are a bit longer.

Dave

[Gina]

Draper 12.7mm diameter x 25mm bit this should do it

[Gina]

Kitchen worktops are 40mm thick and the cutters are a bit longer.

Dave

But these longer ones seem to be 1/2" shank and my router has limit of 8mm.

[Davey-T]

Sorry Gina thought you'd bought a 1/2" one.

Dave