Measure twice, cut once

[ONIKKINEN]

Or drill once, as i did just now drilling holes in a helmerichs carbon tube where i will place all of my current VX8 to complete the un-VX-ing operation of the scope. I measured the holes in the correct places, twice, as the saying goes. Then just drilled them, piece of cake.

Drilled the holes nicely too, not much scruff and bite on the easily biteable carbon tube so everything is clean looking. Just one problem though, even though i had measured the correct locations of all the holes i drilled 2cm away from them for the secondary spider so now the secondary mirror cant get fully under the focuser to be illuminated correctly 🤪. Collimation is still possible but one side of my APS-C sized camera sensor receives 15% less light and under the stars there will most likely be awful tilt issues with star sizes.

So measure twice and cut once, but remember to cut where you measured instead of next to it 🤣.

Thankfully not a huge disaster, just have to find or make my own collimation screws that are long enough to hold the secondary mirror further away. Thing is i already had quite long 45mm M4 screws as the VX8 had a similarly (almost as) far away drilled spider holes. This was one of the things i wanted to fix with the new tube, but for some reason i forgot that and actually made the thing worse. May have to drill new holes and call the earlier ones practice holes.

[DaveL59]

easily done tho. I was fitting a new bath years back, prepped the space it would fit into and checked for fit in the undercuts in the wall then pulled it back out so I could drill for the taps that would be set into one corner. Late at night after a long day and so I marked up and cut the holes dead right, taps slotted in perfectly so fitted up the pipe tails etc.

Only thing was when I went to offer it back into where it'd sit... wrong corner. DOH!

The fix was to flip the bath lengthwise so the taps were in the far corner from the shower and run extra pipes. Just as I'd planned it all along of course  😄 

[ONIKKINEN]

16 minutes ago, DaveL59 said:

easily done tho. I was fitting a new bath years back, prepped the space it would fit into and checked for fit in the undercuts in the wall then pulled it back out so I could drill for the taps that would be set into one corner. Late at night after a long day and so I marked up and cut the holes dead right, taps slotted in perfectly so fitted up the pipe tails etc.

Only thing was when I went to offer it back into where it'd sit... wrong corner. DOH!

The fix was to flip the bath lengthwise so the taps were in the far corner from the shower and run extra pipes. Just as I'd planned it all along of course  😄 

Pipe installment practice run in the end.

I will definitely redrill the holes, looks like i also did not do them symmetrically enough and the spider has trouble having straight vanes because of that. 9mm instead of 8mm holes this time to give some adjustment room, and also this time to the correct place 😉.

[Paul M]

He who never made a mistake never made anything!

My beloved old Fullerscope 6in Newt is like a colander at the primary end of the lovely gloss white tube. I moved the primary up and down the tube to get my SLR at prime focus. I didn't even measure just drilled holes and tried it! Would've been ok if I'd actually taken any images through it 😳 

[Captain Scarlet]

Oh no! What is it about Helmerichs tubes? With mine I spent ages carefully calculating taping marking and measuring. And then I used one of the spider holes as centre for the 80mm focus hole 🤦‍♂️ . My solution was to change ends and use my new huge hole as a mirror access/vent.

Magnus

[ONIKKINEN]

Just now, Captain Scarlet said:

Oh no! What is it about Helmerichs tubes? With mine I spent ages carefully calculating taping marking and measuring. And then I used one of the spider holes as centre for the 80mm focus hole 🤦‍♂️ . My solution was to change ends and use my new huge hole as a mirror access/vent.

Magnus

Yes i remember that, i was dreading the (w)hole process fearing i would somehow fumble with the big hole. I was almost neurotically obsessed with getting that right so must have spent all my available focus on that and somehow let go of the brain after i was done with it. I also see what you mean when you mentioned back that the tube is rigid, i am sure i could drill 10 focuser holes in it and would not notice a change in rigidity, this thing is ridiculously sturdy.

[maw lod qan]

Hate hearing your misfortune. 

Hope you fix it and get your scope in the dark!

We have an old construction joke.

Young apprentice tells his boss, 

Don't know what's wrong boss, I dun cut this board three times and it's still too short!

[ONIKKINEN]

Done and dusted, this time with rightly measured, rightly drilled to the measured places rather than someplace else. Perfect collimation and visually even looking vanes. Looks like my particular spider has a little bit unsymmetric attachment points of the vanes to the central part so may have been on a wild goose chase before with them. Have not noticed this to be an issue in the previous tube so doubt i will care in this one. I will also cover the old holes with velcro tape which i will use to attach a dew shield so nobody will ever know that i had some spider hole drilling practice 😉.

Didn't lose any clear skies in the process, as have not had them for more than 5 weeks, and looks like the situation is not changing for this week either judging from the forecast of snow and warm winter weather. Only once winter really sets in with a cold front we will get clear skies here, this almost winter with barely below 0 is guaranteed full gray sky 24/7.

[kirkster501]

I'm from the measure ten times and cut once school of thought.

[tomato]

Yes, 10 times is good. I recently replaced the doors on a kitchen and made a jig to drill the holes for the door handles. Trouble was it was handed both for the door side and end, so I was ultra paranoid about drilling them in the wrong place. The Mrs was not impressed with how long the checking was taking, but I stuck to my guns and drilled all 20 pieces without making a mistake.

[DaveS]

In my case it's "Measure twice, cut once, then get another piece to replace the one I stuffed up".

[ONIKKINEN]

1 hour ago, DaveS said:

In my case it's "Measure twice, cut once, then get another piece to replace the one I stuffed up".

That would be 6 months of oopsie cooldown with the pace i got mine. Apparently there were some health issues for one of his colleagues and that was partially to thank for the delay but its not an uncommon thing to read online. So best spend some time measuring for the cuts (and actually cut where measured, important bit).

[LukeSkywatcher]

Me and DIY are not good bed fellows. I have tradesmen on speed dial for everything.