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Another episode completed.


Graham

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Up at the crack of dawn to get another days work in on the new scope.

 

The OTA

 

After a few more hours with the power wire brush all the old paint had finally gone on the OTA.

After a good wash down it was time to undercoat.

Decided to re do the fork whilst I was at it.

 

IMG_0030.JPG?raw=1

 

The Light shroud.

 

Earlier on in the week I went over to Colchester to collect my small bit of Acrylic to make my light shroud.

Measuring in at 1870 mm x 1462 mm x 2 mm thick handling it was a tad awkward to say the least.  

Once I had got it home and into the house it was laid on the floor so I could do the transformation work.

I then spent an enjoyable hour or so flocking it.

 

Like a complete numpty I forgot to take a photo of it once it was flocked and trimmed.    Sorry. ?

 

Then came the conundrum.

 

How the heck do you roll up a lump of Acrylic that large so the cut and polished edges meet exactly so they can be welded together with a solvent glue.

After many attempts and quite a bit of head scratching I came up with the solution. ?

 

Yesterday at work I cut and rolled a dozen clamps that were the exact diameter of the finished tube.

Each clamp then had a tag welded onto each end of the rolled section so I had a bit of adjustment and the ability to tighten it onto the Acrylic forcing it into the desired tube like shape.

 

The idea is to get the joint as tight a fit as possible so the solvent is sucked into the joint under capillary action. 

It then melts the edges into a liquid Acrylic which join together at a molecular level leaving no joint as such once it has fully cured.

 

It seems to have worked perfectly as planned.

Once the clamps had been fitted the edges butted up perfectly together.

It was then a case of filling the syringe with the solvent and running a small bead down the joint.

 

Bit of advice which I could not heed due to the nature of what I was attempting.

If you ever use this Acrylic solvent glue do it outside if possible.

To say it is a might overpowering is a slight understatement.

 

Unfortunately it takes 24 hours for the solvent to do its stuff and for the Acrylic to fully harden again so I am stuck with this lump in the middle of my floor until tomorrow.

A small sacrifice to pay if it works.

 

Once it has fully set and I can take the clamps off I will fit the tube into the OTA so I can mark out the hole for the focus tube and the slots for the spider.

These will then be cut out using a milling cutter in a drill.

Once sorted and all ready for final fitting the outside of the tube is going to be covered with an 8G carbon fiber wrap.

 

This is the result so far.

 

IMG_0029.JPG?raw=1

 

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10 minutes ago, Graham said:

Up at the crack of dawn to get another days work in on the new scope.

 

The OTA

 

After a few more hours with the power wire brush all the old paint had finally gone on the OTA.

After a good wash down it was time to undercoat.

Decided to re do the fork whilst I was at it.

 

IMG_0030.JPG?raw=1

 

The Light shroud.

 

Earlier on in the week I went over to Colchester to collect my small bit of Acrylic to make my light shroud.

Measuring in at 1870 mm x 1462 mm x 2 mm thick handling it was a tad awkward to say the least.  

Once I had got it home and into the house it was laid on the floor so I could do the transformation work.

I then spent an enjoyable hour or so flocking it.

 

Like a complete numpty I forgot to take a photo of it once it was flocked and trimmed.    Sorry. ?

 

Then came the conundrum.

 

How the heck do you roll up a lump of Acrylic that large so the cut and polished edges meet exactly so they can be welded together with a solvent glue.

After many attempts and quite a bit of head scratching I came up with the solution. ?

 

Yesterday at work I cut and rolled a dozen clamps that were the exact diameter of the finished tube.

Each clamp then had a tag welded onto each end of the rolled section so I had a bit of adjustment and the ability to tighten it onto the Acrylic forcing it into the desired tube like shape.

 

The idea is to get the joint as tight a fit as possible so the solvent is sucked into the joint under capillary action. 

It then melts the edges into a liquid Acrylic which join together at a molecular level leaving no joint as such once it has fully cured.

 

It seems to have worked perfectly as planned.

Once the clamps had been fitted the edges butted up perfectly together.

It was then a case of filling the syringe with the solvent and running a small bead down the joint.

 

Bit of advice which I could not heed due to the nature of what I was attempting.

If you ever use this Acrylic solvent glue do it outside if possible.

To say it is a might overpowering is a slight understatement.

 

Unfortunately it takes 24 hours for the solvent to do its stuff and for the Acrylic to fully harden again so I am stuck with this lump in the middle of my floor until tomorrow.

A small sacrifice to pay if it works.

 

Once it has fully set and I can take the clamps off I will fit the tube into the OTA so I can mark out the hole for the focus tube and the slots for the spider.

These will then be cut out using a milling cutter in a drill.

Once sorted and all ready for final fitting the outside of the tube is going to be covered with an 8G carbon fiber wrap.

 

This is the result so far.

 

IMG_0029.JPG?raw=1

 

Graham this is starting to look the dogs danglies ,i have the same evolution saw BTW 

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Thanks David.

Got the saw for Christmas from the better half.

Wanted it to make my scope then this one came up so I have not even used it yet.

It will get plenty of use next week as all the timber and stuff for the new obs arrives next Friday. ?

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That's looking great Graham, did you brush or spray the OTA/forks? They look good so far, are they staying that colour??

I've worked with acrylic for 50 years and can't smell it at all now!!!

keep up the good work and photo's mate...

 

Ron 

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Thanks Ron.

I am surprised you can smell anything after using that stuff for 50 years.

All brush coated Ron.

 

Did some more this afternoon.

You have to love this hot weather dried that undercoat a treat.

Managed to top coat today as well -- bargain. 

 

IMG_0034.JPG?raw=1

 

 

IMG_0035.JPG?raw=1

Edited by Graham
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See you've got the step ladder ready fit an eyepiece!! What size?? ???️

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Great progress Graham. Love your solution with the acrylic sheet. ?

 

You're probably as high as kite with that solvent smell in the house. ?

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Thanks Mick

It wont look quite so garish once I get the light shroud inside it.

 

Thanks Pete.

Fortunately I have been outside all day and away from the smell.

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You are doing a great job Graham! And you are making great progress too! ?

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Just as a passing point of possible interest.

As I have the mirror and cell removed it has taken 3 NEQ 6 counterweights bolted to the back plate just to balance the OTA up enough for it to stay where I put it.

Just shows how much the mirror and cell weigh in at.

 

DSC_0177.JPG?raw=1

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Possibly even more than that Ron.

The mirror sits inside the tube a good 100 mm.

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Well after a morning of if anything could go wrong it did I have finally managed to get the light shroud finished.

Temporary fitting to get the focus tube hole marked out so I thought I might as well get a snap whilst it was there.

 

IMG_0041.JPG?raw=1

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It looks very striking Graham.

Great work. ?

 

Spectacular views await, i'm sure ?

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Can't wait to see the size of the observatory ?

 

Great work Graham it looks the bees knees ?

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The obs will be the next installment.

The timber arrives next Friday. 

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You are proper cracking on with this one Graham, it looks completely different to how it was when you picked it up.

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The old owner will be chuffed to see that his old scope has a new lease of life ,

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I have been keeping him updated with the transformation and you are right he is well pleased with it. 

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