intes mak/newt collimation

[ddtwelve12]

can any help ive dialled the collimation in so far but with no central spot on the mirror due to the mirror plug how do you get perfect alignment as you cant use a laser?

[John]

I have one of those - Orion Argonaut AKA Intes MN61

It is an issue - I've been using star testing to tweak mine. Fortunately it's not needed more than fine tuning.

I've been thinking about something like a laser collimator with a grid pattern - I think the Howie Glatter people in the USA do something like that I believe.

Fortunately, once set, these scopes hold their collimation well. Their construction is very refractor-like, in that respect !.

[Carbon Brush]

Sorry I can't help, but I will watch the thread to see if you get any answers.

The only problem I have every had with the MN78 was the secondary way off. A couple of minutes with the laser sorted it. Never did find out why it went out.

David.

[John]

David,

Does the MN78 have the central mirror plug like the MN61 has ?.

[Steve77]

Here is a link to thread on CN, that maybe helpful.

Intes-Micro Mak-Newt Collimation Procedures - How To

[John]

Here is a link to thread on CN, that maybe helpful.

Intes-Micro Mak-Newt Collimation Procedures - How To

Thanks for that but the Intes Micro scopes are a different design from the Intes ones (confusing I know) in that the latter have an alloy plug in the centre of the primary mirror which prevents the use of a laser collimator in the way described.

The stuff in there on star testing is useful though so thanks again

[Carbon Brush]

Sorry for the slow reply. I went out to try to grab a couple of pics. Difficult without stripping the scope!

You can see from the corrector plate pic that the secondary mirror is quite small on this scope. I removed the ali screw cover to expose the secondary collimation screws.

The mirror pic was interesting to obtain. I can assure you the mirror does actually look OK! There is a centre mark thoughtfully on the mirror. No central plug to get in your way.

Hope this is of some use.

David.

[AndyH]

Grid patterned lasers are terribly handy things, but not the easiest things to get hold of over here. No need for centre spots. I got mine from helix-mfg a long time ago and I reckon it's one of the best accessory purchases I've made.

Andy.

[sixela]

I have one of those - Orion Argonaut AKA Intes MN61

It is an issue - I've been using star testing to tweak mine. Fortunately it's not needed more than fine tuning.

I've been thinking about something like a laser collimator with a grid pattern - I think the Howie Glatter people

There's only one Howie Glatter, I think (and he machines all of them personally).

Yes, there's a holographic collimator with a grid pattern and even one with a circle pattern, and it can help set secondary tilt even in the absence of a centre spot. But setting primary tilt without a centre spot still isn't very precise.

The last thing to note is that you actually have to collimate to the corrector to make the on-axis object have no coma, so the "regular" procedure for Newtonians is only correct if the secondary is perfectly placed and rotated, the primary is centred in the tube, and the corrector is square to the tube. So I'd always end with a star test (on Schmidt Newts you can use the reflection of a lamp through the side window off the corrector, but the Mak corrector is diverging).

[ddtwelve12]

Ive noticed that on the main mirror ally central plug there is a drilled minute center spot but with not haveing a laser only a cheshire collimator cant see its reflection

Mine has that feature as well - it's not drilled right though on mine - just a small pit in the centre of the central plug. That does enable a laser collimator to help align the tilt of the secondary but does not help with the primary as there is no return beam to hit the collimators 90 degree face.

I've been playing around with lenses in the path of the laser to spread the light into a disk wide enough for some of it to hit the primary and come back up the tube to the collimator. No success to speak of yet though.

[Carbon Brush]

Aha. The hole will help and a laser collimator isn't expensive.

My Orion Optics Europa didn't have a spot from new. But there is a central hole in the rear cell. Enough laser light gets through the mirror to use this hole like a centre spot.

David.

[John]

My MN61 has a drilled "pit" in the centre of the central plug but that only helps when using a laser to align the tilt of the secondary. I was thinking that a "grid" pattern would partly fall into the primary mirror and reflect back up the tube onto the 90 degree face of the collimator, which is what's needed I think to align the primary.

[AndyH]

Yes, a grid or bullseye pattern laser sets both the secondary and the primary.

Here's how it works for me.

Carefully looking down the scope tube, the pattern on the main mirror lets you tweak the secondary til it's bang on, then you aim the scope at the rooms wall or ceiling, which throws up a nice large reflected pattern and then you adjust the primary screws until the secondary shadow is bang on in the middle of the grid or bullseye dots(as in my case). This will get me pretty damn close to bang on collimation, but I always do a final startest to check.

This is the projected image on a wall. Sadly this pic doesn't pick up the central shadow. edit: but it is just inside the innermost circle of dots and easily seen during the day with the curtains drawn over.

Andy.

[John]

Yes, a grid or bullseye pattern laser sets both the secondary and the primary.

Here's how it works for me.

Carefully looking down the scope tube, the pattern on the main mirror lets you tweak the secondary til it's bang on, then you aim the scope at the rooms wall or ceiling, which throws up a nice large reflected pattern and then you adjust the primary screws until the secondary shadow is bang on in the middle of the grid or bullseye dots(as in my case). This will get me pretty damn close to bang on collimation, but I always do a final startest to check.

This is the projected image on a wall. Sadly this pic doesn't pick up the central shadow.

Andy.

That Helix looks a very useful device Andy - I wonder if they are still available

Perhaps I'll try a "wanted" ad on Astro Buy & Sell.

[AndyH]

That Helix looks a very useful device Andy - I wonder if they are still available

Perhaps I'll try a "wanted" ad on Astro Buy & Sell.

Sadly they shut up shop a few years back. A great shame as these collimators and their alt/az mounts were quite excellent.

[ddtwelve12]

Just been googling and found this

Homepage - HoTech SCA laser collimator

looks as thou there using a crosshair laser system now gonna email hotech as see if there any use

[ddtwelve12]

just email hutech and this is there answer

Hi David,

The Advanced CT Laser Collimator is the most ideal collimator to collimate Intes MN especially with a cored primary mirror. The three collimating lasers will be able to skip the center hole and collimate the entire optical train. However, your Intes MN61 has 6" aperture which is below our minimum 6.7" collimating aperture for the standard model. The collimating lasers of the current available model are 170mm spaced apart which will not be able to enter your primary mirror for a proper alignment. There is a way to gross collimate your Intes using our SCA crosshair laser collimator then final touch up with star collimation. Using a grid pattern projection from other brands of laser collimator will not be able to achieve this. The following is a quick guide for your reference on how to go about with our crosshair laser.

1. Align your secondary mirror with the crosshair laser:

a). 4-corner mark the inside of the hole on your primary mirror.

- You can either physically measure each 90 deg. edges and mark with a white liquid paper/marker, or

- Use a computer to draw an exact sized circle of the primary hole with a center cross. Then cut it out, center lineup to the back of the hole and tape it.

. Use our crosshair laser to adjust your secondary mirror axial alignment to shine the 4 extension lines on each marker or onto the center cross.

2. Align the primary mirror with the reflected crosshair laser:

a). Cut out a target template (I will email you when you are ready to purchase).

. Place the target about three feet directly in front of the telescope, after you lined up the secondary on the markers.

c). Try to center the crosshair line projecting on the target template by adjusting the axial alignment screws of your primary mirror.

- While lining up the reflected crosshair lines to the target, make sure the center shadow (from the secondary mirror) is also concentric on the target template.

3. Touch up the collimation with star, then you are ready to go.

this might do?

[sixela]

Using a grid pattern projection from other brands of laser collimator will not be able to achieve this.

I'd have to disagree with that assessment. There are many kinds of holographic patterns that work for this, and I personally actually prefer the grid for the setting of the primary tilt (even though David Ho's advice for his single cross also works, it's a lot harder to see whether a shadow is centred well than if you have a grid) and the concentric circle pattern for setting secondary tilt.

But given you have to star test anyway, I actually prefer a Cheshire for setting the tilt of the primary. Much less fussy.