13 replies to this topic

[manbot13]

I bought an Intes MK-65 off of craigslist, thinking I could have a fun 6 inch mak to play with. Doing some searching for information on these maks, I found what I think is the exact one here: https://www.cloudyni.../#entry12321000. Other than this thread, there does not appear to be much info out there.

 

This mak does not move the primary to focus, and in addition there are is no external collimation adjustment. There are two attachments for rear, one with a diagonal and helical focuser for visual, and one that reduces to 42mm camera adapter with a non-rotating helical focuser. I'm not the biggest fan of diagonals with only a single screw to hold the eyepiece, preferring brass clamping rings, and seeing that where was little option for an aftermarket focuser (the rear cell uses non-standard 56.5mm threads) I decided to use the camera adapter to take lunar images with a full frame DSLR.

 

This was mostly successful, but the backlash in the focusing made it very hard to make fine adjustments. In addition, the focuser had about 15mm of travel, and required 42mm spacers to get the moon in focus when the telescope was at different temperatures. As part of a package/lot purchase, I ended up with a feathertouch crayford focuser with 1 inch of travel. I thought that this would make a good addition to the set up, if I could figure out an adapter.

 

 

I took some measurements and decided to try to 3d print the adapter in PETG to see if the threads would even work. The focuser was about an M69 diameter with 0.75mm pitch. After some tries, I got the threads to work smoothly and had this result:

 

 

 

I used a baader camera adapter to fit into the 2 inch opening of the focuser. Proud of what I accomplished, I messed with my LOMO refractor for a few weeks before attempting to take my new assembly outside. When I finally did, I found that I couldn't get it to focus! The extra length of the focuser put the sensor just outside of the range required to focus at infinity. One of the issues with this focuser was that the draw tube extended past the mounting flange about 1/4", so I was limited in how close I could mount the adapter to the rear cell.

 

Searching for another T2 camera adapter that was thinner, I found that I still needed a couple of mm to focus at infinity. Purchasing a slim camera adapter would be another $50-$100 outlay so I turned again to 3d printing to just see if this would work.

 

I tried a fully printed one I found online, I decided modified the stl to print just the flange with threads for a 48 mm spacer. The result looked like this:

 

 

I was able to print this flange side down with no supports and with an indentation to lock to the canon camera. This flange was only 2mm thick, compared to the 9mm of the baader adapters and looked like this:

 

 

Taking this out, I could focus with about 4-5mm of room. You can also see how I had to rotate the focuser to fit it next to the battery compartment of the camera. Also with an M48 30mm spacer in the focuser tube, I could also mount the lens further back for terrestrial photography (if desired).

 

Overall I'm pretty happy with the result and wanted to share. Next project that I tackled was fixing the wobbly finder mount, which was another adventure in 3d printing, and required full removal of the optics.

Edited by manbot13, 16 May 2025 - 10:39 PM.

[luxo II]

Well done... the finder and the backend detail indicate that is an early 90's one, later they adopted conventional straight-through 6x30 or 10x50 finders.

[manbot13]

So the next project was making the finder more useful. It's a 30mm right angle finder with a helical focuser on the eyepiece end, and also has a small cross-hair. However, it was screwed in directly through the OTA and into the finder and was non adjustable. What's worse, it was loose and wobbled, and someone tried to correct this wobble with JB weld. "Why not just tighten down the screws," you ask? Well because then you have to remove the corrector, and as I would find out, the primary too!

 

In order to do this I first marked the corrector with a position on the tube. Six M3 0.5 countersunk screws held the corrector assembly in place, so re-installation would hopefully be easy. After removing the corrector (and some screws were quite tight and stripped out a bit on removal) I realized that there was no way to get to the screws holding the finder in place with the baffle tube in the way, so I gave it a twist and the entire primary and baffle tube came out as one assembly. I then removed the finder screws (also M3 0.5mm) and off came the finder.

 

I took some measurements and looked for a suitable finder rail. Not wanting to spend a bunch more money, and not finding something that would exactly fit, I decided to just 3d print the rings. Again, since using PETG, there was too much flex to make a clamp assembly like a typical aluminum one, so I decided to make a rail with a slot, and then print rings that would have a screw pass through the rail and cinch the rings into place. Maybe a little more complicated than necessary, but it fit the 3d printed material properties better and would still be possible to remove the finder for storage without disassembling the scope in the future.

 

 

I utilized a bunch of threaded inserts on got some M3 thumb screws in various sizes. I also printed little caps for the end of the screws on the finder to avoid marring the finder's finish.

 

Once the rail was installed using new screws, it was time to re install the optics. Here's a picture of the empty tube:

 

 

Here we can se the rear of the primary/baffle assembly. There was one aluminum spacer, and one paper spacer, and this was threaded in the rear of the tube. Removing the camera mount allowed me to guide it into place and ensure that I wasn't cross threading it. I also did all of my disassembly and reassembly on my Losmandy GM-8, which helped me orient the tube so I wouldn't drop anything on the primary, and could also keep the spacers in place while putting the primary/baffle in place.

 

 

And here is a rear view of the corrector. There were 3 flat head screws and washers holding the corrector to the metal retaining ring, and many paper spacers between the glass and retaining ring. I made sure not to disturb any of the spacers and simply reinstalled in the same orientation as removed, using the previous markings.

 

 

With everything assembled, I tested it on a star with the Canon 6D and the collimation looked good. I was also able to easily adjust the finder alignment with the new rings. Another test on an almost full moon showed pretty good results, although it was quite low in the sky.

Edited by manbot13, 16 May 2025 - 10:38 PM.

[manbot13]

And here are two images of the moon, one before my project using the Intes camera adapter (2/12/2025 full moon) and after all my fiddling (5/13/2025) on a moon 1 day past full.

 

2/12/2025

 

5/13/2025

 

I really like the way this F10 1500mm focal length frames the moon on a Canon 6D. I take 100 images 1 second apart using an intervalometer, in order to take advantage of the full resolution of the camera. Video mode on this model is 1080p and gets compressed, and images are twice that resolution (I guess 4K).

 

I trimmed the images in PIPP and stacked in Autostakkert 3. In both cases I stacked 75% of the images.

 

And now for some over sharpening in Registax and then maxing out the sliders in photo-editor.....

 

2/12/2025 (for some reason I can't get the image rotated back so everything matches when uploading)

 

5/13/2025

[dave janello]

Focusing is a challenge on these, I have a Moonlite Newtonian Focuser which came with a custom adapter, don't think they make these any more.

Even with the Moonlite, bino-viewers won't focus, I bought a Siebert Optics Optical Corrector which did the trick. Don't know if this will work with the original helical focuser.

[Kefka1138]

Awesome shot of the primary! Wish mine was signed like that.

[bartine]

Very Nice Work!!

[manbot13]

Yeah I initially thought binoviewers would be nice on this scope, but when I got home and realized the mirror didn't move I gave up.

Maybe I should try again with my baader max bright ii and 1.7 ocs and see if it's anywhere close to focus.

I also thought about using this for planetary photography since it'll be easier to set up than my 10" LX200 and I'll have plenty of back focus available with a barlow and ASI662MC.

[manbot13]

I actually had a thought (dangerous right). Since back focus is challenging with this intes mk65, would moving the mirror up by adding a spacer push the focal point out making more room for a focuser and diagonal?

Obviously I'd need a very flat spacer to not need to recollimate. Not that I can even source one right now.

[luxo II]

Yes that will extend the focal plane. A 1mm or 1.5mm disk or shim would add 10-15mm. Cork sheet, or card would do, craft stores carry these.

 

Looking at the 4th photo in your post #3 I’m guessing you would put this over the metal ring securing the primary mirror on the baffle ? Or between the primary mirror and the metal ring ?

Edited by luxo II, 04 June 2025 - 04:47 AM.

[manbot13]

I would assume that either position would be satisfactory. The metal ring was just a loose spacer, the baffle was threaded.

[photoracer18]

Only drawback is the fixed optics Maks (Intes MK63, 65, and 67 mostly) are the only ones that have the correct spacing of each optical element and you are ruining that for what its worth. I have never believed in modifying a scope for a purpose it was never designed to do. I would just go out and get a moving primary model because then I could try using my Intes 0.6x focal reducer. which is how  I acquired my iOptron MAK150. I did go out years ago and replaced my MK65 with an MK66 but I did not own the focal reducer then.

[luxo II]

Only drawback is the fixed optics Maks (Intes MK63, 65, and 67 mostly) are the only ones that have the correct spacing of each optical element and you are ruining that for what its worth.

Disagree - the maks with fixed mirrors are ideal for imaging - zero mirror shift, constant focal length, and external focuser (ideally R&P) that can take an EAF.  

 

And with some thought on the part of the designer, with a low-profile focuser and no junk behind the primary mirror, the backfocus can be minimised, which in turn allows for designs with a small CO.

 

While you suggest altering the mirror spacing is "ruining" it, that's exactly what happens in your MK66 - a mak with moving-mirror focusing - and FWIW of all cassegrains, the Rumaks are surprisingly tolerant of modest shifts away from the nominal focal plane without significantly upsetting SA, astigmatism or coma.

 

A minor shift is not the demon you make it out to be.

Edited by luxo II, 09 June 2025 - 06:03 PM.

[manbot13]

Well i got this scope for $265, the feathertouch focuser is probably worth more than that. I don't feel bad messing with it. I read that there are other focusers that have a draw tube that fits into the baffle, but I had this on hand and it's been fun making it work.

I haven't modified it yet other than 2d printing an adapter and remounting the finder. I wasn't planning on doing any deep sky astrophotography with it but I may see if I can get a reducer to work. I had plans to defork my 10" LX200 and put it on my G11 for planetary and deepsky work, but I may get more mileage out if this and a GM8 since it'll be easier to drag out of the house and setup.