Losmandy Users

Re: Disconnection Losmandy G11 GEMINI LV4

david.partridge@... (David C. Partridge) — Sun, 06 Apr 2025 07:10:44 -0700

It all depends on how good you are at de-soldering and soldering. If in any doubt find a friend who has the relevant skills (and equipment).

David

Re: Disconnection Losmandy G11 GEMINI LV4

astroecliptico@... — Sun, 06 Apr 2025 06:51:31 -0700

Hello Ciril,

Allow me to jump into this discussion to share my thoughts and also throw in a question for the group. I had the same issue a while back, and Paul pointed out the same solution. Needless to say, he was absolutely right �� you really want to have a stable and noise-free connection between the mount and your control software.

In my case, I cleaned all the connectors with Sonax (any similar brand will do), and it helped reduce the issue (it happened fewer times). I've narrowed down the problem to the Gemini RJ port on the gemini board, and I noticed there's an alternative communication method through the hand control DB port that I haven’t tried yet (https://gemini-2.com/2nd_Communication_Port_Cable.html).

Here’s my question: Is replacing the RJ11 (11 or 12?) an easy fix for someone unskilled in electronics like myself, or should we go down the DB15 route instead? Good luck Ciril and thanks in advance for any additional comments on my inquiry. Guy

Re: RA Motor Slop

corey_d@... (WayBack) — Wed, 02 Apr 2025 09:35:21 -0700

On Wed, Apr 2, 2025 at 11:16 AM, Chip Louie wrote:

What are "Paul's Safety Clips"

Chip the comment referred to the earlier comment on this thread. Where Paul mentioned using a washer as a clip hold the motor flange against the housing. Preventing stress on the mounting bolts either before or after repair becomes a requirement.

And the waxed dental thread material for damaged threads also something worth remembering.

{

On Thu, Mar 27, 2025 at 10:36 PM, Paul Kanevsky wrote:

I used the other screws that go into the metal cover, unscrewed them, put a fairly wide, rust-proof washer on them, then screwed them back in

}

Doug

Re: RA Motor Slop

yh@... (Paul Kanevsky) — Wed, 02 Apr 2025 08:33:32 -0700

On Wed, Apr 2, 2025 at 11:16 AM, Chip Louie wrote:

What are "Paul's Safety Clips" what do they do?

/g/Losmandy_users/message/83708

Re: RA Motor Slop

chiplouie@... (Chip Louie) — Wed, 02 Apr 2025 08:16:05 -0700

On Tue, Apr 1, 2025 at 08:17 AM, WayBack wrote:

On Sun, Mar 30, 2025 at 06:21 PM, George Cushing wrote:

However, I came across this.....

I'm not sure of any material advantage exists for not just replacing the part, given this new part exists and installed with fewer unknowns. But that reference link for repair of plastic coverings is a wonderful resource to keep in mind.

Losmandy assembly should really use Paul's Safety Clips to help prevent the issue. And sell a modified short motor hex key tool for these motors. Something that fits straight in, limits torque, and costs $1 but sells for $5 to help with the stocking overhead.

Thank you,

Doug

What are "Paul's Safety Clips" what do they do?

Chip Louie Chief Daydreamer Imagination Hardware

Astrospheric Forecast - South Pasadena, CA

Re: RA Motor Slop

corey_d@... (WayBack) — Tue, 01 Apr 2025 08:17:33 -0700

On Sun, Mar 30, 2025 at 06:21 PM, George Cushing wrote:

However, I came across this.....

I'm not sure of any material advantage exists for not just replacing the part, given this new part exists and installed with fewer unknowns. But that reference link for repair of plastic coverings is a wonderful resource to keep in mind.

Losmandy assembly should really use Paul's Safety Clips to help prevent the issue. And sell a modified short motor hex key tool for these motors. Something that fits straight in, limits torque, and costs $1 but sells for $5 to help with the stocking overhead.

Thank you,

Doug

Re: RA Motor Slop

stm32bluepill@... (George Cushing) — Sun, 30 Mar 2025 15:21:20 -0700

Yes, but in this design there's really no material to take advantage of the helicoils strengths. It can only thread into the same plastic.

A good quality stainless 4-40 has a yield strength of 120 pounds. A 0.112 4.40 tapped hole in 16 ga. ABS has about 60 pounds. No more than 1 in-lb. torque on the screw is recommended.

I've used heat set threaded inserts and they work well with less chance of breaking the plastic. Problem is I've had about 3/16th" plus thick plastic to set them in. The gear housing doesn't look that heavy. However, I came across this you tube, which offers a solution.

https://www.youtube.com/watch?v=a4LoMJGfhzg

Re: Making a model with limited sky visibiltiy.

kevinwalsh324@... — Sun, 30 Mar 2025 10:58:41 -0700

For what it’s worth��

I’ve had my G11 for slightly less than a year now, after years of having Celestron GEMs. The G11 on a permanent pier.
Like with your situation, my sky is limited by my garage and tall trees. Here’s what I did to get to get decent go-tos.

In the daytime I used a ‘carpenter’s level�� app on my phone to set the tilt of the saddle equal to my latitude, then I used a solar app to set the mount pointing due north at local noon. This gave me a rough polar alignment.
I don’t have a polarscope, but at night I was able to see Polaris through tree branches, so I eyeballed through the polar axis to tweak the mount to center Polaris.
I could see a few bright stars, so I then used the ‘Polar Alignment Correction�� app in the Gemini II to further tweak the PA. (Scott Losmandy has a video describing this procedure on the Losmandy YouTube channel.)
After a few months of use I could tell that the PA still wasn’t great so I ran the ‘Drift Alignment�� routine in PHD2. This worked quite well even with my very limited sky.

So now I do a 1-star synchronization on a bright star at the start of each night and then my automatic go-tos are pretty close. Occassionally I need to use platesolving to center the mount. For this I use the DSLR astrophotography software BYE/BYN along with ASTAP and Carts du Ciel.

Another option, if your polar alignment is roughly ok, is to go to a bright star near the object you want to observe, then do ‘Model/ Synchronize�� on the HC. This will improve any go-tos you do in that part of the sky.

Re: RA Motor Slop

chiplouie@... (Chip Louie) — Sun, 30 Mar 2025 07:41:51 -0700

On Sat, Mar 29, 2025 at 06:25 PM, Mike Colyar wrote:

I disagree with the idea that a thread repair solution like a Helicoil is not effective. The approximately doubling of the screw to female thread engagement area makes for a very much stronger fastening. There are several alternative systems on the market but the Helicoil design is probably more likely to be available at any decent sized fastener store. The required inserts, insertion tool and tap is not a five and dime purchase but compared with a replacement motor it is a bargain. And fix all of them while you are at it. Be proactive.

For what it is worth, when I build apparatus for highly stressed environments such as racing cars and aviation related designs, I build thread reinforcements of some sort into the design.

Mike

Mike,

Where applicable Helicoil threaded inserts are an excellent solution for many metal thread repairs. I have used them for decades in street and track car chassis repairs and modifications as well as alloy cylinder heads, blocks etc.

Where applicable are the key words.

Chip Louie Chief Daydreamer Imagination Hardware

Astrospheric Forecast - South Pasadena, CA

Re: RA Motor Slop

mike@... (Mike Colyar) — Sat, 29 Mar 2025 18:25:50 -0700

I disagree with the idea that a thread repair solution like a Helicoil is not effective. The approximately doubling of the screw to female thread engagement area makes for a very much stronger fastening. There are several alternative systems on the market but the Helicoil design is probably more likely to be available at any decent sized fastener store. The required inserts, insertion tool and tap is not a five and dime purchase but compared with a replacement motor it is a bargain. And fix all of them while you are at it. Be proactive.

For what it is worth, when I build apparatus for highly stressed environments such as racing cars and aviation related designs, I build thread reinforcements of some sort into the design.

Mike

Re: Making a model with limited sky visibiltiy.

corey_d@... (WayBack) — Sat, 29 Mar 2025 13:03:58 -0700

On Wed, Mar 26, 2025 at 11:50 AM, David Woolf wrote:

I have limited visibility

With the HC (L6/1.6) you can use the mount to select your stars. Say I set the mount to CWD and Cold Start, then I want to use a visible bright star. Slew the mount manually to point the OTA at the star, well generally near or I use the finder. Press Menu->Identify and select the BSL catalogue. That returns a list of stars sorted by how close within the list the OTA points. This BSL-star will be the top or closest bright star that the telescope points at. GoTo that selection and center in the eyepiece. Enter Menu->Model->Alignment for the 1-star alignment and synchronization.

Then I slew to another star if desired, picking good placements. Remembering we want them separated over the extended quadrant as well as possible for a given model side because any error centering on the cross hairs magnifies as the calculated circles extend to the galactic pole. (A bad model works exactly like a good model, in a like manner). So, if the OTA allows, reach across the meridian without changing saddle sides (without flipping) use these stars too as needed. Visually we need good polar alignment with a 1-star alignment per side. Or near polar alignment (<a few degrees) with three-to-five-star alignment on a side.

Regardless of good or a so-so alignment, as mentioned I too always synchronize on a local star near where any target resides. Again, IDENTIFY can be used to sync and center reliably.

Doug

Re: RA Motor Slop

stm32bluepill@... (George Cushing) — Sat, 29 Mar 2025 09:08:25 -0700

Lots of videos on FB/You Tube on repairing plastic. I generally heat weld plastic to fill the stripped hole and reinforce with fine metal screening that either epoxied or melted in to the plastic. Drill and rethread. $4-40s are a bit light for this purpose and given the size of the structure I'd Try some 3mm screws they are 0.1133" just a bit larger than the #4"s 0.1120". 3.5mm gets you up in the same territory as #6.

Re: Installing Gemini-2 Driver on an Android Tablet

dkfcpalfd@... — Fri, 28 Mar 2025 17:45:30 -0700

Thanks for that, Chip, but we can't connect to the mount. In plugging into the Ethernet Port onto the ASI Air unit, green light comes on, with other end of the cable plugged into the Gemini circuit board.... but I know that doesn't mean much.

The club member is putting a thread onto an ASI Air forum. The scope is in a remote location, and we have to drive there to do anything with the circuit board. It has L6.02 installed which is fairly recent, with V3 software flashed onto the encoders.

I'm thinking we're close to connecting.

Re: Installing Gemini-2 Driver on an Android Tablet

chiplouie@... (Chip Louie) — Fri, 28 Mar 2025 14:48:49 -0700

On Wed, Mar 26, 2025 at 03:36 PM, <dkfcpalfd@...> wrote:

Brendan... please read the post I gave above. ASI Air would not allow any input into the Default Gateway data field.

Look... I have a Losmandy mount. This is a Losmandy forum. But someone with familiarity connecting a Losmandy mount to the ASI Air is going to have to respond to this.

Hi Dan,

Sorry for the off putting PM, I took your post as a demand for an answer, my mistake.

Here is what I think is going on. The reason you cannot put anything into the Default Gateway IP fields is the ASIAIR is probably already in the normal default router mode and doesn't need a Default Gateway because the ASIAIR IS the Default Gateway and is serving packets. So whatever the ASIAIR's IP address is is the Default Gateway to the devices that are connecting using the ASIAIR's Wi-Fi SSID. Does that make more sense?

Chip Louie Chief Daydreamer Imagination Hardware

Astrospheric Forecast - South Pasadena, CA

Re: RA Motor Slop

chiplouie@... (Chip Louie) — Fri, 28 Mar 2025 13:58:10 -0700

On Fri, Mar 28, 2025 at 07:11 AM, Michael A. Covington wrote:

Could you repair plastic threads by putting a bit of plastic cement
(glue) into the threads, letting it harden, and then letting the screw
cut new threads into it?

The gearboxes are a slightly soft plastic so regular plastic glue that melts the plastic to form a bond probably won't work. The heavy dental floss does work and you can adjust how much you use to get a tight mechanical connection. I wouldn't count on it as a permanent solution but it seems to work pretty well. I like the plain stuff but if you like a minty fresh mount pickup the mint flavored stuff. 😎

Chip Louie Chief Daydreamer Imagination Hardware

Astrospheric Forecast - South Pasadena, CA

Re: RA Motor Slop

chiplouie@... (Chip Louie) — Fri, 28 Mar 2025 09:48:50 -0700

On Fri, Mar 28, 2025 at 05:05 AM, <davidrico13@...> wrote:

Helicoil

Not very effective in most plastics especially a thin plastic part like this. The best route I have found is to replace the gearboxes with a new one. Or alternatively use common thread adhesive or a piece of thick dental floss on the hole as the standard fastener is screwed in, (it can take two lengths in the hole for the threads to get good purchase) as an emergency fix while you wait for new gearboxes. The gearboxes are pretty durable if you are careful when staring the fasteners but they tend to be sort of a wear item for those who disassemble their mounts often. Stock a spare.

Chip Louie Chief Daydreamer Imagination Hardware

Astrospheric Forecast - South Pasadena, CA

Re: RA Motor Slop

astro@... (Michael A. Covington) — Fri, 28 Mar 2025 07:11:01 -0700

Could you repair plastic threads by putting a bit of plastic cement (glue) into the threads, letting it harden, and then letting the screw cut new threads into it?

Re: RA Motor Slop

davidrico13@... — Fri, 28 Mar 2025 05:05:50 -0700

Helicoil

Re: RA Motor Slop

brenatlilydale@... (Brendan) — Thu, 27 Mar 2025 19:37:48 -0700

David.

The motors are held against the Plastic gearbox by UNC 4-40 screws. Constant removing, reinstalling or over tightening of these screws damage the plastic threads. Easiest fix is to replace the gearbox and be aware of this issue.

A better fix would be trying plastic welding the gearbox or adding some type of nutsert inter the rear of the gearbox front plate. Which means splitting the gearbox and working out a way to try fit a small thin plated tapped to suit or one of those plastic nut inserts. Something that doesn’t interfere with the gears. Then use M2 long screws to reassemble and secure the gearbox together.

One user, a while back cut a hole in the rear of their gearbox so they can see and adjust the pinion mesh better. Which I think was a good idea if you disassemble and repair the Gearbox

FWIW

CHEERS

Brendan

Re: RA Motor Slop

yh@... (Paul Kanevsky) — Thu, 27 Mar 2025 19:36:14 -0700

On Thu, Mar 27, 2025 at 09:33 PM, David Woolf wrote:

The RA Motor on my G-11 is so loose that I have to slap it back into position in order for it to engage the gears. I don't see any way to "tighten" it so it doesn't wobble in and out of the housing. I fear I damaged something by incorrectly transporting the mount sitting on the motor. Does anyone know the correct fix for that? Photo shows the motor in the "out" position.

Hi David, you probably stripped the thread that the motors screws screw into. That's not hard to do, these threads are plastic.

You can try to repair the threads with some adhesive (something that's designed to bind metal and plastic), use a slightly larger diameter screw, or do what I did. I used the other screws that go into the metal cover, unscrewed them, put a fairly wide, rust-proof washer on them, then screwed them back in. The washers press on the front lip of the motor, keeping it pressed into the gearbox and stopping it from moving. And these screw into metal, so are much harder to strip :) YMMV.