Story of a custom TREX Mount - Part 1

[issdaol (Phil)]

Hi All,

Have been looking for a new Alt/Az Mount for some time and have not been really happy with the choices on the market.

I essentially wanted something that could handle a Takahashi TOA150 for Solar & Lunar observation as well as some general purpose observation leaving the bulk of deep-space and planetary to the Mewlon 300 on the EM400 EQ mount.

The overall concept was to have a mount that provided the following:

• Manufactured in Japan with high quality Japanese construction and materials
• Utilised components from other Tier 1 Japanese and European Manufacturers where possible
• Matched colour and texture of finish to Takahashi Standards
• Fitted primarily to Takahashi Tripods but also other Tier 1 Japanese and European Tripods
• Could handle payload up to TOA150
• Easy setup and transport

Nothing seemed to fit the bill until I got in touch directly with the manufacturer of the TREX to discuss what I wanted. After several weeks of discussion and design ideas going back and forth we determined that a solution was possible with once off customised TREX to test if the idea worked.

After the modification plans were finalised and pricing negotiated I accepted a pro-forma invoice in order to commit the factory to the production of the customised unit.

All dealings with the Manufacturer was very pleasant and professional, with everything taken into account from the material, sizings through to final transport/delivery logistics.

The great thing was the positive attitude from the outset about the customisation to solve a problem. Most manufacturers just say this is the product range and will not entertain modifications outside of their own production plans.

Once all the Items were complete and pre-tested in the factory they were packed and shipped via Airfreight with full tracking and insurance.

As you can see from the attached pictures everything was packed professionally in one box. Using foam balls. Each piece was further wrapped in bubble wrap and major components were additionally wrapped in soft tissue paper to avoid any markings or scratches to the surfaces. Some components were also packed in another internal box and foam for additional protection.

Suffice it to say with all this packing everything arrived in perfect shiny and glossy condition :-)

You can see all of the components laid out in the final photo.

I will stop here and continue on over the next couple of days with additional photos and explanations of each Item and the Modifications and why each was done.

Cheers

[Kunama]

This I will have to see in person Phil. Love the idea, the T-Rex is such a great mount, wish I had not sold mine.......

Waiting for updates to this thread

[The Mekon (John Briggs)]

Yes I have been interested in the T Rex for some time now. I hope you will use the Argo Navis in the setup. Look forward to seeing more!

[issdaol (Phil)]

Following on from my prior post:

As you can see from my prior pictures there are quite a few components included in the TREX box. Most of this components are standard TREX and include:

• Slow Motion Controls
• Encoder Cables
• Alt/Az Axis Lock Handles
• Argo Navis Cradle
• Standard Alt/Az Guide Handles (in Takahashi Green)
• Standard Saddle
• Standard Saddle Lock Bolts (in Takahashi Green)

All tools are included but this is essentially a pack of allen keys as you don't need anything else to put the unit together.

The rest of the items are the customised components which include:

• Customised TREX Mount in Takahashi Green
• Customised Pier Adaptor in Takahashi Green
• Customised Pier In Takahashi Green
• EM400 Metal Tripod Adaptor in Takahashi Green
• Stainless Steel Counter Weight Bar 25mm OD with Brass Lock Nut
• ADM 13inch Saddle Plate for Takahashi Mount 35mm Centre on Centre

Look and Finish:
First off I will point out that I wanted a mount that would match the over look of my Scopes and Accesories so that it appeared to be a total system. Obviously function is more important but I think we all like to take pride in the equipment we have purchased so if we can get it to match without any compromise to function then all the better.

In my case I have a lot of Takahashi equipment and I was using a Takahashi scope so I asked to see if they could do this. Initially the answer was no but interest in the overall project won out so I was able to get a happy yes.

I must say that I am very pleased with the finish as not only is very close to Takahashi Green but they also managed to get the Takahashi textures in the finish (take a close look at the texturing of the paintwork) so the end product looks like a Takahashi product and matches all the accessories.

The finish of the Stainless Counterweight Bar and Brass Lock Nut is nicely finished in that brushed look for the stainless components and polished and chamfered look for the brass.

The Anodised black components also match up well for the Saddle, Counterweight Attachment to the Mount and Argo Navis Cradle.

Running out of time so I will finish off here and continue on in Part 3 :-) Enjoy the Pics so far :-)

[UniPol]

How much did all that cost Phil?

[Kunama]

I like that they matched the texture of the Tak sand casting when painting it.
Looks excellent! I toyed with the idea of painting mine that colour.

[issdaol (Phil)]

Originally Posted by Kunama

I like that they matched the texture of the Tak sand casting when painting it.
Looks excellent! I toyed with the idea of painting mine that colour.

Yes its an amazingly well done match :-)

[issdaol (Phil)]

Continuing on from earlier:

Anyone that has done significant visual observation over many years knows that rock solid stability is key to removing those annoying vibrations and movements that play havoc with focus and make whatever you are looking at a jittery or blurry mess. Often this gets forgotten about or people put up with it to a large degree but for myself I hate it so I try to put my systems together with the view to eliminating it as much as possible.

TREX EM400 Adaptor & Tripod
So step one was selection of tripod for use with the TREX. I had a spare Takahashi EM400 Metal Tripod which is one of the best and most stable tripods around. It has a load rating of 490kg (yes almost 1/2 tonne) witch as far as I can determine is by far the largest load rating of any Astronomical tripod I have been able to find.

Only problem being was the head does not match the TREX Mount or the TREX Pier connection. So an adapter had to be thought up. For this I took inspiration from my Takahashi EM400 mount coupling. As you can see from the pictures the top of the tripod is circular so the an adapter was made up that almost exactly mirrors the one on the bottom of a EM400. We later found out that this piece can actually be ordered from Takahashi (although they don't advertise it) but it would have needed slight modifications anyway to connect to the TREX Pier so we were happy that what we had was perfect for our purposes.

TREX Pier & Pier Adaptors
A pier adaptor was required to raise the mount up to an acceptable viewing level. I prefer this method rather than raising the tripod legs as it keeps the centre of gravity low. Again a major factor in stability especially on uneven terrain and with heavy loads.

In the pictures you can see the top of the pier and how it mates to to the bottom of the TREX using a locating nut and hole (similar to the Vixen mounts and tripod heads), secured by a large bolt through the middle. Then the Pier tube is secured by 3 cap screws around the circumference.

A special modification to the bottom of the pier was devised using a circular slab of aluminum (black) with a protrusion that fitted through the hole of the EM400 mating cap. This is then bolted underneath the cap and the whole pier is again attached by 3 cap screws around the circumference. In the pictures you can see all separate pieces and the last picture show the pier in its final position bolted to the top of the EM400 mating cap/adaptor and on top of the tripod. So apart from the Pier tube and the TREX connection all of these components were custom made and finished. Again great detail and engineering on behalf of the factory to turn out these parts.

The great thing about all this is that when situated on top of the tripod, the three mating screws around the perimeter of the mating adapter can be minute loosened and the whole lot swiveled to allow slight adjustments in alignment to point true south or north.

Also the connection of all of the components takes minutes to achieve as all of the parts are precisely engineered to mate together and there are no concerns of screws being loose or off center.

Need to get back to work so I will come back later with the final discussion and pictures on the mount head and telescope mating.

Cheers

[The Mekon (John Briggs)]

The great thing about all this is that when situated on top of the tripod. The three mating screws arounds the perimeter of the mating adaptor can be minute loosened and the whole lot swivelled to allow slight adjustments in alignment to point true south or north.

Cheers

[/QUOTE]

I don't really follow the reason for this comment. It is an alt/az mount?

Or does this apply to an alternate EQ head?

[issdaol (Phil)]

I don't really follow the reason for this comment. It is an alt/az mount?

Or does this apply to an alternate EQ head?

Yes the Mount is Alt/Az however it has inbuilt encoders. So there are 2 very good reasons to point this out.

1. The mounts encoders can be connected to ArgoNavis for Push-To location of objects. So this requires alignment and best alignment means having the ability to level the mount and point to a known starting position such as true south or north. Without a simple way of adjusting the orientation you may have to unload everything, adjust then reload everything. With this mod the TREX does not need to be unloaded :-)
2. Sometimes even for full manual use it comes in handy to change the orientation of the mount and payload to help avoid tripod legs. This allows you to easily do so again without having to unload anything.

Hope that helps ? :-)

[issdaol (Phil)]

Continuing on from earlier:

ADM Saddle Plate
Obviously a well crafted saddle plate is needed for any telescope and mount. I have found ADM easy to deal with and their Saddle & Dovetail plates to be well made. One of the unique points is that ADM make the plate to be full length clamp rather than just a couple of segments clamping. For me this gives extra piece of mind that a large telescope has a more secure connection across the entire length of the saddle. Specifically for the TOA150 and similar large APO's with the TREX the 13inch Saddle I feel is necessary. Otherwise you do not have the necessary travel for balancing the scope. On lighter OTA's this is much less of a problem.

Counterweight Shaft
The TREX had no contingency for a Counterweight system and with smaller lighter OTA's probably does not need one. However the TOA150 is a lot heavier than traditional OTA's even other 150mm and 160mm APO's. One of my design stipulations was that we could re-use existing equipment either already owned or currently being made. So as I have a Takahashi EM400 mount I wanted to use the spare counterweights that I already had. The EM400 8kg counterweights are very well made and finished and have 2 highly polished and lacquered securing bolts. For such a straightforward item they are little works of art in them selves. They require a bar with OD of 25mm so a brushed stainless steel bar same size and lenght of the EM400 bar was produced. This was finished off with a nice polished Brass lock nut at the end. However a unique connection was required for the TREX mount. So a new receptacle was designed and fashioned from anodized black aluminum and is securely bolted to the side of the mount close to where the standard cradle for DSC attaches. The counterweight bar has one grooved end which mates with this receptacle and is securely fixed by a anodized black bolt.

TREX Mount
The TREX mount itself is largely factory however there are a few very important functional and cosmetic modifications that have been done to enhance it's use and allow it to cater for a scope of the length and weight of the Takahashi TOA150. Many of these modifications have been detailed in the lead-up to this point but I will just briefly cover them off and then move onto my in-use experience so far.

First off is the obvious Takahashi Green Finish :-) This also extends to the texturing as well :-) It's an amazingly well done match.

Next is the customised Counter Weight receptacle and bar. It looks completely integrated and not like an afterthought.

Standard there is the DSC Cradle and Bubble Level. So you have a nice place to hold your ArgoNavis or other DSC and the level does a good job for a inbuilt unit.

More importantly the gearing has been setup to handle the higher load of a TOA150 and was fully pre-stress tested at the factory. While aftermarket adjustments and gearing could potentially be done those mods would not be supported by the manufacturer.

The other customised components already mentioned are the pier and Takahashi tripod adapter.

Setup & In Use
The setup of the the mount is very quick and simple.

1. Place and orient tripod.
2. Level Tripod (I use a good quality digital unit used by many tradesmen)
3. Pre-bolt Pier to Tripod Adapter and ensure that all cap screws and bolts are tightened down (only need to be done once on initial use)
4. Place combined Tripod Adapter+Pier unto mount and tighten down peripheral cap bolts
5. Pre-bolt Pier to Mount Adapter to TREX Mount (only needs to be done once on initial use) and tigten down securing nut
6. Bolt combined TREX+Pier Adapter to top of Pier and tighten all three peripheral cap bolts
7. Bolt Saddle securely to Mount (only needs to be don once on initial use)
8. Connect all other accessories (Slow Motion Controls, DSC Cradle Holder, Axis Lock Bolts.
9. Connect Counter Weight Bar and tighten down.
10. I do a level check at this point as the setup is still easy to maneuver and adjust.
11. Place 1 or 2 8kg Counter Weights on the bar and lock into position and replace brass safety nut. Obviously counter weights will differ depending on OTA.
12. Attach OTA+Dovetail to Mount and level OTA by adjusting position in the saddle and/or adding tube based counter weights.
13. Make sure all Axis Bolts are tightened down

You are now ready to start observing :-)


We have found with testing that the TOA150 is the practical limit of the TREX in it's current customised form. Specific to using the TOA150 or similar size&weight OTA ALL of the customisations (obviously apart from the Takahashi Finish) are needed.


Using a smaller Saddle and Dovetail on the TOA150 makes it much harder to balance out the OTA. Also there is the secure attachment and dampening factors as the larger attachment and surface area involved makes for a much more stable connection.


Also the counterweight bar is also needed as it allows the whole mount and tripod to be much more stable and reduced strain on the gears on that Axis.


With this load the balance is critical to proper meshing and smooth operation of the TREX gears.



The tripod and connection modifications used make the whole system rock solid.


I have found that in the configuration pictured with these modifications that the TREX responds very smoothly with great dampening. The Altitude Axis does feel much more loaded but it still responds smoothly. I can actually unlock both Axis Bolts and the scope will stay in position unless moved manually.


This mount will be an awesome match for anyone with a Mewlon 250/210 and TOA150 or smaller Takahashi scope wanting a Tier 1 Japanese made Alt/Az mount with superb build and support from the Manufacturer.


I hope this report helps anyone thinking of a quality Alt/Az setup


Cheers

[Kunama]

I think this will help lighten my wallet again That looks the goods !!
Having seen their build quality first hand, I think this will be popular as long as the price is reasonable.
Reasonable being a relative term ......

[UniPol]

Originally Posted by UniPol

How much did all that cost Phil?

Must have been pretty expensive then

[issdaol (Phil)]

Originally Posted by UniPol

Must have been pretty expensive then

LoL

This project was a "prototype" modification from the factory to validate the capability so I cant really tell you proper pricing.

Reality is the TREX will never be as cheap as mass produced mounts. But if you compare the build and finish side by side the TREX wins out everytime.

Plus support from the factory is superb.

This may or may not be important to someone but I prefer to buy knowing that

1. engineering specs and build are superior
2. the chances of failure are very low and
3. support is at hand if ever needed

Cheers :-)

[Kunama]

One question that comes to mind Phil, how did you decide the appropriate angle at which the c/w shaft is in relation to the mount? Is this angle best suited to your particular scope (TOA150).

[casstony]

The angled forward CW bar gives more accurate balancing of the telescope centre of gravity which is offset a few inches to the rear.

My home made perpendicular CW bar works almost as well though.

[Kunama]

Thanks Tony, I do recall how yours was set up. I am waiting on some parts from US of A to get mine sorted. Might have to get the Tak green paint out ....... (My son-in-law is a painter )

I really like the way Phil's T-Rex has turned out.

A big thank you my little mate Col who has relinquished the guardianship of the T-Rex back to me much to my wife's chagrin , as she has been trying to curtail my spending on astro......
(to no avail )

[casstony]

Are you fitting an angled or perpendicular CW bar Matt?
I imagine the CW bar and mounting point that Phil has could be purchased from KK and bolted onto an existing T-Rex.

[Kunama]

I am not sure at this stage that I will actually need a c/w bar as I am only using the FSQ106ED on it. I just have to set up the scope further forward using the Casady 14" dovetail and saddle as the FSQ is butt-heavy to the max.

I think in the event of a larger scope the angled bar might be the way to go. I note that Phil's mount has 3 holes drilled in the 'L' plate (2 for c/w and 1 for the DSC).

I am rather envious of the EM400 tripod Phil, I found the standard SW GMT128 was fine till I put the longer refractors onto it in a bit of breeze. Might have to invest in a heavier tripod.

[issdaol (Phil)]

Yes, as suggested by Tony the angle offsets the OTA quite nicely and also means that it is not obstructing any other components of the mount so multiple problems solved at once.

Larger scopes on smaller tripod combinations will find the CW bar to be quite handy.

Plus the CW bar being sized to Tak standard means that nicely finished and matching CW's can be easily purchased.

Considering how smooth and stable this combination is I may look to organise another soon.

Matt if you are after a tripod the EM400 is the best I have used for large and small scopes. Not even a heavy breeze will move that tripod.

Maybe a Mack or Kenworth Truck driving over the top might kill it lol