MikroMounts

Precision 1/12 scale fully operational telescope mounts

 

 

Base model w/manual drives: $420

Base model w/ dual axis motors/gears/clutches/wiring:$540

(Requires control kit listed below to operate)

bronze legs instead of 3D printed structural plastic: +$96

more options below

Note: Before you get too excited, these are not made to track at sidereal rate.

These were made as a very limited run for the collector and can vary slightly from each other.

They are hand made in USA. Prices are subject to change.

 

For video search MikroMount1 in Youtube.

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HISTORY

 

In the mid 1990s I made my first "micromount" that had dual axis motor drives with Northern/Southern hemisphere use. Had sidereal tracking/guiding rates and 10X higher setting rates with just 9 volt battery power. The worm gears were the smallest that PIC/Berg make (64 pitch). The mount had slip clutches for manual override. Miniature Swiss DC servo motors were used with micro-processor control. No expense was spared. Has polar alignment scope and green laser finder on later astrograph version.

Payloads included a 1" f/12 refractor with 7/16" dia. eyepieces. I could replace the refractor counter weight with an Olympus OM 1 film camera and 50mm lens. I also made a miniature illuminated reticle eyepiece for guiding through the refractor @ 20x. Tracking was so good that unguided film exposures of 5 minutes were routine. Later the refractor OTA was replaced with a CCD camera and 50mm lens allowing for really spectacular mini scope CCD images seen below.

 

Old 35mm SLR set-up and result

 

Image is sum of 8 minutes w/1200x1600 Super Star and 50mm lens (unguided) using prototype equipment above.

This mount has just 1/4" axles

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THE PRESENT

 

1/12 scale working telescope mount w/optional model OTA.

Fast forward 25 years and retired, I still wished to dabble in telescope making. I stumbled on a source of miniature 1" diameter 100 tooth worm gear sets. They would be ideal for an even smaller mount. So I began a micromount project and decided to follow the early style 1940s-60s ATM style pipe fitting mounts we made back then.

 

 

 

 

After much prototype testing I decided to produce a limited run of these hand made mounts. I use manual machines and not CNC. They were all machined during the winter of 2017.

 

FEATURES of base version

All metal construction except the 3 pedestal legs and tube saddle that are 3D printed in Alumide (mix of nylon and aluminum powder). It adds strength and has a nice 1/12 scale cast surface. Heavier 3D printed bronze legs are an option.

Ground steel axles of 1/4" dia. This scales to 3" dia. full scale.

Scale bronze pipe fittings (excellent bearing material)

Miniature 100 tooth bronze worm wheel (just 1" diameter with true concave tooth profile). Mounted in adjustable slip clutch assembly.

Steel worm running in double ball bearings. Tiny 1/4" diameter worm and 1/8" bearings.

Fine knurled aluminum RA clutch ring. Just 1/2 turn adjustment range needed.

Scale fasteners from 2-56 to 1-72

Very fine declination tangent screw motion and a positive 2 thumb screw dec axis clamp. Can be lightly tightened for clutch like action.

Stainless steel leveling screws with removable rounded metal pads.

1/4-20 tripod mounting of pedestal

One scale (1 oz) and one large (2.6 oz) stainless steel dec counterweight (movable)

RA/DEC axis intersection centered on main pier/pedestal for optimal balance.

RA/DEC manual motions are very low friction and smooth for 1/12 scale. RA= 3.6 deg/turn and Dec is 0.5 deg/turn

3 D printed tube saddle is radiused for 1 3/4" diameter tube. (19" dia. full scale)

Pier /base assembly painted in dark bronze metalic

Special wrench set for working on MikroMount

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OPTIONS

 

Heavier 3D printed bronze legs can be substituted for plastic legs at time of mount purchase. Adds 2.5 OZ or ~25% more weight. Nice solid feeling. These have a natural bronze patina that closely matches the miniature bronze pipe fittings. Standard painted leg set on left of image.

 

PRICE: $96

 

 

 

 

 

 

Dual axis miniature (10mm dia) gear motors with mounts, 4 brass gears,2 additional clutches and soldered wiring. About 24" of 26 gauge twinned wire with micro connectors to motors. This option can only be installed during mount purchase by me or your mount needs to be sent back later for this option to be installed. NOTE: Even with their super miniature planetary gear reduction these motors will not track the mount at sidereal rate. . ..

With below controller kit the RA speed range is variable 1/2 deg/sec to 10 deg/sec. Dec is variable 1/10 deg/sec to 1.6 deg/sec. RA motion is almost a full 360 rotation. Dec is limited to 24 degrees motorized movement by the tangent screw length. Loosen clamp and dec rotates almost 360 degrees. These motors can be run on 1.5 - 9 volts. Speed range is ideal for a modded 25mm fl. webcam in realistic miniature OTA. You can make you own DC driver as simple as just a 9V battery and 4 momentary switches to run these motors at full speed.

Note: this option will add more rotating friction to the manual control knobs due to addition of friction slip clutch between gear and motor. This can tension be readjusted by customer.

PRICE: $120 installed

 

 

installed motor option/ wiring with white micro connectors

 

Below image = tiny motors/connectiors/power cables to controller

 

 

A reversible/variable speed control kit with 9 volt battery and illuminated on/off switch. Independent operation of each motor and all prewired by me as a ready-to-mount-kit. Just hook up the 4 motor wires and run. You make your own enclosure. No soldering. High quality solid state PWM units with 4 relays, all running off one 9 VDC battery. Very compact and nice hardware. 2 circuit boards are bolted together for simple 1 screw mounting or can be separated. Predrilled mounting cover available below for simple fixed component mounting. A fun project. PRICE: $120

 

 

 

 

PREDRILLED cover w/7 holes. 5 x 5 inches, 1/8 ply for mounting switches etc.

PRICE: $15

 

 

 

 

 

 

 

 

 

Parallel Joystick control with an 8 wire conductor cable, 24" long. This is a switch type joystick. A color coded wire harness with connectors is supplied with this joystick assembly. It needs to be customer wired to above units' 4 switches in parallel to joystick. Must be soldered. Make your own enclosure. This joystick assembly is less than 2" square and nice quality.

Both RA and Dec can be run at same time with joystick deflected to a corner. Once wired, the joystick works in tandem with the push buttons.

PRICE: $60

 

 

 

Aluminum OTA with light weight .035" wall x 1.75" O.D. x 8" length with machined ends. Just 2.4 ounces. A carbon graphite looking cover cloth can be attached for $10 additional. Same as on personal prototype image above except spider vanes and focuser shown are not included. Inside of tube remains unpainted unless requested.

This tube size allows for a customer modified webcam to be placed inside. My modified webcam on the lower right can be rotated in rear of tube for a level image necessary with this German equatorial mount style. Note camera cable is stripped back to minimize weight/drag on the MikroMount.

 

PRICE $36 each (just aluminum tube) NOTE: there is only one special source for these thin wall tubes and then I have to buy 3 at a time plus shipping.

 

 

Custom metal chemical coloring of bronze from tarnished bright on left to rich dark brown to brown black. Oiled finish and nice contrast. The pedestal assembly still remains a painted bronze color.

PRICE: $20

 

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1:12 SCALE

 

What does 1/12 scale mean? One way would be to say 1 inch = 1 foot for sizing. For weight or mass it is the scale 12 to the 3rd power or 12x12x12 or about 1700 times heavier or lighter. So the base version mikromount @ 11 ounces would weigh over 1100 pounds at full size. The mounts tracking speed at degrees per second would remain the same since time and angle won't change with scale. The force or grip of your fingers will be 1700 times stronger to the 1/12 size model! Per below equivalents, one can see that this is a very heavy duty telescope mount.

3/4" metal pedestal / pier dia. = 9 inch solid ------1/4" dia axles = 3 inch------1" worm gear = 12 inch------8" height of mount = 8 feet

Builder's note

I have over 50 years of telescope building experience and also building miniature live steam engines and the sort. Most of the tiny fabricated parts are what I fondly call "finger burners" due to their small size. Many of the components I purchase are not cheap given the small quantities and their precise nature. I will remind you that money does not scale down with size and if anything can scale opposite what we would normally think. You will find that these small working model mounts are very refined, with smooth motions, balance and appearance. An abreviated webpage to some of my previous products is at Centurion18

Hop-ups

Add a webcam to the inside of an OTA and replace its standard 4.8mm lens with a 25mm lens. Both these items can be had for under $30 new on Ebay. Set the scope on your desk top and plug the camera into the usb port on your PC and slew around. Really fun-cool effect! Find something good, take a color still shot.

 

Volcanic mountain is over 4 miles away. WebCam image taken through the double pane kitchen window.

 

This was used for the above mountain comparison pictures. The spider vanes are far field diffraction which won't show.

 

Modify a continuous sweep clock movement to run the RA worm at 1440 rev/day. Add a 50 tooth gear to the minute hand and a 12 tooth gear to the worm shaft. A continuous sweep minute hand clock runs at 30 hertz and not 1 hz. I have taken 30 second wide field exposures with a 50mm lens and CCD camera. This takes a lot of dinkin around to do. Polar alignment and object finding are a challenge with a tiny 10 degree FOV CCD chip. Also waiting for the minute hand backlash to undo. A true clock drive!

Below is actual image taken with this set-up.

 

 

 

Starlight Express Super Star 1200x1600 & just a 50mm fl lens on MikroMount. Stack of 6 @ 30 sec unguided, cropped way down at 200% to show detail. Amazing what you can get away with! Detected to 14.5 magnitude stars.

 

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Use it for a stationary time-lapse dark sky video with a helmet cam.

SJCAM M20 is a nice fit and has a nifty remote control shutter watch option. 2 1/4 ounce payload on 12 ounce mount is solid. There is an excellent Milky Way time lapse video using 30 sec exposures @ ISO 1600 with a SJ M20.

 

www.youtube.com/watch?v=ICbjrXd9eOY He goes by Dakota ...I can offer a second threaded dec axle for this purpose as an option.Note: mounts do have a dec clamp not shown here.

 

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Gallery of MikroMount photos

Left is old prototype astrograph and right is new MikroMount w/ all options+

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My personal 2" Maksutov.

 

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Front and rear

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Tissue roll or kitchen foil roll diy OTAs

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bench work

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my personal controller and joystick

 

Tripod attachment hole in pedestal base

 

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Q&A

1) Can the mount hold my smart phone? No, that would be like putting a 120" flat screen TV on a full size telescope mount.

2) Then what kind of telescope /payload can I put on it? It would have to be a custom made affair or a webcam weighing ~12 oz or less.

3) With an optional 25mm fl lens on a webcam, what is the power? Based on my observations, it is close to what a 7x binocular view is like. The field of view is about 10- 12 degrees. But once the image is viewed on a monitor, it can be greatly magnified, for perhaps an equivalent 30x view.

4) How do I get one of these telephoto lenses? They are a M12 board lens and range from 2 to 25mm focal lengths. Ebay lists them under surveillance cameras or board cameras. They are focusable by turning the very fine thread. Just unscrew the original webcam lens and replace with a telephoto. Be sure to understand where the IR blocker is on your camera. Some are over the chip and others are attached to the rear of the lens. An IR lens has no filter so colors may be reddish. Some sellers show a choice of lenses with or without IR cut filter.

5) Where can I get a 1.5" dia. parabolic primary mirror w/ 1/2" minor axis eliptical diagonal mirror and 1/4" diameter eyepieces? I don't have an answer yet.

6) What is the Maksutov scope above about? It is a heavily modified 2" f/11 that I custom rebulit . Has machined 2.4" dia. aluminum tube with weight of just 8 oz. less eyepieces. There are 10 oz. of dec. counter weights. Total weight with mount is 32 oz. Handles very well. Must be used on tripod. The scale size is a 24" Maksutov tube assembly weighing 900 pounds, about as much as the mount! Fully functional.

7) Are these mikromounts ready to ship? The base models yes, however certain options will add some time prior to sending out. The bronze legs are a buyout item as are the controller kits and aluminum tube and time to wire it together. But they may be in stock.

8) I am a lefty, do you have left handed worm knobs? Yes. we have a few made that way.

9) Why can't the motors run the mount at star tracking speed? That very slow/precise speed is just 1 ~revolution every 24 hrs. (minus about 4 minutes to be more exact). This requires rotating the polar axle twice as slow as the hour hand moves on a mechanical clock. As you can see above, I did try a hack with a clock minute hand which sort of works.

10) Can you customize my MikroMount? Try me.

MikroMount Base Model $420 as pictured

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To purchase a MikroMount contact Jim Riffle by email at mikromount@gmail.com

Only the actual shipping charge will be added on.

I can send a PAYPAL invoice to your email for payment.

The MikroMount is a limited run, therefore subject to sell out.

Any questions are gladly answered, please ask via email.

Link to MikroScope OTAs

Link to Misc optical instruments for sale