Shop Microscope

[Highpower]

I got my Christmas present from the Mrs. early this year thanks to a Black Friday deal.  
It's an AmScope stereo microscope that will for the most part, replace my headband magnifier and $15 plastic USB "microscope".



Unfortunately being an import from China it has a lot of the typical problems right out of the box. First and foremost are the two sliding support rods for the adjustable boom stand. The center support houses some 20mm linear ball bearing sleeves for the upper rod to ride on while sliding back and forth which is great compared to plain bushings. However the manufacturer uses undersized soft steel rods which have a thin chrome flashing applied. Being undersized the rods wobble a bit in the bores. Even worse is that after only a few times sliding back and forth through the hard ball bearing sleeves the chrome on the rod start to compress and begin fretting - making crunchy, crunchy noises and dragging. So the two original rods were the first things to go. I turned two new rods from some properly hardened linear shafting which is a full 20mm OD. Butter smooth operation now.
You can make out some of the fretting in the center of the original shaft below.

   

The other issues are somewhat familiar to a lot of us I'm sure. Chinese hardware and attention to detail. The fasteners are also undersized and flash chromed. The socket head cap screws wobble in their threaded holes and the hex sockets are sloppy and deformed. I've replaced them with quality stainless steel fasteners. Same for thumb screws.

The focus rack that holds the microscope head to the boom stand rotates on the upper shaft of the boom stand to allow adjustment of the head in that axis. It is locked in position by tightening a lever much like the quill lock on a vertical mill. Two tapered cotters are squeezed together against the shaft to hold it in place. Mine would not even tighten up much less lock in place. I found the cotters were twisted in the bore and only a knife edge of the tapers were contacting the shaft. The shoulder bolt that runs through the cotters was hitting the screws that guide them in the bore. This prevented the cotters from getting pushed far enough into the bore to contact the shaft fully.

I had to re-drill and tap two new holes in the bottom of the focus rack on the center line of the bore for the guide screws and move them in more to allow the shoulder bolt to fully tighten on them.

   

I also had to re-drill (straight and perpendicular to the shaft center) and install a Helicoil insert for the SHCS that secures the focus rack to the shaft to keep it from pulling off when the lock lever is loosened. The original hole was sloppily drilled and threaded at a 10-15° downward angle, leaving such a loose thread fit that I could almost pull the screw straight out without turning it.

   

I still need to make an adapter to better secure the camera to the trinocular port. The camera lens just slides down into the port and sits there. The slightest movement of the scope head or USB cable will spin the camera (and your view on a monitor). Ain't nobody got time for that. Hopefully soon I'll be able to begin using it instead of fixing it's shortcomings.  

[EdK]

Nice gift. I've been eyeing those myself but just can't quite get myself to pull the trigger.

Ed

[TomG]

Good acquisition Willie!

I have an old B&L stereo microscope that I break out now and then for milling fine features and it works great. I also have a toolmakers microscope that mounts directly in the spindle that is quite handy, especially as my visual acuity slips.

Tom

[Highpower]

I was tired of trying to keep my 'other' USB scope steady enough to be usable. The plastic stand it comes with is absolutely useless. It weighs 1/3 of the scope itself and falls over constantly. I finally got to the point where I was using it hand held, which has it's own set of problems. And there is no good way to attach it to another stand without it being in the way of the focus ring in the center of the body. The shame is it takes excellent pictures for a $15 Chinese tool as long as you can hold it still and pointed in the right direction.


I've only played with the AmScope a little bit so far but I do like it a lot. It's nice to have a lot of room under the objective lens to work with. The Barlow lenses I have will give me a range of around zero to 11 inches I think. Plenty of space to get a soldering iron under for working on printed circuit boards etc., or getting close in on a lathe bit or end mill to get a good look at the cutting edge. And I can get my hammer and sear jigs under it too.  

This will come in handy for me, especially the next time I get one of those microscopic steel slivers that you can't see stuck in a finger - but can definitely feel!  

As an added bonus, the reducing lens for the camera I got is a "C" mount which means I can also use the Sony CCD camera module that Ed gave me awhile back that I have been using with my borescope. I couldn't get one of AmScope's higher end cameras because my laptops are too old and don't have the processing power needed. But the Sony should work great with a monitor.

[EdK]

Willie,

What's the model number of the AmScope you got?

Ed

[Highpower]

Mine is the SM-4NTPZ-144.

The microscope heads are all the same essentially (same internal lenses) with 2 different options available:

Tri-focal (w/third camera port) -or- not.
Simul-focal (Able to use both eyepieces and the camera port at the same time -or- not. The standard heads switch between one of the eyepieces and the camera port making it monocular if you want to use the camera port.

Or you can remove one of the eyepiece lenses and install a camera there on any of the scope heads.

The difference in magnification ranges/working distance comes from which eyepiece lenses and/or Barlow lenses you use on any of the models.

[Highpower]

UPDATE: This is just an FYI for any other AmScope owners.

I got one of these scopes 2 years ago. Back then they had an adapter for the trinocular port that used a locking ring for adjusting the height of the (focus) tube when using a digital camera mounted to the third viewing port. This is what they showed as coming with the scope on their web site at that time.

   

What I received however was a "new" version of this camera adapter that consisted of a slot in the body of the adapter with a thumbscrew through it to lock it in place after adjusting the height of the tube. There are several problems with this. It is a PIA to adjust the focus this way to begin with, and after tightening the thumb screw it would cant the upper portion of the tube slightly and cause the left and right sides of the image to be out of focus slightly as well when the center of the image is IN focus. Also moving the scope around or accidentally snagging the USB cable caused the camera to spin around along with your image. The reducing lens merely slid down into the adapter tube with no way to lock them together. The other problem is the slot allows dust to get into tube and down into the internal lenses in the scope body. I immediately contacted AmScope and tried to get them to exchange the "new" model adapter for one of the "old" model adapters. They refused. I then asked to PURCHASE one of the old adapters and again they refused.

   

I just found out last week that they now have another new version of this adapter. This one uses a binocular type adjusting ring and has reduction lenses BUILT IN to it so you don't have to use a separate reducing lens mounted to your camera. It also locks the camera, adapter and scope head together securely. No more camera spin. And WAY easier to focus the camera too. The newest adapter (for 0.5X) is also very compact (approx 1.5" tall) compared to the 6" - 8" combination of the 2nd gen adapter and separate reducing lens. The previous set up had my camera sitting way up above the scope body just begging for something to hit it.

I just wanted to let anyone else who has had to put up with these issues, know that there is finally a better option out there if you are interested.