Teaching Microscope Table

[jdbnsn]

I have been picking up project work from one of my old employers, the Shawnee Co. Coroner. He recently asked me to build a small table to mount his teaching microscope on. He wanted the table to be non-metal, cheap, stable enough not to tip over (because people need to be able to look into the scope from both sides of the table, it needed to be narrow), and have a way of using wheels to move it but not be on wheels as it's full time feet. So I have a design planned out for the table and the drop-able wheels, first thing to do is work out the math.

This is math, please double check it for errors...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/1.JPG




I picked up a sheet of MDF and 4 caster wheels. Then following the measurements cut out some of the main pieces...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/2.JPG




Nest I countersank the outer holes for the support beams and screwed them to the side panels...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/3.JPG



And here is a shot with the top lying on it...



http://www.thebestcasescenario.com/jdbnsn/microscopetable/4.JPG

[chaksq]

Table looks awesome so far, the design is great. You are a good guy to help out with stuff like this.

[blueonblack]

Very nice work, simple and looks very sturdy. The math made me smile, thanks. +rep

[DonT-FeaR]

squinting is hard... im sure your math is right..

[jdbnsn]

Well he changed the specs on me mid-build so I had to cut some new braces to extend the table out to 36". I also had to use the last good piece of MDF to cut the new top so the rest of this sucka is going to be from scraps.

I added a third brace for extra stability, and it is off center because he wants to cut a hole beneath the scope which will be mounted. That way he can change the bulbs from under the table rather than dismounting the scope.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/6.JPG


Those edges mounted along the inner base will be the platform for the wheels.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/7.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/8.JPG


I started making a model for the wheels he requested. He wanted them retractable so when not in use the table would not be resting on them, but on a flat surface. So I needed a way to snap them down into place when the table is being moved. I used the same style of mechanism as most table saws or mobile garage equipment, just had to make sure the measurements and angles worked out right. I'm going to the hardware store tonight to find some sort of bearings or bushings to keep them from eroding over repetitive use. Here is what I've got so far...



http://www.thebestcasescenario.com/jdbnsn/microscopetable/9.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/10.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/11.JPG

[OvRiDe]

Very cool Jon, looks like a winner to me!

[DonT-FeaR]

to right looking good mate

[Luke122]

Man you are stepping up the construction skills lately! Good job!

[jdbnsn]

Thanks fellas!

[jdbnsn]

Got some more work done.

Here is the table with it's new 36" hat...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/10a.JPG



I've been working on getting the wheel-mounts built. The bottom part first, I chose to use stainless steel for the main mounting frame with a smaller piece cut and bolted under the wheel base plate to give it the needed lift so that he wheels clear the screws when it spins. I wanted the top to be smooth non-rigid so I covered it with a cut piece of the polycarbonate scrap. Then I used some old pieces of U-channel aluminum strips bolted to the stainless steel as the hinge mechanism. I counter-sank the holes so the foot pedal's ridge can slide well. I need to pick up some more screws to finish the fourth but three of them are done. Here are some pics...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/11a.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/12.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/13.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/14.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/15.JPG

[jdbnsn]

More progress today, I hope to get the other side done tonight.




http://www.thebestcasescenario.com/jdbnsn/microscopetable/16.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/17.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/18.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/19.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/20.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/21.JPG

[DonT-FeaR]

another quality build :P

[jdbnsn]

Thanks bro!

I got a little more work done. To support the axles I cut 4 small blocks and drilled holes in them and the inner panels.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/22.JPG



Then using some scrap stainless steel I cut and bent brackets to support the axles, eight in all.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/23.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/24.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/25.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/26.JPG


Then I used 29/64" drill bit to countersink the holes from the inner side to fit some nylon spacers I picked up. This will keep the wheel pedals from rubbing up against the MDF on either side.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/27.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/28.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/29.JPG


I have removed all of the brackets and stacked waiting to be sandblasted and painted. Last thing for tonight is covering up that ugly pine with some plastic. I dropped by the local plastics distributor and picked up some ABS (acrylonitrile butadiene styrene) and used it to cut panels fitting the triangle shaped braces. Tomorrow I'll do the same for the cross beams.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/30.JPG

[DonT-FeaR]

looking good.... i like it :)

[SgtM]

Awesome build Jon! When can I use it?

[jdbnsn]

Thanks fellas! And Rick, anytime you want to come on down to Kansas and peek through the scopes or watch an autopsy you're more than welcome! I've gotten a bit more work done but haven't got the pics off my camera yet. Maybe tomorrow.

[jdbnsn]

Okay, got some pictures of the current state of progress. I hope to slap a coat of paint on this puppy today and finish it up within coupe of days.


I sandblasted the stainless steel brackets for two reasons, there was some paint from it's original purpose (that I don't know since it was scrap that I kept from an old job) and the sand blaster leaves a nice looking texture. When drilling, grinding, filing, and sanding harder metals like steel it's pretty tough to get the scratches and defects out but the sandblaster paints away all of those things with ease. Here are the brackets after a pass with the sandblaster.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/31.JPG


Here you can see the difference between the original paint (which barely scuffed on a bench grinder's wire wheel, heat stripper, or scraper but came right off with the sandblaster).


http://www.thebestcasescenario.com/jdbnsn/microscopetable/32.JPG


I lined them up and hit them with a couple of coats of primer...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/33.JPG


Now if you've ever worked with MDF you know that it has a unique set of properties that make it both beneficial and cursed. It's pretty heavy and dense, it cuts very nicely, can be shaped with a router easily, and sanding is a breeze, which all make it nice to work with when building simplified furniture/cabinets, etc...

The downsides are that it is not very strong (i.e. flexible and will bend out of shape if a long enough piece is left with room to sag), it chips very easily when drilled, cut, or even bumped against a strong surface. One property of MDF which can be a big problem is it's vulnerability to moisture. If your MDF stock gets wet, it's over. Anytime you finish MDF you must seal it with water-free primer and paint, 100% acrylic based primer is a good choice, stay away from latex paint/primer.

The composition of MDF (http://en.wikipedia.org/wiki/Medium-density_fibreboard) is basically very fine sawdust and a mixture of glue which includes wax resins and urea-formaldehyde which can be quite harmful if you do not wear a respirator while cutting and sanding. And since the sawdust base is so fine, cutting, sanding, or any such action causes huge amounts of powder to become airborne.

Now, I'm pretty close to being ready to paint so I have to fix an inherent problem with MDF. If you try to prime MDF you'll find that the edges soak up the paint as fast as you apply it due to it's highly porous nature. So google taught me a little trick. Take some wood glue and dilute it with water (use 3 parts glue to 1 part water) and paint the edges with a couple of coats of this mixture and let it dry for a couple of hours sanding in between coats. Since the water is mixed with mostly glue, it doesn't cause swelling. This is what I did on all of the edges that will be painted...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/34.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/35.JPG


I painted the brackets with some Krylon black spray paint and screwed then in position to mark the holes for the mounting screws.



http://www.thebestcasescenario.com/jdbnsn/microscopetable/36.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/37.JPG


Almost ready for it's paint job...



http://www.thebestcasescenario.com/jdbnsn/microscopetable/38.JPG

[jdbnsn]

Today is going to be mostly painting.

I wanted the screws to match the brackets and I couldn't find black screws at the hardware store so I decided paint the screws that I had. I know it will not hold up when being screwed in place but I'll touch that up as I go.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/39.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/40.JPG


This is the primer/sealant that I am using...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/41.JPG


Got a first coat painted on...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/42.JPG


I decided to test the edge-absorption theory I read on the web by painting an edge that will end up being sanded down later anyway and it's very true. It doesn't show up well in the picture but the edge on the left of the base was sealed with the glue/water mixture and the edge on the right was not. Even after 3 passes with the brush it still needs more to be sealed. So the glue and water tip works great!



http://www.thebestcasescenario.com/jdbnsn/microscopetable/43.JPG

[Luke122]

Killer work Jon!

[jdbnsn]

Thanks bro!

[jhanlon303]

Very nice work and thank you for the respirator comments with the MDF. Safety is important!

We only get one go around and we ALL need to abide by safety requirements.

john

[jdbnsn]

Thanks dude!


I got some more work done tonight instead of sleeping, meh, the early bird gets worms.

I had to finish painting the inner sides first before I could put it together so I started with the acrylic sealant which worked great, then followed up with some custom mixed paint in a shade called "steel wool" to contrast the black ABS plastic.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/44.JPG


Well the paint on the screws held up against the screwdriver just fine and I got all the mounting brackets screwed down tight.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/45.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/46.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/47.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/48.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/49.JPG


I used large set screws to brace the axles in place so they could be removed in the future if necessary. As you can see, there was a bit a cracking from the base screws, one of the drawbacks to MDF is it's soft composition.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/50.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/51.JPG


Okay, it's on it's feet and ready for the finishing touches. Next I'll use wood filler to fill in the screws on the outer panels and inner panels and paint the rest. I also have two more ABS plastic sheets to glue to the cross braces.


http://www.thebestcasescenario.com/jdbnsn/microscopetable/52.JPG

[jdbnsn]

Wheels go up...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/53.JPG


Wheels go down...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/54.JPG

[DonT-FeaR]

wow... very nicely done...

[OvRiDe]

Very cool setup. That wheel setup could be used in all sorts of applications! And you make it look so easy. Thanks for this project, I see a table saw base in my future.

Nice work on the table!

[jdbnsn]

Thanks very much Curtis! Well, I'm in the home stretch. I got the top piece cut to the size requested by the coroner and also cut a piece of ABS to the same size so next I will need to get those fastened down snug.

Moving back to yesterday, I did some measuring to get the foot pedals correctly sized using scrap MDF blocks. If the hole isn't in the correct position, the locking mechanism doesn't work very well but if you get it placed just right it snaps down and holds well while moving the table around. Basically, you have to measure the distance of the pedal's surface to the axle with the wheel resting on the floor but not lifting the table, and then you take that measurement and add the distance you want to lift the table with the pedal down. Those two measurements are then used to mark where on the block you want to drill the whole for the axle. Here is a shot with the blocks that I will use to make the pedals out of...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/55.JPG


Here I have mounted the top board with long wood screws...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/56.JPG


Now, the ABS has two different surfaces. A rough-dull side and a smooth-glossy side. I checked both out but I was pretty sure I was going with the smooth-glossy side anyway...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/57.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/58.JPG


I also finally got around to mounting the cross brace ABS covers. I used button top hex style machine screws and you can't see them very well so I took a photo and another with inverted light so they show up...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/60.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/59.JPG


These are the foot pedal blocks cut to triangles and fitted with ABS side panels. I still need to get the top pieces made and mounted...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/61.JPG

[jdbnsn]

Whew! Been bustin' it out today! These foot pedals are the last major structural task on the list, and they just need top plates...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/62.JPG


I got the top mounted and used some aluminum angle for trim. Here are some shots with my scopes on it to give you an idea of what it will look like, but I'll try to get some pics with the coroner's scopes on it when I get it delivered.



http://www.thebestcasescenario.com/jdbnsn/microscopetable/63.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/64.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/65.JPG

http://www.thebestcasescenario.com/jdbnsn/microscopetable/66.JPG

[OvRiDe]

Holy Mother of Mary! That top looks fantastic!

[Drum Thumper]

Nice scopes.

Also, how in the hell did I miss this?

[DonT-FeaR]

looks sweet man.. nice work with the feet...

[p0Pe]

nice build jon:D came out really nice!

[Eclecticos]

Ultra smooth execution on the casters.
One hell of a sturdy platform. +Rep

[jdbnsn]

Thanks again for the kind comments guys, much appreciated!


Well, time to wrap it up and deliver this morning. Here is what I have done to complete the project and get it to the point that I'm not ashamed to push it into the office...



After careful consideration, I realized that I was a moron for using MDF as the base material for the foot pedals. The reason being, as I explained earlier MDF is not really that strong when faced with stress and these pedal blocks have a layer of ABS plastic screwed into each side tightly. If I had planned accordingly I would have used long screws that went all the way through using a nut to press the block together, but I didn't think of it. So with the current design and a lack of any long screws I had to scrap the previous blocks and cut some new ones and new ABS side guards. This time I chose some scrap pine from the woodpile and repeated the process of making these damned things for the third time. I also cut some strips of stainless steel to serve as the top piece. I sandblasted the stainless to take away the grime, paint, and blemishes and drilled some holes. Then I got the axles cut to the desired length and rounded up my nylon spacers. I measured the width of the axle mounts and added up the width of the pedals + 2 spacers and found that I needed to remove 1/16" from each spacer to fit the assembly snug. So I sanded them down and got ready for painting the rest...


http://www.thebestcasescenario.com/jdbnsn/microscopetable/67.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/68.JPG


Then I painted the pedals where the pine was visible and the top pieces, 2 coats of standard primer, 3 coats of Krylon flat black, and 3 coats of Minwax polyurethane "fast-drying" clear gloss. Now here is the lesson boys and girls, READ THE CAN and not just the title. Fast-drying my ass! Most of the other paints and sealers I've used dry within a couple of hours but I checked after a a couple of hours and they were still soft and gummy. So I turned the can around and read the directions "allow 24-48 hrs to dry..." Grrrr...I had planned on getting these assemblies done tonight so I could just wake up and go. Oh well, they were nice and dry this morning and the polyurethane is actually a very nice coat, it's quite tough.



http://www.thebestcasescenario.com/jdbnsn/microscopetable/69.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/70.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/71.JPG


Here is the final result of the wheel assembly...



http://www.thebestcasescenario.com/jdbnsn/microscopetable/72.JPG



http://www.thebestcasescenario.com/jdbnsn/microscopetable/73.JPG


Last and final touch. I have designed a logo for their business and website so I thought it might be fitting to stamp this table with it. I made some minor adjustments to the logo after printing a few test drafts and found a good font that stood out over the thumbprint. Then I printed a page on high quality resume paper in the highest resolution my printer could manage (1200dpi) and let the page dry for an hour. Then I cut a shape with a razor knife framing the image and rounded the edges with a shot glass for a stencil. After that I cut a similar but larger shape out of some 1/2" clear (yet slightly frosted on one side) plexi. I sanded the edges of the plexi with 220, then 400, then 600 grit sandpaper and drilled holes for the screws. I counter sank the holes using a larger bit that was just barely wider than the tops of the screws. Then I mounted it on one of the cross beams. Final pics....




http://www.thebestcasescenario.com/jdbnsn/microscopetable/74.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/75.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/76.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/77.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/78.JPG


http://www.thebestcasescenario.com/jdbnsn/microscopetable/79.JPG


Done and ready to ship! Thanks for watching, and maybe I'll get some additional photos of it with the scopes down at the office.


-Jon

[SXRguyinMA]

nice work :up:

[blueonblack]

Beautiful work! +rep

[DonT-FeaR]

wow..
looks great.. good work

[jdbnsn]

Thank you guys, it's nice to hear! The coroner seemed quite pleased with it when I delivered it to his office.

[Frenkie]

Amazing !!!!! You should give yourself an Award ! +rep :D

[OvRiDe]

Amazing !!!!! You should give yourself an Award ! +rep :D

Your ABSOLUTELY right! Thanks for the reminder!


DONE!

:D

[DonT-FeaR]

lol.. :) good work

[BuzzKillington]

now start selling them on ebay for 80 bucks a pop. :P

[rendermandan]

Wow, man that table turned out excellent!!! +rep

[jdbnsn]

now start selling them on ebay for 80 bucks a pop. :P

wow, that's hilarious... I was paid quite fairly for this project, and it took a great deal of effort for me to get it done. I know I don't have any measure of comparison to the skills of many modders in this community, but for my level of ability I thought it turned out pretty good.

[jdbnsn]

I totally forgot to show you guys it's home! This is where the table resides, it props up a teaching scope (Spencer American Optical- forgot the model#) with 3 additional viewing eyepiece sets for viewing pathological slides at Frontier Forensics. I'm nearly done with the website (with a tremendous amount of help from Curtis, huge thank you is in order Curtis!). If you have time, drop by the website and tell me what you think, it will be primarily for teaching purposes and it has many functions not visible to anonymous viewers that the staff use for office organization. You can find it at:

www.frontierforensics.com


Voila!

http://www.thebestcasescenario.com/jdbnsn/microscopetable/80.jpg