miniature model flight simulator

[hobby]

Hello everyone,

This is a picture I found off the innernet, of a full size flight simulator,
I would like to try to make a very small miniature working mechanical model of it.

I'm approaching this with a different concept for the hydraulic cylinders, this time I'm building double acting cylinders, using only one hose connector, which will take care of both the push and pull of the piston. Also I' am machining the threads on the outside of the cylinder to hold the top and bottom endcaps, this makes it much more easier to fit the piston to the cylinder, as well as allows the total length of the cylinder to be made smaller with the same amount of piston movement, as when the threads were internal, as before.

I found a real nice way to make miniature pistons, by using loctite thread locker to hold the piston to the rod, and the use of my lathe as a horizontal press.

Here are the steps in making miniature piston and rod assemblies.

First I machine the cylinder with external threads and internal bore.

Then I face the piston stock, and begin with centerdrilling the proper size hole, for the piston rod.

Afterward I set up for the drilling of the rod,

First, when ever you tighten a chuck key in a drill chuck, sometimes the drill will not line properly up straight out, and the bit goes on a slight angle bending its way into the preveiously drilled starter hole,

I stumbled on a way to make sure the drill bit and reamers ends up on target everytime, by loosly placing the drill bit in the chuck, locking down the tailstock then holding the bit in the starter hole, begin to tighten the chuck, tighten as tightr as possible, and now the drill or reamer is set to exact target of the starter hole.

Now I drill the hole to required depth for reamer to follow.

Then again with the reamer, I set it in the hole left by the drill and proceed to tighten the chuck.

Now back to the piston build.

So Now the piston blank is drilled and reamed ready for it's rod, I then cut the rod blank, to appropriate length.

Then I file off the extreme large burr left by the sawing, to a taper that will allow the rod to slide into the hole in the piston, easily.

Then I take it back out and file the one end of the rod on top to give a slight burr hanging around its diameter.

Now I place the prepared rod in the tailstock drill chuck with the end with the burr sticking out and tighten it and then add loctite glue to the tip of it.

Then proceed to lock down the tailstock and use it as a horizontal press to press the rod into the piston blank.

This ensures that the piston rod is going to be square in the piston blank.

A good test is to run the lathe and check for any runout with the rod.

Then I mark it off where it needs to be cut off at and cut it to appropriate length.

Then the rest is machinig the piston with facing cuts and logitudinal cuts until the piston fits the cylinder.

That's all for now, thanks for watcing.

 

[hobby]

When I used my reamers for the hydraulic cylinders before, they came out good, but they weren't real straight but worked for the experiments I was doing.

But now that i'm building an actual working model, I want the best reaming job I can do with these small dia. cyl. bores.

The problems I was having was with these smaller drills and reamers diameters, I was getting some larger bore at the very begining of the ream and by the time I got to the end of the cylinder the drill and reamer began to tighten up.

I think this is because my tailstock may not be perfectly lined up and also the farther it is extended the less support it has causing the drill to wander a little.

The results is that I could not get a good tight piston fit all the way through the cylinder length, resulting in bad compression, and oil leaking, past the piston.

To remedy this< I do the following.

I set up my drill bit in the chuck, lock down my tailstock, and proceed to drill turning the tailstock handwheel, about 5 revolutions, that's roughly 5/16" depth of cut, then I back the handwheel out, and loosen the tailstock and pull the drill out of the bore, clean off the chips, and slide the tailstock back into the work, until the bit touches the inside of the drilled hole, and lock the tailstock and repeat the procedure, until the drill is all the way through.

Then I repeat the same procedure with the reamer, then as a test I stick the reamer back into the bore, without the drill chuck attracked, and turn the lathe on and check for any runout.

I did this using a reamer of 0.249" dia. to ream the cylinder bore, then doing the static test there was no visual runout, at the end of the reamer, then one final test, I took a 0.250" dia. reamer and tried to stick it in the bore, it would not even start to go in.

That one thousandth, of an inch larger would not go in, that tells me that the intermediate reaming procedure will keep a fairly true and straight bore as long as I take my time doing this procedure.

Then a dynamic test was done to check for piston fit.

I set the cylinder over the piston, and poured some 3in1 oil into the cylinder until the oil reached the top. Then I moved the cylinder up and down over the piston, and seen that the oil level remained steady all the time. As the cylinder was raised up and down the oil formed a column ontop of the piston, remaining at the same height, throughout.

Here is a video of this procedure, demonstrating the oil remains the same height even after movement of the cylinder over the piston.

[ame]http://www.youtube.com/watch?v=EMU8eM_vpjc[/ame]

So now I can move on to the rest of the build.

Thanks for watching.

 

[T70MkIII]

Hobby, you do the most interesting projects! I am looking forward to watching this one grow.

Thanks for the drilling/reaming advice - another one of the many things in model engineering that make so much sense when someone points it out, but I doubt I would have thought of myself.

 

[hobby]

Richard.
Thankyou for the nice compliment.


This model will need at least 12 universal joints, I can go with swivel hinged joints, or ball joints.

I'm going to try with ball joints first, by making one prototype cylinder with it, and see how it works out.

To do this I decided on making a quick dedicated 1/8" radius (1/4" dia.(ball cutter)), to see how it would work, in making a ball at the end of a workpiece.

I took a piece of 3/8" steel, around 3.5" long and ran a 1/8" deep flat across it with a 1/4" endmill.
Then I lined it up on center and drilled and reamed a 1/4" hole.

flipped it 180 deg. and milled a second flat to leave around an 1/8" thick tab at the end of the workpiece with a 1/4" hole.

Then elevated it to around 60* to mill a relief cut across the cutter portion.

Then tried it on a piece of 3/8" alum. rod.

I will try some more with this, and see how easily it will work, then make a prototype cylinder endcap incorporating a ball at the end.

If this works out then for the rest of the ball joint I have 3 options to choose from.

1. make the traditional round divet using a ball endmill on 2 pieces and sandwich the ball section in between.

2. make to 'V' grooves sections and sandwich the ball section between them.

3. bore a hole in a block, then mill out the top section, with a slot almost to the center height of the bore so the ball can fit inside with the stem section protruding through the slot.

Thats all for now.
Thanks.

 

[kustomkb]

Cool project Hobby, nice job on the form tool, I'll remember that one.

I was lucky enough to fly that simulator a couple of times, no aerobatics and I think I spent more time watching the gauges than looking out the window. I wish I could go back and try it again.

 

[kcmillin]

Great Project Hobs!

Thanks for the tips on the radius cutter.

I cant wait to see how your ball joints workout.

Kel

 

[hobby]

Cool project Hobby, nice job on the form tool, I'll remember that one.

I was lucky enough to fly that simulator a couple of times, no aerobatics and I think I spent more time watching the gauges than looking out the window. I wish I could go back and try it again.

Thanks Kevin.

That sounds pretty interesting, I bet you did real well, just one word of caution, I hope you didn't fly it as fast as you work in your shop. (around the earth in a few seconds)... ;D


Kel,
thanks for stopping by, and the nice compliment..

Here is an update of todays shop time.

Todays work was mainly modifying the radius cutter, for best performance, then working on a step by step procedure for making a ball joint.

So far I think I have the ball section, down to a procedure, to make them in a production mode. (I need at least 12 made)

Here is the cutter modified, I made the outsides much thinner, so it cuts into the work better.

To make the ball section of the universal joint.

I cut a piece of 3/8" dia. alu. rod, and finished the length to 0.875".
Then I put it in my lathe and machined a 3/8" long shaft down to 0.25".
This is what the ball section will be formed on.

And now the ball cutter is introduced and the cutting comences. Until a 1/4" dia. is met.

Afterward I switch cutters and machine the shaft to a dia. of 0.100" for a length of 0.250"

Now I turn it end for end and machine a threading nub, 0.100" dia. for 0.150" length.
and then it is treaded with a 4-40 die. cutter.

Now at this step I may make a threaded collet to hold the workpiece for machining the flange.
Right now I just pulled it out of the chuck further and machined half of the flange, to a dia. of 0.200".

Then turned it end for end and machined the rest of the flange.

Now the finished ball pin piece,.

Now that most of the kinks are worked out with this part, I can start working on the rest of the ball joint, such as the base and cap to hold the ball pin.

 

[hobby]

This is a first trial run at building the rest of the ball joint.

A little background on the design.

First a base needs to be made to contain the ball, at a depth almost to the center of it's diameter.
Then once the ball section is placed in it, then a top cap to retain the ball needs to be made.
This top cap will screw down over the base and have a small clearance with the top of the ball section, while at the same time have enough clearance with the ball shaft to allow the ball shaft to swivel properly.

This top cap will need to be made in 2 pieces, due to not having a bottoming tap, (which probably still would not be feasible, for the distance this needs to be internally threaded), these 2 pieces will be a internal threaded ring, and a external threaded flange with a specific hole thru, to contain the ball section.

By doing it with 2 pieces ensures that the internal thread of the ring is all the way thru, to allow a close fit to the ball.
The threaded flange will be glued and screwed together with the ring, forming a cap with internal threads all the way to where the flange internal bore meets the ball, with proper cleareanc being achieved by lossening the entire 2 pc. cap system on the base threads.

Here is the procedure thus far to make this assembly.

The base is cut and finished to length, Then a thru hole is drilled and tapped, 6-32, for the mounting studs in the project build.

Now keeping the tap in this piece, I loosen the chuck and slide out the workpiece required distance for next machining of the thread nub. This helps keep everything square in the chuck when I retighten it.

Now a nub is machined and threaded for 3/8-24.

Now an endmill is used to make a recess to contain the ball to close to half dia. depth.

Now it's time to make the containing ring. It is cut to length drilled and tapped for a 3/8-24.

Now for the containing ring top flange.

A nub is machined and threaded for 3/8-24.

Then a measurement is made on the ball where it sticks out of the base and a drill is chosen at a smaller dia, to drill a thru hole through this flange, this will contain the top of the ball section.

Then this flange is rough cut off of the parent stock.

The ring and flange before and aqfter assembly, being prepared for final finishing of this entire top cap unit.

The machining of the unit. and the almost finished part.

The 4 parts making up the entire assembly.

And the assembled unit.

Whoops.... something wrong with this entire assembly, the ball shaft does not have much freedom of movement, it bangs up against the flange side, restricting it.

To remedy that I put the top cap assembly back into the lathe and using a centerdrill, I chamfered the top cap top portion.

Now the dry assembly of the entire unit. Later thread locker will be used to permanently keep everything together with the needed clearances for proper operation.

Looks like the top tapering did the trick.

ball section seen from the top enclosed with the cap.

These are the 2 units (prototype builds, for testing concepts), so far before building the actual project.

Next I will need to make another lathe cutter formtool, to form the hose connectors, for the endcaps on the cylinders. I decided to make these from seperate pieces so as to use less material, the reason I made this choice is because I experienced real good results with
threadlocker loctite glue, to seal any areas in the threads that could allow leaks, from leaking.

Then I need to fab out the endcaps and a flange to bolt the ball joint assembly to, then do a preliminary dryfit of the cylinder to the balljoint to the floor flange and see if any issues arise that would need any part changes.

Then from there I should have enough proof of concepts figured out to commit to machining in a assembly line all the parts that have past the preliminary tests.

That's all for now.

Have fun.

 

[hobby]

Hi again guys,

Today I started some production work, on this project.

I figured while it is still fresh in my memory, to do the universal ball joints, assembly, since there is a few procedures that need to be followed in a specific order.

So the first order in machining is the complete ball pin part.

The 12 pieces are cut to rough length,

then faced off to finished length of 0.875".

Now here is a procedure I am using for making multiple parts.

First I arbitrarily set my carriage stop close to where I want the workpiece to be located,
and lock the stop down.

Then I bring the carriage up to the stop, as the zero reference.

Now I set my dial indicator to zero, then I back the carriage away from the stop a determined amount, using the dial indicator as the readout.

Once that is done, I then put each workpiece in the chuck and slide it up to the tool, this automatically locates the workpiece

and the distance the carriage is away from the stop sets the depth of cut on the workpiece.

Now all the pieces are machined to the same length of cut.

I repeat this process for every other machining operation on these multiple workpieces.
So all the pieces are identical.

This is the workpieces to where the one end is threaded for 4-40, and the other end is machined to a dia. of 1/4", ready for the ball forming tool next.

The ball is formed on ithem.

Now the shaft is machined above the ball.

And the final operation, the flange is machined down to it's proper diameter.

And the final part after all machining is done to it. 12 pieces.

Next is to put into production the base and top sleeve and cap for this assembly.

Thanks for looking in..

 

[hobby]

Hey everyone,

Here is a nice organinzing tip, when you have multiple pieces of various parts to machine, I put them in a divider box, in the picture below, the front bins are the prototype parts as visual reference to get measurements off of as well as totest newly made parts with, the second row of bins from the front are the completed pieces, while the back row of bins are the pieces that still need some kind of machining done on them.

Any way the production has gone into full swing, starting this weekend,
here are the parts after coming right out of the bandsaw station.

And here are the parts seperated in there respective order, after a days work with all the machinery up on line.

The start of this production is with the universal 12 universal joints.

The 2 skids at the back are ready for the paint booth, while the one to the most right, still needs to go back on the floor for one more machining operation, that is for a larger thru bore, and a chamfer at the top. The finished proto, is leaning up against it, as a reference, that will stay with this bundle until the final machining is accomplished.

The one in front, are the billets ready to go into the lathe area, to be machined as the base units for the universal joint assembly. Again you can see the finished proto, leaning against it in front.

Well that's all for now...

Have fun...

 

[kcmillin]

Lookin Good Hobs!

I love the little pallets your parts are sitting on. Now you need an equally small forklift to move them to the production floor :big:

Great idea with the dividers, and Ice cube trays.

Kel

 

[zeeprogrammer]

Very interesting project Hobby.
And, I'm learning a lot.
Thanks for the tips on drilling and reaming...that'll be a big help for me.

 

[rcfreak177]

G'day,
I second that on the little pallets Rof} It is great to see a build with a difference,
Just wondering if you have considered a small cross section O ring on the hydraulic
Cylinder Piston?

The technique you used to make the ball joints was excellent, May come in handy
for me in the future. Please keep us posted.

Cheers Barry.

 

[hobby]

Thanks

Kel, Carl, Barry,

Barry, I am not using any O Rings, on the pistons yet, but if I have any compression issues, then O rings will be on the grocery list, I'm hoping to get a good enough seal with just the piston, to cylinder alone.

This weekend, I needed to build a quick corner unit to set behind my lathe, to put all my most used tools (for the lathe), on, so I don't have to keep going under the cabinet to pull out tools I need for a specific job.

Now with the project, I began assembling the top ball retainer, to it's outer ring, and then machine the unit to a final form, when I noticed that the retainers were just to big, and kept the whole unit from assembling properly with the base piece that houses the ball, So I got rid of the retainers, becuase the dia. I used wouldn't allow me to machine it properly, for the best fit.

I made new retainers, these retainers are made from 1/2" dia. round aluminum bar, instead of the original 3/8", and the machining procedures that follow allow me to make it properly fit tight to the outer ring, and still have a minimum amount sticking through the ring which gives more clearance for the ball, so the whole retainer/ring unit can be screwed down further on the base piece ensuring a better tight fitting assembly.

However this takes considerable time, for the machining that needse to be done on each piece, needs about 3 operations, before it can be taken out of the chuck, so in essence each retaining/ring unit is made seperately, before moving on to the next one, you will see what I mean with the photos to follow.

First I keep the whole parent stock intact to get best gripping in the chuck, then machine each piece from it.

Here I need to drill a 1/8" pilot hole as deep as possible to give me about 4 retainers at a time.
This hole is used only as a means to line up the workpiece back into the chuck for the final machining on it.

Now a treading nub is machined, it is made to a length of 1/8", which is too large for the application it will be used in, however I need it this large of length so as to get a proper fit for the 3/8-24 die that will be used on it. Later one thread will be eliminated from it so as to shorten it to proper length.

Using my DIRO (Dial Indicator Read Out). To establish tool bit location. Length of cut.

Now the thread nub is machined.

And threaded to 3/8-24.

Now that it has enough thread to the shoulder, I can shorten it by one thread length.

I could use a cut off tool bit, however this little benchtop bandsaw, is more quicker, and very precise, for cutting a small workpiece. I like this saw a lot.

Here is the part after parting it from the parent stock.

Now I thread lock glue it to a outer ring, so the whole unit can be machined together in the lathe.

Now this unit is placed back into the lathe, using the 1/8" drill bit in the tailstock and sticking it through the pilot hole previously drilled in the beginning steps to line it up back into the chuck.
Need to make sure the chuck grips only the outer ring and NOT the retainer otherwise the unit could dissamble from the back side if the retainer has more grip on it then the ring, but by gripping only the ring, then the retainer automatically is tightened up by the force of the tool bit against it as it is rotating.

And now the ball shank clearance hole is first drilled through the unit. Using a #1 drill.

Now I can face off to length the thickness of the retainer, down to around 50 thou..

Finally the chamfering of the top of the retainer so as to give the shank clearance to move side to side.

A little touchup with the file to round over the sharp edge, in front.

And the finished ring/retainer unit.

This shows the bottom side, the amount of clearance the retainer gives, as more threads are shown inside the ring. This then means the ring can thread down farther on the ball base piece, without cinching the ball too tightly.

I need to work on the base units by making the counter bore that holds the ball a little deeper so the entire ball is submerged in it, this gives proper clearance all round for the ball to move it's entire revolution, without any binding.

That's all for now, this weekend has been more of a trouble shooting course in this ball joint design.

Thanks for watching...

Have fun...

 

[hobby]

Ok some more production happened within the last couple days,

The base housings were sent back to the lathe area because of the change workorder, due to the redesigning of the top retainers, see last posts, these base units more or less were just CB. deeper so as to retain the entire ball inside.

Here I'm using the pretapped hole with a tap in the tailstock chuck, so as to ensure a perfect as possible alignment of the workpiece back into the chuck.

I found that a tapped hole in a workpiece that will have a thru hole through it anyhow,, is the best kind of alignment hole so as to put a part back into the lathe, for remachining.

Now a ball endmill is reintroduced into the CB. to make it deeper.

Now the assembly of each unit can begin.

Now all is needed is for pachaging, and these will be ready to be sent out to the job site.

Meanwhile production on the endcaps for the cylinders has also been under way.

First a hole is drilled and tapped to receive the ball joint assy.

Test fit.

All six done with step one.
Next the pieces will be drilled and reamed for the cylinder to screw onto.

Test fits.

Now time to set up for drilling and tapping for a hose bib to later be installed.

Lining up the center of the workpiece with the spindle. Spin jig in the back of the vice on the table in the pic.

Referencing the edge, and then using a DIRO, to set the amount of "X" table travel.

Drill and tap for proper threading.

Now machine a flat in same location, for the hose bib to set on.

First I need to locate the top of the workpiece, this is done by locking the drill quill, so now all "Z" travel is done with the headstock moving on the column, this ensures the most acurate depth controle, becauise now I can use the DIRO on the "Z" axis to watch the depth of cut.
Which is 20 thou. of depth.

The reason for using the spin jig, is these will be reinstalled, in it, and then flats will be machined to form a nut in the area of the bib hole around the endcap diameter.

That's all for now,
See ya later..

 

[kcmillin]

Wow Hob's, you sure know how to play. I like your style, the mini production floor is great.

Keep up the good work.

Kel

 

[hobby]

Hi Kel,

Thanks for the compliments,
yeh, it was fun making those miniature props, it breaks up any potential dulldrum in my build threads, to give a little entertainment to it.


Now it's time to finish the machining on the bottom endcaps for the cylinders.
I need to put the workpieces back into the index jig, so by using the pretapped hose bib hole, I was able to bolt on a piece of scrap stock to use as a depth stop as well as a vertical line up jig

.I turned the spin jig to 90* mark, then inserted the workpiece using a square to line it up vertical.

Here it is sitting back at 0* to check the vertical of the square blade.

Remove the scrap piece and begin machining the 6 (hexagon) flats, turning the index jig, every
60* .

Now all the pieces are machined with the hex form on them, it was time to reinsert them into the lathe, I mentioned this before but this is worth mentioning again, when it comes to remounting a small workpiece back into the lathe chuck, with very little grpping of the jaws, it could be very hard to get the piece to stay concentric.

BUT, if a hole needs to be drilled in the workpiece (especially a thru hole, then I may start using this method I again happened to stumbled upon.

Drill a hole with a tap drill size, smaller than the finished hole would be, and tap the hole, this becomes a very good line up procedure to get the part back into the chuck concentric, by using the tap in the tailstock the workpiece can be slid into the chuck and then by turning it on the tap more or less is like dialing it to the exact area for gripping, and the jaws can grip small amouint yet because the tap keeps everything in line, the workpiece will stay rather concentric throughout the tightening of the chick.

Once the work is tight in the chuck, then either remove the tap from the tailstock drill chuck, or manually spin the chuck backwards to back out the tap.

Here it is being done.

Here is the small area being gripped by the chuck jaws.

And the concentricity when it is spiinning.

Now some tapering at the back of this endcap, so as to make it blend in to the small shaft dia. of the ball joint unit.

That's all for now.

Have fun...

 

[jolijar]

you need one of these for your warehouse.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHA25&P=7
;D

 

[Diy89]

Great work! Would you tell us more about your bench band saw, please?

 

[hobby]

you need one of these for your warehouse.
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHA25&P=7
;D

Yeh, I think I will need one of those to haul all these skids of parts. ;D

We never had toys like that when we were groing up, my tonkas were all manual driven.
Those were mostly steel constructed, built to last.

Great work! Would you tell us more about your bench band saw, please?

Hi,
I got this bansaw a couple Christmas's ago, I was able to get it on sale at the time from Micromark,

However just now, to my surprise when I did a search for it in there website, I found that they discontinued it. That is a nice little item to have on the workbench.

They take the same size blades as the handheld portable bandsaws, they did not discontinue the blades just the saw itself.

Here is a link to there website showing it as a discontinued item.

http://www.micromark.com/PORTABLE-BANDSAW-OUTFIT,8099.html

A google search should bring up this kind of bandsaw outfit, from other places, I know that 'lathemaster' sells a outfit like this but for a pretty substantial price, maybe a better design.

here is a very good one from lathemaster.
http://www.lathemaster.com/Benchtop Bandsaw.htm

But it is a very nice saw for the bench, it is a portable bandsaw hooked up spring loaded to a base with a built in vise, the saw I have from micromark, is in my opinioin, the base seems to be an afterthought, that was not well thought out.

Here is why the blade is very far away from the vise which limits small work from being held.
To remedy that I put a small drill vise on a 2X4 and clamp that in the main vise, that puts the blade around 1/4" away from the drill vise jaws, so as to hold very small workpieces.

Also the rotation of the blade with respect to the vise in my opinion is backwards, the blade is rotating towards the operator, and the moveable jaw is towards the operator, so the force of the saw teeth are pulling the workpiece against this moveable jaw, less rigid then if the saw blade would rotate against the fixed fence.

The reason for this setup, is because the saw was sold mainly as a portable handheld unit, in that case the blade rotating against it's own fence attached to the saw worked.

Hope this helps...