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A power surge on power up.Quote:
any loss of sync is a real problem. Not for the to / from / inop system, which simply fails to display correctly, but it's a problem for the CDI needle, which may go out of range if sync goes belly-up, and wrap itself around the backing plate with extreme prejudice. So my thought is, under what circumstances might that happen?
The 90 degree gear is actually called a Bevel gear. Or you can do it like this:
Thanks. When you said 90 deg worm drive to remove the need for the cords and pulleys, I thought you meant a long lead screw arrangement with some right-angle drive on it. I am familiar with bevel gears (and I'm looking for plastic ones to interface to my existing gear collection - good luck with that, I hear you say :roll: ).Quote:
Originally Posted by AndyT
With the bevel gear, how do you drive the needle without cords? Looks like you still need to translate shaft rotation into linear movement.
… not to use worm gears? I'm hoping that the gearing ratio provided by worm gears will mean that very little load will be applied to the driving shaft upstream from the instrument. And being hard plastic the sliding friction is low. Yet more experimentation required!Quote:
Originally Posted by cscotthendry
P1IC:
Sorry, My bad. I didn't mean that was the obvious solution. What I thought but didn't say was ...grease. Specifically, I was thinking of that white stuff you often find in toys.
BTW, while it sounds like I've been critical of your designs, I actually think you've been quite innovative. I didn't mean to sound critical, in my clumsy way I was trying to be helpful. I'm a problem solver. I see the world in terms of problems to be solved.:roll:
Yes, Grease Is The Word - hey, someone oughta make a song outa that! :DQuote:
Originally Posted by cscotthendry
And you're right about the issues. Sometimes when people (ie., me) get totally into one line of thought, the little problems get ignored. The overall "brilliance" of the concept blinds the designer to the shadows lurking inside. It takes other people looking at it from the other side, where there is less reflected glory, to see these, and then it's really important that they point them out.
Even then, there is the temptation to make quick-fix patches over the issues, rather than looking to see if its maybe the overall concept which is flawed. Like my suggestion that some end-stop sensor on the CDI needle would signal an out-of sync condition, shutting down the instrument and saving the mechanics. That's clearly a fudge, and the overall concept may fall because of it.
That's what I like abut this thread - this critiquing happens on nearly every post, and no one gets offended.
"Even then, there is the temptation to make quick-fix patches over the issues, rather than looking to see if its maybe the overall concept which is flawed."
Tell me about it. I've spent more wasted hours on my e-lab bench than I care to say, and then the next morning (or afternoon) a different approach resulted in the desired solution.
You guys working on this HSI are way out of my league mechanically and mostly electronically, but the same thinking on different levels can produce outstanding results if you can think outside the box.
Explore new directions and ideas that you never considered befrore.
Just a thought from a non-degreed mechanical Boeing Skunk Works engineer.
Listen to this guy! An icon in flight simulation, belittling his contribution. Skunky, you're tops. :DQuote:
Originally Posted by Boeing Skunk Works
P1IC, you give me too much credit. I'm mostly a an electronics experimenter (ICBM Tech) and hardware fanagler (parts fixer).
I just use, and do, what works. You won't find many drawings in my shop. But there are a lot of squares, calipers, and rules along with the machines.
You just have to build something every now and then even if its not for the sim. Engineering in in your blood, even if you didn't study for it. :D
I used to have a stack of 'Engineers Notebooks' for electronics and building trades. I wish I still had them. They had formulas and diagrams for almost everything you could think of.
Ho ho, been there DONE that! The surest way I know to trash a "brilliant" idea is to try and build it.;-) Even so, it's still a useful thing to think outside the box as often as possible.Quote:
Originally Posted by P1IC
Seriously, I don't think the synchronization issue is going to be as big a problem as you suspect, as long as the mechs work smoothly, are reasonably balanced, don't require excessive grunt from the steppers and you don't pulse the steppers too fast. That sounds like a big ask, but it's not really. Just due care and attention to detail... The usual process of making things.
You say you have a lathe and mill, so I'm looking forward to seeing your progress on this. Please post some pics of what you're doing and consider setting up a website for your project if you haven't already.
Ok, Here comes another Andy Scriibble...
P1IC, Try this:
I agree. Time will tell!Quote:
Originally Posted by cscotthendry
Actually i have started a website, not uploaded yet, with the intention of tracking progress. But at this stage I'm still on the drawing board, and I decided that I would wait until my first instrument was running before going live (just in case the whole thing is a bin-job!)Quote:
You say you have a lathe and mill, so I'm looking forward to seeing your progress on this. Please post some pics of what you're doing and consider setting up a website for your project if you haven't already.
And of course I wanted to wait until after the move to our new home, with the change of ISP - and now of course I'm up to my [nevermind] in unpacking, with Her Indoors keeping a beady eye on me lest I get side-tracked, as I do.
Now, just where did I put that soldering station…
Cool :cool:Quote:
Originally Posted by AndyT
I like the idea of a rack and pinion. If I can find a rack to interface to the cog sets I have, that would be just excellent. I'll do a search.
Or I could cut a rack (or ten) with my mini-mill. Just as soon as I get the workbench built, the mill and lathe set up, the kitchen remodelled, the electronics workstation assembled, the satellite TV installed, the cats fed, the grass cut (again - have you guys had much rain this year? Here in Canada it is just as wet as my old place in Scotland, only warmer)…
Wot!? Get sidetracked onto flightsim stuff from unpacking!?!?! Unheard of!:roll:Quote:
Originally Posted by P1IC
Hot off the press. Don't look too closely. I made a couple of mistakes on these first gears.
So long as everyone's posting their work, here's what I was doing tonight - working on a mounting bracket for the CDI servo. One of the best things in Solid Edge is the ability to unfold sheetmetal assemblies, makes them very easy to cut and fit.
They are just gorgeous! :DQuote:
Originally Posted by cscotthendry
OK, Here's the solution! What solution? What was the problem?...
Boring the centres out of the ring gears was a very tedious operation. On the test set, it took 2 hours to bore a 20mm drilled hole out to 60mm through 9mm thickness. What a pain! Quick as a flash you say "Holesaw!". Sorry wrong answer. Holesaws just jam in the soft aluminium, and driving a 55mm holesaw takes a) A lot of torque and b) puts huge loads on the material and the equipment.
Some time ago I fabricated this rig for making mould masters for my throttle quad knobs. It did the trick very nicely and a) It doesn't flog the guts out of any of the machinery, b) it took about 5 minutes to charge through 9mm of metal and c) it doesn't turn the cutout metal to complete waste. The best part is, the disks that come out of the centre could be used later to make smaller gears.
Take a peek.
Nice work mate. Attached, all the gears we'll ever need for the CAD.
Yeehaw! Now that's a compound gear if I ever saw one.
OK, here's attempt #2. Still a minor problem with it. I must have wound the dividing head against the backlash before cutting the first tooth-space as the last tooth ended up a little wider than the others.
OK, all CAD and no cutting metal makes rup a sad boy. So, refer to my Servo Bracket CAD above.
I really need a custom former for this as some of the bends aren't as high quality as I'd like. But overall it works nicely and with a bit more refinement in tooling they will come out true.
It's also gratifying to see it "just work" when you build it totally from the CAD.
If this keeps up, we are going to have a working HSI pretty soon. ;) :D
Hi guys, I was talking to Andy about this not to long ago, but I simply didn't have time to write the PIC code for the microchip controller, but what I can offer is any type of laser cutting or engraving that might be required for the gauge if needed.
You're my new best friend Padraig! Can you mail me at james (at) radsy (dot) com to let me know what sorts of material you can cut and what format you need the files in? A laser cutter/CNC was one thing we were hoping to get access to to make some of the trickier pieces.
And my company is based in Eire so I might even get over to visit ye sometime!
slainte
James
Email sent. I haven't got a CNC router yet, but in the process of acquiring one soon!Quote:
Originally Posted by ruprecht
I tell you somthing chaps ive been reading through all this and i have to admit I am amaized at how you are going about this and the speed of development on what I am sure will be a stunning little product, When its ready I may even revert back to a 747-200 rather than a -400.
Keep up this stunning work chaps and you all know what I am good at so if I can help at all let me know.
BTW, IPC PCB design engineer on Orcad 16 and +10 years of using Solid edge;)
Phill,
Please feel free to help out with a nice PCB design. You will not hurt my feelings!
Hi all:
I would just like to say thanks to Padraig and all the others for their support and offers of help. We really will build these things, but it's not going to be a quick process. We're doing designs and testing building things as you've seen from the pics so far. Some things will work, others may not.
I guess what I'm saying is please don't expect this is going to happen in a week or two. We still have a lot of work to do to make building these things feasible.:)
Thanks, but im not looking for gauges, I just thought that free laser work might be handy towards your project if needed. Either way regardless of time and what not, Im looking forward to seeing your team with a finished product that you all can be proud of.Quote:
Originally Posted by cscotthendry
Did that man say free? Now you're talking my kind of prices.;)Quote:
Originally Posted by Padraig
Seriously, we do appreciate the offer. I hope you won't regret making it as we will most likely take you up on it.
LOL, well now, I meant in helping you make your prototype gauge not a hole army of minions of gauge panels. I simply wouldnt have the time.Quote:
Originally Posted by cscotthendry
Padraig:
I never really thought you were offering to do production run stuff :)
BTW, can your laser cut sheet metal? Say aluminium at 1.4-1.6mm thick?
I know this is now irrelevant :roll: but following AndyT's suggestion to me about using a rack to control my CDI needle, here's my design updating my earlier post of several millennia ago :grin:
The loss of these horrible pulleys and cords is a real relief! And the design is also much simpler to build. Thanks, Andy. I can also use this in VOR and ILS instruments. :cool:
Nice work!!!! Looking fantastic :) :) :) Can't wait to see this in action :) :) :)
Matt Olieman
If its that small then I might be able, but I don't know to be sure, I am still waiting on it to arrive to my port which should be any day now. I have already received some CAD drawings but I think its the face plate. Also, what thickness do you want the face plate in ? I have 3mm Acrylic in clear, white, black. or I could go up to 5mm or 8mm.Quote:
Originally Posted by cscotthendry
Padraig:
Mostly it's the little fiddly stuff that's hard to machine on a milling machine with manual controls. I don't think there will be any "heavy duty" cutting involved. it's just small parts as I mentioned, from light gauge aluminium sheet < 1.6mm thick. (Take a look at the heading bug on the Bendix style HSI)
For my part, I'm still at the development stage so the drawings are not finalized. I'll send all the drawings to you at one time rather than in dribs and drabs. Is that OK?
Quote:
Originally Posted by cscotthendry
Yeah thats no problem. When ever you are ready, there is no rush. As I stated I still have to receive the machine I have on order from the manufacturer but look forward to completing the work for you guys.
Hi all:
Today, I'm trying out gear options and positions. To make it easier to visualize, I did this. I'm sure you'll all agree that it looks pretty speccy (even if it isn't going to be built like this.
P1IC,
You are quite welcome. We can still work on your design also. Nothing wrong with having another design handy.
Scott,
As soon as you get some finalized specs I would like a copy so I can begin work on the interface.