Archive for September, 2006

latest pics

quite a few new bits. 2 more screens, printer, MFD controller PC, side panel
p_long (44k image)
ph34r my untidy cabling!
p_cab (84k image)
the office
p_high (34k image)
the toolbox is going soon, the right console is cut and awaiting assembly
p_side (31k image)

a bumper season for sims

Looks like the “holiday season” is going to be a bumper one for sims this year. Coming up in the next few months we’ve got:

FSX – the new benchmark civilian sim (yeah I know X-Plane has better realism, but it’s not as user-friendly nor as well supported by 3rd-party developers)
Black Shark – finally, a serious combat helo sim looking REAL nice
Battle of Britain – a new benchmark for WW2 props, improving on their own superlative IL2 series

It’s looking like I’m really going to need a TrackIR4 now. All three new sims will make full use of the 6DOF and especially for Black Shark, where the head needs to be on a swivel and the cockpit is crowded, it will make a huge difference.

It’s great to see developers getting behind sims again. It’s a little-known fact that Microsoft Flight Simulator 2004 was the nineteenth-highest selling “game” of the 21st century – higher than Halo. The Flight Simulator franchise has been running for 25 years and 660,000 people bought FS2004. There’s definitely a market – a mature one, with money to spend – and it seems developers are starting to realise it. Good stuff.

live on Technorati

Let’s see if this works…
Technorati Profile

X45 collectiveectomy part 3

Time to start on the collective arm. The logical place to start is the flange, which will allow us to mount the grip to the collective arm.

I started by gluing the (non-pressure) flange to a length of regular non-pressure 40mm pipe. As I mentioned before, the regular 40mm pipe will fit inside the 40mm pressure pipe. The glue used is the special plumbers PVC bondo, which sets to a very firm bond. Once it had dried, I cut off the pipe with a panel saw leaving about 12mm protruding from the end of the flange. I also cut a 12mm section off the end of one of the pressure end caps, forming the grip throttle stop ring. Both cuts were sanded on coarse grit emery paper laid flat on the bench.

left to right: pressure end cap and the section I cut off it; the glued flange and pipe section; bondo and coarse grit emery paper.
flange_start (25k image)

Now, fitting the throttle stop ring flush to the end of the collective arm (40mm pressure pipe if you remember) I drilled four evenly spaced 4.5mm holes through both the ring and the pipe for the mounting bolts. Take care to make a mark to line up the ring with the pipe in future. These holes will accommodate some 3/16″ 16mm countersunk bolts with nyloc nuts to allow a firm connection of the flange assembly to the collective, whilst permitting disassembly for maintenance.

drilling the stop ring and collective arm
flange_drill (23k image)

Once the holes are drilled in the stop ring and collective arm, fit the flange assembly tightly and drill right through. The holes should now be perfectly aligned, and go right through the ring, pipe and inner pipe of the flange assembly. Countersink the outside of the holes using a large-bore drill, but be careful – it’s very easy for the bit to grip in the plastic and instead of a nice countersinking it will bore your hole right out.

Now fit the bolts and nuts. The bolts will probably be too long; eyeball the number of screw threads protruding once fitted and grind the bolts to length with a bench grinder. Space inside the collective shaft will be limited, so make the bolts just the right length. I like to mark the desired length of the bolts with masking tape, then grind right down to the tape. I grip the bolts with compound pliers to make sure they don’t slip while grinding. Be super careful with grinders – they are very dangerous.

bolts taped for grinding down
bolts_grind (27k image)

Now you can reassemble the whole thing. The flange should be securely mounted on the end of the collective arm, with the stop ring there to provide an end stop for the throttle collars.

inside the collective, with the flange fitted. note nice flush bolts.
flange_inside (16k image)

done for now! a fairly neat job, apart from the countersinking of the stop ring bolt holes. note throttle collar fit.
flange_complete (25k image)

X45 collectiveectomy part 2 (photos to come)

Now it is time to make the wire extension cables. I tend to use Cat5 UTP network cable throughout the pit for a couple of reasons. It’s nice and neat, it has standardised connectors (RJ45), I can run 8 signal wires with a single length of cable and I can buy it fairly cheaply. I’d recommend getting a 100m spool of the cable if you’re going to be doing a lot of wiring with it, it’s much cheaper that way. You’ll also need RJ45 connectors, a crimping tool and wire strippers.

There are 25 connections to make and eight wires in each cable, so I’ll need four long cables (long enough to snake through the collective tube) for the grip end and another four short cables for the base end. Each will have bare stripped and tinned wires on one end and an RJ45 connector on the other. This is for ease of (dis)assembly: the bare wires get soldered to the wires coming out of the joystick component, then I can connect each cable to its partner with a standard F-F RJ45 coupler (I bought twenty on eBay for a few dollars – much cheaper than buying singles at Jaycar or Dicks).

four long and four short
cabling_tools (37k image)

Of course, it’s vital to get the wiring of the RJ45′s consistent and to make sure that, for example, wire 1 goes straight through to the matching wire 1 when coupled. Label the cables and keep a record of which wires match which cables. Use your multimeter continuity tester to double check the cables and connectors.

coupled and continuity tested
cable_coupled (21k image)

Once you’ve cut, labelled, stripped, tinned, crimped, coupled and continuity tested your eight cables, it’s time to solder them to the base and grip. Good wiring practice calls for a mechanical lock as well as a solder, so I create a “hook” with the tinned cable end and twist the component end around it before soldering. I’ve also used heatshrink tubing to ensure there won’t be any shorts. I’ve done each wire in pairs, e.g: solder base wire 1 to blue on cable 1 short, solder grip wire 1 to blue on cable 1 long, update the spreadsheet, move on to the next wire pair.

Once you’ve soldered all of your wires, it’s time for the moment of truth. Couple the cables and double check that there are no shorts (at this point they are not heatshrunk in case re-soldering is required). Connect your X45 system to your PC. Run the calibration utility and test all of the buttons again. If all goes well, congratulations! Heat-shrink and retest, then move on. If not, re-check the wiring to make sure everything is wired correctly and there is end-end continuity. Can’t help you there cowboy, mine worked first time :)

That’s a good chunk of the electronic side done. Now for a mechanical interlude.

my evil plan: click for enlargement
{{popup collective_sch_lg.jpg collective_sch_lg 1200×1465}}collective_sch_sm (43k image)

When I was thinking about materials for the cyclic, I realised that in order to make the throttle collars work the way I wanted, I would need to cut two slots in the shaft for the throttle pot arms. This would significantly weaken the shaft’s flexion strength at the slot locations. Aluminium seemed like the ideal material for the shaft as even with the slots I imagined it would have enough rigidity in flexion to resist any deformation in normal use.

What I didn’t count on was a) the difficulty in obtaining aluminium pipe in the dimensions I was after and b) the cost. Not a viable option for a skanky budget cockpit. So, after a research trip to Bunnings, I decided on PVC pipe. (Side note: after I’d bought the pipe I started wondering about scaffold pipe which might not be hard to get – but I’ll revisit that if the PVC doesn’t work out. Side note 2: It seems McMaster-Carr has a good candidate product if you’re in the U.S. – try part # 4561T512).

Now, PVC pipe comes in two variants: regular and “pressure”. Pressure pipe has thicker walls and is more rigid, so is ideal for our purposes. I got a length of 40mm pressure pipe, long enough for the collective shaft, and a short piece of regular 40mm pipe. I considered 30mm, but the larger bore gives me more space inside to fit potentiometers and cables.

The 40mm dimensions are somewhat misleading, as for regular pipe it refers to the outer diameter (O.D.) but for pressure pipe it refers to the inner diameter (I.D.). This does have some useful side effects though. Regular pipe will fit (tightly) inside pressure pipe. Accessories designed to couple with regular pipe will sit flush with pressure pipe (as for the grip mounting flange described later). Finally, and most usefully, 50mm regular fittings will fit snugly, but not tightly, around 40mm pressure pipe, which is ideal for the throttle collars which must rotate around the shaft with no binding and minimal rattle.

My collars are each made up of two pieces (regular 50mm fittings) which screw together. I browsed the fittings until I found something that pleased the eye and rotated snugly around the 40mm pressure pipe. Your local hardware store will probably have different stuff, so try some out until you find something that works.

I also bought two 40mm pressure end caps, which I’ll cut up to form the stop rings. These will fit tightly around the shaft and be screwed in place.

The final fitting was a 40mm floor flange (how’s that for alliteration?). When I fit this to the end and match it with a custom-cut aluminium plate, it will serve as the mounting for the X45 grip.

parts for the collective arm (matchbox for scale). note the two halves of the collar screw together to make a nice looking throttle grip
pvcparts (22k image)

I decided that the slots would be cut vertically, so that the slot is on the pilot side as opposed to the top of the shaft once fitted. This is because the forces that are typically applied to the stick are up-down, so a vertical slot would minimise bending forces in the slot gap. Having said that, I will wait until the grip is mounted before determining what is “up” on the shaft. The grip has a distinct bend in it and I want to try it out to find the most comfortable rotation before I bed it in.

Return top