Wednesday, March 14, 2012
fixed
been too busy to update, but the last repair didn't quite survive the mountain road - although it made it a lot further. blu tack here just isnt the same. A little creative corsetry later and the problem looks to be definitively solved. Until the next mountain ride...
Thursday, March 8, 2012
Captain's log
We hit the mountain road today. So it wasn't exactly warp speed 9, thanks to some slow nissan pickup in front of me for most of the way *fume*, but we got some decent Gs nearer the top.
The repair nearly, nearly made it right up to the top... there was one last problem to overcome for the hairpin turns.
Some blue tack later (except in the US of A they only seem to have some strange not so nice to use white colored putty thingiebob) and that last 0.1% of the problem should be sorted.
I think we're at improvement #10 (or so) at the present... till the next mountain roadtrip.
Anyone out there need their PDO carfm modded to stop falling over? :D
*******
I've been looking around online, and noticed a lot of people are having similar problems with instability in the carfm 4... even with it stock out of the box. Two thoughts :
a lot of the products being sold online are fake. If there isn't a PDO printed on it, or if the rubber "flower" flange near the base isn't grey - it's fake. If it can't rotate 90 degrees - it's a fake. Then there's every reason to expect it to be unstable.
But if it's an original, that's a whole different kettle of fish - that means the stock unit itself is defective. And J, who has another unit for her own car says it's been acting up too of late. Perhaps as the grey rubbery thing ages it stops working so well.
Well... for a small fee (negotiable) I reckon I could solve the problem. Even without the blu-tack the last repair will hold up well on singapore roads without hairpin bends.
:D
The repair nearly, nearly made it right up to the top... there was one last problem to overcome for the hairpin turns.
Some blue tack later (except in the US of A they only seem to have some strange not so nice to use white colored putty thingiebob) and that last 0.1% of the problem should be sorted.
I think we're at improvement #10 (or so) at the present... till the next mountain roadtrip.
Anyone out there need their PDO carfm modded to stop falling over? :D
*******
I've been looking around online, and noticed a lot of people are having similar problems with instability in the carfm 4... even with it stock out of the box. Two thoughts :
a lot of the products being sold online are fake. If there isn't a PDO printed on it, or if the rubber "flower" flange near the base isn't grey - it's fake. If it can't rotate 90 degrees - it's a fake. Then there's every reason to expect it to be unstable.
But if it's an original, that's a whole different kettle of fish - that means the stock unit itself is defective. And J, who has another unit for her own car says it's been acting up too of late. Perhaps as the grey rubbery thing ages it stops working so well.
Well... for a small fee (negotiable) I reckon I could solve the problem. Even without the blu-tack the last repair will hold up well on singapore roads without hairpin bends.
:D
Tuesday, March 6, 2012
How to fix the PDO Car FM 4
This is the culprit in question. Exhibit A.
J (now the missus) sent it over via her mahjong kaki , L. Unfortunately, on arrival it was missing the baseplate (that rubber and metal nipple thing at the bottom) which interfaces with the cigarette charger. The friend, L managed to find the fuse in her luggage. No music for JT and I on the drive back from San fran = sadness.
In my opinion the PDO Car FM 4 has a serious design flaw - the base plate spontaneously falls off. J had this once before with her old one (v3?) - she left it in the boot of the merc and lo and behold, the baseplate went walkies by itself, never to be found again. In retrospect I should have checked the emergency tyre recess more carefully, it was probably hiding there. I kept it for a while, but it eventually wound up in the trash after spring cleaning, I think. :( No biggie, because I bought J a v4 (yay, newer, shinier etcetc) for her car, and she got me one for mine.
So it was a knife to the gut to wind up with my own personal v4 from my own car, having traveled the entire pacific ocean to die the same ignoble death as its predecessor. I resolved to resurrect it and rebuild the baseplate.
This isn't as trivial as a task as it seems - that grey rubber flower is there for a reason - the device is very top heavy (especially with phone mounted) and there is a very strong tendency for it to sag in the anterior/posterior axis, breaking the contact with the ciggy lighter. Worse still, the torque forces that build up during a sharp turn are considerable and there is an incredible, incredible tendency for the whole unit to rotate in its socket. This doesn't always break the contact, but makes driving annoying. The rubber "flower" resists all this to some degree, but it wasn't perfect either, especially the way J drives (F1 style). I couldn't replicate the rubber flower because it's not really made out of rubber, and I just can't find a material with the right properties for the job - unless I strip it from the top part of the unit, which I really don't want to. Cardboard proved hopeless, and finding a soft rubber sheet that thin, and soft enough to fold up in the top of the lighter and provide tilt support, yet "sticky" enough to provide rotational support is really tough.
PDO tried to fix it in iteration 5 - no more unscrewable bottom. Fuse not meant to be replaced, if the unit blows its dead. Greater stability through a stumpier, broader base unit, and no possibility of spontaneous self disintegration. Oh yes, did I mention if it disintegrates inside the socket (unlikely) when you remove the unit it can either short your lighter ($5 for a new car fuse) or blow its own fuse ($0.20 for a new 20ma fuse) But a lot of people are still complaining so I guess it didn't quite work out.
It took me quite a few attempts, but this is my best to date, and it didn't cost much. Perhaps someone else will find this useful.
I found one of these in our prototyping lab :
It's a plastic join for garden hoses, available at hardware shops for a buck for four or something. Fortuitously, the thread fits the bottom of the PDO unit almost to a T. I took a bandswa to it and cut off the "top" bit above the hexagon, and shortened the screwthread. A screw through the end of the "hexagon" provides the contact with the fuse on the other side. I initially used a sharp tipped screw but this indented the fuse, and made me uncomfortable - so I switched out to a blunt "flat" tipped screw. The screws are the really tiny ones - about 0.8 cm long available at hardware stores for mounting small thingiebobs.
The unit was still much too long and my intial attempts to stabilize the PDO device with the long pipe connector resulted in loss of signal everytime JT turned the wheel.
External stabilization just wouldn't cut it - the car pulls too many Gs (perhaps because it's an M3) while cornering, and the rotational forces at the end of that very long radius are tremendous - I tried holding it in my hand while he cornered and it was challenging)
So it was back to the bandsaw to cut the end of the hexagon off, shorten it, and superglue everything back together in a vise. I was terrified that the black plastic / PVC would prove unsuperglueable, but luckily "medical device grade adhesive" does the trick.
I did a lot of tweaking, and revisited the lab several times - good old bandsaw and lathe -- and managed to get a pretty decent rig that resisted turning and disconnects. Now for the test drive...
:)
a celebratory plate of $1 oysters from drake's bay...
*******
live test 1 : exceptional performance. no cutouts. However we had frequent cut-ins from passing cars with their own fm transmittors. These sound different because they last for such a short while and are incredibly clear, compared to a cutout when it usually goes to static or low quality radio on the "empty" preset channel. Have moved the set down to 88.1 which is a little less busy.
Till test 2, when we hit the mountain :)
J (now the missus) sent it over via her mahjong kaki , L. Unfortunately, on arrival it was missing the baseplate (that rubber and metal nipple thing at the bottom) which interfaces with the cigarette charger. The friend, L managed to find the fuse in her luggage. No music for JT and I on the drive back from San fran = sadness.
In my opinion the PDO Car FM 4 has a serious design flaw - the base plate spontaneously falls off. J had this once before with her old one (v3?) - she left it in the boot of the merc and lo and behold, the baseplate went walkies by itself, never to be found again. In retrospect I should have checked the emergency tyre recess more carefully, it was probably hiding there. I kept it for a while, but it eventually wound up in the trash after spring cleaning, I think. :( No biggie, because I bought J a v4 (yay, newer, shinier etcetc) for her car, and she got me one for mine.
So it was a knife to the gut to wind up with my own personal v4 from my own car, having traveled the entire pacific ocean to die the same ignoble death as its predecessor. I resolved to resurrect it and rebuild the baseplate.
This isn't as trivial as a task as it seems - that grey rubber flower is there for a reason - the device is very top heavy (especially with phone mounted) and there is a very strong tendency for it to sag in the anterior/posterior axis, breaking the contact with the ciggy lighter. Worse still, the torque forces that build up during a sharp turn are considerable and there is an incredible, incredible tendency for the whole unit to rotate in its socket. This doesn't always break the contact, but makes driving annoying. The rubber "flower" resists all this to some degree, but it wasn't perfect either, especially the way J drives (F1 style). I couldn't replicate the rubber flower because it's not really made out of rubber, and I just can't find a material with the right properties for the job - unless I strip it from the top part of the unit, which I really don't want to. Cardboard proved hopeless, and finding a soft rubber sheet that thin, and soft enough to fold up in the top of the lighter and provide tilt support, yet "sticky" enough to provide rotational support is really tough.
PDO tried to fix it in iteration 5 - no more unscrewable bottom. Fuse not meant to be replaced, if the unit blows its dead. Greater stability through a stumpier, broader base unit, and no possibility of spontaneous self disintegration. Oh yes, did I mention if it disintegrates inside the socket (unlikely) when you remove the unit it can either short your lighter ($5 for a new car fuse) or blow its own fuse ($0.20 for a new 20ma fuse) But a lot of people are still complaining so I guess it didn't quite work out.
It took me quite a few attempts, but this is my best to date, and it didn't cost much. Perhaps someone else will find this useful.
I found one of these in our prototyping lab :
It's a plastic join for garden hoses, available at hardware shops for a buck for four or something. Fortuitously, the thread fits the bottom of the PDO unit almost to a T. I took a bandswa to it and cut off the "top" bit above the hexagon, and shortened the screwthread. A screw through the end of the "hexagon" provides the contact with the fuse on the other side. I initially used a sharp tipped screw but this indented the fuse, and made me uncomfortable - so I switched out to a blunt "flat" tipped screw. The screws are the really tiny ones - about 0.8 cm long available at hardware stores for mounting small thingiebobs.
The unit was still much too long and my intial attempts to stabilize the PDO device with the long pipe connector resulted in loss of signal everytime JT turned the wheel.
External stabilization just wouldn't cut it - the car pulls too many Gs (perhaps because it's an M3) while cornering, and the rotational forces at the end of that very long radius are tremendous - I tried holding it in my hand while he cornered and it was challenging)
So it was back to the bandsaw to cut the end of the hexagon off, shorten it, and superglue everything back together in a vise. I was terrified that the black plastic / PVC would prove unsuperglueable, but luckily "medical device grade adhesive" does the trick.
I did a lot of tweaking, and revisited the lab several times - good old bandsaw and lathe -- and managed to get a pretty decent rig that resisted turning and disconnects. Now for the test drive...
:)
a celebratory plate of $1 oysters from drake's bay...
*******
live test 1 : exceptional performance. no cutouts. However we had frequent cut-ins from passing cars with their own fm transmittors. These sound different because they last for such a short while and are incredibly clear, compared to a cutout when it usually goes to static or low quality radio on the "empty" preset channel. Have moved the set down to 88.1 which is a little less busy.
Till test 2, when we hit the mountain :)
FixIt
We're going to leave this house in better shape than when we got it...
Fixed - sliding thingie under clothes closet door that was broken, using replacement thingie that was in garage and a command strip.
Not shown - sliding thingie under JT's closet door, using a piece we bought for $2
Fixed - curtain rail organizer thingie, using wall screw bracket thingie, hammer and screw. All from garage tool cabinet. Previous owner was a carpenter and has the whole of homefix in his garage :D
Fixed - sliding thingie under clothes closet door that was broken, using replacement thingie that was in garage and a command strip.
Not shown - sliding thingie under JT's closet door, using a piece we bought for $2
Fixed - curtain rail organizer thingie, using wall screw bracket thingie, hammer and screw. All from garage tool cabinet. Previous owner was a carpenter and has the whole of homefix in his garage :D
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