Posted by dannparks on Monday, November 13, 2006 @ 01:04 AM:
I'm sitting here looking a a pile of rusted metric bolts after dissassembly and wondering..
1. Where is the best place to get metric hardware? Not just plain nuts and bolts, but the the aircraft-specific parts like the drilled bolts and hex-heads?
2. Should I be thinking about converting what I can into AN hardware? I know where to get that.
Obviously you can't convert everything -- there are some complex custom fittings and the engine. But does it make any sense to convert some, or is it better to try to find a good source of Metric stuff.
--------------------
Posted by Admin on Monday, November 13, 2006 @ 10:31 AM:
This is getting easier all the time. Even Dodge builds cars with metric hardware now!
For aircraft stuff, try Metric Screw and Tool at 1 (800) METRIC-1, Maryland Metrics and McMaster Carr Supply Co (www.mcmaster.com) Metric Grade 10 is usually considered suitable for aircraft use. - There are several other sources. I usually end up drilling my own safety wire holes.
6mm is close to 1/4" and some people ream the hole out to 1/4" and use US hardware - I have done this in a few places on the Bucker. - Buy the reamer from McMaster Carr. 8mm is so close to 5/16" you can usually use it unmodified.
Steve
Posted by eugenio on Monday, November 13, 2006 @ 06:09 PM:
Aeronautical metric hardware is used on french produced aircraft (Socata, Morane etc) but on fourniers (and in all german produced gliders) practically all hardware is standard 8.8 that can be found in every hardware store in Europe. The most used measures are 5mm (eq.to AN3) 6mm(AN4) and few 8mm (AN5). on controls you cannot change the bolts (5mm) because of the bearing hole, and AN3 is only 4.8 mm so it does not fit correctly.
Eugenio
Posted by flyingkroeger on Monday, October 6, 2008 @ 11:42 PM:
Hi Guys,
On this topic, what are the specs of the original hex screws that hold the instrument panel of the RF4D in place? I seem to have misplaced mine, as there is only one of four left.
I thought it was M5, but on closer inspection the thread is a bit too coarse for that, around 0.9 mm in fact. The diameter of the screw is exactly 5.0 mm though…can anyone help?
BR
Tim
Posted by Donald on Tuesday, October 7, 2008 @ 07:23 AM:
Not sure this is any part of an answer but are there not two different metric standards? DIN and ISO.
Since the RF4 is German in manufacture I'd suppose their bolts and nuts would be to the DIN standard. My RF3, being French, I would suppose to be to the ISO standard. I could of course be talking rubbish.
Posted by eugenio on Sunday, October 12, 2008 @ 03:02 PM:
ISO and DIN are the same, there are normal (MA) and fine (MB) standard threads plus a lot of others (usually finer or between the two).
ISO is the International Standard, DIN is the German Standard, NF is the French Standard, but the threads are always the same.
The hardware normally used on RF's like on almost any european produced glider is common MA 8.8 (MA=thread, 8.8=hardness)
If you found a different thread probably is a modification from the previous owner.
Usually coarser threads are Withworth and were used in carpentry and can still be found in some chinese products like carts, lamps, benchs etc. (I refer to Europe, since in the US they are still used, I suppose)
If in this case you refer to the screws holding the panel to the silent block, all depends on the silent block thread.
hope this can help
ciao
Eugenio
Posted by flyingkroeger on Sunday, October 12, 2008 @ 11:22 PM:
Thanks guys for all your replies. My bolts are neither metric fine or coarse, nor UNF or UNC, BUT, I found the original ones, hence the panel is in place as it is.
Now I need to get that tacho fixed…after we got the engine going last weekend, we realised that no RPM were showing.
BR
Tim
Posted by eugenio on Monday, October 13, 2008 @ 03:29 PM:
Check the cable, mine broke some months ago. Just before the tach end of the cable.
Eugenio
Posted by flyingkroeger on Monday, October 13, 2008 @ 06:25 PM:
Hi Eugenio,
Unfortunately it’s the tacho itself. We pulled it out, cable is OK. We spun the cable with a cordless drill and the tacho needle doesn’t move. There is some clicking and whirring inside the instrument, so there is definitely something wrong.
Also, do any of you guys have a CHT gauge?
BR
Tim
VH-TKD (formerly N7720)
Posted by eugenio on Tuesday, October 14, 2008 @ 09:13 AM:
On Jaeger tach a clicking is normal, it's the way it works, but if you hear the clicking and nothing moves probably there is a worn gear inside. Try a watch repair shop, probably they can fix the problem.
I have the CHT on all my RF's. It's a VDO one and the sender is installed on #4 plug. You can find it everywhere in an aftermarket/tuning shop.
ciao
Eugenio
Posted by Collin on Tuesday, October 14, 2008 @ 12:31 PM:
Hello,
I have CHT and EGT from Aircraft Spruce.
http://www.aircraftspruce.com/catalog/inpages/micro4egt.php
Posted by Bob Grimstead on Sunday, October 19, 2008 @ 09:58 AM:
Hey You Guys!
It's an interesting conversation, but we've wandered off topic again here.
Maybe in future it would be a good idea to start a new thread each time we open a new topic?
Otherwise it's a little confusing for the newbies, who only read the threads which seem relevant to their needs.
Thus, nobody would think to look here for info on instruments?
Back to Metric hardware.
Does anybody have a source for the PAL nuts used as lock-nuts for the Rectimo's exhaust studs?
Everywhere I ask, in England or Australia, hardware suppliers say, 'Oh yes, we used to be able to get those, but we can't any more.'
Does anybody have a current source?
Yours, Bob
Posted by Bob Grimstead on Sunday, October 19, 2008 @ 10:03 AM:
More on metric hardware (sorry tacho lovers),
My local (Perth) fasteners aces, Searle's Fasteners, say that the little bolts (screws?) holding the carburettor's air filter casting in place are 12g UNC 24 tpi. They also say they have nuts, but can no longer obtain the bolts/screws with this thread.
Can anybody confirm this?
Does anybody have a source for these?
or do I have to drill out and replace with metric bolts?
You see, I cut slots in the ends (facing forwards, and so much easier to unscrew with a slot and a screwdriver) but now one has snapped in half (ish).
As always, any help would be appreciated.
Yours, Bob
Posted by Donald on Sunday, October 19, 2008 @ 12:33 PM:
Bob, on PALnuts google brings up a couple of suppliers in the UK. Not sure if they have the required size.
http://www.toolfastdirect.co.uk/acatalog/Pal_Nuts.html
http://shop.comdir.co.uk/Products.aspx?intGroupID=918&strProductID=lvqmtyppjc&strWebTemplate=C
On the other matter you might try this place. http://www.bernie-bolt.com/ I have an ancient paper catalogue of theirs which suggests it might be the sort of place to get odd sized stuff.
[Edit by Donald on Sunday, October 19, 2008 @ 12:54 PM]
Posted by Bob Grimstead on Monday, October 20, 2008 @ 09:47 PM:
Thanks Donald,
That's great. Being an oldie, I never think of looking at Google for this stuff.
Next rainy day, I'll try ordering some.
Meanwhile I have to get in all the practice I can on my new routine before Red Bull Final on 1st November.
Yours, Bob
Posted by flyingkroeger on Tuesday, October 21, 2008 @ 07:58 PM:
Hi Eugenio and others,
Bad news about my tacho, it is beyond repair and even that verdict from the instrument people cost me 100 bucks.
Since there is not a lot of room behind the instrument panel, I have my doubts whether a standard GA tacho (e.g. Mitchell) would fit.
Any suggestions? Cheap alternative would be a digital tacho (tiny tach for instance), but since my instrument panel is otherwise original vintage, I do not really want to do that unless as a last resort.
Thanks to all in advance. Hopefuly this is the last issue keeping VH-TKD from taking to the air again…
BR
Tim
Posted by Donald on Wednesday, October 22, 2008 @ 11:37 AM:
Westach do an 80mm dia, 240 degree sweep, tach that drives of the ignition pulse. My RF3 came to me long after the original had been replaced with a tiny electronic device and when I had to get a new one I got one of these. It is wired into the ignition switch and seems to work OK.
Many electronic instruments are 90 degrees sweep only, but the 240 degree sweep is a nice approximation of a 'real' tach.
Posted by Jorgen on Wednesday, October 22, 2008 @ 01:06 PM:
Hi.
XST has a "real tach", which is evident as you have to tap it before the needle will show you a smaller than 300 rpm change in throttle setting.
Of course you want as original as possible, but it´s also nice when things work properly. So don´t feel bad if you have to put in a "modern" tach, Tim!
Take 5(b) just 4 fun/ Jörgen
Posted by Bob Grimstead on Friday, October 24, 2008 @ 10:15 PM:
Hi Guys,
Our British Fournier has a ninety-degree Westach electronic tacho. It's cheap, and works off the ignition lead, but I really cannot recommend it.
It always reads 300 rpm when the enigne is stationary, and I can hear that when the engine is running at 1,000 rpm, the tacho is way out (1,400-1,500 rpm).
Furthermore, with the actual prop off our Aussie Blue, the tacho reads quite different numbers (all higher) in flight.
It might be better if we could adjust the zero (knock 300 rpm off all readings) but there does not appear to be anyadjustment screw.
Unless any of you know of a hidden one.....?
Yours, Bob
PS, it was also held in place (like most of the other instruments, including the compass!!!! by magnetic steel screws)
Posted by Donald on Saturday, October 25, 2008 @ 09:23 AM:
Here (I hope) is a photograph of my Westach 80mm dia, 240 degree sweep tacho.
Donald
Well maybe not quite, but you can see the picture with that link. Perhaps Steve would d/l a copy and place it in my post.
[Edit by Donald on Saturday, October 25, 2008 @ 09:44 AM]
Posted by eugenio on Saturday, October 25, 2008 @ 05:01 PM:
If you need a mechanical tacho Limbach still sells them, the make is Motometer and are the same as the old VDO.
I have no other source to find them, but maybe in the US Collin will be able to find some.
If you want an electronic tacho you can search for a VDO coupled with a sensor to be fitted in the tach drive of the engine, the only problem is that you need power (12V) to run the system (but is the same also with the other electronic devices). Mitchell mechanical tacho are also good, but as say Bob, they reach only 3500 rpm.
About metric/non metric hardware, while working on a newly arrived RF4, I found some very strange bolts, 5 mm in diameter, but a strange thread, it is not MA nor MB, is coarser, but it is not the original part. Somebody used two of them for the stabilizer so the anchor nuts riveted to the fittings got the thread stipped away.
I would like to warn all of you, do not use non standard metric hardware, or you will do damages. All fourniers uses only ISO hardware (that is standard MA) and only a few items uses MB.
About the PAL nuts, if you mean the M8 nuts holding the exhaust stacks you should use standard brass nuts, is the best choice, and surely they won't unscrew. If you use any other kind of nut you have good probability of removing the stud when you unscrew it because the rust glues everything.
Posted by flyingkroeger on Sunday, October 26, 2008 @ 05:05 AM:
Hi All,
Thanks again for the suggestions, there is a new thread on tachos...
BR
Tim
Posted by Bob Grimstead on Tuesday, February 3, 2009 @ 03:46 AM:
Hi Folks,
Forgetting tachos and concentrating on metric hardware, the rear wing fitting attach bolts (fairly important) called up by the RF4 drawings are:
This spec does not seem to accord with what Eugenio so expertly says above.
My local hardware specialist says the HZ 6. 32,5 simply means High-tensile, Zinc-plated 6mm diameter, 32.5mm shank, and has supplied me with appropriate bolts.
The numbers and dimensions seem absolutely correct, but I'm not sure of the material specification
Can anybody tell me if this is wrong?
Yours, Bob
[Edit by Bob Grimstead on Tuesday, February 3, 2009 @ 03:53 AM]
Posted by Markku on Tuesday, February 3, 2009 @ 06:53 AM:
Hello Bob
Metric aircraft bolts are nowadays hard to find, I just got a set of M4 and M5 bolts to my project from Sauer flugmotorenbau. Standard is LN 9037 (LN for Luftfart Norm)
