Hi Rob Re your note to Ian:
When I got my Dimona it had the rigid tailwheel. I had a flat tailwheel in the first year and eventually the shaft got bent. The sprung tailwheel was fitted in 1990 and I've had one flat tyre since then - but it was a puncture rather than a deflation! Comments from the UK about the tailwheel: 1) Make sure that the horizontal shaft is kept lubricated - there is no proper lubrication method so I drop oil into the gaps in the middle using the dipstick. 2) Apparently the vertical shaft of the tailwheel assembly goes into a wooden block. With the original un-sprung design this could break up, increasing the castor angle of tailwheel shaft. Regards Michael From: Rob Thompson Sent: Saturday, February 20, 2010 5:11 AM To: [email protected] Subject: Re: [DOG mailing list] thanks Ian Hi Ian, Thanks for the offer to organise a draftsman. A couple of questions about the sprung tailwheel... - How often do you get flat tailwheel tyres? We get them a fair bit and I think it's due to a fair bit of weight on the rigid tailwheel. - Do you get much "bunny hopping" on uneven ground with a sprung tailwheel? cheers Rob PO Box 129, Lawson, NSW, 2783. mobile 0429 493828 ............................................. -------------------------------------------------------------------------------- From: Ian Mc Phee <[email protected]> To: [email protected] Sent: Fri, 19 February, 2010 2:42:03 PM Subject: Re: [DOG mailing list] H36 owners with sprung tailwheels Got a guy who is in drafting in anything engineering (usually does high rise windows!!!!) so will get him to have a look when here next - Also Nigel should be here in the next few weeks. My aircraft welder Rowan must have forgotten to call in when driving past -he could look and give a round figure price. Another alternative I have always thought of is instead of 250-4 tire is change to the bigger tyre (will look up size) as used on some C185s - I saw this used on every Pawnee in Sweden but never seen it on a Pawnee in AUS. Possibly a simpler mod but it may effect shimmy- Yes it would be a bit heavier but not much and from memory most Dimonas would benefit from bit more tail weight Guess it would need EO also but I always know bigger bag tyres smooth up ride (going from 800-6 in pawnee to 850-6 is leap forward as was going from 500-5 to 380-150 in 2 wheel falke. Ian mcphee On 19 February 2010 11:36, Rob Thompson <[email protected]> wrote: Do you have a H36 Dimona with a sprung tailwheel and wouldn't mind me sending around a local draftsman to draw up some plans? If so please let me know... I wouldn't require the tailwheel to be removed - we will draw up the shaft plans from our H36. Thanks in advance! Rob Thompson [email protected] PO Box 129, Lawson, NSW, 2783. phone 02 47592307 mobile 0429 493828 ............................................. ------------------------------------------------------------------------------ From: Laurie Hoffman <[email protected]> To: [email protected] Sent: Mon, 1 February, 2010 9:04:20 PM Subject: Re: [DOG mailing list] H36 spung tailwheel Firstly you raise the tail off the ground and then after you have spung the wheel around and around of course Nige! Then you can say that it has been spung. Regards Laurie Hoffman 46531233 ------------------------------------------------------------------------------ From: Nigel Baker <[email protected]> To: [email protected] Sent: Mon, 1 February, 2010 6:57:29 PM Subject: Re: [DOG mailing list] H36 spung tailwheel I'm interested in what this Spung Tailwheel is. I know what a Sprung wheel is but what is it when it is "Spung" :) ----- Original Message ----- From: Rob Thompson To: [email protected] Sent: Thursday, January 28, 2010 10:33 AM Subject: [DOG mailing list] H36 spung tailwheel I'm keen on the idea of getting a sprung tailwheel on our H36 - the rigid one is not at all good on rough surfaces. I think the sprung wheels may also reduce the "bunny hopping" on rough runways....can anyone enlighten me as to whether this is the case or not? Last time I saw a sprung one I didn't think it would be particularly difficult or costly to manufacture - perhaps we could get some plans drafted from one of the dimonas with a sprung wheel and see about getting a few made up with appropriate approvals. How many of you would be interested? cheers Rob PO Box 129, Lawson, NSW, 2783. mobile ............................................. ---------------------------------------------------------------------------- From: Ian Mc Phee <[email protected]> To: [email protected] Sent: Wed, 27 January, 2010 11:39:22 PM Subject: Re: [DOG mailing list] Dimona 1984 Interesting about tail wheel mod from Michael - sure gives smoother ride. You mention the heads/valves lasting only 300hrs. I would recommend to all analysis of exhaust at FULL POWER with lamdameter etc. You may find it is running slightly lean on full power (actually plugs look OK) but gas analysis does not lie. More recently i have been using digital CHT and you can really see what is happening. I set them up so full power CHT rises to about 170degC then very slowly falls. If you bring throttle back just a bit in revs CHT will quickly rise to 180degC and beyond. This proves to me you are running rich on full power- also confirmed on EGT. To achieve this it may be necessary to carefully thin out the end 6mm to 8mm of each the needle in carby and thus achieve the low CHT on full power. (do not think of touching jet) Fuel is cheap when compared to repairing heads. Limbach Tech bull 53 makes mention of max on climb of 180degC (forget what max the manual says - that is stupid value) Also Tech bull 44 (11page edition) is well worth a read. Ian mcPhee 2010/1/27 Michael Grimwood <[email protected]> Hi John and Lasse I have owned a Mk1 H36 since 1988 (G-MRG in the UK, now VH-VRG in Australia). It originally came with an un-sprung ---------------------------------------------------------------------------- Yahoo!7: Catch-up on your favourite Channel 7 TV shows easily, legally, and for free at PLUS7. 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