cornish wood burner

Depends on temperature May / June and if I feed them, but we are a bit warmer here I guess. Mine is also more wildlife/ plants than Koi. Apart from the Koi, I have a 25 year old golden orfe which had a narrow escape from a heron years ago. Two marks on its back but it's smaller companion wasn't so lucky. It seems to get on very well with the Koi. I presume your pond needs to be quite deep to get over the winter freeze where you are.

My koi spawned yesterday which is the latest I've known. Anyone else had spawning this late.

I've either built dwarf walls or just had concrete pads for supporting the central area. Much easier and stronger than posts if it's a low deck.

Yes but who did they copy the design from? I think they have got the angle wrong anyway! While we are on the subject of shovels, I once heard that two Cornishmen raced a 3 tonne mini digger loading stone and at the end of an hour it came out even. I don't believe that for a minute though. It would never take TWO Cornishmen to keep up with a 3 tonne digger, unless of course they stopped to eat their pasties half way through.

I believe the Cornish tin miners used pointed shovels for shovelling the tin ore. The point slides past the stones rather than a square edge being stopped by one. Presumably the underground shovels were shorter handled to work in the confined space loading the ore into the rail skips. The long handle completes the Cornish shovel as we know it now. The long handle enables extra leverage when digging and also can enable extra push on the lower hand with the users leg. Another a big advantage is the user can stay upright. Ideal for moving small trees, just work around the tree then use the long handle to lift the root. Everyone should have one

Cornish shovels are great tools.

Set screws ( fully threaded bolt )are not ideal because they do not bear fully on the shear plate holes. If the sets are highly stressed or not tightened enough, you will get wear over time because of the poorer fit in the holes Best option is to use weakened high tensile bolts.

We moved a few the same way. Dig down so the manitou bucket can go in level with the bottom of the root ball, then use the digger to push the tree into the manitou bucket. The bucket keeps the earth on the root ball and no manual handling or bagging, not that you can do much by hand anyway with a tree of any size. You will need a reasonably sized bucket though. All ours survived and it's not our trade

Not something I've bought for a long time. You might find a few shear bolts in 4.8 but will be rare now. I would try a fastening supplier for what is basically a mild steel bolt. Just had a search and K engineering list 4.8 bolts. A plain shank coach bolt must be about 4.8 but you need a means of holding the head while you tighten. Tackweld a nut under the head of one if you fancy doing a trial first perhaps? As I mentioned previously you will need a reasonable well engineered shearing mechanism to cut the bolt. If the plates can part you will find the broken bolt will bend too much before it breaks. It will then give you grief to remove. Might be too weak anyway but you might have an idea of the power required from listening to your tractor. I have seen grooved shear pins around so I think we might have missed the boat on that one. Also I've sold my lathe so I couldn't make you one anyway. As an option if the bolt is long enough to hold you could take some of your 12.9 or 8.8s to your local machine shop and get them to machine grooves to reduce their strength. Get the groove in the right place and it would be better than 4.8s if that is what suits. Run an angle grinder cutting disc around a bolt is another thought. Not accurate but might work. A few options for you, good luck with it.

If your shaft transmits 60 hp with a 12.9 bolt A8.8 gives you 41 hp A 4.8 gives you 22 hp This is a very rough calculation with unknowns of a good shearing mechanism which could make a difference.

You could try a 4.8 bolt. However the weaker and more ductile your shear bolt is the more important the shear plate design is. Ideally the plates should be held tightly together with a hard replaceable insert to cut cleanly. If this is not the case you might have a few problems getting the broken pieces out as it may not be a clean shear.

Drop down a grade or two 8.8 or 10.9 to shear quicker without stalling the tractor

Shear bolts were often used in a softer form years ago. The old grade 2 imperial which was around 30 tons per sq inch. Metric equivalent about 4.6 to 4.8. Shearing action was often quite plastic especially if the plates and bushes were a bit worn. Bolts are more commonly 8.8 or 10.9 now and tend to snap cleanly in comparison. I've no doubt weaker bolts are still available but the shearing action works best if it was designed to use them.

Depends on what power you want to put through it. If you had a 200 hp tractor with a shear pin to suit then the pin probably wouldn't shear but the machine would be damaged first. Shear pin should be the weak link and break before your machine or tractor drive train should.

When a tractor stalls the engine rpm drops from around 1500 rpm to zero in the blink of an eye. The inertia of the engine will either cause the pto clutch to slip or twist the shaft. Either way it will put more strain on the tractor drive train than the engine power alone can produce.

Not quite true. You haven't considered the tractor pto drive. Constant shock load coupled with the engine inertia will exceed its design strength. Probably enough built in safety margin but who knows.

Actually I doubt whether the machine would take 200 hp before the shear bolt sheared. You could try as soft a bolt as you can find. Even aluminium and work up to a 4.8

First of all you will need the tractor pto torque. If you don't know this the engine spec might tell you. Multiply engine speed divided by pto speed x engine torque at rated pto speed, this will give pto torque. Find the radius of the shear bolt from the centre of the rotating shaft. Calculate the force on the bolt using torque divided by radius Diameter of shear pin will give you the cross sectional area of the bolt. You then need force/ area in whatever units you are working in to give the required shear strength. Find a bolt with that shear strength. However I suspect you will need to go down several sizes of bolt if your machine covers 200 to 20 hp

Just read that as well. Similar topic on the screwfix forum and it seems we are not alone in finding rubbish ply. If I can get that phenolic ply at a reasonable price then it should be worth a go. Thanks to all for the info

My last WBP ply floor lasted about 20 years. However we use a lot of ply at work and we find it often delaminates and also has gaps in the centre. Not made like it used to be. Perhaps the glue had some environmental or H&S issue or its just made too cheaply now.

I would certainly prefer phenolic but I have only seen thinner around this area. l will give new world a ring tomorrow. Thanks guys.

I'm after some exterior ply for a small trailer floor. I've been offered cross grain birch ply. Anyone know how that compares to normal WPP which seems to be very poor now.

Exactly. No doubt the wealthier white Americans have a different view but until the politicians address the unequal unemployment, poverty etc there will be problems. Couple that with access to firearms and you have a recipe for bloodshed.

Those nail clippers must have looked really dangerous to them or is widespread gun ownership generating that sort of instinctive reaction throughout the security forces. While on a cruise we heard a couple of Americans talking about their extensive security measures at their homes. Any society with a mix of wealth and cultures will of course have a degree of envy, friction and unlawfull redistribution of wealth, but it sounds very extreme there if those two guys were representative of the average home owner. They obviously intend to keep their wealth by using their ability to buy bigger and better guns to drive off those less than model citizens. Perhaps some fundamental changes are needed from the politicians to reduce the war.

American security does seem very paranoid in my experience. Going through customs entering America an X-ray picked up a pair of nail clippers in my hand luggage. Not scissors but the ones with the jaws at the front, activated with a lever on top. I explained what it was and should then have been obvious, not thinking I reached in to show them. Big mistake John Wayne had nothing on these guys. Bearing in mind the bag had been x rayed so obviously no guns etc, why did they go for their guns. Never had anything like that happen anywhere else.