Here is a list of all the postings BOB BLACKSHAW has made in our forums. Click on a thread name to jump to the thread.
|Thread: Lucky find|
Thanks for the replies,
The photo I've taken does not give the how well they are made,the pivots have two machined slots then screwed together. Early twentieth century could well be correct as the box has a fabric type covering with a silver name plate, so much better quality then todays sets .
Yesterday I was in Bedford looking around some charity shops, and looking through a large basket of boxed items I found this broken box with all the instruments at the bottom.
I instantly recognized them as the same as Brunel`s instruments in the Rocket book. They are in very good usable condition, actually better than what I could buy that day in Bedford, they are so well made.
As they must be made by the same company as Brunel`s drawing set, and have lasted in the condition of the photo, what type of coating and material did they use? as there is no trace of corrosion what so ever.
|Thread: Boiler making problem.|
I've sort of finished the first boiler, just needs the wood cladding on it and some brass bands. I made the boiler 67mm dia with six 8mm tubes crossing the flue with the top having a few rings of copper tube for the superheater, the pressure gauge comes off the safety valve extension tube, it blows at 40ib but needs a stronger spring.. I found the silver soldering quite easy with the correct burner. just needed some practice first and confidence, I was concentrating so much on the job when silver soldering that I put the tube upside down so the water gauge is more at the bottom but seems ok. All the fittings took the time and are cheaper to buy then make. The base is a baking tray nicked out of the kitchen but needs more air vents as the gas tends to go out when more heat is needed. I pressure tested it at around 90lb and held up ok so I'm confident its fine, it has a 18g tube and feels quite a lump. I intend to make a 4 inch boiler next this is 16g and will be a different design, horizontal, Ive got all the tubes needed, just not the silver solder.
|Thread: Propane gas adapter|
Thanks for the advice, I have four types of gas canisters and thought at least one would have fitted.
I have just brought this propane gas burner, but what type of propane tank will this fit. The adapter should fit the hand held tank but has no thread for it to hold on to, the other that is on the gas tube what type of tank do they fit. The propane tank that I have is just a blue tank with the dimple that is used as a pierce fit. I have tried my local DIY shop and non of his gas tanks fit.
|Thread: Beginners models|
I had a very basic training with lathes and milling many years ago then brought most tooling that's needed over four years. I'm still learning the hard way so bar stock is the way to go for me,l would find castings even after four years a hand trembling experience and mind concentration that I will muck it up, so not yet for me. I started with Elmer's engines which are free on the internet I learnt a lot doing them then done a couple of Potty mill engines. Just the cost of materials needed plus a few bolts and not the worry of mucking up an expensive casting till you feel confident that your ready for that.
Still learning the hard way. Bob.
|Thread: Silver solder|
Thanks for the replies which has helpt me a lot here. This is the first time for a large silver soldering area that I've done and so far it has not come out to bad, but if starting again could of done it better.
My next dumb question is pressure testing it, obviously a non return valve. I was thinking of using a cycle valve but this would melt the rubber washer when making a fitting into the 1/4 ME thread bush, not sure what thread the cycle valve is and will mean buying a cycle innertube.
What other ways of doing this please
I am silver soldering a copper boiler and have used two melting point rods. A part that has been solder using high melting rods I think has not quite taken, is high and low rods compatible if used together. When I use the low melting rods I want to touch up one of the bronze bushes.
|Thread: LPG heater- fumes|
As above comments don't use the open flame, look at a green house when using paraffin ln the morning full of condensation on the glass. When buying a electric fan heater check that the thermostat shuts off between a few degrees. usually the cheap fan heaters don't. I use a fan heater which clicks on and off set at a low temperature all night and no problems with condensation.
I have a Carcoon for my MGB but I don't use it, its covered over with a cover and a fan blowing underneath with two carpets on the concrete floor and no condensation.and in my opinion as good as a Carcoon. So air circulation and insulation is all I have found needed over winter.
|Thread: A very old model marine engine|
I have been looking at the pencil type butane torches which I could install as a heat source for the small boiler in the boat.
Any idea how long a full charge of gas would last, I've looked on e-bay at them but this is not on there description. I don't want to spend a lot of money as I will only use it a few times.
I've just brought a micro camping burner for the boiler I'm making, its got every thing I need at a fraction of the cost of the ones with ceramic burners.
With the pencil burner if they last 10 minuets I will be happy with that
|Thread: Lathe belt broken|
Thanks for the replies, my tensioner is misaligned, before I converted to the inverter some of the pullies needed the tensioner and the belt did twist over when on those pullies, so I now know the reason why I have this problem.
The belt that has just split lasted around 10 months with a fair bit of use, so I can still use my spare as its set up. My new belt 730 will need the tensioner sorted, as I forgot that it did twist over.
Surprising the difference in cost for Gates belts, one company £26.00 with postage, another £8.35 each with £10.00 postage but free postage if £33.00 spent, so four belts for £8.35. Trouble is four belts if the set up is ok could be years before the last is used and could perish.
We 9x20 owners should get together and buy a few at £8.50 and send the out to each other for a pound postage.
Actually I have just been thinking this, Ive always used a 710 belt as that was the belt supplied with the machine, so I will try a 730.
To answer Bill`s question, when I got the 9x20 lathe the belt was tight on 3 off the pullies so when changing over to another pully it was a thumb push to get the belt off. The tensioner in my opinion gave even more strain on the belt and I didn't use it until the belt came looser or changing to the other three pullies which didn't have the tension and the tensioner was needed. Now its on a inverter only three pullies are used and they are tight on all three so the tensioner is not used.
If I remember a Myford lathe the tensioner was used to slacken the belt to change pullies, the 9x20 as I've said the belt is tight even when the tensioner is off.
The Gates belts are suppose to be the best and are used with cam shaft drives on cars, so changing over on other pullies must be damaging the belt. Is this a design fault? are there any other 9x20 users having this problem.
Ive looked at the photos and its non of those, mine has a complete split.
The photo is rubbish , cant get close for a good photo.
Old thread but still splitting the belt.
I have put a three phase on the machine two years ago and in that time I have gone through three belts, so its not the sudden start off of the motor.
When changing the belt I push off the belt on to the other pully and its quite tight so its not loose. I don't use the tensioner at all as all the pully positions are a good belt tension.
The pulleys are all lined up, as I used a straight edge when setting up the three phase.
The only problem I see is changing to another pully, its pushing the belt over the pully wheel which could be damaging the belt over a period of time. If I left the belt on one pully I'm
sure it would last.
The belt turns over on its self on the pully, and that's when it cracks up .
Any suggestions please, as I've gone trough a number of belts since I had the lathe.
|Thread: Miitutoyo caliper error|
The Aldi body with the Mitutoyo caliper has a very smooth feel to it,the only alteration was to drill a few 2mm holes. It's still working okay, handy spare.
|Thread: Smiths Astral Clock|
I cleaned the main body and platform in petrol,then used clock oil.The platform I just oiled the pivots very lightly. The clock worked the same before I touched it .
I've got a problem with a Smiths Astral mechanism, it works for around two days then stops,I've stripped it down and given it a good clean but again the same happens, in the end it becomes fully wound up with two days of it working.
So the mechanism will not fully unwind, the platform to has had a clean but I think that this is the problem. I have three other Smiths ships clocks in the loft with platform problems, but the cost of replacing them if you can get them makes them worthless.
Is the platform on the clock the cause of not letting the mechanism fully unwind, any help please.
|Thread: Miitutoyo caliper error|
|Thread: Carbon steel taps and dies|
I have started to make my own water gauges and other fitments needed for my boiler that I am making.
I have some M E taps already 32 and 40 tpi HSS but need a few other sizes for threading brass.
If I but HSS its three times the price than carbon steel so now its cost as I a few more taps and dies.
My question is will the carbon taps and dies be any good just for brass, and what is the best to get 32 or 40 as the part that will fit in the bushes I have done 32 tpi. but I am not sure about the union nuts are they 32 or 40.
As the cost is going up and up it would have been cheaper to buy the fitments than making them, but I prefer to make them myself.
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