CHUK, yes another one

[Jo]

For someone in Graham's situation does he pay £350 for a Femi bandsaw and buy barstock to cut bits off or pay 50p each for individual cast items in the quantity needed with each set of castings? .. 700 bits need to be sold just to pay for the bandsaw outlay 

Jo

[Jasonb]

Jo As I said in post #54

Jo I was thinking more along the lines of just selling the main castings and then leaving the builder to source the remaining barstock for simple items.

Less capital outlay, less hassle getting basic parts cast, less problems dealing with defective castings, No problem when he can't supply an individual casting due to problems without getting the whole match board recast , all good reasons for someone doing it on the small scale that Graham now does, different for someone selling a lot more where costs could be recovered faster.

And lets face it if he had billets of CI on the shelf you would not have had issues with yours and had to pay twice for the same item ( original castings and replacement barstock) or only once  (barstock)if he only supplied the main castings

[Jasonb]

Jo, this is the exchange of posts I mentioned back in post #46, even Graham thought it a good idea

[Jo]

I am confused I thought you were talking about Graham supplying bar stock for the basic covers rather than the real castings.

Most of the problems encountered are in the complex castings like the flywheel which was offset which had lots of chilling and Graham had a cylinder that looked more like a screw thread  . Those were poor foundrymanship.

I didn't pay  for those bits of CI I am looking to reuse 


Sorry don't have enough time for Farcebook: I am retired so I am always busy 

Jo

[crueby]

Oh My!  Jo, just because he wouldn't give you more castings, you didn't have to feed Surus to the baby Anteaters!!!   

 

[Jasonb]

I am confused I thought you were talking about Graham supplying bar stock for the basic covers rather than the real castings.

Again, right from the start #46 I said that the builder could supply and Graham just do the main castings and have confirmed that 3 times (4 now) so don't know how you are getting confused.

I'm not suggesting things like flywheels, bases, cylinders but the parts with little or no shape to them that can easily be made from barstock, For example the cam disc and crank, both thin items and likely to have some chill even from good foundries could both easily be made from steel (no need for iron), round billet in the case of the cam and piece of rectangular bar or round stock in the case of the crank. The bearing supports would easily come out of rectangular bar or flat plate and as I said no need for bronze/brass as bearings are being used which removes the risk of impurities and porosity like the one you were sent that looks like it had already been started and rejected by someone else, you would  have machined every surface of all these parts so what's the point of a casting?. Piston and cyl head would also be candidates for builder supplied.

[Jo]

If I was supplying small scale sets of castings like Graham I too would supply the basic covers as castings as I would have had to visit the foundry to drop off the patterns and the simple bits just fill the box: so they have next to no time or cost associated with them, doing it any another way would.

As some one with lots of zero cost bar stock hanging around sometimes I choose not to use a casting as a bar offers alternative holding opportunities and allows for modifications like with the crank which I am lengthening to get a longer stroke. But as a rule using bar stock takes longer as those of us with out a Femi have to cut it off as well 

Jo

[Jasonb]

using bar stock takes longer as those of us with out a Femi have to cut it off as well

But don't you have a horz hacksaw and vertical metal cutting band saw and a hefty lathe that should be able to do a bit of parting off

[Jo]

I have a mechanical hacksaw which takes a long time to cut in comparison with modern metal cutting circular blade saws. I rarely use this - its a bit like using a shaper I set going and walk away for 5 mins.

I have a Startrite 352 Wood bandsaw that I can fit metal cutting blades to but it is single speed which is too high for metal. Its purpose is converting brown stuff into lumps suitable for burning in my log burner 

And as you know 5 Lathes that are all capable of parting off, which is what I am about to do to make the next couple of bits.

I also have a number of hand hacksaw frames which are very effective for hand sawing metal and of all the above options the cheapest and take next to no space.

Jo

[Alyn Foundry]

Well....

Which ever way you look at it I'm a casting man !

A casting carries the shape and form envisaged by its creator.

Put the pattern in the hands of a " skilled " foundryman, the results speak volumes....

Cheers Graham.

[Jo]

I am pleased to report the postman was trampled on the drive   has delivered the castings so I am about to see what can be done 

Jo

P.S. Why they don't let the Postlady deliver them I will never know, she knows how to safely deliver castings without any problems

[Alyn Foundry]

Hi Jo.

Great news, the term  " Royal snail " springs to mind....

Cheers Graham.

[Admiral_dk]

Looks like you got your missing millimeters 

[Jo]

Thanks Per 

Decision time what to do  I decided to make up the crank and the cam so I could see things better. It did not tell me much as blanks so I went ahead and finished machining them.

The cam was again machined using the boring head: The main disc was machined with a 62mm outside diameter, the boring head set at 65mm outside turning diameter and then slowly offset across the face by 9.5mm to give me 8mm of cam movement. Five holes were drilled to lighten the cam on the other side to make up for this.

The crank throw was decided on as 28mm and allowing for a big end on the piston rod of 19mm I need 37.5mm from the centre of the crank to the base  I first tried packing it with two parallels (4.8mm sq tool steel  ) and that seems to give me the right height and still fitted between the A frame  . Fingers and toes I can get the centre height using the bearing blocks ideally I would like the crank centre line 32mm up from their base

Jo

[Jo]

My crankshaft has gone up in the world 

As a result of fitting the new crankshaft bearing housings it is now 3.5mm higher and the flywheel fits nicely into its cut out in the base 

I am still going to have to machine a little clearance under in the base for the crank web and the piston rod's big end: the original Plank engines had this and Graham's casting has enough depth to enable it to be scooped out   

Jo