Member postings for michael burton 1

Hi all just started back on my model for the winter period................. Now that I have most of it built I really need to take a serious look at getting a boiler design sorted I know all the sizes and wp I would like but designing it is completely a miss for me.......

BBassicly needs to be 20 inches long end to end

5 inches diameter

Working pressure of around 100 psi

Ideally gas fired

thinking twin flues with 2 burners and multi cross tubes

Basiccly that's pprett much what I require does any on on here think that would be possible to design

Atb mike

Photo is in my album as not sure how to add on to the post

<linked to photo in album - Neil>

Edited By Neil Wyatt on 13/05/2014 18:20:21

hi could anyyone surgest a steering shaft thread fo my model i was thinking something like 3/8 whitworth or a bit of 10mm x 2mm pitch leadscrew heres a pic of the model so you can get an idea of the size

also while were here would the saftey valve go on to the boiler like a locomotive as im using a steam take off pipe to the reg chest or on top off the reg cover like traditional traction engine just so i can make a bush and get it fixed onto the cover while im there

Hi Jason it has a separate pipe that takes the steam supply to the reg chest

hi i have my model running on air and have put to use my mechanical lubricator the was on enougher model,

now the question is were is the best place for the oil to be put

a) into the steam inlet pipe

or

b) directly into the reg chest

or

c) somewere else

also as to the size of pipe to use i have 3/16 pipe and quarter pipe or do i need a much smaller diameter,the cylinder bore is around 1 3/8 and a 2'' stroke

hopeful for some advice mike

hi i have used all listed there apart from ekp but i favour m achine for the amount of differant stuff they carry and there prices are reasonble especially when you do only need an inch or 2 i did a largish order must of weighed around 10+ kg and i had it next day

im using a stop collar design and not the type were you use a plate with a curved slot

hi how do you work out the drive pin locataion on a slip eccentric iv got the eccentric with a 7mm off set to give me a 14mm throw...

is it critical as to were the drive pin is located

cheers all

now i get it brain was working over time and simply over complicating things thank you jason

right ok i have some questions so i can try and get my head around all this lets say just for an example that the 2 steam ports were one inch apart and were 1/4'' wide ............... the throw is that measured overall so would be 1'' with a off set to give you a movemant 1/2'' eaither side of centre how would you come to the point of knowing what the off set should be to give you that 1/2'' movemant eaither side that is required and and the relationship to the diameter off said eccentric

i picked these measurments to make my life simpler for understanding ( i hope )

im trying to get my head round this and have searched on the net but came up a blank

i could ask someone to just give me the answer but then i wont learn so if any one could explain using these measurments how to come to an answer it would defo be apprecaited go easy and hopefully itl come to me soon enough

thanks for your time and understanding

so iv just machined my cylinder for my one off design traction engine the original plans had the cylinder on the left but i wanted it on the right so it was more like a full size anyways i get off the phone to my wive look at it and after a slight naughty word realised that iv machined it back to front so oh well i guess the bore will have to be on the left whoops

hi will brass work as a slide valve material just i have a big block of brass that i can use the cylinder is cast iron so will brass work at the mo i cant afford to get any differant material so would rather use what i have??????

also were would engineering plastics come in to use could you use somthing like acytel or delrin............... this is just a courious question

the model is only going have minimal use

atb mike

currently making some now just having a little break

hi what other options other then cast iron rings are there for a cast iron cylinder/piston combonation, i could make the rings but dont want to get in to that to be fair so what else could i use

mike cheers

cheers jason

hi on the model im building it uses slip ecentric valve gear, now the orignal design is a 1.5'' disk with a 1/8'' deep grove so giving 1 1/4'' running surface with a 1/8'' off set bore.

now the stroke and bore have been enlarged as the model is a fair bit bigger so now has a 2 inch stroke how do i work out the new ecentric off set and size

i tried working it out and got no were how does the ecentric size relate to the off set the port spacing is yet undecided but would imagine the ports would be around an inch outside to outside im still new to this so i would like some guidence about this

it may not be a straight forward answer but im all ears for sugetions of how to come up with an answer

i did come up with a disc of 2'' od but this would look stupid on the model so mayby theres a way around this with a diff offset and final diameter

atb mike