mw54 home build

[blighty]

hi all

thought you guys might like to see the turbine im building. I'll add some more pic's in a day or so.

it's the Wren mw54 mk1. you can get the plans from them for under £20. they are very helpful, even when you phone them up with stupid questions. and any part you can't be assed to make, they will have it.

if you have any questions or comments it would be nice to hear them.......... and yes i know the counter sinks are a bit wonky.

[RotarySMP]

Nice Work. Could you post a pic of the tool post drilling attachment please.

[blighty]

Hi RotarySMP

i will put some pics up tomorrow night for you.

[blighty]

that wasn't the question i was expecting...... but here you go, plus some more turbine pics.

[RotarySMP]

Did you machine out that diffuser yourself? I take it was a three axis tool path, with a fourth axis just indexing right? Will those blunt trailing edges be shaped by hand?

Did you make the spindle your self? What bearings are you using in there?

I like your solution for indexing in the lathe spindle. On my Mini lathe I something similar using an existing gear on the spindle (unfortunately 45 tooth is not that useful). For drilling I mounted the black and decker on the cross slide. Your solution is much more elegant.

[blighty]

Did you machine out that diffuser yourself? I take it was a three axis tool path, with a fourth axis just indexing right? Will those blunt trailing edges be shaped by hand? Did you make the spindle your self? What bearings are you using in there?

O ha ha very funny

the diffuser was first machined out on a lathe then put up in a mill to get the fins. just a 2.5d path to make them. we mounted the part in a dividing head and turned it 10degres by hand for a total of 36 fins.

yes i will have to Sharpen the trailing edge by hand. we did a number of test cuts before machining the real part and it was half way round before i noticed.

Did you make the spindle your self? What bearings are you using in there?

not sure if you mean the turbine spindle or the drill post spindle by this one. it would be yes to both. turbine spindle was made from a M16x140mm high tensile bolt, put between centers and turned to size. the drill post one was a MT2 drill arbor, again turned between centers down to 12mm to fit plain old bearing. the bearing's for the turbine will be ceramic bought from Wren.

like your solution for indexing in the lathe spindle.

thanks.......

the lathe i have is a myford ML7 and the indexer for the head is a stupid price, so i made that plate that fits on the spindle then the chuck gos on and holds it in place. only problem with doing it this way you have to mount the plate before you start turning your part. normally you can turn your part take the chuck off(with the part still in it) put the chuck back on and still be in center. if you don't put the plate on first it gos a bit off center when you put the chuck back on.

[RotarySMP]

I have a colleague at work here who builts model turbines. He has bought a bag of ceraminc balls, and is going to reload his own 608 bearings. It is supposed to save you about 90%.

Nice job on that diffuser with two D tool path plus height control and manual indexing - should be about 2.75D right

Have you made up a spot welder for the CC yet?

[blighty]

didn't know you could do that with the bearings. I'll think I'll buy mine. has he done that with his other turbines?

in two minds about the spot welder. i don't think i would use it again unless i make another turbine, but i have been looking into tig welders and i can think of a million and one uses for it...........well maybe a couple.

Nice job on that diffuser with two D tool path plus height control and manual indexing - should be about 2.75D right

well the Z was ramping.... you could call that a 3d cut, plus the manual indexing .so i make that......... 3.436729D milling.

[mcmurray]

How's progress Blighty?
Any new pics?

[blighty]

hi mcmurray

not at the mo. apart from the wedges on the diff there is not a lot of machining left. i have the fuel and gas supply screw things to turn up and I'm going to start the fuel ring next week. just after xmas I'll star the CC and the Econe. Feb-March time when my bank account has recovered from xmas I'll place an order from wren for the bits i can't make. then hopefully go for the first start in April.

[LN-JET]

Nice work on the Wren! I assembled one of the early Mk1 kits back in 2001, and have ca.100 flights on it. I have seen some of the modifications put into the mk2 and 3, and it's a pity that Wren won't update the drawings. The tunnel with a single dia bore, and the new cc would be easier to make.

Regards

Lars

[blighty]

hi LN-jet

i hear you there.

the diff in the mk1 is a cow son to make. i have seen the other diff they use for the 54. don't know if its for the mk2 or the mk3, but you would need a cnc to make it.

single dia bore

didn't know that. the mk1 tunnel wasn't that bad to make. it was just a pain to take it out and re-mount it to turn the other end.

next time i phone wren with a stupid question i'll see if they are going to update the plans.

so then............what's it like when you start them up for the first time?