Swifty's build of Nemett Lynx

[Swifty]

Great idea Brian, it will be the middle of spring here then and it can be great at that time of year.

Paul.

 

[gus]

The postman bought 2 presents for me today, my 1/4x32 tap from a local supplier and my 1.5mm slitting saw from Shanghai. I paid $6.93 including postage for the saw and included in the package was a $5 voucher for my next purchase, great will have to see what else I need.

Now I have to make a holder for the saw, then continue on with the head.

Cylinder Jacket now screwed on to crankcase. I deviated from drawing. Outer-Head will be next but next week.
Bearing Housing/Cap. Bearings bought. Will figure out how to machine Housing. The bearing fit will be tough on Gus.


Paul

Hi Paul,
Please advise slit saw supplier address.

 

[gus]

I've always wanted to visit Australia. October, ---Let me talk to my wife---

Brian .

See you at the October 2014 Melbourne Show. Australia is quite a country.

Crocodile Dundee country up north. Been there in 1999.

 

[Swifty]

Hi Gus, here is the link direct to the supplier, http://www.uxcell.com/80mm-15mm-22mm-milling-cutter-72t-slitting-saw-blade-p-339395.html

I bought mine through eBay for only $6.95 posted, I see that they are charging a higher price through their store. Check eBay, there are quite a few suppliers.

Edit: I just checked my order info, my saw has 50 teeth and is 75mm dia.

Paul.

 

[gus]

Hi Gus, here is the link direct to the supplier, http://www.uxcell.com/80mm-15mm-22mm-milling-cutter-72t-slitting-saw-blade-p-339395.html

I bought mine through eBay for only $6.95 posted, I see that they are charging a higher price through their store. Check eBay, there are quite a few suppliers.

Edit: I just checked my order info, my saw has 50 teeth and is 75mm dia.

Paul.

Thanks for the link.

 

[AussieJimG]

I've always wanted to visit Australia. October, ---Let me talk to my wife---

If you are coming, please put aside a couple of days to visit and to explore Canberra and the surroundings. We have a guest cottage on the property for just this purpose.

Jim

 

[Brian Rupnow]

AussieJimG--If I were to come to Australia I would have to leave my return to Canada "open ended". I have always been fascinated with Australia, and if I do come, it will be a once in a lifetime thing for my wife and I.--Who knows?--You might end up with a grumpy old man and his beautiful young wife as cottage guests!!--Brian

 

[Swifty]

I keep plodding away whenever I have some spare time, I have been working on the cam box that sits on top of the cylinder head, I made an alteration to the holes that hold the camshaft bearings, these are the holes on the front and back, the drawing states 10.5mm dia. but I wanted a bigger hole so I used a reground cutter that was 11.7mm dia. The idea around using the bigger hole is for 2 reasons, firstly it will enable me to have more material surrounding the needle roller, original only had 1.25mm per side, and I'm hoping that I can make the cams integral with the shaft instead of using loctite to hold the lobes on, if I do it this way, I will need to slip the cams in through the holes.

Here is the cam box with fastening holes drilled and slot roughed out with drill.



And here is the slot after milling.



I cant resist having trial assemblies, no fasteners, just to see how its shaping up.



Paul.

 

[Brian Rupnow]

Nice work Swifty. It is coming together very well.---Brian

 

[Swifty]

and I'm hoping that I can make the cams integral with the shaft instead of using loctite to hold the lobes on, if I do it this way, I will need to slip the cams in through the holes.

Looking at the drawings further, the cams may fit through the hole size called up on the drawing, no matter, I still achieve my purpose of making the bearing surround bigger. The instructions call up for the cam lobes to be loctited on to the shaft, this would have made it fairly permanent anyway, and the shaft with cams attached would have to be able to be removed through the existing hole. I'm still going to look at beefing the cams up a bit though.

Paul.

 

[gus]

Looking at the drawings further, the cams may fit through the hole size called up on the drawing, no matter, I still achieve my purpose of making the bearing surround bigger. The instructions call up for the cam lobes to be loctited on to the shaft, this would have made it fairly permanent anyway, and the shaft with cams attached would have to be able to be removed through the existing hole. I'm still going to look at beefing the cams up a bit though.

Paul.

Good idea. Will do same.

Had a great day .
An old friend and fishing guide took
us to his spots. Brought two but lost 6 Groupers due to snaggy terrain.
Will be many return matches. Gus & Co versus the Groupers.

 

[Swifty]

I machined up the bronze bearing housings for the camshaft box, in the rear housing, the holes are countersunk as the timing adjuster fits flush up against this. I mentioned in an earlier posting that the local purchased 20 tooth wheel will lose the shoulder when I ream it out, so I had a go at making my own. I turned up a blank, ground a broach to suit the tooth profile, placed the blank in a chuck on my rotary table and broached the teeth by moving the spindle up and down. I forgot to take a picture of this operation, but you can see the purchased and home made wheels in the picture below. Also in the picture, in the top left corner, the bearing housings snuck in.



Paul.

 

[Swifty]

Started work on the crank now, I turned the web out of some hot rolled steel, then put it in the mill to drill/ream the other holes. While in that setup, I milled a witness for the material that has to be removed, I then held it sideways and roughed it out. Next I pressed in a couple of 10mm dowel pins and returned it to the vice, this enabled me to mill both sides in one setup, using the witness previously milled as my guide. Deburred and rounded a few corners, and this part was ready.






Next step was to make a start on the shaft, I used a piece of 1/2" 4140 that I had, put it in the lathe and turned one end down to 10mm press fit for the web and also drilled a centre in the end. I reversed the part and trimmed the shaft down to length and put a centre in this end as well. I then pressed the 2 parts together with a bit of loctite for good measure. The drawing also shows three M3 holes put in the join of the shaft to the web to actually key the parts together as well, I'm not sure why there needs to be 3, I would have thought that one would have been enough.

Here is a picture of the shaft attached to the web, I intend to finish turn the shaft between centers, using a pin in the web as a driver against the chuck jaw. For a centre in the chuck end, I always use a piece of scrap stock and turn the centre 60 deg in place.



Paul.

Footnote: The Australian / English spelling of CENTRE is always being corrected by my computer to spell it CENTER, so you might see the 2 different versions in my post. I think that I will have to load the English dictionary to fix this.

 

[Swifty]

I carried on machining the crankshaft today, first thing to do was put a piece of material in the chuck and turn a centre on to it, this is so it runs spot on true.


I roughed out the shaft, then swapped over tools for the finish turning. 4140 sure is a pain to get a nice finish, I ended up with some wet and dry paper to smooth the finish. The fits on the 2 bearings are a nice finger push on the shaft. Next to last thing to do was screw cut the M8 thread on the end.


Final operation was to machine a groove for an E clip, 4mm from the end of the thread, this is a safety device in case the nut comes loose. Here is the finished crankshaft.


I'm working down in size with the parts now, I may do the prop driver and washer next, this will finish all the parts that attach to the front of the crankshaft.

Paul.

 

[Swifty]

I finished turning the prop spinner and the taper lock today, then milled the grooves on the face of the spinner and drilled the driving pin holes.
I don't know why I need the grooves when there will be 2 pins in the spinner to drive the prop, did them anyway. I didn't take any photos while I was machining the parts, only the finished items. I still have to mill a slit on the taper lock, I just ordered a 0.5mm slitting saw to do it with.



Paul.

 

[gus]

Hi Paul,

You are leading and I am falling behind which is good. Will monkey see,monkey do. The two day one nite fishing trip was bad.Spots overfished.And its weekend fishing again.

Trying hard not to rush. Two reworks by now. Will turn the crankshaft the ''Swifty'' way.
No distraction for next week planned. Will be good progress.

 

[Jasonb]

I don't know why I need the grooves when there will be 2 pins in the spinner to drive the prop, did them anyway.

After Malcom had a prop come off the prototype while doing a demo at a show he decided to play extra safe.

J

 

[Swifty]

After Malcom had a prop come off the prototype while doing a demo at a show he decided to play extra safe.

J

Hi Jason, yes that's what the E clip is on the shaft for, I was just wondering why the driving grooves are needed when there are two pins doing the driving of the prop. Thanks for looking at my posts.

Paul.

 

[gus]

Hi Jason, yes that's what the E clip is on the shaft for, I was just wondering why the driving grooves are needed when there are two pins doing the driving of the prop. Thanks for looking at my posts.

Paul.

Hi Paul,

Will be puttting on the CI Pulley. I have Prop-Phobia. Seen some my rich class mates get bad cuts from aero-model props. Will use lock nuts and Loctite for insurance.
Next week will cut crank disc.

 

[Swifty]

Hi Gus,

I will also be using a flywheel to run it, but will have a prop for display purposes only. I value my fingers too much to run it with the prop. That's the reason that I made the crankshaft the longer size to suit a prop, I will just design my own flywheel to suit the length.

Paul.