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Hi Tony
Is the back improving now I hope the meds are working OK for you. I don’t know if you are checking the site but this is where I am up to, facing the .08” surplus off the cam was a bit of a disaster I managed to turn the gear location dia .02” u.size must learn how to read a mic.I thought of a few options but decided to remake it as it was a nice job to do originally & would let me get more use from the milling fix. I made it exactly the same except the marking out which I did similar to the crank image below, grind a knife edge on a piece of round HSS & mount in the spindle grip cam blank in dividing head chuck & set in freewheel mode & use the DRO to space out markings lot easier than height gauge.The spare cam will be useful for a trial heat treatment if necessary. Started on the crank faced both ends & mounted in vee block to centre both ends in mill using DRO I remember doing an actuator gearbox many years ago where the gear centres were lapped before grinding between centres so I lapped these with an old dead centre & fine lapping paste it cann’t do any harm, then turned down to ¾” dia from 1.1/4” which was the size in the kit. I have not used this material before it seems very similar to S1 mild steel picks up & tears very easily when turned. I roughed main journals plunge cutting with Iscar self grip p/off tool & 3mm neutral insert tried most of speeds available for this, 500 rpm seemed to work best when I tried this on the other journals it would not cut just tried to push away from the job probably due to interrupted cut I ground up 3mm wide HSS groove tool & used this 1 pass down centre then 1 either side to about .4” dia which is where I am at now, 315 rpm seemed best, worked OK. The tool chattered a lot as can be seen from the image due to interrupted cut I think it will improve when down to a full dia. It needed a regrind on top face about 4 times per plunge cut this was indicated when the swarf changed from fine needles to lumps of swarf. I did 1 journal per day as I lose patience easily, when finished I released pressure on the tailstock for the night & noticed when I tightened it up for the 2nd journal a very slight pressure caused the first journal to start to collapse I don’t know what it will be like when they are turned to size will have to make some small turning tools maybe modify 2mm insert p/off tools. Checked between centres when finished & got 0.012” TIR not bad considering the amount of material hacked out & it not being a very symmetrical shape, will set on 2 vee blocks & use press to straighten before final turning .Going on hols at weekend so will check if it moves while I am away maybe I should leave it outside to weather like a casting!
Hope you are soon back in shop making swarf with a pain free back.


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P5100119.JPG
 
Thanks All for the many well wishs
The back is much better. I'm going to give it another week, I have to take the 6" RT off the mill. I think putting that beast on took care of the back!

Hi tombstone,
I've been watching. Looks like your really progressing on it. I'm going to have to work 24/7 on it to catch up :big:

Tony
 
How not to machine a crankshaft #1
How the hell did I manage to do that

P5130122.JPG
 
Are you using the E16T material for the crank or a substitute? I have read 4340 but also hear it is a bugger to machine. What do others use for IC engine cranks?

Steve C.
 
Hi Waltnor
Yes it was E16T I have ordered 2 more lengths so I will have a spare it is not easy to machine on c/lathe I think probably due to limited range of spindle speeds available HSS seems to work best. I have not used 4340 before is it an AISI spec?The only other material I have to hand is some lengths of Hy-Tuf (AMS6418) in pre-heat treat state but feel hard of putting work in to make crank if material is no good for job
 
Hi Tony,I usually fit a wedge or nut and bolt between each web as this helps stop the flexing.What are you going to use for the bigend bearings.Make sure to have a small rad in the corners as I snapped a crank and luckily didn't do much damage but nearly gave me heart failure.
regards Frazer
 
Hi Frazer Thanks for that this is 1st crank I have tried to make & am learning as I go,the nut & bolt should be a neat way to go the gap is .33" wide.It was flexing quite a lot with very little tailstock pressure on the 1st effort.I was going to take final pass with V style insert with .015" rad. Ray
 
Could one of you gentlemen tell me what E16T steel is comparable to. I have seen this designation used more than once.
I have used durabar cast iron, 12L14, 1144 stressproof and 1018 CRS for cranks. I have never had any problems with any of the listed materials but then again these cranks are only used in engines for demonstration purposes, 10 minutes here, ten minutes there. Each of my engines has a different type of lubrication system, some splash and some with gear pumps.
gbritnell
 
Hi gbritnell ,
EN16T is for the the crank on the Whitttle, I would suspect 4140/4142 or in that neighborhood.

Tony

Good to be back.....no pun indented
Noting wrong with chrome moneel 4130 either
 
In Part 8 of the build series Mr. Whittle makes a few recommendations for material substitutions. He feels 4340 is a good substitute for the EN16T. Also the HE30 aluminum is equivalent to 6061-T6 and HE15 can be replaced with 2024-T6511. It sure would be nice to have "standard" material designations!

Steve C.
 
Not trying to tell my Granny how to suck eggs but if you go for the nut and bolt wrap a bit of tape round the web or a tye wrap to keep it in and stop it flying out .Good luck with the build its well worth it even though at times its hard going
regards Frazer
 
Frazer many thanks this is all new to me any help gratefully recieved
Cobra Don't lift any heavy weights in shop & start on crank soon please
If the chart downloads ok it may be of intrest

View attachment steel.doc
 
tombstone
Thanks, I've been trying to get to the shop. But things where a little buzzy

Tony
 
Hi Cobra
Glad you are on the mend & getting back to the shop take it easy before doing too much it can be a mine field if you are you are not 100% fit as we all know. Just managed to keep ahead of volcanic ash to go on hols for 5 days. The next job is shown in photo, fit a new cross slide screw & nut the old one is shot the backlash comp is worn out in the middle of the thread , the new part is wrapped in crocell on top slide, as it is a critical part decided to purchase from Colchester (600 UK Group) direct as they had one on the shelf I could probably have purchased a new Chinese mini lathe for similar money. Will have to move lathe to centre of shop to remove cross slide from the back and have to make sure it is done right so will take some time to do, the drive belts are also shot so will change them at same time. Have just received 2 pieces of 1” EN16T for next attempt at crank should be no trouble now!!
Take it easy. Ray

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Ray,
I think I'm going to use a tapered pin reamer for the front. 5/0 looks about right. I really don't want to deal with the 7-1/2 deg hole in the thrust washer!

Good luck with your next try

Tony
 
Cobra
make the hole with what youve got & turn shaft to suit always a good strategy does this mean your going to start cutting metal cant wait to see photos
Ray
 
Hi Ray,
Planning to get in the shop tomorrow.
I was also thinking of making a step to stop the drive washer and key it with a 1/16 pin

Tony
 
Hi Tony
I had not given much thought about the drive washer until you mentioned it I had a root around a box of old tools & found a taper pin reamer which would do the job so I think I will go with that, the way I see it the main force when running with a prop is radial so I think that a taper is best solution same as morse taper tooling, the only experience I have had is with an ED Bee 1cc about 55 yrs ago & can remember it had an ally drive collar with a taper the main problem was removing it without damaging the case. If the engine is only for demo runs I think a drive pin would be OK. When I started my mate who is a R/C model aero fanatic said he is going to build a DH51 replica to fly it in he reckons if he starts the build in 2 yrs time we should be finished together. Incidentally I read an article in one of his R/C mags which said one of the most common parts damaged in a crash is the crankshaft. Hope to start stripping Colchester tomorrow so have a few days to think what to do with crank, fcheslop’s tip with the nut & bolt sounds very good I will go with it.
Ray
Ps just a thought it might be possible to use shrink fit on a parallel dia to fit washer similar to the tooling used on high speed machining centres I heard that hot air is used now used to be induction coils but this was since I retired.
 
Hi everyone! I'm glad to see there are others insane enough to take on the eyestrain associated with this project! :big: Thank you to Iain who pointed me to this WIP thread.

I'm a little behind this build is some areas and ahead in others. Wait till you get to the heads, they area ton of fun. I won't clog up the thread with a bunch of stuff, so if you want to see pics of the heads go to

http://www.dragondark.us/projects/wv8/wv8index.html

Nice to meet you all!
Rob

 
Rob,

Welcome to our forum. wEc1

Nice website. :bow:

How about telling us a bit about yourself by posting an intro in the welcome board. ???

Best Regards
Bob
 

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