Author Topic: Making a flywheel  (Read 58515 times)

bogstandard

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Re: Making a flywheel
« Reply #25 on: March 18, 2009, 07:01:37 PM »
Glad you guys are enjoying it as much as I do. :thumbup:

Now a question for yourselves, to help me in the future.

On the last bit of this post, I showed measurements using my DRO.

To those who don't have such things, did it detract or help the post by seeing it displayed like that? or did it come across as if I was just boasting I have DRO's (that is one thing I don't want to do).

This is a rather important issue to myself, as it is very difficult to explain about putting on exact cuts using text only, and if people do find that pictures like that help, without feeling 'substandard', then it will help me a lot in explaining in future posts.

Thanks

John

« Last Edit: March 21, 2009, 06:58:09 AM by bogstandard »

Offline sbwhart

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Re: Making a flywheel
« Reply #26 on: March 19, 2009, 04:07:47 AM »
Glad you guys are enjoying it as much as I do. :thumbup:

To those who don't have such things, did it detract or help the post by seeing it displayed like that? or did it come across as if I was just boasting I have DRO's (that is one thing I don't want to do).

This is a rather important issue to myself, as it is very difficult to explain about putting on exact cuts using text only, and if people do find that pictures like that help, without feeling 'substandandard', then it will help me a lot in explaining in future posts.

Thanks

John


Cracking write up John  :clap: :thumbup: :clap: :thumbup: :clap:

Any one who's met you would know you havn't got a boastfull bone in your body.

A few creaky ones yes but no boastful ones.

Never used a DRO  (hoping to fit some in the near future) I understand that as well as accuracy the other advantage is that they eliminate/reduce back lash effects, and I think dealing with back lash is where a newbie will strugle.

I've only ever used dials, the way I deal with back lash.

1:- Always come on position from the same direction where posible.

2:- Zero dials where you're going to repeat moves ie 0 move 5mm move 6mm etc mark dials with coloured crayon

3:- When you have to change direction of fead to avoid climb milling again use coloured crayon to mark dials.

4:- Plan ahead do a sketch what you going to do direction of fead etc and have this andy to refer back to.

And be methodical

Cheers
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Stew
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Location:- Crewe Cheshire

Offline Stilldrillin

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Re: Making a flywheel
« Reply #27 on: March 19, 2009, 04:35:43 AM »
VERY well put Stew,  :clap:

I`ve just come back to dials & backlash, after 1/2 a lifetime spent with CNC & DRO.
It`s like being an apprentice all over again.....

Your comments mirror my thoughts exactly.   :headbang:



John,

I`m sure DRO makes the tale much easier in the telling...... Keep on keeping on mate!  :thumbup:

David.
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Still modifying bits of metal... Occasionally, making an improvement!

Offline Darren

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Re: Making a flywheel
« Reply #28 on: March 19, 2009, 07:46:16 AM »
Hi John,

I have started to read this section a couple of times. I have to admit that it got a bit heavy going for me.

NOT, your fault, it's mine. I've been working hard outside whilst the weather has been with us and I'm very tired by the evening to concentrate properly.
This is a very involved thread and needs careful study to comprehend it properly, I will get to it... :thumbup:

As for the DRO's, carry on. I think most of us would like a similar set-up and to see it in action is very enlightening.

You do it your way, we have the  :borg: to adapt it to our equipment. Well some do, not necessarily me  :doh:

Very nice thread BTW  :ddb: :ddb: :ddb:
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Offline Bernd

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Re: Making a flywheel
« Reply #29 on: March 19, 2009, 10:18:27 AM »
John,

Aftering working on the Grizzly mini-mill w/o DRO and then having the Bridgeport with DRO I'd say what you presented was excellent. One needs to work with what ever equipment they have at the present. If they can't figure it out than we as a collective can help out. Remember 1000 words = a picture or something like that.  :)

As far as boasting, I never thought you were boasting. You showed what can be done with a machine equiped with a DRO system and that it makes it easier. And now with our comments added here a newbie should understand that.

Keep at it John. I want to see what the finished product looks like. :thumbup:

Bernd
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Offline foozer

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Re: Making a flywheel
« Reply #30 on: March 19, 2009, 10:52:54 AM »
Glad you guys are enjoying it as much as I do. :thumbup:

Now a question for yourselves, to help me in the future.

On the last bit of this post, I showed measurements using my DRO.

To those who don't have such things, did it detract or help the post by seeing it displayed like that? future posts.

John



Variety of learning styles, some can read and get it, others like photos to fill in the blanks. The tactile learners, well don't know.

Question tho on your DRO readouts. On all shots save one you have an additional 0.005 added to the stated dimension, I gather this is to account for hole growth, what muddies the pattern is your last DRO photo did not have this 0.005 added.

Nothing wrong with showing the most accurate method possible with equipment on hand. Its the sequence and fore-thought illustrated through your postings that carry weight



Ignorance is Bliss, thus I aim for Perfection

bogstandard

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Re: Making a flywheel
« Reply #31 on: March 19, 2009, 04:17:16 PM »
Fellow MM's,

Many thanks for your enlightening replies, it looks like that the DRO shots do help, so will be used in the future.


Foozer,

That is a very good point about the '5's' on the end of some readings. That is such a small measurement that I usually totally ignore it.

I must in the future keep that in mind, I don't want to confuse people by showing my ignored figures.


I am going to TRY to finish this exercise over the weekend.

Other things are beckoning my attention (and maybe another topic).


John

bogstandard

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Re: Making a flywheel
« Reply #32 on: March 22, 2009, 08:53:41 PM »
HOW LONG DOES IT TAKE TO MAKE A BLOODY FLYWHEEL?

Well certainly not the two weeks it has taken me. About 3 to 4 hours if you are up to concentrating that long.

I have a bit of a confession to make, this is a new setup from where I last left it, I had a little job come in that required the RT to be removed from the table. So the RT had to be set up from scratch and the job realigned perfectly to how it was.

So what you see here was my next step. I have blued up the whole lot, and using an old ballpoint (doesn't scratch like a scriber) I drew on what needed to be removed. I also fitted a one sized smaller SLOT DRILL. The slot drill will cut all the gooves much easier that an end mill, and by going one size smaller, if I cut to the original dimensions used for the holes, it will leave a small amount of material to be removed to clean up all the edges. You could use the correct size of end mill for doing this first stage and miss out the second, but your hand cleanup time will take much longer.
I will be going thru the whole sequence twice, the cleanup one takes hardly any time at all.




The top slot is done first, but if you remember, the holes were drilled offset to allow for spoke width. So what we do is have no offset, and just set the Y distance at 38mm, the distance we used for the original holes.




Now there is no angle used for this part, it is all done by eyeball. What you do is start in the middle of the arc and cut using the RT wheel until the cutter reaches about half way across each end hole. I did these at a cut of 1mm deep each time until it had penetrated thru (8mm), in fact I took mine to 9mm, but don't go much further or you will be cutting chuck jaws. It will also get you into the correct routine for which way to turn the RT wheel. That becomes critical, as you will see later.




So all you do is jump to the next sector and repeat the same. This shot shows how far I went into the end holes.




Eventually you will have all the top arcs roughed out.




This is where the angles now come into play. 360/0, 60, 120, 180, 240, 300. and also the spoke offsets.
When the first outer holes were drilled, they had a positive offset of 6.5mm in the X axis, and the inner holes were drilled at 13mm from the centre of the wheel in the Y axis. Forget about the 30 degree setting for the inner holes, that is all taken care of. Just set up with 6.5mm offset, 38mm in the Y axis and 0 degrees on the RT.




So basically, with the cutter at the above setting, put a cut on and wind it fwds in the Y axis until you hit the hole at 13mm. Again, I tend to only cut part way thru the holes at either end. Keep repeating until all the way thru.




This is what it should look like while cutting. If you notice, the inner hole is automatically lined up.
Once you have completed one slot, move fwds 60 degs and do the next one using the same technique, carry on until all are completed.




Put the offset to minus 6.5mm in the X axis and repeat the same for the slots on the other side.




This is what it should look like for this operation.




Once you get to the bottom of the cut, the redundant middle bit SHOULD fall away, but sometimes they can fly, so be ready for it.




We have a rough flywheel. The next stage is to clean it all up.




So the cleanup begins. I fitted a correct sized END mill (8mm). What you will be doing is plunge cut the full depth, then proceed to cut along the slot edge until you reach exactly 13mm. I will only say this the once. NO CLIMB MILLING, use standard cut only. So that means, on the minus X offset, you move from 38mm to 13mm, on the plus offset, from 13mm to 38mm.




So using the same settings as the rough cut.




Plunge down until the cutter is just thru the spoke depth, then a nice smooth feed in the Y axis until you reach exactly 13mm, then retract the cutter. Do your 60 deg fwds feed on the RT and repeat until all sides are done. Put the X axis onto the positive offset, and starting the cut at 13mm, move to 38mm. Repeat as before for all six.




We now need to clean up the 13mm holes, So using 30, 90, 150, 210, 270 & 330 degree settings, we are going to plunge down each hole to clean them up.




Set up with zero X offset, Y distance to 13mm, and just plunge thru with the cutter at the above angle settings.




The next bit is cleaning up the outer radii. So X offsets to 0, and Y to 38mm. Again this is a bit of an eyeball job, you take the cutter until it just touches the original walls of the drilled holes. To do a standard cut you should be moving from the left hole to right. So plunge cut as close to the left hand hole as possible and wind until the cutter is in the correct hole position, then gently wind on the RT until you reach the other hole.




If you do it all right, you should end up with a flywheel that requires very little hand dressing to get it looking great.
Unlike myself, who turned the handle the wrong way and cut in to one of the spokes, no excuses, I balls up at the final hurdle.
I did a quickie rescue job on it by putting the same cutout in each spoke, and in fact it looks rather good to my clapped out eyes.




Finished on the RT (maybe), time to do a bit of a tidy up on the lathe.




Remounted onto my favourite soft jawed chuck. Even though the chuck had been off the lathe, after it was remounted in the same position, it was still spot on.




A quickie grind up of a quarter round edged boring tool (make 'em up as you need 'em).




It blended the spoke outer faces nicely into the rim.




Remounted and the hole opened up with drills, boring tool to make sure everythin was straight, then cleaned up with an 11mm chucking reamer.




I didn't go any further as I need to fit a brass hub to the flywheel, and I am a bit undecided what type of clamping device would be best. A grubscrew is easy but crap looking, a taper lock looks the part and does a grand job of keeping everything from wobbling. So a decision will be made when I have had a good look at the full sized engine plans.

I think you must all be thinking, 'all that crap just to make a flywheel'.

In fact it is a lot more difficult to describe how to do it, than it is to actually make one.

If you followed these posts to the letter, you should end up with the flywheel I need to make. This is just an exercise to show you all the different things that are involved, not for you to make one. It is the principle you need to get your heads around. If you can do that, flywheel making becomes just another job.

The final bit of this project will be shaft fixing and bling.


John




Offline Darren

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Re: Making a flywheel
« Reply #33 on: March 22, 2009, 09:10:20 PM »

I think you must all be thinking, 'all that crap just to make a flywheel'.


More like "bloody ek" will I ever manage that?

But I can see most of it is repettetive and it's just a few simple steps joined together to make a sentence.. :ddb:

One question, when we spoke in person regarding milling, you suggested, if I understood you correctly, that milling depth should be about half the cutter dia.

"give it some work to do" or some such comment.

Here, on the flywheel you took several passes a 1mm depth.
May I ask why?

Nice looking flywheel btw, those oops marks look quite effective  :clap:
You will find it a distinct help… if you know and look as if you know what you are doing. (IRS training manual)

bogstandard

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Re: Making a flywheel
« Reply #34 on: March 22, 2009, 10:16:14 PM »
Darren,

Quote
"give it some work to do"

I am a person that gets down to the fine stuff as quickly as possible, not one who would take 50 cuts all the same depth. So I can usually look at the material, type of cutter, and decide very quickly how much I can safely remove in each swipe.

I think you might have slightly misunderstood me. The rule of thumb of 1/2 cutter diameter is the MAX depth that should be taken off in one go, and only under ideal conditions, not the norm, and that would usually be a very roughing cut. By not using cool/lube would easily knock that figure down by at least 1/2 if not 3/4's.

It is also dependent on material as well, I for one wouldn't try it with stainless, but would with free cutting mild steel, in fact on some non ferrous, I have gone as deep as full width, but chip clearance and lube starvation started to rear it's ugly head. 1/4 D would be a normal sort of cut.

No wonder you were breaking cutters.

Sorry if I mislead you in any way.

The above is all dependent on feed and cutter material as well. A cutter can only clear swarf away at a certain rate, too fast and it will get choked, usually ending up with chipped cutting faces, or in the case of ali, metal welded to the cutting edges.
I also have what are called rough cutters and finishing cutters. That bagfull I gave you were rough cutters. Once one of my HSS milling cutters is used on ferrous, it will never again be used for non ferrous work unless it is for rough cutting.

The reason I only went for shallow cuts is that as material is being removed, the structure is getting weaker. To such an extent, if you took too large a cut, it could easily pick up and wrap the spokes around the cutter, or pull the job out of the chuck jaws.

I don't think things like cutting depths, feeds and speeds can be taught, purely because every job has it own little challenges, and they can only be solved by experience. There are charts for all these things, but are only generalised. If you followed them to the letter, you would be almost guaranteed to fail, as in the real world there are just too many variables.
The difference between mills or lathes have a massive influence on cutting rules. If I can wack off say 1/2" on my mill, yours might struggle with 1/4", so the 1/2D rule has been killed off in one shot. As I said, too many variables.

You will get the 'feel' soon enough, and when you do, you will realise where you were making the mistakes.

John

Offline foozer

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Re: Making a flywheel
« Reply #35 on: March 22, 2009, 10:26:22 PM »
Quote
a taper lock looks the part and does a grand job


1 vote for a taper lock. They look proper and its a piece of toast I can surely burn.

Thank You for the informative post, the language is clear and concise, even for us colonist.
Ignorance is Bliss, thus I aim for Perfection

Offline John-Som

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Re: Making a flywheel
« Reply #36 on: March 22, 2009, 11:38:16 PM »
John, it's reading notes like that that brings home to me that I am only scratching the surface with my efforts at machining. The logic and precision involved, to me, is awsome. It also underlines what a fantastic hobby this is - always new challenges to conquer and techniques to learn. And the ability to describe the process in such a clear (and entertaining) style is truly a rare talent.

John S
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Offline sbwhart

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Re: Making a flywheel
« Reply #37 on: March 23, 2009, 02:14:23 AM »
John, it's reading notes like that that brings home to me that I am only scratching the surface with my efforts at machining. The logic and precision involved, to me, is awsome. It also underlines what a fantastic hobby this is - always new challenges to conquer and techniques to learn. And the ability to describe the process in such a clear (and entertaining) style is truly a rare talent.

John S


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Stew

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Offline Stilldrillin

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Re: Making a flywheel
« Reply #38 on: March 23, 2009, 03:21:23 AM »
So very many imparted packages of information, in one posting.....  :D

And so well explained......  :clap: :clap: :clap:

Thanks John!  :thumbup:

David.
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Still modifying bits of metal... Occasionally, making an improvement!

Offline SPiN Racing

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Re: Making a flywheel
« Reply #39 on: March 23, 2009, 04:18:22 AM »
John I wanted to take a sec to thank you for this posting...

It is very simple when you thing.. Oh rotary table... cut some spokes.. turn some cranks.. easy peasy.

And it is.... Hoever it does require a lot of very clear thought as you so beautifully pointed out.
The DRO.. Huge help for me.
I read the part about the spokes.. and the 6.5 offset.. and was scratching my head.. and kept reading waiting for the light to go on... I saw the DRO.. and the offset cut.. then as the light was coming on I saw the -6.5 cut and it all made sense.

Thank you for taking the time to explain this stuff. As you said.. taching us to suck eggs.  :D  But as I have told the wife and kids, and even my parents(in thier late 80s).. things that are simple to you... are not so obvious to us who have not done it before. And all the info is hugely helpful.

Whats really interesting to me... The peck drill is done.. and I took it to the race shop where I have been helping. They were shocked by it, and surprised. (Yes I need to get my pics cropped and finish my post on it) The amount I have been absorbing from everyones posts, and simple methods, and or long convoluted learning curves.. helps us all. Im certain there are a lot of people who dont bother to post, and or dont register and read all this.

Thanks again.

(Starts thinking of which engine design to build first)


Scott
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Offline Stilldrillin

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Re: Making a flywheel
« Reply #40 on: March 23, 2009, 04:48:20 AM »
John I wanted to take a sec to thank you for this posting...

It is very simple when you thing.. Oh rotary table... cut some spokes.. turn some cranks.. easy peasy.

And it is.... Hoever it does require a lot of very clear thought as you so beautifully pointed out.


Up to 3 years ago I did this sort of thing (& much more), for a living......

I could still do the job, no problem (probably).....  ::)

BUT I couldn`t possibly explain how to do it, to anyone, using the written word.......  :scratch:

Blummin well done john!  :clap: :clap:

Thank you.  :thumbup:

David.

David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline SPiN Racing

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Re: Making a flywheel
« Reply #41 on: March 23, 2009, 04:52:07 AM »
Yep exactly my poorly written point.. LOL

It sounds easy till you think about the steps and it gets very complex fast. But... masterfully written  :clap:
SPiN Racing

Offline Darren

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Re: Making a flywheel
« Reply #42 on: March 23, 2009, 06:28:20 AM »
Thanks John, that explains a couple of things  :doh:

So, if you were to square off the side of a 20mm thick block with the side of the cutter, would you do this full depth?

You are right about getting a feel for things, it's coming slowly, cut less, go slower and don't go to a depth of half dia of cutter  :lol:
You will find it a distinct help… if you know and look as if you know what you are doing. (IRS training manual)

bogstandard

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Re: Making a flywheel
« Reply #43 on: March 23, 2009, 07:52:08 AM »
Gentlemen,

Many thanks for the very kind and encouraging words.

What takes 10 minutes to physically do, most probably takes an hour to do in words, as most of you that do this sort of posting must realise by now. It cannot be avoided. So if a post is a very long drawn out affair, it doesn't mean the job takes the same sort of time.

I am in the shop today trying to finish it off completely, but if I do get it finished it won't be posted, as usual, until the early hours, or even the next day.


Darren,

As long as you are only removing smallish quantities (say 0.25mm) using an END MILL, you could actually use the whole length of the side flutes, even if it was say a 10mm diameter cutter but with 30mm length flutes. It is when you put deep end cuts on that you get the crappy finish, the cutter can't get rid of the swarf fast enough, so carries it round into the next cut and tries to embed it into the metal face while still trying to do the next cut. Air blowing or flood coolant helps because it cleans the swarf out of the flutes.

It is when end milling that you should really beware of climb milling. I am reluctant to do it even on my size of machine, and try to plan my jobs using standard cuts. Sometimes you have to do it, in which case, reduce the cut amount and slow down the feed, that helps to prevent the cutter trying to bury itself in your job, or yank the job out of the vice, both of which usually destroy both the cutter and the job.
 
You really need to have anti backlash leadscrews to make it so that the machine can do both types of cuts with no problems.


John

Offline Darren

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Re: Making a flywheel
« Reply #44 on: March 23, 2009, 09:45:21 AM »
Thank you John for your relentless offers of help and advise.

I wanted to make sure I wasn't trying to do something that I shouldn't be doing  :bang:

A bit more practice is what I need now  :thumbup:
You will find it a distinct help… if you know and look as if you know what you are doing. (IRS training manual)

Offline Brass_Machine

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Re: Making a flywheel
« Reply #45 on: March 23, 2009, 10:16:19 AM »
John...

This is a great 'how to'. Muchly appreciate the info!

Eric
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Offline shoey51

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Re: Making a flywheel
« Reply #46 on: March 23, 2009, 03:10:11 PM »
a very informative thread but for me I think I will leave it to the experts.
trying to convince  swmbo that I need a mill is another thing entirely

Offline Bernd

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Re: Making a flywheel
« Reply #47 on: March 23, 2009, 04:27:31 PM »
trying to convince  swmbo that I need a mill is another thing entirely


 :lol:    :lol:    :lol:    :lol:    :lol:    :lol:    :lol:    :lol:
I've been trying to convince mine I need a bigger lathe, but haven't figgured out how to make a food processor out one yet.

Bernd
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bogstandard

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Re: Making a flywheel
« Reply #48 on: March 23, 2009, 08:51:47 PM »
This was going to be the last post, but is now the penultimate one. I just didn't feel like getting filthy, polishing up the wheel today, so that is the pleasure I have to look forwards to tomorrow.

On the last post I left it in limbo, deciding whether to go for the grub screw or the taper lock. The hub size was a little small for putting a taper lock into it, but decided, if I could keep things tight on measurements, I just might be able to squeeze it in. So that is what this post is about.

First off though, before going any further, the flywheel needs certain areas blending in. Even when machined to very tight tolerances, you will always get slight mismatches. On this pic, #1 shows where it is on this job, where the sides of the spokes blend into the inside hole. By using a combination of smooth files, a scraper and emery cloth I got all 12 areas blended in, #2.




Now that all the blending was finished, I could concentrate on the job in hand.
First off. I made the flange for one side with a core plug attached, this was a nice tight fit in the 11mm centre hole, and once it had a touch of loctite on it, it was going nowhere.




The plug went right the way thru, and was flushed off level with the ali.




I need this hub to have a tapered bore, starting at 8mm on the flange side, ending up at 9.5mm where the plug is flush with the ali. I got these figures out of my head, and a little mental calculation at this time showed me I could squeeze in a couple of 2mm cap screws for locking the taper. A quickie calculation gave me 3.5 degrees for the angle. In fact it was just a tiny bit larger, so I rounded it down.
To save me having to swing the topslide over twice, and matching up the tapers. If I could cut from small to large on the internal taper, then I wouldn't have to move the topslide to do the external one, and the tapers would automatically have a perfect match.
The flywheel was again mounted in the soft jaws, with the small hole sized flange on the outside. By coming up gradually thru a range of drills, I ended up putting a 7.9mm thru.




The topslide was swung over 3.5 degrees in the correct direction.




Everything was locked up, and the boring feed was done manually by using the topslide handle. I gradually came out until the bore was at my 7.9mm hole edge. A cut of 0.05mm was put on, and the bore given the final cut. This would be close enough for me.




This was how the internal tapered bore turned out.




The tooling was swapped over for external cutting, and still using the same topslide setover and feed, I started to cut the external taper.




When it was starting to get close to size, the flywheel was tried for fit after each cut. You only have to remove a very small amount each time, and it is very easy to take too much off.




I eventually got to where I wanted to be, a gap of about 0.25mm (0.010").
Before I parted this bit off, I put a hole up the centre, for when I start to bore for the shaft.




Internal and external tapers.




The two were tightly pushed together and a bit of old superglue smeared on the back of the joint. This will hold the parts together while I do a bit of drilling, but I will easily be able to break the joint apart.




The wheel was remounted onto the RT, which was still in the zeroed position.
By using my mental arithmetic, I drilled holes for the clamp down screws, complete with head recesses and the two jacking screw holes to get the bits apart.




The glue joint was broken and all old glue cleaned off. The four holes were tapped 2mm course thread, and the whole lot screwed up tight. It was a very tight clearance fits all round for bolt heads and threads, but there were no compromises, everything fit just right.




First off, the topslide was put back to zero. The wheel was again mounted onto the lathe, this time with the screwed bit on the inside. The excess of the taper was faced off, and the thru hole bored for a nice sliding fit on the shaft.




The last job before final assembly was to put a hacksaw cut along the length of the removeable part until the cut reached the centre bore. What this does is allow the taper to collapse down the central bore, and so grip the shaft, very accurately.
Here it is finished, you can just see the saw cut.




The back side.



This really was a tight squeeze getting it to fit into such a small area, but it works, and that is all that matters.

Get you sunglasses ready for the next post. Bling time.

Bogs

Offline Darren

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Re: Making a flywheel
« Reply #49 on: March 23, 2009, 09:00:11 PM »
Never seen that method before, how so neat  :clap:

As usual, a very tidy job, looks very mechanical. I like that.... :thumbup:
You will find it a distinct help… if you know and look as if you know what you are doing. (IRS training manual)