By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Jan 24th

How to machine a flywheel ?

Correct positioning on the face plate.

All Topics | Latest Posts

Search for:  in Thread Title in  
Brian John01/08/2015 07:35:52
1455 forum posts
579 photos

How about this method that I have read on the internet which does not use a face plate but the flywheel must be small enough to be held fully within the jaws of the lathe chuck :

1. Hold flywheel ( 3.5 or 4 inch) in the lathe chuck by the outer rim ( They recommend a 4 jaw chuck but I am not sure why ?)

2. face the hub and the rim on one side.

3. Spot drill with 6mm spot drill bit

4. ream out to correct size. (I have been thinking of using 6mm axles instead of 1/4 inch)

5. take flywheel out of chuck and fit mandrel

5. place mandrel in lathe and face the other side

6. finish by facing the main outer surface of the flywheel

I have been looking at mandrels from Arceuro : straight shank expanding mandrels (5.5mm to 7mm)

**LINK**

JasonB01/08/2015 08:09:52
avatar
Moderator
18868 forum posts
2069 photos
1 articles

It works for small flywheels, larger can start to chatter but I don't think I would want to do a 4" flywheel on a 6mm mandrel, nice as the ARC ones are you could make your own which would be a lot shorter and therefore less prone to flex/vibration.

4-jaw is because casting will not be perfectly round so needs adjusting to turn as true as possible hence the adjustment of the jaws

Steve Withnell01/08/2015 09:22:43
avatar
815 forum posts
217 photos

Before you ream to size, I'd try a test on some similar material, the last one I did, I wasn't 100% happy with the fit, it felt a little loose so tend to bore to a fit now, but that's with 3/8th axles, might be less of an issue with 6mm.

MIght have been the reamer or my reaming technique though! One thing to check for is that you drill to the correct size before reaming - the reamer mustn't have too much work to do or too little.

I can't see any issue with using 6mm instead of 1/4inch. The thing I like about building these small engines is that you can vary things to suit and try out your ideas in the build. There tends to be only a few critical dimensions to watch for.

Steve

Neil Wyatt01/08/2015 10:33:53
avatar
Moderator
18232 forum posts
714 photos
77 articles

Trouble with reamers is the usual ones we get are H6 and they are a wee bit too loose to ensure something as wide in relation to its thickness as a flywheel is accurately aligned.

Worst is in cast iron, where the freshly machined part is a snug fit and two days latter its become a tad loose as the dust shakes out

Neil

Brian John01/08/2015 11:11:38
1455 forum posts
579 photos

Jason : I do not have a slit saw.

Steve : I would not use a reamer unless I had to.

JasonB01/08/2015 12:03:56
avatar
Moderator
18868 forum posts
2069 photos
1 articles

Brian you don't need a slitting saw, your junior hacksaw will do the job, infact you can make one without a saw.

Michael Gilligan01/08/2015 12:05:34
avatar
16358 forum posts
712 photos
Posted by Brian John on 01/08/2015 11:11:38:

I would not use a reamer unless I had to.

.

?

Are you planning to just drill it then?

... or will you be boring 6mm on your new lathe?

MichaelG.

.

P.S. ... a 'D-bit' is probably the best tool to use.

 

Edited By Michael Gilligan on 01/08/2015 12:13:56

KWIL01/08/2015 12:26:09
3308 forum posts
63 photos

First pass with a pencil, can be used to show where the maximum runouts are. Just move towards the part in question, slowly until a single (or more) touches show.

Dinosaur Engineer01/08/2015 16:42:35
146 forum posts
4 photos
Posted by Neil Wyatt on 01/08/2015 10:33:53:

Trouble with reamers is the usual ones we get are H6 and they are a wee bit too loose to ensure something as wide in relation to its thickness as a flywheel is accurately aligned.

Worst is in cast iron, where the freshly machined part is a snug fit and two days latter its become a tad loose as the dust shakes out

Neil

The normal "cheap" reamers are H7 . The tighter tolerance more expensive H6 grade are not stocked by the some of the modeller's stockists. It is possible to stone a reamer to cut a little smaller.

Brian John01/08/2015 17:09:31
1455 forum posts
579 photos

It would seem that reamers are no more accurate than drill bits ! What do they mean by H6, H7 and H8 ?

Michael : I was planning to drill the 6mm hole in the flywheel. It seems simpler than boring it. If this did not work for some reason than I would have to reconsider.

Edited By Brian John on 01/08/2015 17:09:45

Neil Wyatt01/08/2015 17:28:19
avatar
Moderator
18232 forum posts
714 photos
77 articles
Posted by Dinosaur Engineer on 01/08/2015 16:42:35:
Posted by Neil Wyatt on 01/08/2015 10:33:53:

Trouble with reamers is the usual ones we get are H6 and they are a wee bit too loose to ensure something as wide in relation to its thickness as a flywheel is accurately aligned.

Worst is in cast iron, where the freshly machined part is a snug fit and two days latter its become a tad loose as the dust shakes out

Neil

The normal "cheap" reamers are H7 . The tighter tolerance more expensive H6 grade are not stocked by the some of the modeller's stockists. It is possible to stone a reamer to cut a little smaller.

Oops I'm all sixes and sevens...

blush

Neil

Michael Gilligan01/08/2015 17:53:01
avatar
16358 forum posts
712 photos
Posted by Brian John on 01/08/2015 17:09:31:

What do they mean by H6, H7 and H8 ?

.

Brian,

This table is reasonably helpful.

MichaelG.

Muzzer01/08/2015 18:28:07
avatar
2904 forum posts
448 photos

And of course you need to consider both the shaft and the hole when trying to ensure a given type of fit between the shaft and the hole. The hole is specified with capital letter and a number, while the shaft is specified with a lower case letter and a number.

There are preferred fits ie combinations of shaft and hole tolerances, as shown in the site MichaelG linked to. These apply to threads as well as shafts, so a thread might be specified as M8x1-6g and the mating nut M8x1-6H to ensure the correct fit. We don't normally get into that in the home workshop.

Murray

Brian John03/08/2015 08:02:36
1455 forum posts
579 photos

I have just bought the Optimum lathe for $715 plus $60 delivery :

**LINK**

Unfortunately, they told me AFTER I gave them my card details that delivery cannot be made until the end of the month due to stock availability. That is a bit annoying so I will just have to wait.

There is no face plate or 4 jaw chuck for this lathe so I may not be able to machine the flywheels on it. The supplied 3 jaw chuck is only 80mm in diameter so I think it will be too small to machine 3.5 inch and 4 inch flywheels on it even if they were concentric in the casting ; the chuck guard will get in the way. But at least I can lift this machine by myself when necessary.

Edited By Brian John on 03/08/2015 08:03:05

Edited By Brian John on 03/08/2015 08:03:45

mechman4803/08/2015 08:20:39
avatar
2746 forum posts
422 photos
Posted by Brian John on 03/08/2015 08:02:36:

I have just bought the Optimum lathe for $715 plus $60 delivery :

**LINK**

Unfortunately, they told me AFTER I gave them my card details that delivery cannot be made until the end of the month due to stock availability. That is a bit annoying so I will just have to wait.

There is no face plate or 4 jaw chuck for this lathe so I may not be able to machine the flywheels on it. The supplied 3 jaw chuck is only 80mm in diameter so I think it will be too small to machine 3.5 inch and 4 inch flywheels on it even if they were concentric in the casting ; the chuck guard will get in the way. But at least I can lift this machine by myself when necessary.

Edited By Brian John on 03/08/2015 08:03:05

Edited By Brian John on 03/08/2015 08:03:45

I'd have shopped around for other suppliers that would have a lathe in stock & supplied the above as standard... Just another way of getting more bucks out of you for 'optional extras' ... not an uncommon trade practice.

Brian John03/08/2015 08:24:16
1455 forum posts
579 photos

The factory does not make a faceplate or 4 jaw chuck for this lathe. It is a new model and they may make them in future but nobody is certain.

john carruthers03/08/2015 08:31:05
avatar
606 forum posts
177 photos

Chucks etc are available for your lathe, you may need an adapter plate but I imagine you'll find one that just bolts on, same with a faceplate. You will probably find they are held on the spindle by 3 or 4 bolts. Once you know the bolt pattern you can order accessories to fit.

This sort of thing...
**LINK**

Brian John03/08/2015 11:47:06
1455 forum posts
579 photos

Okay, I will wait and see what the bolt pattern is when it gets here in 3 weeks ! I had assumed that lathes were like cars and parts from one brand do not fit the other brands ?

Brian John03/08/2015 12:23:49
1455 forum posts
579 photos

Amidst all this talk of flywheels, chucks, drills and reamers I have just realized that the axle is going to have to be machined too. How is that done ?

Brian John03/08/2015 17:51:02
1455 forum posts
579 photos

Does anybody in the UK make these live tailstock chucks with the MT1 arbor ?

**LINK**

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Support Our Partners
EngineDIY
Eccentric July 5 2018
cowells
emcomachinetools
ChesterUK
Warco
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest