How to adjust magnet height?

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Model T Ford Forum: Forum 2016: How to adjust magnet height?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Saturday, January 30, 2016 - 10:31 am:


Yesterday I put the magnets back on the flywheel and installed the screws.


Not having the special tool, I measured magnet heights this way.


The highest was 2.744" and the lowest was 2.724".

From what I've read, the way to adjust them is to lower the higher ones to match the lowest. Which is the best method: tap them down with a hammer (Ford bible); tighten the screws more on the high ones to compress the spacers (Fahnestock); squeeze the high ones lower with a big C clamp (Jelf).


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Todd, ............Red Deer, Alberta on Saturday, January 30, 2016 - 11:05 am:

DON'T " tap them down with a hammer (Ford bible)", it doesn't work.

Best way I found was to raise the lower ones w/shims between the spool and the flywheel. Make U shaped shins to slip in.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Saturday, January 30, 2016 - 11:10 am:

I just finished assembling the magnets to the flywheel after recharging them. I find the highest one, then grind the spools one at a time using my belt sander to achieve the same height on each.

Steve I think you should consider making or borrowing a magnet height tool. I've seen some made using pipe fittings and a swivel wheel caster from Home Depot that worked just fine.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tony Bowker, Ramona, CA on Saturday, January 30, 2016 - 12:26 pm:

Why does the hammer technique not work. Was Ford wrong?


Top of pagePrevious messageNext messageBottom of page Link to this message  By R.V. Anderson on Saturday, January 30, 2016 - 12:56 pm:

That technique was fine for its day, with everything new or relatively new and a lot of flywheels to be done. Now, 100-odd years later, it just ain't the same. The aluminum spools have hardened and are brittle, the magnets have (presumably) been painstakingly re-charged, and we can't jut walk over to the stock room and get new ones of whatever we need.

Rapping the magnets tends to remove the charge that has just been put in. It's much better to shim low spools than try to compress century-old cast aluminum. It's easier on all the parts and the results are a lot more accurate.

I don't like to even re-use the original aluminum spools, squashed or not. Better to machine new ones from aluminum or brass tubing.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tony Bowker, Ramona, CA on Saturday, January 30, 2016 - 01:27 pm:

Thanks for the info, learn something new every day.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Saturday, January 30, 2016 - 01:36 pm:

Agree with what RV said. The Ford technique is just not a good idea. I used to do that but changed my ways in light of the age of all the items involved.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Brancaccio - Calgary Alberta on Saturday, January 30, 2016 - 01:42 pm:

Notice Steve's measurements, they are different on each side of the keeper.

What do you do about that?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Saturday, January 30, 2016 - 01:47 pm:

You don't do anything about that Chris, you are trying to get to a clearance of .030" + / - .010" - there is no need to fix stuff that isn't broke. The higher dimension at each magnet keeper is the only one that needs to be considered.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Barker, Somerset, England on Saturday, January 30, 2016 - 03:46 pm:

I believe it's possible to remove the spools without touching the magnet-retaining bolts around the centre. Remove the brass screw and gently lever the magnets up a tiny bit. Then the spool can be filed down and replaced.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Saturday, January 30, 2016 - 04:29 pm:

Notice what kind of spacers I'm using. Is there any reason other than cost that Ford switched to another material?


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Dewey, N. California on Saturday, January 30, 2016 - 04:33 pm:

Isn't the differences cause by the thickness of the magnets? Would it be worthwhile to pass the ends of the magnets through a mill and plan them all to the same thickens on the ends (you'd just need to do the ends for the area the retaining clamps cover, and only on the clamp side, as I see it)? One would do this before magnetizing, of course.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Saturday, January 30, 2016 - 04:45 pm:

I get pretty good results without doing that David. It's not something that would be of any benefit in my opinion. If you are getting 6 - 25 or more volts from a T magneto - as I do - your spark is going to be awesome. You are setting clearance on a Model T magneto, no need to make it any more difficult than it needs to be.


Top of pagePrevious messageNext messageBottom of page Link to this message  By R.V. Anderson on Saturday, January 30, 2016 - 05:14 pm:

Yup. Kind of like Dom Perignon with a Big Mac: Overkill.


Top of pagePrevious messageNext messageBottom of page Link to this message  By john kuehn on Saturday, January 30, 2016 - 05:23 pm:

Are the reproduction aluminum spools OK? I have always used the old spools and they seem to be Ok but haven't heard any much about the repos.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Dewey, N. California on Saturday, January 30, 2016 - 08:44 pm:

R. V. No, the Dom Perignon is used to wash away the taste of the Big Mac! :-)
OK, it was just a thought. I suppose it also depends on whether or not you have a handy-dandy mill in the shop to do it!


Top of pagePrevious messageNext messageBottom of page Link to this message  By mike windsor on Saturday, January 30, 2016 - 10:10 pm:

Here is a photo of my tool that uses the transmission shaft. the rest was made from mahogany and the probe on the end was a machine screw that provides adjustment .


Top of pagePrevious messageNext messageBottom of page Link to this message  By mike windsor on Saturday, January 30, 2016 - 10:13 pm:

Here is a photo of my tool that uses the transmission shaft. the rest was made from mahogany and the probe on the end was a machine screw that provides adjustment .


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kohnke Rebabbitting, Clare, Iowa on Saturday, January 30, 2016 - 10:56 pm:

We level the plates to with in .020 plus or minus .010, and tighten up the brass screws, and then the bolts.

Then peen the brass screws.

Then bolt a known straight transmission shaft in the flywheel, and put the shaft in between centers of an 18 inch lath, and trim the plates level with center of the flywheel.

You never have to hit the magnets, and they are all level.

No beating on the magnets or flywheel, no crushing or cracking of the spools, or having to shim, ect.

Herm.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Saturday, January 30, 2016 - 11:14 pm:

Herm, your process works just like I have mine done, except mine may be even gentler. My local machine shop fits the flywheel to their grinder, and the keepers are ground true. With the grinder there are no interrupted cuts like you get when machining the keepers in a lathe.

I ask them to stop grinding when the last one or two keepers are just marked, rather than grind them all perfectly flat.

Hope this helps.
Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Noonan - Norton, MA. on Saturday, January 30, 2016 - 11:33 pm:

I agree with Herm on this, especially if you are having your flywheel balanced as well. I know some like to do all the work themselves as done back in the day, but sometimes having a machine shop that has the equipment most of us don't own is surely a plus. I had my flywheel balanced and they surface ground the magnet plates as well which made adjusting the gap much easier and for very little extra cost. I have wrenched virtually every nut and bolt on my T at some point, but sometimes it pays just to send it out and save yourself a little bit of aggravation in the long run.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Noonan - Norton, MA. on Saturday, January 30, 2016 - 11:43 pm:

And with Allan it seems, boy do i type slow :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Lovejoy, So Cal on Sunday, January 31, 2016 - 11:27 pm:

I did mine in my garage and found it to be quite the challenge. I was really pressed and had to tale several tries at it. My spools, magnets and even the little steel plates were not the same sizes. Some varied by as much as 15 thousanths. I tried the hammer and was amazed how hard you had to hit them to make a difference. I finally machined the spools to as close as I could to the same size and picked the best matches on my magnets I could find. Got it in spec's - barely. Mine was from a mix of who knows how many assemblies.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Monday, February 01, 2016 - 11:41 am:


A nice variety of suggestions here. I'll try the shims and see how that works out.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Monday, February 01, 2016 - 06:31 pm:

Steve, I like your shims and the fact they will be captive.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Semprez-Templeton, CA on Sunday, April 03, 2016 - 06:17 pm:

bump


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Semprez-Templeton, CA on Sunday, April 03, 2016 - 06:22 pm:

Steve, I assume you are using original brass spools did you anneal them first? I plan to reuse the brass spools that I took off my very original "16 flywheel.


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