# [EVDL] Minimum Milling Machine for Adapter Plates



## EVDL List (Jul 27, 2007)

I don't have experience specifically making an adapter plate, but I work as a machinist and have done lots of other large plates and such. 

The first one you posted, the vertical/horizontal mill would get the job done, but it's going to take some time since the travel on that machine is not likely to be large enough to cover the size of the adapter plate needed. So it will have to be moved and re-clamped, which requires that it be placed correctly in order to insure holes line up and machine surfaces are parallel and such. 

That mill would likely be able to make any additional parts that you need, but you may have to get creative with how you go about making certain things. 

As for the skills, if your local community college offers a class on machining, that would be a good option. I know the schools around here only offer it as a 2 year program because there is a lot of material to cover to fully understand what is going on when you are cutting metal. It's really easy to mess things up and break tools and parts. 

Are you wanting to learn machining as a hobby or just for this project? There is a lot of used milling equipment out there, so before you buy something new, check around your area to see what is up for sale, sometimes you can find a much nicer more industrial capable machine for the same or less money than a new lighter duty machine.

Chris Leone
University of Florida
Student of Mechanical Engineering
352-278-1176



----- Original Message ----
From: Chet Fields <[email protected]>
To: EV List <[email protected]>
Sent: Friday, May 2, 2008 11:16:53 AM
Subject: [EVDL] Minimum Milling Machine for Adapter Plates

Hello All,

I was curious if anyone would know or care to recommend a minimum
milling machine or what the specs would have to be for one looking
to create his/her own adapter plates and couplers, and optionally
be able to fabricate just about any part needed for an EV
conversion.

Just as a couple of examples:

http://www.grizzly.com/products/Horizontal-Vertical-Mill/G3617

http://www.grizzly.com/products/Combo-Lathe-Mill/G9729

Also what basic milling skills or specialized skills would be
required to learn in order to do a good job of it. Would there be
courses at the local community college that would teach it instead
of having to earn an engineering degree or go to a trade school?

Thanks,

Chet

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## EVDL List (Jul 27, 2007)

See if you have a Vo-Tech school in your area (usually associated with 
the high school). Ours has evening classes - continuing ed, and they are 
great. I took a welding class and managed to build several projects 
during the course. The plus is that they have all the equipment, access 
to material, expert advice, and help. Sometimes they will also take on 
small projects for the day classes to do.

- SteveS



> Chet Fields wrote:
> > Hello All,
> >
> > I was curious if anyone would know or care to recommend a minimum
> ...


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## EVDL List (Jul 27, 2007)

Hello Chet,

I just got done talking to my master mechanic, and he says that the maximum 
tolerance of any rotating material, should not go over 0.001 inch, but is 
best if you can get to 0.0001 in some machines for the maximum tolerance.

The transmission pilot shaft to motor shaft center line are normally kept 
not more than 0.001 inch for 6000 rpm or less.

Roland

>


> > Chet Fields wrote:
> > > Hello All,
> > >
> > > I was curious if anyone would know or care to recommend a minimum
> ...


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## EVDL List (Jul 27, 2007)

> Jeff Shanab wrote:
> > The typical 2HP bridgeport has a very short cross travel and can't do
> > an
> > adapter in one setup. :-(
> ...


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## EVDL List (Jul 27, 2007)

> Chet Fields wrote:
> > Hello All,
> >
> > I was curious if anyone would know or care to recommend a minimum
> ...


----------



## EVDL List (Jul 27, 2007)

> Jeff Shanab wrote:
> > The typical 2HP bridgeport has a very short cross travel and can't do
> > an adapter in one setup. :-(
> 
> ...


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## EVDL List (Jul 27, 2007)

Pssst, that is TWO setups 
>


> Jeff Shanab wrote:
> >
> >> > The typical 2HP bridgeport has a very short cross travel and can't do
> >> > an
> ...


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## EVDL List (Jul 27, 2007)

My lathe/mill was about $600 on sale from Harbor Freight. You can see a picture of it here:

http://www.saltflats.com/dymaxion.html

I don't think it would be up to machining stainless steel or titanium, but is OK for light cuts on mild steel (therefore aluminum should be easy).

A rotary table gives you more flexibility, and you can machine larger parts than you can with a lathe. I would be nervous about bolting on and unbolting the part unless you are accurately jigged, it is difficult to get it reattached with 0.001 inch accuracy. With a rotary table you can do 1/2, and turn the crank to then do the other half.


----- Original Message ----
From: Chet Fields <[email protected]>
To: EV List <[email protected]>
Sent: Friday, May 2, 2008 9:16:53 AM
Subject: [EVDL] Minimum Milling Machine for Adapter Plates

Hello All,

I was curious if anyone would know or care to recommend a minimum
milling machine or what the specs would have to be for one looking
to create his/her own adapter plates and couplers, and optionally
be able to fabricate just about any part needed for an EV
conversion.

Just as a couple of examples:

http://www.grizzly.com/products/Horizontal-Vertical-Mill/G3617

http://www.grizzly.com/products/Combo-Lathe-Mill/G9729

Also what basic milling skills or specialized skills would be
required to learn in order to do a good job of it. Would there be
courses at the local community college that would teach it instead
of having to earn an engineering degree or go to a trade school?

Thanks,

Chet

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev



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## EVDL List (Jul 27, 2007)

There is one more step that can be added to this setup. You will note that 
the bolt holes in the transmission bell housing is a little larger than the 
bolts. They are not a press fit. A 3/8 inch bolt is actually 0.371 inch 
diameter or you have 0.004 in clearance. A 1/2 bolt is actually 0.495 or 
has about 0.005 in clearance.

The next time you remove the motor from the transmission bell housing, you 
could be 0.002 to 0.025 inch off center if you do the do the spin balance 
again.

To be on center all the time, the manufacture have two press fit guild pins 
that is press into the engine. These guild pins insert into the 
transmission bell housing with a clearance less than 0.001 inch. So every 
time assemble the transmission or any other transmission that is design for 
that motor, it should fit in with that specifications.

Roland




----- Original Message ----- 
From: "Lee Hart" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Saturday, May 03, 2008 1:27 PM
Subject: Re: [EVDL] Minimum Milling Machine for Adapter Plates




> > Jeff Shanab wrote:
> > > The typical 2HP bridgeport has a very short cross travel and can't do
> > > an adapter in one setup. :-(
> >
> ...


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## EVDL List (Jul 27, 2007)

I like using slotted pins for aligning parts. They come in many different
sizes.

Mark Grasser



-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Roland Wiench
Sent: Saturday, May 03, 2008 5:09 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Minimum Milling Machine for Adapter Plates

There is one more step that can be added to this setup. You will note that 
the bolt holes in the transmission bell housing is a little larger than the 
bolts. They are not a press fit. A 3/8 inch bolt is actually 0.371 inch 
diameter or you have 0.004 in clearance. A 1/2 bolt is actually 0.495 or 
has about 0.005 in clearance.

The next time you remove the motor from the transmission bell housing, you 
could be 0.002 to 0.025 inch off center if you do the do the spin balance 
again.

To be on center all the time, the manufacture have two press fit guild pins 
that is press into the engine. These guild pins insert into the 
transmission bell housing with a clearance less than 0.001 inch. So every 
time assemble the transmission or any other transmission that is design for 
that motor, it should fit in with that specifications.

Roland




----- Original Message ----- 
From: "Lee Hart" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Saturday, May 03, 2008 1:27 PM
Subject: Re: [EVDL] Minimum Milling Machine for Adapter Plates




> > Jeff Shanab wrote:
> > > The typical 2HP bridgeport has a very short cross travel and can't do
> > > an adapter in one setup. :-(
> >
> ...


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## EVDL List (Jul 27, 2007)

> David Dymaxion wrote:
> > My lathe/mill was about $600 on sale from Harbor Freight. You can see
> > a picture of it here:
> >
> ...


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## EVDL List (Jul 27, 2007)

Of course you must firmly bolt the plate to the rotary table (it has slots for this purpose), and must bolt the rotary table firmly to the machine. I'm not sure the exact source of your concern. Check out my picture at http://www.saltflats.com/dymaxion.html , I have milled with a rotary table an accurate 4 inch center hold, milled the face to make it flat, milled the edge to make it pretty. My measurements show it is coming out very accurate. Like I said before, I wouldn't do this for a hardened steel, but for mild steel it seems to be working great.

As you noted, not all transmissions and motors use dowels for precisely locating relative to each other. On my Porsche, an accurate concentric raised ring does the job. The adapter is way too big to spin on a lathe that mere mortals can afford, so a rotary table is perfect to make the male raised ring to fit the tranny. It would be very tough to do this accurately, manually, using an xy table (although CNC could do it). Using a rotary table also insures the tranny raised ring is concentric with the centering ring on the electric motor.

I did rough cut the outer edge using a plasma cutter. I then machined it down a bit to save a few grams of weight  , but the real reason was to make it prettier. I did learn a lesson there. The plasma cutter hardened the metal and made it hard to machine -- so you should either machine off the excess (cut a groove with a small mill), or only use a plasma cutter (a guided, steady cut really isn't that bad, some Por15 would make it pretty then).

Anyway, glad to hear your adapter has worked well -- hopefully I'll be reporting the same, soon!


----- Original Message ----
From: Alternative Energy Guy <[email protected]>
To: Electric Vehicle Discussion List <[email protected]>
Sent: Saturday, May 3, 2008 3:49:51 PM
Subject: Re: [EVDL] Minimum Milling Machine for Adapter Plates

Unless you have a very large and rigid rotary table or you are making a very small adapter plate, this will be a very bad idea. The plate needs to be very firmly attached to the table.

Transmissions are usually located to engine with 2 locating dowels. There are only 3 points that have to be very accurate: the 2 locating dowels and the center of the motor shaft. All the other holes have enough slop in them to allow the bolts to slide in easily.

As far as using a milling machine to machine the outside contour of the plate, just make it from steel and cut it with a plasma cutter.

I made my own adapter plate a couple years ago for another project. I relocated the plate on my milling machine and it worked excellent. That vehicle has been running for 30,000 trouble free miles. 



> David Dymaxion wrote:
> > My lathe/mill was about $600 on sale from Harbor Freight. You can see
> > a picture of it here:
> >
> ...


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## EVDL List (Jul 27, 2007)

Jeff,

Thanks for the link. I am just north of Dallas. So the one that's
planned for Austin would be the closest. Still a bit of a drive (~4
hrs). Looks very interesting. 

However, I'm also into wood working and wonder if a dual purpose
machine would end up not being good enough for either.



> --- Jeff Shanab <[email protected]> wrote:
> 
> > Chet, where are you? Do they have a techshop nearby?
> >
> ...


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## EVDL List (Jul 27, 2007)

I have one of those. You can do stainless if you just take it easy.
I don't plan to make an adapter on mine though, not near enough
travel!!

Be gentle with the vice on that thing... I stripped the nut out of
mine trying to grip a piece of aluminum for milling. It's designed as
a cross-slide, not a milling vice. *rolls eyes*

Trot, the amaturely-machining, fox...



> David Dymaxion <[email protected]> wrote:
> > My lathe/mill was about $600 on sale from Harbor Freight. You can see a picture of it here:
> >
> > http://www.saltflats.com/dymaxion.html
> ...


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