EVC rear "drop-in" cupholders - best way to enlarge the holes

[HeyCrutch]

Desire: I'd like to expand the two holes bored into the rear driver's side counter/shelf for cupholders. The current bore is 3 1/2". I'd like to increase the overall diameter to 3 3/4" (or 1/8" all the way around), to accommodate what I think would be an improved cup holder (and not just as trays for screws and random bits and bobs)

Background: My 1997 EVC did not have cupholders in the flat space that is situated above the "fold-down-door" cabinet and below what most call the Vanity Cabinet (the one with the mirror). In the 1997 EVC the cutlery drawer is found in the space so having cup holders there would get in the way of opening the drawer.

At some point (either 1999 or 2000) the cutlery drawer was relocate to the upper half of the main lower cabinet, below the sink. Winnebago closed off the old cutlery drawer's location with a solid panel and deepened the Vanity Cabinet to make use of the space previously allocated for the cutlery drawer.

And they added plastic drop in cup holders to the small flat counter space in front of that solid panel.

The cupholder design is one that, at best, holds a soda can (shallowly), and at worst, becomes a foil for anyone trying to constrain larger sized vessels (they are sure to tip and fall over since they aren't actually being "held." The cup holders have a stepped-design that I presume someone thought would prove to be flexible, but almost nothing will sit in place safely in the first "wide" step, given how shallow it is.

Soda can fits but isn't truly supported on the sides very much due to the stepped design

Something the size of Nalgene won't fit (it won't fit the proposed cup holder either, but at least the proposed cupholder would be both "wider all the way to the bottom" and deeper, which would accommodate much more than a soda can.

I've been wanting to rectify this by creating a cup holder that would drop in to the existing hole without the step design so that any cylindrical vessel up to a diameter of 3 1/4" would fit. I contacted Chris at Uniwerks to see if he could design a better cup insert (many of us have purchased his cup inserts for the front console), but I elected to not move forward with that idea because he wanted me to send him one of the cups - given how hard it is to find replacement items for Winnebago EVCs I didn't want to risk it being lost in transit. Since he and I emailed several months ago I haven't thought much about it.

Well I was looking online and found a website that sells cups that "almost" fit that are pretty much what I'm looking for. At $33 they aren't cheap, but they seem to be well made.
https://www.cupholdersplus.com/spun-aluminum-large-cup-holder-insert-matte-black.html

The outdoor diameter of this cup is 3 3/4". The current hole that is bored into the shelf is 3 1/2". The measurements are close, but for sure will require expansion of the hole. And everyone knows expanding holes is tricky business. I doubt I'll find a step bit that will work for this. Not sure filing or sanding will yield a truly round bore with the dimension I seek. A hole-bore saw poses issues because of the existing hole.

Ideas?
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-2003 EV MV Wk - Forest - 51k
-2002 EV Camper - Ghost - 82k
-2003 EV GLS - Fluffhead - 176k

-1997 EVC - 12vVR6 (SOLD 5/2025)

[kourt]

You have to fasten a sacrificial board underneath the counter surface to accept the pilot on a larger hole saw. Then run the hole saw from up top. That is the easy way. Monitor your screw depth to make sure you don't puncture the top surface.

The hard way is to use a router to make the hole larger, and this will have lots of opportunity for error.


kourt

[VanGeek]

+1 on Kourt's recommendation for a sacrificial board to guide the bit for a larger hole saw.

I do think that the uniwerks idea of having adapters is ideal if you have a few favorite sizes of cups or bottles that you typically use. On my weekender, I designed my own adapters to fit snugly into the original holes and each adapter has a top portion that is designed to securely hold the bottles we use. I've not released them on thingiverse nor here because uniwerks sells their own designs.

Anyhow -- specific adapters work much better than universal types. I have a few modern vehicles with cupholders designed to accommodate a variety of different bottle types. None of them hold large bottles (like your nalgene) and taller bottles that fit typically wobble and risk falling-out while driving on twisty roads.

I had two adapters. One for a nalgene and one for a thermoflask and all was good. .....until my wife decided her new favorite is a very awkward, narrow-bottomed, top-heavy insulated stanley cup. So I've gotta redesign and print a new one.

If you're not equipped to design and print your own adapters, uniwerks seems very good at what they do and IMO you'll have the best solution for the (hopefully small number of) cups you want to accommodate.

[kourt]

Also, I use these, mounted in good places on the walls:

https://www.ultimatecupholders.com/fischercupholder.html

The very best cup holders ever. Still won't take a 1L Nalgene bottle, but will hold almost everything else.

kourt

[HeyCrutch]

For sure, the Uniwerks cup holder adapters are great for the late model center floor console in the front cabin.

And the cupholder that Kourt just referenced, which I believe GoWesty has since added to their items for sale, is great - I have two of them. They are designed for side wall or side door mountings.

Still want to deal with the two cupholders I mention in the first post, as none of Uniwerks adapters are designed to work in those cups or the holes (at least as far as I know).

Will see if I can manage the Sacrificial Board method with a larger hole saw. One more new skin to learn.
_________________
-2003 EV MV Wk - Forest - 51k
-2002 EV Camper - Ghost - 82k
-2003 EV GLS - Fluffhead - 176k

-1997 EVC - 12vVR6 (SOLD 5/2025)

[rizzag]

Most good hole saw arbors have enough thread to spin on two hole saws. Put the new size on first, then screw in the old size. It will center the hole.
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flossin, tossin, dippin, and trippin

[Wyotdi]

If going the hole saw route, start out with the drill in reverse to score the top sheet and establish a groove.