# Plunge base for Bosch 1606



## carlseibert (Jun 22, 2008)

Hi,

I have a Bosch 1606a router motor without a functional base. 

I want to obtain a plunge base that would fit this router. A little shopping on eBay tells me that Bosch plunge bases are uncommon and really expensive. Porter Cable and Dewalt bases seem pretty common and the prices are reasonable.

Has anybody here mixed brands of motors and bases like this?

It appears to me that the governing parameter here is the diameter of the motor. Are the diameters standardized such that a nominally 3 1/2 inch motor will center properly in another brand's 3 1/2 inch base?

I don't need for either part of this tool to be interchangeable with anything else. I'm perfectly happy to modify either or both pieces, so long as the modifications can be done with handheld tools and I can keep accuracy. (I don't have a lathe, in other words. I could easily grind off an unneeded alignment shoulder or install set screws, but turning the motor body is out of reach.)

Thanks for any help anybody can offer.

-Carl


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## Mike (Nov 22, 2004)

Carl, the 1606 router did not have a plunge base, but there are a couple of options you can follow: You can build a table lift, a very unusual table with a tilting router (by Bill Hylton) or purchase a standard base. You will find information on these ideas by searching the forums. Another option is to sell your router motor to an optical company. This motor fits into Horizon II eyeglass lense shaping machines. (See this posting: http://www.routerforums.com/lobby/4351-router-duplicator.html )
The original motors were designed with two bolt holes in the case for mounting but are not required and are no longer available. As the cases wear out from multiple bearing changes the companies are faced with a very expensive conversion to Bodine motors or finding your motor. A reasonable asking price would be $100-125. I own one of these routers with the standard two knob handle base and am saving it till the price peaks.


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## carlseibert (Jun 22, 2008)

Hi Mike,

Very interesting idea. But of course if I sell the motor for enough money to buy the base, then I don't have a motor. Kind of a catch-22. 

So the question returns to whether or not my motor would fit accurately into any given base. I read somewhere (and of course now can't find the quote) that the 3/12" Bosch motors would fit properly in Porter Cable bases. 

If I had an example of one of the bases in question, it would be a matter of a minute or two to see if it gripped the motor securely with the shaft centered properly. But I don't know anybody who has one I could measure.

Does anybody out there have Dewalt DW616 or a Porter Cable 690 and a caliper large enough to measure the diameter of the motor barrel?

How about the clamping mechanism on the PC or Dewalt bases? Are they simply split cylinders with a binding bolt? The Bosch motor casing is pretty much just a cylinder. Anything meant to clamp onto a cylinder of similar diameter (a few thousandths, I would guess) should be able to deal with it.

-Carl


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## bobj3 (Jan 17, 2006)

Hi Carl

I think you'er right the Bosch motor will fit the Porter Cable plunge base...I also think it will fit the Craftsman plunge base...no guide pins/slots to talk about.

Update below ▼
Here's some dimensions for the routers..

PC= 3.504 OD x 3.333 long with pins slots in the base.
Craftsman 3.502 OD x 3.833 long with a rack slot.

The PC you can find on eBay for about 25.oo the Sears one you can get from the service center for about 30.oo, or online parts center...

***
Tell you what, mic. the Bosch you have and I will check the PC's/Craftsmans I have...to see if they will take on the Bosch..
A picture of the Bosch motor would nice to see as well..

http://www.searspartsdirect.com/partsdirect/retrieveSubComponentPartsAction.action?diagramPageId=00003&componentDescription=PLUNGE%20BASE&documentId=50030388&modelNumber=32017543&productCategoryId=0740000&brandId=0247&modelName=ROUTER&backToLink=Return%20to%20Sub%20Components

http://www.routerforums.com/jigs-fixtures/7607-colt-plunge-base.html


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carlseibert said:


> Hi Mike,
> 
> Very interesting idea. But of course if I sell the motor for enough money to buy the base, then I don't have a motor. Kind of a catch-22.
> 
> ...


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## carlseibert (Jun 22, 2008)

*measurements*

Hi Bob,

The Bosch is almost exactly 3.500", give or take a thousandth or two depending on where exactly I put the jaw of the caliper. 3.501 seems to be the nominal dimension.

There is about 3" from the base of the plastic body at the shaft to the bottom of the depth index. Another 1 1/4' would be available if the raised index was removed. (Which would be no problem; it wouldn't do anything beneficial in a plunge base.)

As you can see from the pictures (assuming I'm able to successfully post them), the body is pretty much a cylinder. The groove near the bottom engages a spring-loaded latch that keeps the motor from tumbling out of the base if it's released while upside-down.

There are two slight flats, along the part line of the mold, which I assume are there to ease handling in manufacture, since they don't appear to have any function otherwise. 

The raised index rides on a spiral shape at the top of the base to provide depth adjustment. (You gotta give the person who designed this thing points for simplicity and durability). 

From your measurements it looks like this will work. I'll try to grab a base on eBay and I'll report back.

Many thanks,

-Carl

I attached two photos. The attachments don't show in the preview. Hopefully, you'll be able to see them.


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## bobj3 (Jan 17, 2006)

Hi Carl

You'er Welcome 

I would suggest the Craftsman plunge base,,,320-17543 router combo plunge base because the dog on the Bosch is almost in the same place as the gear rack on the Craftsman motor ,it's about the same size and about in the same place and would give you a holding point for the motor but both should work OK I think...
Plus it comes with a vac.pickup unlike the PC...

=========



carlseibert said:


> Hi Bob,
> 
> The Bosch is almost exactly 3.500", give or take a thousandth or two depending on where exactly I put the jaw of the caliper. 3.501 seems to be the nominal dimension.
> 
> ...


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## Mike (Nov 22, 2004)

The motor will fit into the 690 series fixed base, the limitation is you will have no fine adjustment other than moving the motor up and down by hand. This will work ok. When the motor is inserted into the 690 series plunge base the depth tab will keep the router too high to be safe or useful. This means the PC 890 series fixed base will work as well.


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## bobj3 (Jan 17, 2006)

Hi Mike

DO you by chance have the Craftsman plunge base,,,the slot for the gear rack looks about the same size as the plastic bar on the side of the Bosch motor...and should let it drop down inside of the plunge base...all the way.




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Mike said:


> The motor will fit into the 690 series fixed base, the limitation is you will have no fine adjustment other than moving the motor up and down by hand. This will work ok. When the motor is inserted into the 690 series plunge base the depth tab will keep the router too high to be safe or useful. This means the PC 890 series fixed base will work as well.


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## carlseibert (Jun 22, 2008)

Hi Mike and Bob,

First off, thanks for your thoughtful responses. This is a great forum.

It appears to me from Bob's measurements and Mike's pictures that either base will work with appropriate modifications.

In the case of the Craftsman, a relief in the base to clear the depth adjustment rack means that only a little (or maybe no) modification to the depth index on the Bosch will allow it to fit properly.

In the case of the PC, the depth index will have be completely ground off (which doesn't look difficult at all.)

The Craftsman would be easier; the PC is more readily available. We'll see what the shifting winds of eBay and Craigslist produce.

Mike - about far is optimal for the bottom of the motor to protrude from the casing of the base? I would guess I'd be going for a position that is secure and puts the end of the collet about at the baseplate when the plunge is all the way down. Are there other considerations?

-Carl


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## Mike (Nov 22, 2004)

BJ, I do not have one of the new Craftsman routers and none of the local members do either.

Carl, while your plan will work consider that you can sell your motor for enough to purchase a new combo kit from Sears... new should mean longer life and both a plunge and fixed base. If you are determined to grind off the depth tab you can remove all of it without effecting motor or case integrity. Your idea of depth sounds about right. I would opt for the PC plunge base over a fixed base since the adjustment will not change the height in the base. That should be far easier than guessing with a fixed base. The good news is there are lots of PC plunge bases out there.


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## carlseibert (Jun 22, 2008)

Porter Cable base - perfect fit for Bosch 1606 

Hi Bob and Mike, 

I snarfed up a Porter Cable "6931 - Type 2" plunge base on eBay and it turns out to be a perfect, drop-in fit for my Bosch 1606 motor, with no modifications necessary at all. 

I had laid out my Dremel tool and files on the bench and was ready to go to work modifying the motor and lo and behold, the motor fit perfectly. The depth index bar clears the clamping body of the base with the motor at the proper depth of insertion. What's more, if I ever need to move the motor down to put the collet below the base (and I will someday soon build a pair of speakers where I may just need to do this, actually) I can, because there's a channel in the base that will accept the index bar. I'll attach some photos. 

I guess this must be the exact model of PC base I once read about fitting the 1606. 

I passed on a Dewalt that may have worked and the Craftsman is apparently made of unobtanium. There was one Craftsman on Craigslist, but it had a motor, which kind of defeated the whole purpose of the exercise, and it was 3/4 of tank of gas across town. 

If anybody in the future has the same question, maybe this thread will be helpful. 

Thanks again for all your help! 

-Carl


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## bobj3 (Jan 17, 2006)

You'er welcome for my small part,,,Looks great Carl

I'm glad you got the job done  and it worked out right..


Thanks for the snapshots...
===========


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## Bailb (Nov 18, 2021)

carlseibert said:


> Hi,
> 
> I have a Bosch 1606a router motor without a functional base.
> 
> ...


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## John Smith_ (Jan 10, 2020)

welcome to the forum, Balib.
not really understanding your post - could you add some of your own information to the quote ??


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## old55 (Aug 11, 2013)

Welcome to the forum @Bailb


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## jw2170 (Jan 24, 2008)

Welcome to the forum, @Bailb .

If you have a specific question, could you make a new post with that question? The original post was from 2008.


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