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New Forster Co-Ax question - Cam over?

DellaDog

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Full Member
Minuteman
Feb 23, 2017
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DFW, TX
Finally got the Co-Ax but a bit confused on the positive stop.

When lowering the press handle the ram makes positive contact with the shell plate screws before hitting the hard stop. There’s about a 1/4” gap between the press and the hard stop (due to touching the shell plate screws first)

Lowering the handle completely, the press cams over and hits the stop.

Just curious, is this normal? Is the cam over feel normal?
Seems odd to have the shell plate screws act as the “first stop”

Thanks
 
Ram makes contact with the screws... huh? Got pics?

If you lower it completely it works... so what the heck are you doing that can somehow cause it to not work?
 
huh? Got pics?

Sure.

Here’s the handle down and you see the press contact the two button head screws.

3098AACD-8273-4E96-B1CC-F1B4026181C1.jpeg


Here’s where the full stop tab is when the press contacts the screws. 1/4” short of the stop.

3C08616A-AC67-43E6-AA7C-147A1210EADE.jpeg


Now “cam over” the press (because its contacting the button head screws) and you reach the full stop limit.

DF53E693-396A-4443-9885-10D44E1E037A.jpeg
 
I’ll be damned...

I don’t think mine does that, I think there’s plenty of space but I won’t be home from hunting until later tonight to check on that and get a pic myself for you.
 
I’m fairly certain mine also stops on the hard stop, not the screws. Guess anything is possible. You may call Forster tomorrow and let them know
 
The plate that is under your shell head holder is much too thick. The one that came with my press is about 0.035" thick. Its main purpose is to be able to flip over the shell holder to install it without it falling apart. I don't see where including it is necessary but I leave mine installed all the time because it does not cause any problems. Your photo is blurry but there appears to be posts or retainers on the far side of the shell holder. Was this piece just packing?
 
Mine has .250" of clearance between the press body and screws. The spacer under the jaws on my press is a very thin piece of shim stock.
 
I encountered the same problem when I bought their quick detached shell plate holder because it is a lot thicker than the stock. I counter sink a screw I bought at Home Depot, filed the counter sink head. Rough on the counter sink drilling but it works. Problem solved!
 

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Me thinks the press is out of spec as suggested. Molon’s picture shows proper clearance.
I’ll call Forster tomorrow.
Thanks all.
 
“Thanks for contacting us about this, there are some rare occasions where with the taller quick change assemblies the screws end up contacting the frame casting. This is not really of issue, however can put some un-needed stress (though very slight) against the Guide Block. If you would provide me your address, I would be happy to send you some modified screws that will alleviate the contact here.”

Not sure I like having that rare exception nor comfortable with the “unneeded stress,” but I’ll see how the modified screws work.
 
Could someone please measure/provide the gap/distance between the guide block and press. The shaved screws provide paper thin clearance, but not enough clearance for the KMS light kit.

Also finding the Josh Badeau modified linkage works great with the original plate, but unfortunately not with the quick change jaws.

Thanks

1613704346812.jpeg
 
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Could someone please measure/provide the gap/distance between the guide block and press. The shaved screws provide paper thin clearance, but not enough clearance for the KMS light kit.

View attachment 7561018View attachment 7561018
You should have plenty of room with KMS light kit. I don't have the press in front of me but I could probably put 2 or 3 quarters on the shell plate and still not hit the light.

As stated before, it appears your press is out of spec - I would not continue to run it in that condition.
 
DellaDog, the shim plate is typically not used with the quick change jaws. They are thicker. The shim is just to help you hold the jaws and springs in place if you use the jaws/plate that came with the kit. If I use the plate and jaws I have the same issue with my inline fab linkages and the factory linkages. I use the quick change jaws as well as some jaws someone machines off of one of these forums. I can look up his name if you are interested.
 
I could probably put 2 or 3 quarters on the shell plate and still not hit the light.

Thanks, with the quick change jaws?

This is why I ‘d ask someone with considerable clearance to provide a measurement. Forster seems to think its fine.
 
What is the problem if a die isn't in its slot?

Once the base of the die touches the top of the jaws you can mash all you want but can the case go any deeper into the die?
 
Could someone please measure/provide the gap/distance between the guide block and press. The shaved screws provide paper thin clearance, but not enough clearance for the KMS light kit.

Also finding the Josh Badeau modified linkage works great with the original plate, but unfortunately not with the quick change jaws.

Thanks

View attachment 7561018
IN my unadulterated version I have ~.050 of space between the screw and the top. When all the way up that washer I stuck in there can barely squeeze in so maybe a thou or two more but not much, it was a pretty perfect fit.
And without the plates Im getting .483
1613744024096.png
 
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Spife isn’t using the quick change jaws, so this is not an apples to apples comparison. I will go measure with quick change jaws, and with quick change jaws and shim plate for you here in a bit. I will also bust out the jaws that came with the press, intended to be used with the shim plate, and get some measurements on that too. Your press is likely good to go is my suspicion.
 
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Thanks stewarmy01, Spife’s .483 measurement without plates is helpful.

Here’s my measurements as best I can take them -

Clearance from top plate to lower plate measured closet facing you:
(The top plate is actually lower in the rear)
OEM linkage = .460
Joshua Badeau Improved C linkage = .440

OEM jaws, no screw = .285
Buttonhead screw = .100
Total = .385

Clears both linkage sets even with light kit. Light kit is closest in the rear because the top plate is closer in the back of the press.

Quick change jaws, no screw = .340
Buttonhead screw = .100
Shaved screw = .075 ish

Clears light kit using OEM linkage, but not improved linkage.
 
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Not for nothing but I would either use the original jaws or the shell holder conversion. Modifying the press any further is ridiculous. If you need light then use magnetic base lights. I get what you're trying to do but the further you move away from Bonanza's original intent the worse this gets.
 
@DellaDog if it would ease your mind I would be willing to make the sacrifice. Please pack it all up and ship it to me for some lengthy side by side testing with my perfectly functioning CO-Ax that has the newest quick-change shell plates. Once I am satisfied yours has been tweaked to the same quality of mine we can make some arrangements to return yours to you.
What can I say? I am just a "giver".;)
 
Not for nothing but I would either use the original jaws or the shell holder conversion. Modifying the press any further ..

Not really, as having the the quick change feature, additional hand clearance, and lighting is really quite nice.

I’ve now found a workable solution that allows left hand insertion and right hand press pulling - with additional lighting and sufficient clearance. The press stops on the right side OEM linkage.

(Were I to have @spife7980’s additional .020 clearance, none of this would matter.)

Additionally, the Forster designed quick change jaws should fit *all* Co-Ax presses without the need to shave the screws.

F0AF6BDE-A981-4346-8983-B5415990DEF1.jpeg
 
(Were I to have @spife7980’s additional .020 clearance, none of this would matter.)

View attachment 7561356
I may have screwed up in my measurement... or at least not done it thoroughly enough. I just did it again much more thoroughly and it seems that the underneath surface of the top piece is actually slanted up towards the front on mine. If I go in around the back of the linkage I get a much shorter measurement and I get somewhere .454, and if I get it sort of midline its .469ish and if I measure up at the front real easy like I get my prior .483.

But from the top of the base up to the top of the die slot where the lock ring would interface with the press is 1.190 pretty consistently from what I can get to with my calipers.

My jaw stack with all pieces is is .287 thick with a .1 screw for .387 total.
 
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Thanks again for your efforts @spife7980, that all adds up.
The press top definately slopes rearward, and that‘s the area where an additional .020 would be helpful.

And as a final thought, hats off to @SICARIO ’s RCBS bullet puller solution .

F7CDEBC4-7AEB-46C3-A14B-9A01458F89A5.jpeg
 
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That bullet puller looks like the bees knees! If you want me to take those measurements for you still let me know, just finished up with work. It looks like you and Spife got it and your press is fine!
 
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Not really, as having the the quick change feature, additional hand clearance, and lighting is really quite nice.

I’ve now found a workable solution that allows left hand insertion and right hand press pulling - with additional lighting and sufficient clearance. The press stops on the right side OEM linkage.

(Were I to have @spife7980’s additional .020 clearance, none of this would matter.)

Additionally, the Forster designed quick change jaws should fit *all* Co-Ax presses without the need to shave the screws.

View attachment 7561356
Would love to have a set of these!