Boxcar Base and 12x18 Chandler and Price
Hi guys, I just bought a 12x18 Chandler & Price, I really want to print in tabloid so I thought on buying the 13x19 Boxcar Base and having them cut in 12x18 and so I asked the Boxcar guys and they told me that they recommend me to cut it 1.5 inches less than the default press size, that would mean that the base would be 10x16 at least they recommend that because they say it’s very dangerous to have your hand inside the press with the base that big, is this true? Because I mean i really would love to be able to print in 12x18, help please!
Also they told me that it can’t be 12x18 because I need to adjust the base with quoins inside the chase is this true? Also I don’t know what kind of quoins the press needs, I know Hi-Speed Quoins but what size and how to I know if a Quioin Key really works? In Mexico they’re kind of expensive but on ebay there pretty cheap, Can you guide me guys?
Thanks a lot in advanced!
There are some nice videos on youtube that show you how the quoins work in a letterpress chase.
http://www.youtube.com/watch?v=Zd8Ml5Unf3g
If I were going to make such a purchase as you are considering I would want to understand the process from start to finish before I buy. There are standard proceedures for these old presses and then there are some corners you can cut safely, but If the base is to big to fit in the chase with a quoin, how are you going to hold it in there? You would want to figure that out before you get stuck.
You need leave room for furniture and quoins to lock the base into the chase. You also need to allocate enough room on the platen to have your guides without crushing them into the base, damaging both. Whatever Boxcar Press tells you, believe. They’re the top source for the questions you have.
You can buy quoins and keys from hundreds of sources, but you might want to check barplate.com- their stuff is great
If you will never print anything smaller than 10x15 inches or so it might be safe to use such a large base — but Challenge High-Speed quoins are 4 picas wide, a bit over 5/8 inch, closed. I would suggest that the largest the base should be is 10-1/2x16-1/2; 10x16 fives you a bit more maneuvering room. I would plan to lock up with four 10-inch-long Challenge High-Speed quoins, on all four sides, with a little bit of furniture or reglet to fill in the gaps. That way you have a little space for your gauge pins at the bottom and side and a little bit of wiggle room if your pp plate gets installed mis-aligned. But this set-up should only be used for full-size sheets so your feeding and taking-off hands never have to reach more than a couple of inches past the top edge of the platen. And run the press slow!
Bob
no need for quoins on 4 sides just 2 sides the off side and the top opposite the front lays. Use reglet and furniture for the gaps, avoid lead that is higher than the chase where you may have your hand.
It might be viable to have a machinist drill and tap the chase for grub-screws to hold a 12x18 base instead of using quoins.
But keep in mind the press could be impressing more area than the press design originally intended.
Another problem you might encounter if you decided to screw the base to the chase as AnonyMouse suggested is this; The quoins not only hold the base in the chase but they allow the base to move slightly so that the bottom of the base makes firm contact with the metal bed of the press behind it when the type contacts the platen so that there is a firm impression. If the base is secured to the chase with screws and the base needs to move or adjust during the impression then the resulting stress would be bourne by the chase which might bend or break or just give a poor impression. Well maybe not, but something to think about anyway.
Bruce
Good point, so perhaps a small gap to allow for steel shims between the chase and base, the shims keeping the grub screws from digging into the base. IIRC, some small presses are setup similarly.
Take a look at a Heidelberg platen skeleton chase it has screws on the offside handy when no room for a chase. heck I’ve even made steel rule dies that mimic the outside of the chase, good for unprinted work.
Thanks a lot for your ideas!! I definitely need to test with a smaller base, I’m looking for a 9x12 perhaps, so I can get a more clear idea.
IMO - The Chases are cast steel and thin - Drilling them and adding taps (Similar to what Kelsey did with table tops) will decrease the strength and on a base that big, there is a lot of pressure on all three axis - X, Y and Z - That often doesn’t get accounted for as we operate within the confines of the strength of the pieces.
Also, I see no one else has mentioned the platen - There is a maximum grippable area, and a max-sized base will just cause damage.
Also Also: I see the suggestion of tapping in reglets or leading - I suggest against this as well, as you’re unable to gauge the amount of pressure when doing this and could stretch the chase, bend it or damage it in some other way that prevents an accurate print. This of course again, can lead to breakage of the chase or other parts of the press.