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RFQ: 48" x 84" x 1" Test Bed Fixture Plate - Tapped

RevMachLLC

Plastic
Joined
Apr 10, 2013
Location
Michigan, USA
Looking for a shop to machine and deliver an oversized machine fixture plate. Please quote price and timing with delivery to Livonia, MI (Metro Detroit, MI area).

Sketch attached. Material must be a weldable steel, not cast iron. A36 seems appropriate, but I'm open to feedback. End use customer is looking for cost savings, so I'd like to get this quoted two ways:

1) Unground hot rolled finish top and bottom, 1" nominal thickness
2) Blanchard ground both sides to 1" final thickness and black oxided.

Plate contains an on-center grid of 405 qty 3/4-10 tapped holes. Plate edges should be mill supplied finish or equivalent to a slow torch cut. Corners need to have a slight radius (1/4" approximate, snag grinder is good enough, cnc cut is fine too). Edges need to be deburred and free of significant warping and drip if this is torch cut.

Thanks,
JimTest Bed .jpg
 

RevMachLLC

Plastic
Joined
Apr 10, 2013
Location
Michigan, USA
Positional tolerance on holes ?

I might need some help coming up with a solid number, but this is NOT high precision. Also waiting for customer feedback. This is a mechanical load table where samples will be bolted down with toe clamps, or occasionally thru holes in the parts themselves (welded brackets and formed steel, mostly). Adjacent holes could probably be +/- .010. Cumulative tolerance for the farthest apart holes could be +/- .5" and it wouldn't matter too much.
 

DDoug

Diamond
Joined
Oct 18, 2005
Location
NW Pa
I might need some help coming up with a solid number, but this is NOT high precision. Also waiting for customer feedback. This is a mechanical load table where samples will be bolted down with toe clamps, or occasionally thru holes in the parts themselves (welded brackets and formed steel, mostly). Adjacent holes could probably be +/- .010. Cumulative tolerance for the farthest apart holes could be +/- .5" and it wouldn't matter too much.

Try .018r positional for a simple tapped hole sir.

Fairly common, achievable tolerance.
 

Ox

Diamond
Joined
Aug 27, 2002
Location
West Unity, Ohio
Who can black oxide sumpthing that big?

I don't think any of my guys can, but would be interesting to know if that's common?


I have my big mill torn down currently, otherwise would be a good job.


----------------------

Think Snow Eh!
Ox
 
Last edited:

DanielG

Stainless
Joined
Oct 22, 2014
Location
Maine
Rather than getting a machine shop to do it, you might look at getting it done by a steel yard that has a drill spindle on their plasma table. I've done a fair number of plates like this where they drilled it and then sent it to blanchard. Getting the burnout and drill/tap done in one setup can save a lot of money.

My local-ish burnout place, Quality Flame in New Hampshire has one, but I don't know if they've figured out tapping yet. I'm sure someone in Michigan has one as well.
 

RevMachLLC

Plastic
Joined
Apr 10, 2013
Location
Michigan, USA
Who can black oxide sumpthing that big?

Think Snow Eh!
Ox

I'm not sure, each time I've had a similar project, the boring mill shop I usually use has handled it. I've got my first quote back, and they indicated that the plate would be dipped from each end.
 

RevMachLLC

Plastic
Joined
Apr 10, 2013
Location
Michigan, USA
Rather than getting a machine shop to do it, you might look at getting it done by a steel yard that has a drill spindle on their plasma table.


I'll look into it, thank you for the suggestion. My company's place in these projects is usually as an integrator, assembler, and consulting on some aspects of the functional design. I'm a bit out of my element on direct sourcing.
 

jmullett

Aluminum
Joined
Apr 22, 2009
Location
Northwest Ohio, USA
I can't get black oxide that large, but I can do electroless nickel which is far superior in corrosion resistance. I've moved away from black oxide on my tooling the last 5 years as the nickel is not that much of a premium and the nickel guys care so much more about the quality and handling of the finished parts. If you are interested, I can work a price up for stress relieved A36 cut on our water jet plus blanchard grind.

So once this plate is flat what is it going to sit on to keep it that way? How you going to move it around? Do you have some sort of frame it sits on? Would this be better as a weldment? Similar to a design of a cast iron tee slot floor plate?

I am in Livonia all the time. I could meet with you when things normalize with the shutdowns. My shop is located in Ohio not too far from I-75.
 

greggv

Hot Rolled
Joined
Feb 15, 2006
Location
so cal, usa
I'd be really curious if that blanchard plate will retain it's flatness after all the drilling and tapping? Me, I'd do the machine work prior to grinding.
 

david n

Diamond
Joined
Apr 13, 2007
Location
Pillager, MN
I'd be really curious if that blanchard plate will retain it's flatness after all the drilling and tapping? Me, I'd do the machine work prior to grinding.

It more than likely would stay flat.....................through holes usually don't cause issues. When you start removing material from one side and not the other is when things usually start to move around. But why not drill and tap before grind if ya can..............................
 

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana
A36 hot rolled would probably stay pretty darn close to whatever it was when you started. More relevant than movement after machining would be what that plate is going to be laying on or welded to after it's machined. A 4' × 7' plate that's only 1" thick and perforated with that many holes is gonna be pretty floppy.

You fellas worrying about the plate going out of whack after drilling and tapping are wasting brain cells on an irrelevant problem IMO. One of the quotes is for an as-rolled plate for crying out loud. It doesn't need to be fussy. Adds unnecessary cost.
 

RevMachLLC

Plastic
Joined
Apr 10, 2013
Location
Michigan, USA
You fellas worrying about the plate going out of whack after drilling and tapping are wasting brain cells on an irrelevant problem IMO. One of the quotes is for an as-rolled plate for crying out loud. It doesn't need to be fussy. Adds unnecessary cost.

This is spot on. We've made smaller versions of this up to 36"x60" with a finish thickness of 5/8" (1/2-13 holes). The underlying frame will take the load. The grinding we've done in the past was more for ease of setup, and the black oxide for appearance only.

I've got one quote so far, and it is from a local guy. My two other regulars don't want to touch it due to size.

@jmullett: I think it would be safe to waive any plating considerations. If you want to quote from as-rolled stock, please do so.

-Jim
 








 
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