Etching Press Design - Part 2
Building an Etching Press
Part 2: Specs and Research
Etching Press SpecificationsPart Dimensions* Material* Notes* Fully Assembled 25"H x 33"W x 40"L -- -- -- Mounted to Stand: H=55" Print Bed 1-1/8"H x 18"W x 38"L Aluminum
(T6061) incl. 1/16" Thick HP Laminate
Applied to Top & Bottom Top Roller 1"T x 7"OD x 18"W HR Steel Electroless Nickel Plated Bottom Roller 5/8"T x 4"OD x 18"W DOM CR Steel Electroless Nickel Plated Top Roller Shaft 1-1/4"OD x 25"L TG&P CR Steel -- -- -- Bottom Roller Shaft 1-1/2"OD x 26-1/2"L TG&P CR Steel 1" Keyway on Drive Side Sideframes (2) 1/2"W x 8"H X 40"L HR Steel Powder Coated Opening between
Bed and Top Roller 2-1/2" Maximum -- -- -- Provides Extra Clearance
for my Registration Sled Drive Type:
Bottom Feed 45 & 10 Tooth Sprockets
with #50 Roller Chain Steel Final Drive Ratio=4.5:1
* H=Height, HP=High Pressure, L=Length, OD=Outside Diameter, T=Tubing Wall
TG&P=Turned Ground & Polished, DOM=Drawn Over Mandrel, CR=Cold Rolled, HR=Hot Rolled
The Research Phase
Below is a coarse outline of my research process and is simply one possible approach in a sea of infinite variables.
- Assessed my press requirements by determining the best press type and dimension needed for the work I generally create.
- Determined a budget.
- Looked for a commercially available press which fit all of my dimensional requirements and budget (see the resources part of this write-up for a list of commercial press sources).
- Determined many commercial press designs matched my specifications but none fell within my budget constraints. I began investigating the possibility of modifying a commercial press to fit my needs.
- Again, no commercially available press option could be modified to fit my requirements which led me to consider the idea of building a press. I started this process with an honest assessment of my building skills, including an inventory of my tools and equipment that would allow me to construct all or part of the press. The primary purpose of this exercise was to determine my exact limits (what aspects of the construction I could personally complete versus what aspects would need to be outsourced to a competent builder). I concluded that with my existing skills-set and tools I could complete about 70% of the construction. The remaining 30% would need to be completed through a mix of purchasing or borrowing missing tools and shopping out tasks to competent fabricators. Included in the Resource part of this write-up will be a list of the various skills and tools that were needed throughout this project.
- Began searching for existing press plans that could be used directly or altered slightly to fit my press requirements (see my resource page for some sources I found useful).
- Obtained complete plans and chose to modify the plans to more closely match feature sets in other press designs I had used extensively. As part of this process I took notes and measurements of favorite features in existing designs and began to analyze their purpose/function to determine if they were essential to the design. For example, nickel plating the rollers makes the press look nicer, but I had to question whether it did more than that? In this case the answer was yes, the plating also created an extremely durable oxidation barrier on the steel rollers which, if left unprotected, would rust immediately if exposed to even the slightest amount of moisture. I also looked at why plating might be the best option and whether other coating materials might perform the same function at a reduced cost. The conclusion was no, the other options I investigated (including paint, chrome plating, and powder-coat) would not hold up to the high pressures applied during printing. Then I was curious if the press would still be functional without plating? Absolutely! Going through this process of examination helped me to rule in/out certain features that could be modified to accommodate budget shortfalls or gains.
- With all of the above information garnered I began drawing plans. Throughout the drawing process I looked for simplicity in my design, primarily ways in which I could reduce material dimensions and the number of parts in an attempt to keep costs to a minimum. In addition I needed to determine the tools required to fabricate the necessary parts and what fabrication process would be required to join parts together. Another exercise I went through in this designing/drawing phase was to look for ways to minimize material waste. i.e., could smaller parts in the design be created out of off-cuts from larger parts?
- After completing the plans I generated a materials list of parts and raw materials needed to construct the press. This led to the pricing phase to determine if I could keep within my budget. I began pricing the commercially available parts (bearings, sprockets, and chain) through on-line and local industrial parts distributors/suppliers. In terms of quality and lowest pricing, on-line retailers and surplus industrial supply houses proved to be the best sources for these parts (check the Resource part of this write-up for a list of on-line sources I found useful). I then proceeded in pricing raw materials from local metal suppliers to avoid shipping fees for the heaviest materials. I did use on-line sources to determine an average for material costs which let me know if I was garnering any savings through local suppliers. A benefit I discovered through many material suppliers was their ability to cut material to length as part of their pricing which helped eliminate an expensive tool that I did not have; a metal cutting band-saw (note: this service does not include precise cuts, it's typically within an eighth of an inch over your required dimension. Precision cuts may be available for a fee). Lastly, I began getting time and cost estimates for the parts that would need fabrication. Fabricators may also sell raw materials and it’s worth investigating whether there is a time/cost benefit through this approach.
- Upon reviewing all of the above data I concluded the press could be constructed in the budget I had set out and I began ordering the necessary parts and materials. For the fabrication aspect of the build I started to break down the plans into manageable pieces (sub-assemblies) and then proceeded to fabricate any aspect of the design which would later need a third party fabricator to complete. The final aspect of my research was setting time schedules for fabricating parts, access to tools, lead-time and deadline requirements for individual fabricators, and overall completion of the press.
Click the link below to read the third part of this five part series:Part 3: Plans and Parts