1972 FJ55 Tailgate Handle Base by jrh00800 on Shapeways
1972 FJ55 Tailgate Handle by jrh00800 on Shapeways
Wondering if anyone has used these, can't find any feedback.
Product Description
Mounting holes require drilling and tapping of existing pilot holes
In order of tapping difficulty: 5mm drill bit (75% thread) / #4 wire gauge drill bit (50% thread)
M6X1.00 bottom tap
Shapeways Stainless Steel Tapping Best Practices
Stainless Steel Tapping Best Practices
I apologize that there hasn't been any feedback until now.
Definitely check the tapping best practices, good eye
@J Mack
In particular:
GlenG - You need to trust me when I say carbide tooling is the only practical way to drill, tap and machine this material. Slow feeds and plenty of lube. Playing with hole diameter would help. Expansion contraction is minimal.
gNSortino - Here is another update on this subject. I decided to test out the feasibility of tapping further.
What I did was create 3 small Shapeways Stainless Steel (SS) pieces with a .339", .34375" (11/32) and .375" (12/32) diameters. I put a slight taper on each of these to make it easier to start the tap.
I also wanted to test a straight imperial (non-tapered) thread to see how that worked as well. For this test case I created a 50%, 25%, and 15% thread for a 1/4"-28 UNF machine screw. This equates to a diameter of .2281", .23905", and .24343" respectively. Each of these also had a slight taper to help with threading.
##Setup##
For my tapping equipment I used a standard ratcheting tap wrench and the following taps:
1/4"-28 Cobalt Steel (McMaster Part # 25215A61)
1/8"-27 NPT Cobalt Steel (Mcmaster Part # #2662A26)
I chose cobalt steel taps because they have a Rockwell hardness between C30 and C45 whereas Shapeway's Stainless has a hardness of 20-25 (
https://www.shapeways.com/rrstatic/material_docs/mds-stainle ss.pdf)
I also used a drill press to align the tap in the hole. Very similar to this process here:
. This was the first time I've used a drill press to align a tap and I found it did a very good job.
##Test Results##
I did the imperial 1/4"-28 (UNF) taps first starting with the 15% thread and moving up to the 15%.
All 3 threads were fairly easy. The easiest being the 15% thread and while the 50% was noticeably tougher although it was not what I would consider difficult. I was not concerned at any point the tap was at risk of breaking. As would be expected the thread on the 15% was barely noticeable. However, it would still mate with a machine screw and if screwed all the way in it would hold pretty well. The 50% created a really nice thread and the 25% was somewhere in the middle.
Next, I did the NPT taps starting with the 12/32" diameter and working my way to the smaller diameters. The 12/32" was very easy to do. It only produced a slight thread but it would mate with male NPT thread. The 11/32" was noticeably more difficult towards the bottom of thread. I stopped tapping with about 6-7 teeth still visible on the tap, which I believe is typical. This created a pretty well defined thread that mated very nicely. The .339", which is a standard "R" 1/8" NPT tap drill size was about the same difficulty as the 11/32".
##Closing Comments##
Based on these tests I would say that tapping Shapeways SS is definitely doable. I cannot say how much of an effect the cobalt steel taps or using the drill press for alignment had but I suspect they both helped significantly. I don't think the slightly tapered start had much of an impact but I also don't think this hurt things either.
While tapping I noticed that the chips were much finer that when you would typically see when tapping free machining metals. They were almost like large grains of sand. The material made a grating sound as it was tapped and even though the chips were smaller they still had to be broken (eg. back 1/4 turn for each turn forward). Also, the material did not get very hot like you would typically see when tapping something with a low heat transfer coefficient. I suspect this was due to the 40% bronze content.
