Umbrella ATC - Acorn Compatible

[ShawnM]

Yes... That is why I wanted to use the MIC6 or ATP5 material I have on hand. Maybe I should see if I can order 1/4 inch flat stock from somewhere else. When ever I ignore some small error... It finds me later

Let me know what you need for aluminum scraps or drops. I have 100's of pounds of aluminum drops from 1/8" to 1" pulled from our laser cutter. I have piles of it that get recycled each week. I'm in Florida so if shipping costs aren't an issue let me know what you need. Priority mail is up to 70 pounds. Most of it is 6061 and some of the thinner stuff may be 5052.

[RJS100]

Wow Shawn... Thanks for the offer. Really appreciate that. I will message you with what I am looking for.

Kind of funny. I looked online to see what a small piece of 1/4" flat stock like MIC-6 would cost. After seeing a cost of $85.00 + shipping I spent a couple hours with a buddy and a 2-ton hoist tramming the mill. It always kind of bugged me knowing it was out of tram a bit.

When I finished, I realized it was probably a waste of time. If I face the stock and remove most of the material with a 3" fly cutter, then finish with a .75" index cutter, the stock would probably just as flat as a piece of MIC-6. But then again, it just makes you feel good knowing the mill is perfectly trammed

[RJS100]

Carousel Fork Thoughts:

The plans for this ATC call for a two-part fork with aluminum on the top and Delrin on the bottom. Earlier in this post, it was suggested that the fork be made from one piece of Delrin. I modified the fork design to make it from one piece and 3d printed a test sample. For what it is worth, another YouTuber made a similar one-piece design and said it worked great.

Here is what it looks like:
https://www.dropbox.com/scl/fi/lp3l48ml ... cy83r&dl=0

The red arrow points to a small "fin" that fits into a groove in the tool holder. The groove is about .010" thick and the fin is .095". This requires perfect alignment to work properly. These are the dimensions used in the original plan. I experimented making the fin thinner, but don't know how thin you can make it from Delrin without it breaking.

I think the reason the design called for a two-part solution is if the top part is made from aluminum, you can make the "fin" thinner. You can then make the bottom out of Delrin and adjust the fit to control how tight the fork grabs the tool holder.

Here is very short video that shows my one-piece fork: https://www.dropbox.com/scl/fi/u6w686x3 ... 58ygs&dl=0

I purchased another set of plans for an ATC. This plan was designed to work with Tormach mills. This plan also uses a 2-part fork design. Both fork designs are very similar with one exception. On this plan, the "Fin" of the aluminum fork is only .059" thick. Looking at the 2-part design, you can see one additional advantage. The fork holds on the bottom of the tool holder as well (see below).

With these observations in mind I have two questions:
1. Reducing the fin to .059" think will make alignment of fork and tool holder much easier. Do you think if the fin is .059" tall, can it be machined from Delrin and not break prematurely?
2. Do you think the two-part design may be a better solution?

Second Fork Design: https://www.dropbox.com/scl/fi/t7au9fjj ... rd4yr&dl=0

[ShawnM]

Wow Shawn... Thanks for the offer. Really appreciate that. I will message you with what I am looking for.

Kind of funny. I looked online to see what a small piece of 1/4" flat stock like MIC-6 would cost. After seeing a cost of $85.00 + shipping I spent a couple hours with a buddy and a 2-ton hoist tramming the mill. It always kind of bugged me knowing it was out of tram a bit.

When I finished, I realized it was probably a waste of time. If I face the stock and remove most of the material with a 3" fly cutter, then finish with a .75" index cutter, the stock would probably just as flat as a piece of MIC-6. But then again, it just makes you feel good knowing the mill is perfectly trammed

You use a 2 ton hoist to tram your mill? I use a couple of dial indicators.

If you need MIC-6 for some reason I don’t have any of that, I only have 6061 and 5052 drops that I could send you.

[RJS100]

I have been working on the fork design for the tool changer. The plan I purchased has the fork as a 2 part design with aluminum upper and Delrin lower. I machined one and has some reservations, and designed my own fork made as a 1-piece design made soley out of Delrin. Here is a video that compares them. I would love your thoughts.

One thing I forgot to mention in the video is one advantage of the one-piece fork is that during the initial setup, if the spindle is not perfectly aligned with the TTS tool holder, it will bend the fork when it comes down. With the 2-piece solution, this will most likely bend the central disk that the fork is connected to. With the one-piece Delrin fork, I think the fork will just bend.

Video: https://www.dropbox.com/scl/fi/vdis9gid ... gmi8i&dl=0

Richard

[ShawnM]

I machine a lot of Delrin and other plastics and have only made tool forks with Delrin or HDPE. I would never want any metal on a tool fork for a few reasons. I have only made tool forks for ISO30 and HSK32 tool holders for router spindles. I've also made tool pots from HDPE for ATC routers. I have not seen your type of tool holder before but if I did a plastic tool fork is all I'd use. No wear and tear on the tool holder and if anything goes wrong during a tool change you only damage the plastic fork. I have a spare or two always laying around from customer builds. Just my 2¢.

[RJS100]

Thanks so much for your thoughts. Totally agree! BTW. Do you find much of a difference between forks made from hdpe vs delrin? Does the HDPE machine as well as Delrin?

[ShawnM]

Thanks so much for your thoughts. Totally agree! BTW. Do you find much of a difference between forks made from hdpe vs delrin? Does the HDPE machine as well as Delrin?

HDPE does machine very easy but it's a lot softer than Acetal. Still hard enough to make test forks from. Acetal (Delrin) machines a lot better and wears a lot less and is the preferred material for me for forks. I have tons of HDPE scrap in the shop of several thicknesses so I used that when I was prototyping forks and the final forks are made from Acetal. Alro Metals has a huge warehouse here in town and they also have their "Alro Plastics" division not far from that warehouse. I can drive there and buy drops and scraps of Acetal by the pound in a variety of thicknesses which is perfect for making small parts. Acetal is expensive so buying drops by the pound to make small parts is great.

[RJS100]

Thanks Shawn. Great idea.... Just ordered some HDPE. I am going to make the first set with HDPE... Probably tweak it a bit then make the final deal from Acetal.

[RJS100]

Quick question. I am testing the fit of some components. So far everything looks good. The directions indicate greasing the linear rails with the suggested NLGI 1 or NLGI 2 grease. I happen to use NLGI 2. I noticed after greasing that the blocks moved with considerably more resistance than prior to greasing. Is this normal, or would I be better off with NLGI ?

Richard