Just got a brand new 270WI and time to dial it in for espresso. I have a few questions.
I was wondering where "about" to start from and where your Sette 270 grinders are set to for espresso?
What is the weight of your single shots and your double shots?

Last question, how do I know if I need to put in the shims?

Thanks in advance.

I shimmed my 270 as soon as I got it and after a year of use, it settled to around 5-7 for espresso. If the coffee is super old, you would need to go finer. I don't do singles and my doubles are between 18 and 22g depending on the basket I'm using. I have a 18g vst and a 22g rocket basket.

I have mine right around 5c currently and it seems very stable.
When I have time, need to read more as well to see if I should shim it.

I currently have mine Set at 4d, which lets me do a 20 second line pressure preinfusion. I added a shim to mine when I found myself going continually finer to stay dialed in, maybe 2 months or so after I started using it.

Iowa_Boy wrote: When I have time, need to read more as well to see if I should shim it.

The only reason to shim it is if you can't grind fine enough. I preemptively shimmed mine as I thought there would be a big change as the burrs seasoned. It went from around 8-10 when it was new and now it's at 5-7 after a year of use(6-8 shots a day)

I tried all the settings in the comments here on this tread. From grinder setting 5 thru 9 but my new ECM Profe wont pull a shot thru that fine of a grind. I wonder why?

Some of the more recently produced models come from the factory with a shim installed. So you might need to start coarser. The grind setting will differ from machine to machine and from bean to bean, and will be impacted by your dose. So just keep grinding coarser until you get a good extraction.

Also note that after the first 5-10lbs of coffee you will need to grind finer, once the burrs are seasoned. So you might need to start higher and then over time move into the ranges people are talking about.

For example my Sette 270 started around 10-12 and after a couple months I am down to the 5 range

Thank you Chris65, will use your suggestions on my grinder. However, I am more concerned that my new ECM Tchnika Profe is getting choked.
What are your thoughts on why?

The setting number is irrelevant and will vary from grinder to grinder, antd here is no value whatsoever in shimming your grinder so as to make it dial in to any particular burr setting. It will vary dependent on whether Baratza put shims in at the time of manufacture (usually there's one in there), vary as the burrs season, vary with the coffee being ground and so on. As for choking your machine, if you can do this with your grinder you don't need shims. I suggest you should start to consider shimming when you can no longer choke your machine on the finest setting. You certainly need to add a shim when the dial must be set to or very near the finest setting to be able to pull proper espresso.

Nunas, I understand what you said that there is no need to shim based on the fact that I do not have a need to grind at the lowest setting and that I can choke my ECM Profe at a much higher setting of a 9 and 10. I was barely able to pull a shot this morning at a 12 grinder setting.

My concern right now is not the 270wi grind settings, but instead my concerns are that the ECM profe is being choked at a relatively high grind setting of a 9 and 10. I suspect the choking "can" be based on a few variables or a combo of variables. 1) my grinder is over dosing, will check with separate scale tonight. 2) Tamp might be a bit over done based on the over dosage 3) Grinder 'might" be grinding much finer that what the adjustment ring shows. Again, I was barely able to pull a shot this morning at a setting of 12 on the 270wi. Too fine mixed with an over dosage = not good. 4) possible low pump bar. Was at 8 bar even when choked. Did not budge.