Myford S7 with stepper on cross-slide

This is the S7 gearbox encoder mount:

And this is the mount on a non-gearbox S7:

I have thinner pulleys to use for the non-gearbox setup but will fit later. The bracket is such that the encoder is flush with the inside of the housing.

Matt

Edited By Matt Harrington on 25/04/2023 18:22:14

Matt,

What is the ratio between the encoder and lathe main spindle? Is it 1:1 ? difficult to see gear sizes, but the spindle gear to feed reversing cluster looks not to be 1:1 ?

Yes, the two pulleys are the same diameter - 1:1

Matt

Sorry, I was not clear enough - the GEAR ratios, not the pulleys - as in the edited photo below - what is the spindle to cluster gear ratio?

The cluster gear to spindle is also 1:1 (The tufnol gears have no effect on the ratio) Matt

Thanks Matt. From the photo is appears that the spindle gear is larger - normally is as it sits around the spindle which is a large diameter - also has the through hole in it...But perhaps it is larger and the cluster gear at the bottom - the one to which your drive pulley is affixed, is also larger, ie , the same size as the spindle gear. Moot, as you say it is 1:1 all the way through!.

Neat way to fit the encoder drive train.

A bit of an update on my Rocketronics journey, stepper fitted, encoder fitted, electronics installed In cabinet, some how I made a balls up, the instructions said to connect encoder using Rj45 connector but some how when fitting the Rj45 plug the live ( red) and ground ( black ) got crossed so have had to order another encoder from Germany, so waiting for that to arrive, a bit annoying but there it is.

while I await the encoder I am having a think as to fitting the X stepper onto the back of the crosslide, not sure how I am going to do that yet as I don’t want it on the front.

I have since the picture was taken cut the banjo arm to just leave the bit around the leadscrew, and fitted the belts to make sure everything runs true although I have removed the spindle to encoder one.

Dell

Great progress. Have you fitted a differential line driver to the encoder or does it have one built in?

Matt

Hi Matt

that question went straight over my head, this is the encoder

**LINK**

Dell

Dell,

If you connect the encoder to the ELS box using the screw terminals, then you don't need a differential line driver but if you decide to use an RJ45 (shielded ) cable to connect to the encoder to the box then you do. The diff. line driver staggers the signals to reduce any chance if interference. (my description!!)

I made us a neat little inline RJ45 connector using Rocketronics line driver so I could easily connect up the encoder. (as per photo below)

There is some more info on this page:

Rocketronics line drivers

Matt

Thanks Matt

would that be how I buggered up the encoder and as I haven’t got that thing then would I be better connecting direct ?

Dell

PS hope you don’t mind but I have sent you a pm asking a question as I am not very up on electronics.

I have replied to your message. You need to connect the spindle encoder in the bottom left of the photo - ie section 'spindle encoder'. If using the RJ45 then use a line driver. If not line driver, then the connector.

Thanks for the replies but as the benefit of the Rj45 is the shielded cable according to Rocketronics and as I am using shielded cable anyway I can’t see it would be any different, so have decided to wire direct.
Finally finished fitting the X stepper today, the end of the leadscrew had no thread on the last 12mm but was tapered so I turned it true using a graver then used a length of 10mm silver steel bored a hole to suit the leadscrew and then drilled both for a pin but I also used locktite, so that is all the mechanical work finished now also been doing some of the wiring while I am waiting for the new encoder to arrive

Dell

Grand - you'll be knee deep in swarf soon!

Matt

Had to clean the swarf before I started, then I had three clocks come in so I had to make a mess again to make some screws as a few were to damaged to repair, it’s fun making 10 & 12 BA screws on the Myford, it was easier when I had the Pultra but don’t have room for both much to my annoyance.

Thanks for your help Dell

ITS ALIVE

I have spent the last god knows how many days wiring everything up and although I I have only made sure the steppers are working I am chuffed to bits, I have only tried the fast and slow jog on both the leadscrew and the crosslide they are working albeit the wrong way round but that can be easily changed in the settings along with some other settings IE pitch of lead screws , how much backlash each screw has ( very hand that it takes that into account)

plus a few other settings, I have already put the leadscrew 8 tpi converted to 3.175mm in the settings but I am unable to find the pitch of the crosslide screw , I would have thought it would be in the manual but I can’t find it, so if anyone knows what the pitch of a Myford 10 imperial crosslide screw is it would be much appreciated.

Dell

never mind I have found it 10 tpi converts to 2.540mm.

Edited By Dell on 06/05/2023 16:07:34

First cuts with the Rocketronics ELS, Not the best of videos but at least it shows the ELS working , I didn’t have the backlash setting correctly with the first cut but after checking several times in various places it averaged out at 0.003” so the second cut was pretty much spot on

**LINK**

Dell