New CX machine - Leadscrew possibly causing ratcheting and head pressure issue.

[betto]

The machine arrived promptly and without damage.

When I first got the machine, I checked the head pressure and it was correct. The crank ratcheted a little on the way down, but it read around 85 lbs. when it ratcheted on the scale. It was about 80 degrees that day. Went to run a project a couple days later and the head won't crank down without ratcheting most of the way and won't read past 40 lbs. on the scale. The temp was around 50.

I tried squaring up the posts using the process in the manual and posted on the forum. I tried about 4 times with no success in correcting the issue.

The machine came with a lot of grease on the leadscrews and pinion gears Since the issue appeared in a little colder weather I assumed the excessive grease may be causing the issue. I have the machine mostly tore down now and am in the process of removing all the grease and using the Blaster Dry Lube with Teflon as suggested in the forum.

While working on the machine I noticed the leadscrew on the keyboard side was not tight between the two nuts where it connects to the head assembly. There's a lot of play in it (at least 1/2 inch) and I need to know if it is supposed to be tight like the other side. My thoughts are that it is supposed to be tight and is actually the cause of my ratcheting issue due to binding or misalignment, but I want to make sure as I am new and not familiar with this machine.

The other thing I noticed is the guide rods on the keyboard side do not let the head assembly slide freely. There are tabs at the bottom that make contact with the rods. The other side's rods slide freely, and lock when the tabs are pulled up against them when the lockdown lever is pulled. I need to know if the rods not sliding freely on the keypad side is normal.

I'm looking forward to getting my machine all squared away and put back together so I can get started on some projects. Don't mind working on the machine to make sure it's "right" I'm just getting eager to run it.

Any help or additional suggestions are welcome.

Thanks,
Brandon

[SteveNelson46]

When I worked on mine I found the lead screw nut on the side opposite of the LCD panel loose also. I tightened it and it seems to be working okay. A word on dry lube. If you use it be sure that all parts are completely clean and free of any other type of lube. If it gets mixed, even slightly, it will gum-up and create a real problem. My experiences with dry lube have all been not good. Especially on the guide posts. IMHO, it is better to use the recommended lube. In this case I think it is white lithium grease.

[bergerud]

Went to run a project a couple days later and the head won't crank down without ratcheting most of the way and won't read past 40 lbs. on the scale......

The other thing I noticed is the guide rods on the keyboard side do not let the head assembly slide freely. There are tabs at the bottom that make contact with the rods. The other side's rods slide freely, and lock when the tabs are pulled up against them when the lockdown lever is pulled. I need to know if the rods not sliding freely on the keypad side is normal.

There is your problem. Those lock tabs are somehow binding and stopping the head from moving. They should release when the lock handle is in.

Welcome to the forum!

[betto]

Wow! Thanks for the quick response.

I will tighten that loose lead screw and second think using the dry lube. I did fully degrease everything before coating them, but don't want to cause other issues if the dry lube causes problems. The machine is still apart so it's not too late to change my mind, wipe it all back down, and go with white Lithium on it. It came with a thick bluish green grease of sorts and seemed like there was a bit too much of it.

I'll have to look at the tabs and stuff tomorrow and try to figure out why they aren't releasing. The other side does move when the handle is moved. The LCD panel side didn't look like it moves the same way, but I may be mistaken or I need to look at it closer. I'll also take a closer look at the parts diagram to see if I can get it figured out.

Thanks again for your quick responses and help, I'll keep you posted on the progress.

----- Brandon

[betto]

Update - Looks like the tabs were my fault. I caught something or did something wrong when I was putting the guide rods back in. Got those squared away and working as expected now. No drag on the guide rods.

I still need to tighten the leadscrew on the LCD side. Found I don't have a wrench or crescent that big. What size are those? They look to be 1.25" and 1", but I wanted to make sure before I put the word out to see if any of my buddies have the right wrenches.

Thanks,
Brandon

[bergerud]

Are you sure you have to tighten the lead screw nut on the keypad side? It may have to float to stay aligned. I am not sure but I remember thinking that it was floating by design.

[betto]

Hey bergerud,

Called support and you are correct, the lead screw on the LCD side has to float. They explained that it being loose allows it to ratchet as well as pull away from the crank pinion gear when the head is cranked all the way down on the board.

Looks like I'll be ready to button this thing back up tonight to see if the ratcheting issue is all fixed <fingers crossed>. I'll post an update.

Thanks for the great info and quick response.

----- Brandon

[SteveNelson46]

That's interesting. I guess I'll have to readjust mine.

[betto]

UPDATE - All fixed -

Turned out being the lock tabs after all. The ones on the LCD side weren't releasing when the lockdown lever was pushed back in.

Talked to tech support to see if there is a trick to adjusting those. The tech said to get them unstuck and don't use the lockdown lever. The newer machines really don't need it.

Removed the LCD side panel, had to rap the tab bracket with a rubber mallet to get them to release. They were pretty stuck. Loosened the 3 allen screws holding the tabs bracket on, bent the tabs back a little with vise grips, removed the connecting rod running to the lever (just for that side), and tightened the tab bracket back up.

Buttoned the machine up, took a head pressure reading (80# on the nose), and ran a test piece not using the lockdown lever. Everything worked like a charm.

Thank you guys for your input and help on this. I learned a lot and my new machine is working great now.


Brandon
www.brandonetto.com

[mtylerfl]

When I worked on mine I found the lead screw nut on the side opposite of the LCD panel loose also. I tightened it and it seems to be working okay. A word on dry lube. If you use it be sure that all parts are completely clean and free of any other type of lube. If it gets mixed, even slightly, it will gum-up and create a real problem. My experiences with dry lube have all been not good. Especially on the guide posts. IMHO, it is better to use the recommended lube. In this case I think it is white lithium grease.

Hi Steve,

You might be the only person in the world that prefers the lithium grease over dry lube on the four posts! That lithium gums up pretty badly (especially in cool shop conditions), causing all sorts of head pressure or "uneven" raising/lowering issues - the cure is switch to dry lube (or a graphite-based lube like the Lead Tech at CW uses).

TIP: I spray the dry lube on the four posts at the beginning of every project. I also wipe some onto the rails for the Y and Z trucks. S-m-o-o-th sailing every time!