Mounted X-rack's with different heights - causes step at joint.

Barman · #1 Sun 08 March 2009, 04:13

Before doing something myself , I want a opinion .
After mounting the rack on the x–rail, I noticed that there was a difference ( about 0,5 mm) in the rack height .
Could this be a problem for the future?
What I want to do is, file of about 0.25 mm from the first tooth .

Kobus_Joubert · #2 Sun 08 March 2009, 05:23

I would take it apart, put another piece of rack on the bottom part where the two meet. Clamp it all together then weld it again. This way it will line up perfectly.

Gerald D · #3 Sun 08 March 2009, 06:40

Bart, did you use an extra piece of rack to hold them while you welded? If yes, then the pinion should roll smoothly and you can do nothing more. (The pinion does not contact the tips of the teeth).

J.R. Hatcher · #4 Sun 08 March 2009, 06:42

The teeth look like they all bottom out on the same line. My guess is they are all right, I think the pinion will ride just fine. The piece of rack on the right side looks like it has short teeth or the left one has long teeth. Do you have more racks to compare them to, see which one is right. If the pinion doesn't have a tendency to ride out on the short one, it will be OK. I don't think you will be able to tell when the motor crosses it.

Gerald we were writing at the same time?????? I agree with you.

Barman · #5 Sun 08 March 2009, 16:39

Thank you all for your quick reply.
I just came back from my work so ...

Yes, I did use an extra piece of rack to hold while welding .
The other x-(rail / rack) is ok.

To test the movement of the pinion on the rack , I had put a pencil in the hole of the pinion.
In this way, I moved the pinion over the rack .
I noticed that the pinion got stuck at a given time.
See accompanying photo.

If I have to remove the rack from the rail
I think that I ‘ll better buy a new rack.
And measer the rackheight to the supplier.

I am still hesitating what I will do .

mhhh

Gerald D · #6 Sun 08 March 2009, 20:31

It is obvious that your rack supplier has a quality control problem, and I think he is receiving metal bar with different dimensions from his supplier. My feeling is that the teeth of the rack on the left are too high, and this caused a bad match when you welded the rail.

Undortunately, our discussion here will not fix it. The best is to take it back to your supplier.

Barman · #7 Mon 09 March 2009, 03:10

OK , I' ll start over again .
This time I will measer the rackhight at the supplier .
Thanks

domino11 · #8 Mon 09 March 2009, 07:04

It almost looks to me like the rack on the left did not have the teeth finsish grouind to the proper height. They look like they have more of a point than the ones on the left? Would it be possible to have the manufacturer resurface the one rack to match the other one?

Barman · #9 Mon 09 March 2009, 15:59

That , was perhaps a solution.
But , today I have already cut the rack loose of the rail with a stanley knife.
I know now that 3M VHB 4991 is strong enough to hold the rack under the rail.

Barman · #10 Tue 17 March 2009, 03:03

Before I bought a new rack,
I had put the two ends of the old rack together .
What was formerly the weld, were than the new ends .
The result was slightly better, but not satisfied .
Eventually I bought a new rack.
Now the result is good.

I put the rack back on the rail with the VHB tape and left it for 4 days in the living room at
room temperature , because the average temperature in my garage is still about 10 °C.

domino11 · #11 Tue 17 March 2009, 07:03

OOh, 10 DegC, I am still waiting for that nice warm weather.

You are lucky Bart.
Glad your rack is working now.