DT40 Pro tuning howto

[cruch]

Maby one of you pro guys can make an "howto" to tune the DT40 Pro galvos to us unskilled newbies!
Highly preciated

Thanks

[MechEng3]

It took Bill from Pangolin about 10 minutes to actually tune them. But then He can do this in his sleep...... He just knows it.....inside and out. I think Buffo has-had-or is in the process of video recording the actual steps involved. It is nice to have LD 2000 ......it will display patterns that are crucial to the fine tuning.

[carmangary]

I learned how to tune using the write ups on the laserfx webpage. I think Bill from Pangolin actually wrote one of them. But, it would be great to see a video or an explanation from someone else as well. Although I think I got it right, it always helps to have a different explanation just in case some points were lost in the first one.

[buffo]

Making a video documentary of how to properly tune a set of galvos is indeed on my list of things to do. I actually planned to do it at SELEM 2007, since Bill was there and ended up doing a *lot* of tuning for the members there. (Thanks Bill!) However, my video camera shit the bed (as everyone knows now), so I didn't get any video of the tuning process.

However, all is not lost. First, I fixed the problem with the camcorder. (Damn broken spring in the loading door made the camera think there wasn't a tape inserted, so it kept ejecting!) But that's fixed now, so I can shoot video again.

Second, Bill Benner has tentatively agreed to attend FLEM Mark II in February of 2008 - assuming his schedule permits it. So for sure I'll be able to get some video and some good instructional tips then.

Third, while Bill won't be able to attend FLEM 1.5 in October of this year (prior commitment overseas!), Hayden will be there, and so will Don. Both of them are familiar with scanner tuning, so I plan to get some video of them while at FLEM 1.5. I will then incorporate that into the rest of the video that I'll get in February when Bill is able to show us his methods.

One thing that I learned is that Bill has a few tricks that he uses that are not spelled out anywhere. The laserFX tutorial is a good start, but Bill goes well beyond that. I want to get *all* his tricks captured, so that everyone can learn from it. Unfortunately, it's going to have to wait 'till at least February of 2008... Sigh.

If you need to tune your galvos right now, the LaserFX website is a great place to start...

Adam

[cruch]

I just remembered yaddatrance did tune a DT40 pro here!
I added a picture for the DT40 Pro's tunable inputs
(blue pots on the picture) Copyed from his .pdf
Thanks to yaddatrance It has been over an month since he had been online, maby he has som inpus on this.

Heh, I've been putting some work into tuning the DT-40 pros... One caveat to note is that the amp comes tuned for single ended controllers. If you have a "real" controller (i.e. pangolin) you will want to turn the ISC pot way down.

This is an internal document I am posting to help you guys, so please do not spread the document outside this board. (If I see it in use professionally by non-photonlexicon members, I will avoid posting more documents in the future. So keep it on your hard drive and tell other people to sign up on PL to get it.)

The DT-4XXX amp is a cost-cut design very similar to a cambridge's. The galvos are internally different and is actually better IMHO than a 6800 but worse than a 6215 in terms of absolute performance. This is based on some tests we ran.

To make connection easy... (some of this information was posted before, but to clarify)

If you have a differential controller:
attach pin 1 to the leftmost pin on INPUT on the X scanamp,
attach pin 14 to the rightmost pin on INPUT on the X scanamp,
attach pin 25 to one of the inner pins on the X scanamp.
attach pin 2 to the leftmost pin on INPUT on the Y scanamp,
attach pin 15 to the rightmost pin on INPUT on the Y scanamp,
attach pin 25 to one of the inner pins on the Y scanamp.
(Note that while normally you do not want to route pin 25 to a differential amp, due to some internal details the DT40's will probably thank you for it.)

If you have a single ended controller:
(and if your controller does not use pin 14/15 for return...)
- attach pin 1 to the leftmost pin on INPUT on the X scanamp
- attach pin 25 to one of the inner pins on the X scanamp
- attach pin 2 to the leftmost pin on INPUT on the Y scanamp,
- attach pin 25 to one of the inner pins on the Y scanamp.
(or if you controller uses pin 14/15 for return)
attach pin 1 to the leftmost pin on INPUT on the X scanamp
attach pin 14 to the rightmost pin on INPUT on the X scanamp,
attach pin 2 to the leftmost pin on INPUT on the Y scanamp,
attach pin 15 to the rightmost pin on INPUT on the Y scanamp,
(on a single-ended controller with floating pseudo-differentials, you may also need to tie pin 25 to the amp)
attach pin 25 to one of the inner pins on the X scanamp.
attach pin 25 to one of the inner pins on the Y scanamp.

[Pangolin]

We have a mod that we have been doing to DT-40 amps. The mod removes 3 (pretty much useless) pots, and the result gives better performance. Since you wind up with fewer pots, it is actually easier to tune, if re-tuning ever becomes necessary (which it shouldn't).

Basically, I recommend people send the DT-40 to Pangolin for the mod. We perform the mod and re-tune the system. Although I have produced a document for Jian and shared it with a few PL members, I don't recommend others do this blindly. You need a scope and some skill to do the initial tune-up...

As for tuning without the mod, I wouldn't recommend it because it's pretty nightmareish.


Best regards,

William Benner

[cruch]

Thats sounded ok by me Bill! Just contact you trough the pangolin's contact form?

[cruch]

I must add, again Pangolin has a great service!!
Your service is above all companys that I ever had to do with.

[carmangary]

Can you describe the theory behind the mod? I don't have DT40s so really don't care about the details of which wire to cut, etc. But since I do have a set of scanners similar to them I'd be interested in just hearing about what is going on.

[andy_con]

how much for the mod???