Aerotech DMS delay tool
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Using no washer is zero.
Wouldn't that be either 4 second or 8 second delay? The washer takes away 2 seconds. I'm thinking that 2 washers on the 4 second side would be zero, but i only have 1 washer. I could measure the washer and try to find something that would work, but it would be easier if there were a specific length! Thanks!
This one?
Or this one?
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They only give you one washer with the UDDT. One of the tool side takes 8 seconds off the delay, the other side 4. Use the washer and you get 6 and 2 seconds removed, respectively. The provided washer is 1/8 inch thick.
Now, I personally think Aerotech is doing us a disservice. Their DMS engines come with 14, 16 or 18 second delays and you can only remove in two seconds increments. Why? How many sims have I run that call for an odd-seconds delay? Many! So, I have brass sheet I use for shims and zipperless designs. I just cut out circular shims of the right thickness with a tin snips the size of the washer and can do 1 second increments from 14 down to 6 seconds. Easy Peasey.
Note: It makes no sense to use two 1/8 inch washers on the 4 second size of the tool. You would remove no delay material and it would leave you at the max delay of the engine. On the 8 second size you would remove 4 seconds, which you can do with the 4 second side and no washers. The key is being able to get 1 second increment....
P.S. Don't mess with the set screw unless you determine the setting is off and the delay you expected is wrong. These are set at the factory. Loosen that set screw and let the drill bit slip and you won't be calibrated anymore and you'll be....screwed!
Now, I personally think Aerotech is doing us a disservice. Their DMS engines come with 14, 16 or 18 second delays and you can only remove in two seconds increments. Why? How many sims have I run that call for an odd-seconds delay? Many! So, I have brass sheet I use for shims and zipperless designs. I just cut out circular shims of the right thickness with a tin snips the size of the washer and can do 1 second increments from 14 down to 6 seconds. Easy Peasey.
Note: It makes no sense to use two 1/8 inch washers on the 4 second size of the tool. You would remove no delay material and it would leave you at the max delay of the engine. On the 8 second size you would remove 4 seconds, which you can do with the 4 second side and no washers. The key is being able to get 1 second increment....
P.S. Don't mess with the set screw unless you determine the setting is off and the delay you expected is wrong. These are set at the factory. Loosen that set screw and let the drill bit slip and you won't be calibrated anymore and you'll be....screwed!
Yeah, that's the problem. It was loose in the package. So having 2 washers on the 4 second side should zero it out. I don't have 2, so i thought there was a way to measure from the knob base to the tip of the drill. I can find washers or shim material to do it, but a number would always be there! :0) And i totally agree about the odd numbers!
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There is another thread on the forum somewhere where someone asked about the differences between the UDDT and the RDDT (reloadable delay drilling tool). They are NOT interchangeable and in that thread someone provided the specs (positioning of the bit) for each.
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What do you think 1 second changes is going to gain you? The tolerance for delays is greater than that per nfpa. Ignition time also varies the delay time. The general rule is 1/32" removal per sec of time.
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Also remember that ejection delays vary with altitude. How the perform at sea level is different than how they perform at 5k.
Alan Whitmore
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I'm not sure that anybody has answered speed's actual question. The delay tool consists of a drill bit held in place with a set screw, if the set screw comes loose, how much drill must protrude from the black knob to give the correct amount of delay element removal? I asked Karl Baumann about this a few months ago, and he sent me the correct distance, so I was able to reset my tool to the correct length. Unfortunately, I recently replaced my computer (after being dragged into the Windows10 morass very much against my will) and I was unable to transfer my old email files, so I can't give you the exact measurements that he sent.
However, I did adjust both of my tools to that precise length for certification work, and they are both (RMS and DMS versions) between 2 1/8" and 2 5/64". Somebody should ask Charlie over on the "ask Aerotech" thread.
Alan
However, I did adjust both of my tools to that precise length for certification work, and they are both (RMS and DMS versions) between 2 1/8" and 2 5/64". Somebody should ask Charlie over on the "ask Aerotech" thread.
Alan
The distance is in the first video. 2 washers thickness. Then to the delay grain. Then tighten. The thickness of the washer is given in the video too but I forget off the top of my head. I want to say 1/16” each washer but check the video to be certain.
I watched Tim's video, common sense really. I know that 1 second = 1/32, so 4 seconds would be .125(1/8") and that would work fine. I only have 1 washer and was trying to avoid driving 30 miles round trip to get another washer that may or may not be exactly 1/16' or 1/8" or combination of 32nds. Years ago i made and still have one for RMS delays out of a screw and nuts. I thought just buy the tool for the DMS motors and have no worries! I'll get some washers and do what i have to do to get them to the right thickness. 
)
)
You could just go ahead and buy the RMS delay tool now and use the washer from that. Or drill a hole in a piece of 1/8 balsa scrap and use that
Thanks for sharing that Apogee DMS delay tool video. I'm going to check mine to see if it's "zero'd" correctly as I've been a little suspicious of it lately.
Hooked On Rockets
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Here's What I have, the DMS adjustment tool...
.
"Housing"=1.238"
"2 Second Washer"=0.057"
.
"Housing"=1.238"
"2 Second Washer"=0.057"
Hooked On Rockets
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View attachment 399863Racked and stacked...
0.842" +
0.057" washer +
1.238" Housing =
2.137" Total Bit Length +/-
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I found out that making a washer out of a 2 1/2 gallon water container is exactly half the thickness of the provided 2 sec washer, and therefore a 1 sec washer. I needed it to take 7 sec from a 15 sec engine delay. I needed an 8 sec delay.
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