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498 air hammer

dmaxfireman

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I've had an Astro 4980 air hammer for a little over a year now and have a few questions;

Can I rebuild / change the trigger valving for better trigger control?
Does the CP717 have more trigger control?
Is there another .498 air hammer with better trigger control?

Perfectly happy with the power it has, just not the lack of controlability.
 
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ihateminimumwage

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I had the Astro 4980 and while it had tons of power, the on/off trigger was a big problem working on heavy equipment. I bought a used CP717 and had the two next to each other. While the Astro is a good copy, when opened up none of the trigger parts will swap.

CP717 has variable trigger control which was a major improvement.
 
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bsaint

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The CP most likely is a true 8x or 7x rivet gun. Not sure if the astro is. A rivet gun you can really feather the trigger. Like a Sioux hammer for instance.
 

rlitman

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I own two CP717 hammers. One is made in New York, while the other is made in Japan. The far newer Japanese one more closely resembles the Astro than it's identically named brother.
 

Torque Test Channel

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The CP most likely is a true 8x or 7x rivet gun. Not sure if the astro is. A rivet gun you can really feather the trigger. Like a Sioux hammer for instance.
Both are 5X .498 riveters, the CP just has a bit more trigger control. I haven't got my hands on an old US made one to see if there ever was a massive difference
 

setfocus

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From what I've read here on GJ, of the 3 affordable .498 hammers the CP is best then AP and air cat brings up the rear

I don't own a .498 hammer but I've used the CP and the air cat but years apart so I can't really compare the 2. .498 air hammers are just difficult to control in general IMO. Finesse type work is better suited to a .401 shank air hammer.

If you want a really nice air hammer get an industrial air riveter like an atlas copco
 

rsanter

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Do you need more throttle control or you need to limit max hit?

You can limit max his by adding a small ball valve inline the air Intake port
 
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Iridium rand

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Sep 23, 2021
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If control is important to you then go with something marketed/labeled as a rivet gun, they’re the exact same tool as an air hammer just with better triggers. More expensive especially buying new, but there’s plenty of great affordable used/surplus options on yardstore, got an ingersoll rand AVC26 from them and it’s a beast with very precise control

ebay too is a good option if you want to try an atlas copco, well regarded as the best of the best but make sure you get a model ending in TS not PS, push starts don’t work unless you’re pushing down on them. Nice thing about air hammers too is they’re among the most durable power tools in existence, very unlikely to get one that’s broken or worn out in any way making the used option very appealing
 

ihateminimumwage

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.498 air hammers are just difficult to control in general IMO. Finesse type work is better suited to a .401 shank air hammer.
I came into my previous employer with a Snappy PH3050 (401) and bought the Astro 498 (after breaking and tearing up 401 bits). When I finally bought the used CP (and about every bit offered in 498) I was able to sell the AP and PH3050. The CP717 covered everything with the variable trigger; can actually feather it instead of all out carnage.
 
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dmaxfireman

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Thanks everybody. I need the trigger control, not limit on the max. I need the power of the 498 and use it just about daily. I'm going to plan on wearing this tool out and in the mean time look into a cp717 or an atlas copco as a replacement
 

Iridium rand

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Also when looking at rivet guns the max power is extremely confusing with the #X system, many 7x guns are more powerful than 9x for a complicated reason someone fully explained a long time ago here, I suggest looking at the max rivet diameter capacity on the MFG’s website to get the true power figure
 
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dmaxfireman

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Wanted to update this thread...

I purchased a Atlas Copco RRH12P-TS to use, and the trigger control is great and it thumps good. I kept the Astro 4980 and tore it down to figure out the trigger control issues. I looked up both parts diagrams to the CP717 and the Astro 4980, the two tools are extremely similar.


So looking at the Astro diagram I removed part #'s 11,12,13,14 and I ordered, from the CP diagram, 12,5,11,3 and used o rings from an assortment I had already. If you don't have an oring assortment you will need parts 7 and 4 as well.

I quickly learned that the stem on the throttle valve on the Astro is 1/4 and the stem on the CP is 3/16, so the brass bushing inside was far too loose. I ordered part 9 from the CP diagram next and found, though the diagrams design look different they are identical except for the stem hole. I made a blind hole puller to remove the brass bushing from the Astro tool handle, and pressed the new bushing into the handle, ensuring to keep the air hole aligned properly.

Once the new bushing was pressed into place I ran a 3/16 reamer through the hole due to it deforming slightly while being pressed into place.

Reassembled the valve and had some air bypassing, when putting the brass spring cup in, I oriented it according to the diagram but the diagram has it upside down, and stops the center potion of the throttle valve from closing. Once flipped over and reassembled it seals and works amazing.

I was able to do this for just shy of $100 after shipping and getting the brass bushing off ebay in a stroke of luck. Worth every penny.


Part numbers needed to convert your Astro 4980 to have better trigger control:

P074486 Bushing
A113836 Stem-Valve
A113837 Valve-Throttle
C069083 O-Ring (-010)
C087316 O-Ring (-006)
A113838 Cup-Spring
P002521 Throttle Valve Spring
 

ihateminimumwage

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Glad someone took the time and work to mess with the parts! When I had both next to each other, I popped both of the valves out to see if parts could swap over, but didn't dig any deeper than that.
 
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