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Rob Allen 120 railgun band / shaft configurations

NicholasCLF

Member
Oct 27, 2016
37
6
23
34
Caribbean
Hi Guys,

I have a 120 RA railgun. 2 x 14mm green bands cut to 70cm each. 160cm x 7mm shaft (0.49kg). I am interested in playing around with different configs and I'd like to know if anyone out there has done the same or has any opinions/advice:

Option 1: Switch to 7.5mm x 150cm shaft (0.515kg) - I think the shaft will be Can I use the same 14mm rubbers with good performance? Or would I need to change to 16mm bands.

Option 2: Switch to 7mm x 150cm shaft - Can I use the same 14mm rubbers as is? Or will the shorter lighter shaft be overpowered?

Option 3: Install Meandros Reverse Trigger mech - Will I have to change the length of bands (using same shaft)? Can I use the same rubbers without overpowering (as there will be some more band stretch)?
 

hteas

Well-Known Member
Mar 9, 2005
943
128
148
72
Anchorage, AK
I shoot a RA 110 with 140x7 shaft and 2 14mm bands. It's very accurate and is not overpowered. If you go up to a 7.5 shaft, you might need the 16mm bands.
 
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mariusshobo

Well-Known Member
Sep 22, 2013
205
66
68
romania
I have a 120 RA railgun. 2 x 14mm green bands cut to 70cm each. 160cm x 7mm shaft
Looks good as it is, even if the shaft is a little long for 7 mil dia. But if it is accureate, then ... good.

I shoot a RA 110 with 140x7 shaft and 2 14mm bands. It's very accurate and is not overpowered. If you go up to a 7.5 shaft, you might need the 16mm bands.
This setup loks perfect.

My setup : gun 120cm, 150cm 7mil shaft + 2 x 14 mil Primeline bands. The 14 mil primeline's works better then 14.5mil Sigalsub Reactive on this shaft.

Option 1: Switch to 7.5mm x 150cm shaft (0.515kg) - I think the shaft will be Can I use the same 14mm rubbers with good performance? Or would I need to change to 16mm bands.
I would try 14mm rubbers, but considering also 14.5mil Sigalsub Reactive (the brown ones). Even the diameter is almost the same, the Sigals are somehow stronger ...

Option 2: Switch to 7mm x 150cm shaft - Can I use the same 14mm rubbers as is? Or will the shorter lighter shaft be overpowered?
14 mil mands shoud be ok.

Option 3: Install Meandros Reverse Trigger mech - Will I have to change the length of bands (using same shaft)? Can I use the same rubbers without overpowering (as there will be some more band stretch)?
? I do not know. You have to try it. Just make longer dineema wishbones and adjust them till you find the sweetspot.

Make a target for the water, spend a morning trying different setups and see what works. That is the best way to figure it out.
 
OP
OP
N

NicholasCLF

Member
Oct 27, 2016
37
6
23
34
Caribbean
Looks good as it is, even if the shaft is a little long for 7 mil dia. But if it is accureate, then ... good.


This setup loks perfect.

My setup : gun 120cm, 150cm 7mil shaft + 2 x 14 mil Primeline bands. The 14 mil primeline's works better then 14.5mil Sigalsub Reactive on this shaft.


I would try 14mm rubbers, but considering also 14.5mil Sigalsub Reactive (the brown ones). Even the diameter is almost the same, the Sigals are somehow stronger ...


14 mil mands shoud be ok.


? I do not know. You have to try it. Just make longer dineema wishbones and adjust them till you find the sweetspot.

Make a target for the water, spend a morning trying different setups and see what works. That is the best way to figure it out.
I have a 110cm with a 150cm x 7mm shaft. I think I'll put it on the 120cm gun and play around with it. I heard that sometimes it is harder to aim with a shorter shaft...
As for the rubber, its RA rubber and if I'm not mistaken, he uses primeline rubber.
 

Dogmatrix

Deeper Blues pet
Jun 4, 2002
210
19
108
37
Townsville, Australia
Visit site
If I could make a suggestion...

How you chose to set your gun up generally depends on how you use it... and what your loading abilities are.

For the Rob Allen 1.2M with a 160cm 7.5mm shaft I would run either twin 16mm rubbers or if you don't have loading difficulties a tight 20mm or 18mm single rubber would be fine also... the advantage of runing a single larger diameter rubber is reasonable power and a much faster reload.

DM
 
OP
OP
N

NicholasCLF

Member
Oct 27, 2016
37
6
23
34
Caribbean
If I could make a suggestion...

How you chose to set your gun up generally depends on how you use it... and what your loading abilities are.

For the Rob Allen 1.2M with a 160cm 7.5mm shaft I would run either twin 16mm rubbers or if you don't have loading difficulties a tight 20mm or 18mm single rubber would be fine also... the advantage of runing a single larger diameter rubber is reasonable power and a much faster reload.

DM
I'm using 7mm shafts. I just bought some small id 14mm to try out. I also have a piece of 18mm as well that I could try.
 
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