Author Topic: QB79 Ninja - The $200 PCP (Read 127740 times))

Buldawg76 · « **Reply #280 on:** February 28, 2016, 05:09:57 PM »

Kirk
Is that a harbor freight lathe I see or if not what brand and size is it, how do you like it as I am in the market for a small work bench size lathe and would like some first hand experience with just what quality and performance the small ones like that give for the dollars they cost.

Your thoughts.

Mike

SpiralGroove · « **Reply #281 on:** February 28, 2016, 06:11:31 PM »

Mike,
I absolutely love it. It's the 12" Harbor Freight model. I got it for 33% off, plus on sale - so I paid about $410 + shipping. I originally got the 10", but it felt too cramped. The 12" actually has a 14" bed.
I hadn't worked on a lathe since High School and really wanted to get back into making things. It was my 54th birthday present in 2013.

It has been a Godsend as far as tuning airguns. I spent about 2 days refining the chuck, ways and Gibbs and generally cleaning off all the grease. I think I need to look at adjusting again to better align the tail stock with the chuck.

Many people have knocked it's quality, but you should be able to do many things with it. Out of the box, this lathe is pretty rough, but kind of like the QB78/79. A little work goes a long way.

Good Luck

WECSOG · « **Reply #282 on:** February 29, 2016, 12:34:45 AM »

Quote from: SpiralGroove on February 28, 2016, 02:28:18 PM

Hey Mike,
That's it ............. not that hard.
Yeah, I try NOT to take apart my guns too much as it becomes a whole day affair. Replacing o-rings, lubing, bluing, or losing parts.

My shop bench is very messy after making my last LDC. I don't dare do anything until the whole garage is cleaned and tools found .

For a minute there, I thought you had somehow posted a photo of my workbench. Seriously!

I have the same mini-lathe, a similarly messy bench, and my propane torch even has a tank of the same blue color!

ETA: Actually, I have the 7x10. But I also have a Grizzly 9x19, so it's all good!

Buldawg76 · « **Reply #283 on:** February 29, 2016, 01:06:04 AM »

Quote from: SpiralGroove on February 28, 2016, 06:11:31 PM

Mike,
I absolutely love it. It's the 12" Harbor Freight model. I got it for 33% off, plus on sale - so I paid about $410 + shipping. I originally got the 10", but it felt too cramped. The 12" actually has a 14" bed.
I hadn't worked on a lathe since High School and really wanted to get back into making things. It was my 54th birthday present in 2013.

It has been a Godsend as far as tuning airguns. I spent about 2 days refining the chuck, ways and Gibbs and generally cleaning off all the grease. I think I need to look at adjusting again to better align the tail stock with the chuck.

Many people have knocked it's quality, but you should be able to do many things with it. Out of the box, this lathe is pretty rough, but kind of like the QB78/79. A little work goes a long way.

Good Luck

Kirk

Cool that's good to know and we have finally got a harbor freight here in town now so I would not have to pay shipping and will just wait for a 33% off and on sale as well.

I had a two year course in machining taught to me by a master machinist when I worked for Harley as a research and development mechanic so I know just how much fun and use I would get out of having one to make parts with. I have access to a friends shop at his house with a lathe and mill and do a lot of stuff there but having one in my own garage would just be icing on the cake.

My friend is wanting to sell his lathe and mill but they are big footprint items with the lathe being an old south bend 10x 48" model and the mill a huge upright one and I just don't have the room for the big footprints they command in my garage. I can get the lathe for 1000 bucks with all the attachments and its 40 years worth of attachments and cutters mills and such but just don't have a 4 foot area to place it and it only a 1 inch pass thru so while its plenty long enough it is limited in the diameter of material that it can machine and I know the small lathe is only a 3/4' pass thru but it also only takes up 2 feet of work bench if that. I have not ruled it out but will have some serious clean up to do to make room for it but would never have to buy any tooling or attachments for it since its already been bought. He did lots of gun barrel work over the 40 years he has had it.

Mike

SpiralGroove · « **Reply #284 on:** February 29, 2016, 02:29:53 PM »

Yeah Mike,
The South Bend lathe is WAY WAY way better then the HF 12".

The whole thing only weighs about 100 lbs., so I bolted it through the underside of my bench for more stability.

The HF lathe is equivalent to a QB; whereas the South Bend is a RAW or Flex.

Buldawg76 · « **Reply #285 on:** February 29, 2016, 02:37:16 PM »

kirk
I agree 100% with the HF being a QB and the south bend being a RAW or Flex and the price is right but like I said its just got a huge footprint and will have to find room to put it some where as it would engulf my workbench so that it could not be used for anything but the lathe. Plus I don't see me ever making anything close to 4 feet in length that I need a lathe of that size.

Still not ruling it out yet though.

Mike

rsterne · « **Reply #286 on:** March 08, 2016, 07:05:04 PM »

Recently one of our GTA members, Ribbonstone, noticed a slight bulging of the end of the tube on his QB79, in the thin area adjacent to the screw holes for securing the tank block.... The gun was operated for a time at 1250 psi.... In response, I have done an analysis of the tank block attachment, which is detailed in this thread....

http://www.gatewaytoairguns.org/GTA/index.php?topic=105712.

If you are building a QB79 HPA conversion of any kind, you should read that thread.... If you are using more pressure than the 1100 psi factory setting for a Ninja SHP regulator, I am now recommending that you pin the tank block with two additional 4mm or 8-32 screws, or a 5/32" shear pin, between the O-rings.... If you want to be more conservative, you might want to pin the block when using the SHP regulator.... or even with a standard 850 psi Paintball regulator.... Complete information is in that thread....

Bob

Buldawg76 · « **Reply #287 on:** March 09, 2016, 02:19:07 AM »

Bob
I have been following that thread with great interest and deciding on the method I will use to make my gun at least at a 3:1 safety margin if not 3.5:1 as I may go to 1500 psi output pressures from the pro SHP regulator. Like I have said my main goal is to get as close to a 20fpe FT hunter class gun as possible without exceeding that power limit so actually want 890 to 900 up to 920 fps with JSB 10.34s which is right at 18.6 to 19.44 fpe.

Right now just getting all materials on hand and formulating a plane to proceed.

Mike

454 Big Block Chevy · « **Reply #288 on:** March 09, 2016, 09:45:32 AM »

I'm looking at this, except in .177. Interested completely!!!

rsterne · « **Reply #289 on:** March 09, 2016, 01:35:59 PM »

You can build an EXCELLENT 20 FPE .177 cal around this platform.... Using the 10.3 gr. JSB Exact Heavies at right around 900 fps it was extremely accurate and delivered a ton of shots.... enough for an entire FT course with sighting in.... from a 13 CI tank.... Most FT guys find the accuracy is best with those pellets between 880-900 fps....

Bob

Buldawg76 · « **Reply #290 on:** March 11, 2016, 04:57:15 AM »

Quote from: rsterne on March 09, 2016, 01:35:59 PM

You can build an EXCELLENT 20 FPE .177 cal around this platform.... Using the 10.3 gr. JSB Exact Heavies at right around 900 fps it was extremely accurate and delivered a ton of shots.... enough for an entire FT course with sighting in.... from a 13 CI tank.... Most FT guys find the accuracy is best with those pellets between 880-900 fps....

Bob

Agreed 100% as far as velocity is concerned for the best accuracy with 10.3 JSBs and is why I want to build the gun as I have stated so I can sight in and shoot the entire match on one fill. I use a GEN 1 Mrod now tuned to shoot the JSBs at 890 to 910 fps for a 20 ES spread and get 50 shots per fill to 3100 psi down to 2100 psi with good results but its to heavy for me to hold steady in the off hand and kneeling lanes so that is why I am hoping to shave a couple pounds off with the QB and still get the accuracy and shot count to only fill once per match. Our monthly club matches are only 48 shots but a sanctioned match is 60 shot per day for two days so the QB would be ideal for that with the 13 ci bottle.

I have an extra FWB 300s stock that is broke at the knee and am going to see if it can be pinned or doweled and glued for repair so it can be inletted to accept the QB action for a nice FT stocked gun.

Mike

454 Big Block Chevy · « **Reply #291 on:** March 11, 2016, 09:46:42 AM »

Quote from: rsterne on March 09, 2016, 01:35:59 PM

You can build an EXCELLENT 20 FPE .177 cal around this platform.... Using the 10.3 gr. JSB Exact Heavies at right around 900 fps it was extremely accurate and delivered a ton of shots.... enough for an entire FT course with sighting in.... from a 13 CI tank.... Most FT guys find the accuracy is best with those pellets between 880-900 fps....

Bob

I have probably 10,000 Crosman 10.5 domes, all from the same lot, from when i had my Marauder. I would shoot those for a good solid backyard plinker/starling buster. if they shot accurate of course. i really want to build this... would the regulator be better set at 1000 psi instead of 1200 for a .177 gun?

nervoustrigger · « **Reply #292 on:** March 11, 2016, 10:05:19 AM »

What energy level are you wanting to achieve?

454 Big Block Chevy · « **Reply #293 on:** March 11, 2016, 10:08:06 AM »

honestly a 7.9 CPHP at 900 would be ideal for about 100+ shots. but the SHP regulator would probably scoot a 7.9 a little faster than that, so i have the 10.5's i really like 900 fps as i am getting really good at learning distance drop at 900 fps. and faster than that i get erratic accuracy with some pellets.

nervoustrigger · « **Reply #294 on:** March 11, 2016, 10:37:41 AM »

That's virtually identical to how we have my son's QB79 tuned on a 1000psi setpoint. Right at 900fps with 7.9gr, 875fps with 8.4gr, and 830fps with 10.3gr. It's opened up pretty well for flow and has a skeletonized valve but if I were building one today, I would use the rear spring approach. That is, an ink pen spring on the valve stem held by an E-clip, totally doing away with the front (aluminum) half of the valve.

454 Big Block Chevy · « **Reply #295 on:** March 11, 2016, 10:43:49 AM »

Well. I am looking really hard at this setup. Reading lots. I would like a plug n play setup. I don't want tobspend any time tuning. I want a fun light weight backyard plinker that's cheap to shoot and accurate

SpiralGroove · « **Reply #296 on:** March 11, 2016, 10:49:29 AM »

Hey Big Block,
I have found that the QB's really like boxed CPUM in 7.9 gr. or 10.5 gr.

JSB's might shoot a little better, but now you could put those pellets to good use.

nervoustrigger · « **Reply #297 on:** March 11, 2016, 11:59:42 AM »

Well, cheap and accurate and no time tuning isn't a realistic mix. It's kinda like the racing adage of cheap, fast, and reliable...pick any two.

That said, if you do the right set of mods, there shouldn't be much tuning required in terms of getting good efficiency and low ES. Doing the RVA mod or a SSG will help immensely.

Buldawg76 · « **Reply #298 on:** March 11, 2016, 04:40:44 PM »

All the fun is in the tuning and tinkering to get the satisfaction of doing it yourself

Mike

SpiralGroove · « **Reply #299 on:** March 11, 2016, 05:08:43 PM »

Yeah,
For me the "tinkering/tuning part" is very satisfying, that's why US afflicted tend to go from project to project

. With of course, a short break in between. Once you're satisfied the gun is finished, all frustration (if any) experienced throughout the project, seems to vanish.

I just need to work on drilling more precise holes with my drill press

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QB79 Ninja - The $200 PCP

Author Topic: QB79 Ninja - The $200 PCP (Read 127740 times))