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Core burner or End burner?


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Posted

What is the difference and what would you recommend for a first timer at rocketry. I want to buy a 4oz rocket kit but I don't know which one it is.

 

Thanks guys

Posted (edited)

The difference between end burners and core burners is core burners have a long hollow core going up the fuel grain; core burners use a nozzle with a wide opening, or no nozzle at all; and usually core burners use a slower fuel, such as 60 30 10; core burners are used for lifting stuff like shells. End burners have little to no core going into the fuel grain; a small opening in the nozzle; and a hot fuel is used, often 75 15 10; these rockets have less power than core burner rockets but can go much higher.

I would recommend an end burner for the first time, mainly because there is less chance of a CATO due to less fuel burning at one time.

bob

Edited by bob
Posted

Thanks Bob, This one I'm going to copy and paste into my notes. Then an end burner it is. :)

Posted

I think there is some value to starting with core burners. They use less fuel, burn quicker, and have more lifting power.

Posted
I think you would enjoy a core burner more... but that's just me.
Posted

The only "end burners" i got are stinger kits. And truth be told they have both a nozzle, and a tiny core.

Go with core-burners, they make a lot more sense.

B!

Posted

I made successful end burners with very hot fuel and aluminum rocket bodies in the early 1960s when I was a teenager. Today, working with small-diameter cardboard motors, I've only tried core burners or nozzleless engines. For the core burners I've had to make a 60:30:10 B.P. to avoid CATO.

Posted

Thanks guys. it's a lot to think about. I do have a rock tumbler but not lead balls. Just regular ones. :) I do have a box of 30 cal. 180 grain copper rifle bullets (not loaded) to use. Will that work to mill with?

Posted (edited)

If they are pure copper, give them a good wash.

 

I like my end burners a lot the small ones only use 5g of bp, core burners in the same size use more.

3/4" use about 25g, the same size in core burner uses 50g.

You can lift shells with endburners just not the same weight as core burners in the same Id, 10mm endburners can lift 30g cored 60g. 3/4" endburners 100g ish, 3/4" core burner over 200g.

 

The choice Is yours, you'll probably get both eventually. I started with endburners and was quite satisfied with them for years.

 

It really depends what you want to do with the tool, endburner tools can also make fountains and wheel drivers, inserts etc.

 

Dan.

Edited by dan999ification
Posted

well, i suggest trying both. as you notice some people preffer core burners, some end burners. presonaly i more preffer core burners, due to wider fuel range, better efficency, and it's more easily to lift payloads with coreburners due to more powerfull,but shorter burn. but i think end burners has a great potential at boostin planes and gliders, due to nice steady burn. also before doing endburners you need to be able to make good and hot BP.

Posted

I do want to play with both, end burners and core burners but just to get stated I think I'll start with end burners then move up to core burners and see witch ones I like best. I'll have to wait until Skylighter get more stuff in. I guess it will be a few months so for now I'll try to perfect BP making. I made it in the 60's when I was young with my older brother and that was a lot of fun.

 

Thanks to all of you and for all of your comments, suggestions and all around good info. So far this forum has help out A LOT!

 

Mike (MWJ)

Posted

If it makes the decision any easier, you need to be able to make hot BP for end burners to function correctly. This will probably revolve around having a ball mill and a good understanding of making BP. This will also likely include having a hotter charcoal than the commercial airfloat that skylighter sells.

 

Core burners are a little less picky, and can be made to work with screened fuels using less reactive charcoals. Also, if you get core burner tooling, you can always make nozzleless rockets, which use as hot of fuel as end burners, but don't have a nozzle.

 

If I were doing this all over, I'd probably get real core burner tooling. It's not too difficult to make end burner tooling on your own actually, or just drill a small core by hand. If you decide that that isn't for you, or it's not reliable enough, you can always get it down the road.

Posted

I agree I'd never buy endburner or fountain tools since they are so easy to make ( apart from drilling dead centre in the rammer)

I started by hand drilling to get my dimensions right but then made tools as hand drilling is not easy in small sized motors to get repeatable results.

 

Dan.

Posted
I have lead balls if you want for sale and can making tooling on my lathe.
Posted (edited)

I have lead balls if you want for sale and can making tooling on my lathe.

 

Sorry about the double post on my phone and it said not allowed to post or something so I reposted and there was two.

Edited by ianagos
Posted

i would say core burner is better very simple o make plus you can use a sugar fuel and hat takes about 0 skill unlike a perfect bp that is rather hard

Posted (edited)

For media, I believe I mentioned this before, and I can't emphasize this enough. Steve, here on AmateurPyro, known as LeadBalls as his username sells the hardest grinding media for the best prices you can ever get. Don't buy that junk from PyroCreations and some other websites, and the media PyroDirect has is from Steve, except PD sells it more expensive for a profit.

 

Don't use Copper, you're asking for trouble. To be honest, don't be a cheapskate when it comes to safety. If it's not Lead or Brass (or even Alumina), don't mill BP with it. It must be 100% NON-SPARKING to be used for milling BP. Just because Copper works one time for somebody, doesn't mean the next day your mill won't explode.

Edited by LambentPyro
Posted

I am quite pleased with my YSZ media.

 

Does it bother you that you have lead in your powder?

Posted (edited)

I am quite pleased with my YSZ media.

 

Does it bother you that you have lead in your powder?

For me, yes, I think of it has a risk when it comes to using it for stars where other chemicals are present that could react with the Lead and Lead Oxides (also the Antimony in the media too). I don't play around with contamination and I wash everything right after I am done using it for less chance of cross-contamination for the potential hazard of unwanted reactions.

Edited by LambentPyro
Posted

I believe some pyros have had success with copper rod stock, cut into chunks, but only for milling BP.

 

Lead though, is where its at!

Posted

I'm curious as to why you'd advise against using copper?

 

 

For media, I believe I mentioned this before, and I can't emphasize this enough. Steve, here on AmateurPyro, known as LeadBalls as his username sells the hardest grinding media for the best prices you can ever get. Don't buy that junk from PyroCreations and some other websites, and the media PyroDirect has is from Steve, except PD sells it more expensive for a profit.

Don't use Copper, you're asking for trouble. To be honest, don't be a cheapskate when it comes to safety. If it's not Lead or Brass (or even Alumina), don't mill BP with it. It must be 100% NON-SPARKING to be used for milling BP. Just because Copper works one time for somebody, doesn't mean the next day your mill won't explode.

Posted

I'm curious as to why you'd advise against using copper?

 

It is a very good conductor and sounds to me as it would tend to produce a spark when friction is made with another metal.

 

Not only that, but I have not heard of one ball milling accident that was caused by lead media sparking while milling straight BP. Other stories involve metals that have the ability to spark, can Copper? Yea, can Steel? Yep.

 

I am just shocked that people (especially on here) don't hesitate using a sparking media for milling BP. I just don't see how being cheap comes first to safety.

 

Bottom line is, if you're willing to take that risk, proceed. We're in a dangerous hobby as it is, and at least I know I can be a bit more confident in my safety measures that an accident will be less likely to occur because I am using the correct materials.

Posted

Copper, many copper alloys, and certain grades of stainless steel are all non-sparking or spark-resistant (which is the same thing). They produce cold sparks if any at all. The same can not necessarily be said of ceramics, which you seem to be fine with using.

Posted (edited)

Copper is non sparking, but there is one reason to not to use it, copper is ductil and can smear. Nothing you really need to worry about. Brass is just much better, as it is less ductil/harder

 

BTW. Does anybody know about SiC media? It relly cheap andSiC media? It's cheap and commonly available

Edited by schroedinger
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