TruCore casing spare parts

ID is about .818. Casting tubes and liners from Rcs, using the .808 od casting tube as the liner and the .772 od for casting tube.

I think for the 24s this was the tubing, turned down to 24mm:
https://www.onlinemetals.com/merchant.cfm?pid=13227&step=4&showunits=inches&id=71&top_cat=0

This is the schematic I drew up with my design that Ed worked off to make the first 24mm motors for me. His handwriting on the bottom with machining prices hopefully it helps.

This is excellent
Thanks
I will do the drawing and cad files over the week end

Kosdon ran 1" OD x 0.065" thickness cases: https://www.onlinemetals.com/myaccount/index.cfm?fuseaction=orderdetail&orderid=1153175

That allows you to use the same liner as Aerotech 24mm: https://www.rocketmotorparts.com/Paper_Motor_Liner,_24mm/p1577809_7795898.aspx

That said, Frank left them 1.0" OD which required the use of an adapter to 29mm. I love my little 1.0-40 E40F motor, I think I still have 7-8 Frank reloads for it and I have a ton of materials from RCS to make more reloads...someday!

This is the tubing used for the 24’s it was from Aircraft Spruce not online metals. Also reminder that Ed added a liner step on the bulkhead same as the nozzle.

I like the kosdon 1” also but need to find a way to seal the delay bulkhead for ex.

I have received my first 29mm and 38mm nozzles
Should test them over the week end

bdureau said:

I have received my first 29mm and 38mm nozzles
Should test them over the week end

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Who did you get those from?

They were made for me

I tested a 38mm 4 grains motor and it worked quite well

Here is the video

and this is the nozzle after firing




I now have spare parts for my Trucore motors that are no longer available and I would like to thanks all the members of the forum who helped me retrieving the nozzle and casing measurements.

I am now getting the casings and forward plugs done. I am going to get them anodized as well.
Which aviation grade aluminum would you recommend? 7075? 2017A? or any other one?

I would stick with 6061 unless you have some reason for 7075.

bdureau said:

I am now getting the casings and forward plugs done. I am going to get them anodized as well.
Which aviation grade aluminum would you recommend? 7075? 2017A? or any other one?

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NFPA 1125 requires commercial motor casings to be made of 6061-T6. Those requirements only apply to commercial motors, but I know of no reason not to emulate what commercial mfrs. do.

I thought that 6061 was food grade aluminum? Is it strong enough?

6061-T6 is what AT, CTI, and Loki all make their cases out of.

It's not as strong as 7075 at room temperature, but at acceptable firing temps a lot of that difference disappears.

7075 is also more expensive, more difficult to machine, and corrodes more easily.

bdureau said:

I thought that 6061 was food grade aluminum? Is it strong enough?

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It has been strong enough for many years. [emoji3]
Keep in mind that more strength isn’t always a good thing. If there’s a crack in a fuel grain that causes a cato you want the failure to happen at a lower pressure rather than a higher pressure. The failure will happen no matter what, but failing at a lower pressure results in the parts flying less distance.

7075 tends to be frangible (lots of pieces if it bursts) while 6061 cases tend to stay in 1-2 pieces.

7075 is also more difficult to anodize than 6061, and is extremely prone to corrosion.

6061 is also a lot less expensive than 7075.

I will only use 7075 for small, single use, thin wall cases where I need every ounce of performance out of a completely custom motor/airframe.

Landru said:

7075 tends to be frangible (lots of pieces if it bursts) while 6061 cases tend to stay in 1-2 pieces.

7075 is also more difficult to anodize than 6061, and is extremely prone to corrosion.

6061 is also a lot less expensive than 7075.

I will only use 7075 for small, single use, thin wall cases where I need every ounce of performance out of a completely custom motor/airframe.

Click to expand...

This is why we use 6061-T6, casing is only split, no fragments.

ok
Thank you all for your replies. I am trying to get those made before the summer so that I get test my new altimeters
I suppose the same goes for the forward plug

I managed to get the plugs done


and I got them anodized.
Not being a machinist myself It is going to cost me more than the original but it is fun to do. A lot harder and more expensive to get those done than PCB's which is something I am used to.

I have tested the forward plug and they work quite well

I think that I now have spare parts for the rest of my life

next I need to get the tubes done

Holy Mackeral. Those are Beautiful.

+1, looks great! Any chance of the 24mm .scads on GH?

dhbarr said:

+1, looks great! Any chance of the 24mm .scads on GH?

Click to expand...

I have started drawing them but I have not published them yet. I will do on my github.

cwbullet said:

Holy Mackeral. Those are Beautiful.

Click to expand...

Well they are but the anodization will not last long on the inside
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Hello everyone
It has been 3 years since I started making spare parts for TruCore casing and after spending quite a lot of money I finally got where I wanted with the help from a friend in my rocketry club who is a machinist in his spare time.
The first parts that I got made such as nozzle and forward plugs were machined in China. The anodization on the plug does not last long so I have decided not to do that on the latest casings. Selecting the right graphite with high density as also been a been very challenging. We have also been able to find the correct aluminium tubes so that we do not have to drill them.... This is very expensive when you have to drill them
So my friend has been able to machine 29mm, 38mm and 54 mm casing.
In the last 6 months; we have tested extensively the 38mm from 1 grain to 6 grains and the results are very good. The casing tube is anodized in black or colorless, the plug are not anodized and the nozzle are polished.
We even made 600 meters of casting tubes and liners which should last few years for our own use between us to.

The reason we did it is because we had a shortage of commercial motors in Europe in the last 3 years so we had to come up with solutions to continue launching rockets!!!!
They are slightly different from the original TruCore but still compatible
This is what they look like from 1 to 6 grains


The nozzle. We are also optimizing them for sugar propellant


The plugs. Because we are in Europe and we use metrics you can screw a 6mm screw



And the casting tubes (we have few boxes of those plus some liners)


The retainer for the motor is just an external circlip


This is a picture of one of the flight my friend did with a 54 mm 2 grains sugar/titanium based propellant


Overall it was a very interesting experience for the 2 of us dealing with various suppliers but it is not cheap !!! between the two of us we spent few thousands dollars and ended up buying all the tools to make them!!!!

Now if anybody is interested to byy some custom parts I cannot do them myself but PM me and I give you my friend details and he might be able to do some for you.

When you say plugs do you mean forward bulkheads? If you plan to release for public sale I would drop the anodizing and polishing and pass the savings on to the customer. Non of Ed's stuff was anodized. Good luck with your future endeavors.

We do not anodized the forward bulkheads anymore because it does not last, however the tubes are anodized either in black or colorless.
I have done many test, go stuff made in China and then my friend started making them. So far we have done them just for ourselves . I personally need to do lots of launches to test all my electronic hardware and with Ed stopping making them and commercial motor shortage in Europe I had to find solutions to continue.

Very nice. The loss of Tru-Core has been devastating for research rocketry.