Follow-up Letter To Semroc About The POINT Build

Here's a copy of the correspondence to Semroc and

Randy's note to Phil in Semroc R&D - 

Hi Randy,

I'm doing a build of the Semroc POINT kit for the blog. 

I wanted to give you a heads up - 

There are problems!

* The holes punched in the motor mount tube are too low!

The holes punched at the center should be higher up on the tube so the ejection charge hot gas will escape above the top edge of the main body shroud. 

Where they are now, they could char the inside of the shroud.

Not really a problem, I have some ST-7 tubes. I cut and punched a new tube.

Here's where the real problems lie - 

* The shroud print is smaller than the original kit shroud.

The outside edge of the angled fins will not correctly contact the inside of the shroud.

This sets the mount too low inside the shroud.

The base rings do not fit the base of the shroud.

They might fit if almost 1/8" is cut off all the way around the base disk.

The vertical red ring had to be cut down to half it's height (now 3/8") to fit the shroud.

I hope you didn't have many of these printed, I know these things can happen.

Anyway - not complaining, I've had to do some revisions in my kits, too!

Happy Thanksgiving!

Chris Michielssen 

Odd'l Rockets 

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Response from Randy at ERockets/Semroc - 

Ouch,

It looks like the tool was made wrong for the punching the tube, all of our inventory is bad, this likely happened 2 years ago when we made duplicate tools so each SKU would have its own.  

The shroud is the wrong size and we have been printing from the master all this time, this last batch I could not get our printer to print on the correct paper so I sent it out to be done.  But it came back exactly like the master.  So I don't know when we went bad on this part.  I think this is the key reason the kit is not going together correctly.

The red ring has always been that size, not sure if it was a mistake Carl made in the design or if he did that on purpose.

Based on the proportions the inside red ring does not line up correctly.  Sure, if the Shroud is not right this is not going to fit.

 

The canopy wrap looks like it was always wrong, I think it is better to be slightly larger because the cones can very in diameter slightly so it needs to have some give.  The same problem existed on my kit made 10 years ago when Carl had Semroc.

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Notes from Randy to Phil in Semroc R&D - 

Phil,

I started cutting parts up on the kit I placed at your desk.  Could you please build one of these and make the needed corrections.  Hopefully, the originals are in the development folder.  I am also leaving you my kit that was built about 10 years ago, it has an astronaut signature on it so please handle with care.

I am removing this kit from inventory until the needed corrections are done.  I am fixing the tool for the tube punching now, and will destroy the wrongly punched tubes too.  I am leaving it to you to make the other corrections.

Respectfully,

Randy Boadway

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Semroc is fixing the kit!

What conclusions can be drawn? 

Too many different computer formats can produce different size prints.

Have you ever reproduced something from an online source to find out

you didn't adjust the PDF to print full size? 

I worked in a print shop for years. Things happen.

In my experience producing kits and Accessories, mistakes were made. 

Some vendor errors: 

I received an order for 2,500 Raise Springs, all were wrong!

An order of 100 custom balsa nose cones were the wrong shape.

Half an order of Ceramic Blast Deflectors were unusable and had to be thrown away.

Even the largest rocketry vendors had a run of 10,000 kits including a very wrong part.

A part was been missing in a short run of Odd'l kits. Thank goodness it was only a run of ten kits!

I've been there, we've all been there.

Before you complain on a forum, give the vendor a chance to make it right.