Replies

1. 
   patternmaker | Oct 21, 2003 12:31am | #1

   I use helicoils extensively in the jigs and fixtures that I make in the shop.

   For those who may not be familiar with the term,a helicoil is an item to line a softer material with metal threads. If a part must be removed and replaced often,screw threads ,in soft wood or plywood wil eventually strip out.

   However,in your case.you might consider re taping the screw holes to #10.

   Work safely ¬¬¬¬¬¬¬¬¬PAT¬¬¬¬¬¬¬¬

1. 
   beekeeper | Oct 21, 2003 03:54pm | #3

   Thanks Pat. It has been a long time since I have had anything to do with helicoils; my early days with Prat Whitney engines in the then Air Corp. I think I will try using bigger screws.

1. 
   patternmaker | Oct 21, 2003 04:41pm | #5

   My pattern making days started with the Stinson Aircraft Corp. in 1940,A.D.that is.What an experience that was. Coming up with new ways to do things. I remember when the epoxy casting compounds were first developed.Made it so much easier to make matching moulds. We no longer had to scoop out the female half from wood and checking with blue chalk.

   Most tooling was temporary,since the design changes were so frequent.Masonite form blocks for wing ribs and similiar parts. Male parts only,since the high pressure rubber presses automaticly provided the other half.

   Please forgive the ramblings of an auld man.

   ¬¬¬¬¬¬¬¬¬¬PAT¬¬¬¬¬¬¬¬¬¬

1. 
   IMERC | Oct 21, 2003 04:54pm | #6

   Did you know another pattern maker by the name of Rich Lambeck? He was lead there. Latter he went with Grumman.

    

   Who ever invented work didn't know how to fish....

   Edited 10/21/2003 10:20:32 AM ET by IMERC

1. 
   patternmaker | Oct 23, 2003 10:24pm | #9

   Imeric:

   I seem to have gotten you confused with Elcoholic.

   See 14316.9

   Work safely ¬¬¬¬¬¬¬¬PAT¬¬¬¬¬¬¬

2. 
   Elcoholic | Oct 21, 2003 05:51pm | #7

   A friend of mine restored and flies a Stinson :"Flying Station Wagon".  It's not very fast but it hauls a pretty good payload.  I think it's a '47 or '49.John O'Connell - JKO Handcrafted Woodworking

   Life is tough.  It's tougher if you're stupid - John Wayne

1. 
   patternmaker | Oct 23, 2003 12:06am | #8

   No i don`t remember the patternmaker that you mention. Stinson moved their operation from Wanyne Michigan to Nashville Tn. in 1939. During that time I remember three aircraft. One was the Stinson Reliant.Aka the SR10 A plush 5 place gull wing plane with a radial engine.It was the corporate vehicle of the time.All leather inside and a cargo hold that you wouldn`t believe. Another was the 105.A puddle jumper that i think IMERC is referring to. In WW2 it was used by the military for cargo pickup and as a hospital plane to evacuate the wounded. It required a very short runway and could land and takeoff from roadways and vacant fields. Next was the O-49. It was an aircraft with slotted wings and could hover almost motionless in the air. It was used as a target spotter for the artillery units. The fuselages were welded from high strength steel tubing.4130,I believe,and covered with a linen like cloth. After a trip thru the paint shop,these skins looked and felt like celluloid. The wings and tail surfaces were basically wood beams and wood ribs.Wings were covered the same as the body,but as I remember,the tail surfaces were covered with 3/32" plywood. This was the last of the Stinson planes manufactured in Nashville. Now the facility was aquired by Vultee aircraft. Vultee made the A-35 Dive bomber.They also made various parts as a sub for other aircraft.Another plane from this plant was the P-38,a famous WW2 fighter. Chance Vought(spelling may be in error)had tail sections made in this plant for the FU7 shipboard fighter. When the plane landed on the flight deck, the bottom fairing strips would take a beating.The engineers designed a wood fairing that would bolt to the bottom and protect the metal.After a number of landings,the disposable unit would be replaced with a new one.This was a part to be contracted out. Every inquiry to bidders was returned with no bid. They were all afraid of the tight aircraft tolerences. PAT TO THE RESCUE.I was now shop foreman. Since a contract could not be given to an employee,I resigned,and spent the next several years building these parts.When the job was recalled to Texas, I started building engineering models and casting patterns for the casting trade. I have enjoyed every minute of my working life. And for this I owe an eternal gratitude to the man who taught me so much in the early years. He taught me what to do and how to do it. For this Mr. CroneyThank you,wherever you are. ¬¬¬¬¬¬¬¬¬¬¬¬PAT¬¬¬¬¬¬¬¬¬¬

2. 
   JohnWW | Oct 21, 2003 02:59am | #2

   Beekeeper,

   How did a loose bit tear out the screws holding the router in the table? - it must have been exciting when it let go.

   A simpler, and much less expensive, solution to your problem would be to drill out and retap the damaged hole to a larger size thread and use new bolts to mount the router in the table.  The old screws were probably metric, but you can tap the base out to an inch size thread. 

   Helicoils need a minimum thickness of metal to work in, the base casting may not be thick enough.  The minimum diameter for a Helicoil is for 1/4 inch or 6mm thread which will require drilling around a 5/16 in. hole.

   John W.

1. 
   beekeeper | Oct 21, 2003 04:14pm | #4

   I guess you could say it was exciting. I was cutting an ogee in purple heart with a quarter inch shaft bit (one of the few I have left). The shaft was bent 90 degrees, but never came out of the table. Took some metal off the face of the router. I attributed this accident to dust in the collet at the time. A few test cuts on scrap showed that no matter how clean or how tight the bit crawled out of this collet. Thanks for your input. I think I will go to a larger fastener.