Hip Pocket Builders' Forum

General Forum => In the Work Shop => Topic started by: RolandD6 on July 22, 2018, 07:22:11 AM



Title: Another Trailing Edge Tool
Post by: RolandD6 on July 22, 2018, 07:22:11 AM
I have started a separate thread to avoid polluting the other similarly named thread started by pedwards2932.

The first image shows the assembled device with a bit of 4mm wide balsa to illustrate the carving procedure. The idea is based on the old two piano wire sanding trick except the balse is carved with just a very light finish sanding. Heavy sanding can cause the balsa strip to curve.

Part A is an extruded aluminium rectangular box section.

Part(s) B are thin strips riveted to A to create a restraining ledge for Parts F.

Part(s) C are an extruded angle and a flat strip. They could have been a single Tee section but I did not have anything suitable on hand. They are both 1.5 mm in wall thickness.

Part(s) D are packing strips. The image shows a 1.5 mm thick strip and a 1 mm thick strip. I also use a 3 mm thick strip when needed. Combinations of these strips can allow for TE's of these widths (mm), 1.5, 2.5, 3.0, 4.0, 4.5, 5.5, 6.0, & 7.0.

Part(s) E are hardened stainless steel engineers rules that have been lapped straight on the upper reference edge. The carving blade is guided by the lapped edges. The blade can be a single edged razor as shown or a razor plane.

Part(s) F are clamping plates that hold Part(s) E up against Parts(s) C & D.

Part(s) G are 3 mm threaded hex tubes (electronic circuit board standoffs) that screw onto Part(s) H (see next image) to hold the clamping plates (F) in place. Only light finger tightening is needed.

Part(s) I are 4 mm jacking screws used to support and position Part(s) E.

Part(s) J are small pieces of Tee section used to keep Parts C & D in alignment while the clamping screws (Part(s) K) are tightened at each end of the device.

The fifth image is an end view that shows Part L which is a 6 mm square bare that is tapped to accept Part(s) H

The last image shows the the flat screw driver slots cut into the ends of the jacking screws (Part(s) I)

I use the depth measuring part of a standard vernier caliper to set the edges of Part(s) E above the reference surface created by the assembly of Part(s) C & D

It is necessary to do some sums or drawings to determine the correct height of Part(s) E above the reference surface created by the assembly of Part(s) C & D

Remember the carving blade is guided by the inner edge of the highest Part E and the outer edge of the lowest Part E

It is necessary to carve slowly keeping one's fingers clear of the blade while also using them to hold the balsa strip firmly against the reference surface.

It all works for me.

Paul







Title: Re: Another Trailing Edge Tool
Post by: Bargle on July 22, 2018, 05:26:43 PM
Wow, nice rig.


Title: Re: Another Trailing Edge Tool
Post by: fred on July 22, 2018, 07:53:01 PM
Fascinating Lotsa Work building that Gizmo.
Frankly though... the Simple Stoopid 2 pieces of Piano wire method is both  dead Easy and Reliable.


Title: Re: Another Trailing Edge Tool
Post by: RolandD6 on July 22, 2018, 08:00:27 PM
Fascinating Lotsa Work building that Gizmo.
Frankly though... the Simple Stoopid 2 pieces of Piano wire method is both  dead Easy and Reliable.

It the journey through life that matters. I enjoy designing and making stuff and in the end what ever we do is unlikely to be valued by anybody else and yes two pieces of wire will work.

Paul


Title: Re: Another Trailing Edge Tool
Post by: OZPAF on July 22, 2018, 09:13:37 PM
Fascinating design and build Paul. I'm afraid jigs/fixtures/tools intrigue me as well and agre the jurney and problem solving is an interest in itself.
Thanks for posting.

John


Title: Re: Another Trailing Edge Tool
Post by: RolandD6 on July 22, 2018, 11:26:24 PM
Thank you for your support John.

Paul


Title: Re: Another Trailing Edge Tool
Post by: LASTWOODSMAN on July 22, 2018, 11:59:11 PM
     Hi Paul (RolandD6)  That is a very clever tool you built.   Guys also like to make things out of steel and aluminum.   Did you work in the machining trades such as "Tool and Die" and "Mold Making"  ?     You obviously know your way around a machine shop.   8) 8)

LASTWOODSMAN
Richard


Title: Re: Another Trailing Edge Tool
Post by: RolandD6 on July 23, 2018, 04:43:28 AM
     Hi Paul (RolandD6)  That is a very clever tool you built.   Guys also like to make things out of steel and aluminum.   Did you work in the machining trades such as "Tool and Die" and "Mold Making"  ?     You obviously know your way around a machine shop.   8) 8)

LASTWOODSMAN
Richard


The short answer is no.

I was educated though the old Technical school system in Victoria Australia. The politicians in their misplaced wisdom killed off that style of education. We learned metal working and carpentry trade in addition to formal maths, science, technical drawing and so on. Metal working included sheet metal work and fitting and turning on machine tools like lathes, milling machines and shapers. No CNC in those days.

After that I did stress analysis work at an aircraft factory and structural design at Alcoa of Australia. Later work was not engineering related because nobody wanted someone with experience in aluminium structures and I had a family and mortgage to feed.

Paul


Title: Re: Another Trailing Edge Tool
Post by: BG on July 23, 2018, 06:28:25 PM
Wow .... that is waaaay more sophisticated than my method of simply: 1 placing sheet of appropriate thickened on edge of table. 2. mark width of TE required, 3. plane TE with razor plane to near as dammit dimensions. 4. Strip TE off of sheet. 5. Use new TE to build next wing.

It works every time, takes minimal effort and time, no setup to speak of, never had a dud.

BG


Title: Re: Another Trailing Edge Tool
Post by: RolandD6 on July 23, 2018, 08:21:05 PM
Wow .... that is waaaay more sophisticated than my method of simply: 1 placing sheet of appropriate thickened on edge of table. 2. mark width of TE required, 3. plane TE with razor plane to near as dammit dimensions. 4. Strip TE off of sheet. 5. Use new TE to build next wing.

It works every time, takes minimal effort and time, no setup to speak of, never had a dud.

BG

I have done that before too but I have had to prepare for the inevitable probability that I would not have a sacrificial table or bench in a workshop. All of my special purpose tools are in custom boxes etc. so that they can be quickly put away complete with any work in progress in the hope that I MAY be able to continue model building perhaps in a kitchen or living room (fingers crossed). That time has come due to family health reasons. A new future awaits me.

Paul


Title: Re: Another Trailing Edge Tool
Post by: OZPAF on July 23, 2018, 08:40:32 PM
Well - all the best with the future then Paul.

John


Title: Re: Another Trailing Edge Tool
Post by: RolandD6 on July 23, 2018, 09:43:01 PM
Well - all the best with the future then Paul.

John

Thanks John

It is going to be a tough.

Paul


Title: Re: Another Trailing Edge Tool
Post by: DavidJP on July 24, 2018, 05:06:17 AM
Spiffing!  Things like that I admire and the ability to fashion them.  Now obviously your talents extend beyond making goodies for aeromodellers.  Bit of a sad reflection on today‚Äôs world perhaps that there is not a sufficient demand for them.  I do wish you well.  Thanks for the enlightenment.


Title: Re: Another Trailing Edge Tool
Post by: BG on July 24, 2018, 09:35:23 PM
ahhhh clarification and context. Makes sense. Good luck with the future ... may you always have a few square inches to model in. It is actually amazing what can be done with minimal space if you are well prepared, and that TE tool certainly classifies you as well prepared.  ;)


Title: Re: Another Trailing Edge Tool
Post by: DavidJP on July 25, 2018, 03:53:46 AM
Some of the best modellers I have known have made do with minimal,space and facilities.  Harold Underhill produced incredibly detailed sailing ship (static) models on a card table.  His silver soldering technique, using a piece of rubber tubing on the gas stove and a tube in his mouth to solder eyes to mast rings was something to behold.

So having seen an example of your ingenuity I doubt your modelling will wane.