Logging Arch

[Rick_Marty]

Hi all,
Have been meaning to get these built every since I finished the Cat 60’s a couple years ago. It has taken quit a while to run down enough prototype information to satisfy my mind about the build.
Anyway finally getting a start and thought somebody (besides me) might be interested in the process.

This arch is located at Collier State Park in Chiloquin, OR and is a modern (1930’s) all welded Fairlead Arch with Athey Truss wheels. I have no idea what the extra framing on top of the boom is all about, some kind of a later years adaptation for a use other than logging arch I assume.

This particular arch caught my eye because of its wide stance, look at the width of the cat tracks in the background, it could carry a 5 foot diameter log with no problem. That width probably took some getting use to by the “Cat Skinner” before he quit hanging a track up, probably a good thing those Athey tracks were flippers.

Anyway I will get some build pictures up soon.
Later
Rick

[Ray_Dunakin]

Cool project! I’m sometimes a bit envious of you guys who model logging RRs. There’s so much interesting equipment you can build.

[Paradise]

The tracks make it a more difficult model to make than some logging arches.

British Columbia Forest Museum

(http://steamplace.com/images/BCForestMuseumLog_00.jpg)

Andrew

[Rick_Marty]

Ray,

Loggers were much like miners in that they could take little or nothing, add a little ingenuity and sweat and create very usable and unique equipment to get the job done. But I guess that is true in a lot of trades/professions/industries even today.

Andrew,

The rubber tired arch, the next step in the evolution of equipment to lessen stand damage. It helped some but the “cats” were still churning up the ground. “disclaimer” that was not a political statement just a fact.

On with the build.

For some reason it seems like I always start with the wheels on most any build project, I think it is because I like playing with the lathe. Anyway for this build I used ¾ inch PVC pipe and turned it down to the required inside and outside diameter and cut a shoulder in that the spokes would mount into. Duplicating the first one 15 more times was a bit tedious but they all came out usable, well, 16 out of 21 ain’t too bad.

The “Athey Truss Wheel” for the actual wheel part has a 9 spoke layout between hub and rim. This took some head scratching trying to remember how to lay out a regular polygon in a circle that wasn’t an oct or hex. This layout works for any un-even number of points with all sides of the polygon being equal. I can give an explanation of the diagram if anyone is actually interested.

With the 9 point polygon laid out on a jig piece I cut .020 styrene to use as a base to weld the spokes to. I decided to use a stock ½ round styrene shape as the spoke as nothing in a triangle shape matching the prototype was available. By using the backer piece it allowed me to tie the hub and spokes together in a solid unit.

That’s it for now,

thanks for taking a look.

Rick

[Gary_Armitstead]

““This took some head scratching trying to remember how to lay out a regular polygon in a circle that wasn’t an oct or hex.””

Hey Rick,

I love watching and “drooling” over your projects. I also like to see your geometry work with the nine point polygon. Next time you need some geometry work, let me know upfront and I can lay it out for you on Mastercam and send the full-size hardcopy by email. Less time than you can draw it.

[Rick_Marty]

A little more to show.

After the hub and all the spokes are glued to the .020 disc they are trued up in the “poor man’s mill” to fit into the recess cut into the wheel rings. The .020 backer is then cut out from between the spokes leaving a solidly constructed wheel center.

This picture is just showing an assortment of pieces that went into the wheel construction.

A set of completed wheel “rims” set in the track assembly and held in place with the wood block. The track is an extra set I ordered, with this project in mind, when I built the Cat 60’s, they are not really correct for the Athey Truss Wheels but more on that later.

Question; what glue, preferably a welder will work to attach Styrene to PVC? The welders I am using, Bondene and ProWeld, will attach the pieces but they are easily broken apart so there is no true bond there.

Thanks for taking a look.

Rick

[ctown2 (Craig Townsend)]

Rick,

I’ve had success using MEK to bond styrene to other plastics like PVC, and ABS. You can always also try CA if MEK doesn’t work.

[snowshoe (Shawn Viggiano)]

Nice work so far. I really need to get a lathe. They sure do come in handy.

[Nico_Corbo]

Thes sell a nice small lathe at harbor freight.

http://www.harborfreight.com/7-inch-x-10-inch-precision-mini-lathe-93212.html

[Bruce_Chandler]

Those wheels look great!

For PVC to styrene, I use the TAP Acrylic cement: http://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_acrylic_cement/130

You’ll also want an applicator: http://www.tapplastics.com/product/supplies_tools/plastic_tools_supplies/hypo_type_solvent_cement_applicator/409

I prefer the little bottle.

Weld On #3 is also a nice liquid.

I suspect you could also just use PVC cement from the hardware store.

[catherine_yronwode]

Just a round of applause from the sidelines: Beautiful work! A joy to see!

Awaiting more photos as this project continues…

[Torby (Tom Ruby)]

Gary, a master tradesman like Rick doesn’t need a computer to do things like that, just his compass and rule. Computers are for the rest of us unskilled.

[JRad (Jon Radder)]

Wow. I am very impressed with the work that went into those spoked wheels. Excellent.

BTW - I’ve used Weldon 16 for Styrene to PVC and have also used PVC Pipe Cement from the hardware store. The latter is a bit messy and can warp the styrene if you use too much.

[Rick_Marty]

Back with a little more progress. It has been a fun build so far trying to engineer from pictures is always a little problematic. I always find a few spots where I scratch my head and think “why didn’t I take a couple more pictures or measurements in that spot?”

The “Athey Truss Wheels**”** did not have cleats on the track pads so obviously the “cat” tracks had to be altered to make them at all usable. I found that I could mount the track section in the drill press vise and hold them reasonably well while I ran them through the mill and cut the cleats and bolt heads off. There was quite a lot of variance in the cuts because each individual pad would be held tight or not so tight depending on the part of the casting clamped in the vise. I only ruined 3-4 pads but they are easily replaced and when all done everything had to be hand dressed with a file for uniformity anyway.

The completed “Athey Truss Wheel” assembly with the axel beam in place. The tracks look alright on there but they are definitely not a reproduction of the original. I just do not feel that this project warrants fabricating a master, casting 96 plus pieces, then assembling them to get a finished product that will look so similar once painted that not one in a hundred will know the difference anyway

(

Thanks to all for the tips on glue for the Styrene/PVC connection. I was able to get a can of the Weldon #16 that seems to have really done the job. I remember using this stuff several years ago and found that once you open the can the shelf life is very limited due to rapid evaporation. As for using PVC pipe joint glue, well, it might work fine but I have enough trouble trying not to make a mess without using that stuff.

Thanks for taking a look, more to follow.

Rick

[JRad (Jon Radder)]

That looks great Rick. I buy the Weldon 16 in a large tube. The tube I have s well over a year old and I used some today - just like new.

[Rick_Marty]

Hi Jon,

Yes I have used it in the tube form before, but I have also had some that was a water thin liquid in a can (if my memory serves). What I asked for this time was weld on 16 and was sold a can of liquid and being in a hurry didn’t look at it that close, brought it home opened it and used it on a couple wheels, worked great. What it is actually called now is Weld-On Sci-Grip 3 clear, water thin, solvent cement. Looks just exactly like what I used before.

I don’t know

[Rick_Marty]

Another update, this project is taking much longer than expected due to the fact that real life keeps interfering with model building time. I need to come up with some way to correct that, any ideas?

The angle arch was laid out and cut from 1/4 inch Sintra and laminated between sections of .030 Styrene sheet. In this picture I am drilling the holes for the “Athey Truss Wheel” axles before laminating on the edge pieces of .040 Styrene strips.

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This picture shows the Truss Wheels mounted to check the axle bores and the truss wheel clearances before beginning the edge strips.

OK, for a way to anchor the vertical arch to the angled arch I had to stop and rethink the possibilities. My original idea was to just use some Styrene plates glued to the angled arch and drilled to hold the vertical arch pin bolts, but I realized (in time, which is unusual) that this could be a very weak point in the model construction. So, after a lot of foot dragging I decided that there was only really one way to do it. Route out both sides on the top of each arch leg and insert a brass plate that would tie the truss wheel axle to the vertical arch pins. This procedure though time consuming (Sintra doesn’t grind worth a darn) is proving to be a very good solution.

This view shows the edge pieces in place but needing the uneven gaps along the edges filled with putty. You can also see the brass anchor plates that will hold the vertical arch in place once everything is assembled. After routing out the areas for the brass connector plates I had to cover the mess with Styrene “patch” plates. I don’t think this will be much of an issue, if you go back and look at the prototype pictures you will see similar plates in different places.

Just a glamour shot showing the tracks draped over the wheels and Ole Hansen, the shop foreman, getting another photo op.

More to come.

Thanks for taking a look

Rick

[docwatsonnc (Don Watson)]

Absolutely fantastic work Rick. The detail is amazing. Great modeling tips for future reference.

Doc Watson

[Bruce_Chandler]

Wow, those edge pieces sure make the difference, don’t they? I like the use of brass for the connector plates.

Very nice work.

[Rooster]