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Post by rosco01 on Jan 5, 2015 16:10:06 GMT -5
Thanks Phil, frats, Rosco
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Post by rosco01 on Jan 6, 2015 16:11:56 GMT -5
Spent more time on the body yesterday - wheel inserts. One of my suppliers inserts needed sanding down and the spokes cut out - all 6 inserts - 8 spokes each... glad that job is done. The other supplier came with them already cut - but with openings through the centres - I'm guessing for the axles to run through and elude that they are wheel bearing caps.
Wheels and crowns/pinions have arrived - absolutely brilliant.
Still waiting for tyres - PG and a full range of crown/hub spacers.
Going through as meany pix as I can to find detail on these little cars at present.... either the web doesn't have many - or I am not looking in the right places... Old23 has given me lots of info on his builds... driver height might be an issue yet... The dash on both my casts will need work to lift it to the correct height - the model from which these were molded obviously had them far too low for assembly purposes.
Still working... not missing. Will post some more up when I actually have something to show....
And - from which character in Planet of the Apes was chosen for some of the driver's faces I have seen? Surely, it's tongue-in-cheek?... I have two hmans who can be used for my models, with a bit of period customising - but looking through the rest of my spares box - they all appear related... and not homosapien.
I intend to purchase Black Jack for my Brabham BT-3.....Immense Miniatures... if I were to do a BRM - it would simply just have to be GH.... what a casting.
frats, Rosco
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Post by slo on Jan 10, 2015 21:08:28 GMT -5
This is a very neat build Rosco, especially for a first timer. Enjoying watching your execution of both your builds. Keep up the good work. How did you get the axles so parallel without the use of axle ride height blocks or jigs?
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Post by rosco01 on Jan 11, 2015 17:27:47 GMT -5
Thanks Slo, I suppose I sort of use a jig to some extent - a ceramic tile with lines marked exactly centre-line and also at right angles - without those, I don't believe I would have been able to get anything even close to usable.
To start with, I scribed a line along the base of the rear bracket marking off exactly the same distance from the bushing mount holes then filed it down and finished of by rubbing it on a metal plate backed series of wet'n'dry papers.
This allowed me to fit the bracket firmly down on the board. I had cut two nicks in the front wall for the rails to sit on - so, that part went together square - I had not paid any attention (read below) to the face of the bracket nor the vertical squareness of the sides.
I set rear axle alignment up by using aluminium tubing through the rear bushes. By adding tubing through the bushes - I was able to control both the square and parallel alignment of the axle to the build - I simply used pins at both ends of the tubing to control both height and alignment, and tied them off in position using fine copper wire.
The front bracket was likewise added - with the rail/rear bracket assembly firmly held down on the board.
By sighting from the front along the board - I could position the front axle assembly likewise - to that of the rear.
When I had equal distances at each end between both axle tubes - I soldered the front bracket in... the rest was easy.
Making up the 1/8" front axle tube and 3/32" hollow axle to length was all cut, re-cut and file/sand down until I had just enough clearance for a 0.5 mm thrust washer to be fitted both sides of the free spinning hubs.. a firm interference fit eyelet was then pressed in at both ends of the hollow axle (removable) to hold the hubs in place.
Ok - bit of meat in this, but hope my failure might prevent another newbie following this thread to repeat it. Anyone who is aware of "non-square" components need read no further - I'm almost certain most of us have done this once.... but certainly only once.....
I returned to chassis #1 yesterday after satisfactorily fitting the new RD wheels and PG tyres to build #2 during the week (thanks to both - they are simply brilliant!).
I struck trouble with chassis #1 - ended up stripping it right back and straightening parts.
I purchased a number of brackets from member of another forum and foolishly went ahead with assembling chassis #1 - foolishly believing the brackets to be folded perfectly in a jig.
The build of C#1 had only reached the bracket to rails point - if I'd managed to get the front bracket in as well, I'd have had more to pull apart and redo... so, a faint ray of sunlight probably shone through the very "grey" day I had yesterday.
When I came to fit the front bracket yesterday, nothing would line up - all issues seemed rear bracket related... and "then" I finally set about measuring it.
With C#2, I had noticed that the motor mount face was curved (perhaps the "one" which slipped through QC) - and rectified that one.. then set the sides square and parallel to it, in the belief that I'd actually sent them out of kilter with my pressing the front plate...
I had initially set it up C#1 on the rails by using a length of 3/32" aluminium tube through the soldered in bushes - that part of it was fine... the bushes were slightly cock-eyed to the face of the bracket - but true to the centre-line of the build - and horizontal to the build plate.
My issue came up when I fitted the motor and tried to get it sitting between the rails. I did not have the motors when I put this first chassis together - I'd have certainly noticed when setting things up on the board..
The motor neither ran along the centre line nor parallel to the board surface... no amount of playing with it rectified any satisfactory result... the face of the bracket was out of square to the rails......so - de-solder then took the bracket out to the garage for a "pressing" between specially made up metal blocks for another project.... then set the side faces up square and vertical to that.
When I set it back onto the board for re-soldering - the bushes were now cocked - because they had been soldered in with them in alignment with an out of square bracket.
I tired to prise them out with the solder at melting point - I don't know why, but these won't come out - no matter how big a soldering iron I use..or how much weight I placed on the bushes in the process - but, I did get to straighten them and managed to get the tubing through.. so, they are in alignment and the axle runs freely within.
I then repeated the procedure of setting the bracket up on the rails and soldered it back into position.
So folk, end of yesterday's entire labors was a return to where I started - a pair of rails and a rear bracket...... now fully square..
A lesson learned - and one I very much hope I do not ever repeat..
I'll attempt to now fit the front bracket today..
Again, sorry about the length of this post... I've been missing for a spell - so, maybe I'll be forgiven.
frats, Rosco
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Post by Phil Kalbfell on Jan 12, 2015 0:46:23 GMT -5
Ross I think this will save a lot of other people some problems when they go to use these brackets. They will now know that they need so realigning.
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Post by rosco01 on Jan 12, 2015 5:28:26 GMT -5
Yes Phil, another huge day on the workbench today - Chassis #1 is now back together. I have yet to cut the axles to length and fit the thrust washers and eyelets to the front axle - but, for all intents and purposes - I have the two T-53 chassis in bare-bones assembly, rolling along the set-up block truly and all four wheels firmly down pat on the deck.
I had to use 0.10 mm spacers on this one - to shim up both crown to bracket internal gaps - they are indeed a task to fit when your tweezers are magnetised..... grrrrrr!
The RD 24 tooth crowns are a joy - Steve simply has done magnificent work in machining them - the brass pinions took a bit of work to get the imperfections removed - but the mesh on both these little chassis is as good as anything I have.
Waiting for the Slot-It HRS plastic track guides to come now so that I can set the height of the guide post bearing and washer.
All coming good - and well worth the effort to correct the previous issue before it got any further into the build.
frats, Rosco
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Post by rosco01 on Jan 15, 2015 17:47:09 GMT -5
Ok, little bump along to catch up with proceedings. I now have two powered chassis which run on the bench like a dream - the precious little bit of dressing I did to the pinons has really paid off. These gear-sets run ever so sweetly on the Slot-It 3/32" hardened steel axles I am using.
I am at the point of gluing and truing tyres. I have done a lot better with the front ones than the rears... I might have to address what's going on with the rears, but they are pretty much within what I want them to be... just a bit more "truing".
Ok question time - front guide. I was going to use the Slot-It revision 2 guide with four grub screws, but it was suggested to me that this would cause issues with "corner marshalls" - I still don't know why, but I'm not really savvy with racing events and procedures yet....
I did take advice and order in the Slot-it universal HRS guide for plastic track - and this is causing grief. I have had to change my bearing tube size - and can't find one which is a snug fit.....
Which sized tube do members use for these guides - the guide pin is too large for 5/32" OD brass tube - and too narrow for the next size up... I'm hoping there is something available which will prevent me having to dress down the pin and ream out the tube like I spent nearly two hours doing yesterday.... I have another 3 of these set-ups to complete.... if there's tubing available for this recommended guide - I'd sure like to know about it......
For the front axle assemblies - I've managed to get them running ever so free, yet with minimal run-out. I used 1/8" brass tubing for the bearing - which was soldered to the front bracket. Inside this, I fitted a "hollow" 3/32" Slot-It axle. On the inner hub faces I fitted a 3/32" 0.25 mm thick thrust washer then added the narrow little RD wheels (absolutely perfect, Steve). I then fitted another thrust washer outboard and used a Slot-It brass eyelet which was inserted into the hollow axle.
One of these eyelets was crushed slightly and a very small coating of Loctite ensures that it won't come out. I will repeat this on the other end when I have completed the suspension detail...
Final trimming to length of the axle is yet to be determined - but at present, I'm within another 0.25 mm thrust washer .. which I might just add to the assembly.
The running of the wheels is very, very free - and there is ever so little wobble in the tracking of the front wheels - if I remove all of this the wheels will drag.. so, I'm of the opinion it better/more advantageous to run as is....
Once the guide issues are rectified - I can then place the model on a track and do some "testing".... so, folk - another great sequel to "Tolstoys W&P"... but one I hope someone might glean some info from....
frats, Rosco
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Post by rosco01 on Jan 17, 2015 3:29:38 GMT -5
As promised.... and less words... Cooper #2 has reached chassis track running stage - only now needing the leads to be attached. The rear axle has been shimmed down to 0.1 mm on both sides of the crown - it runs in beautiful mesh with the pinion and within the rear bracket bushes. The guide has now finally been fitted - a huge job to ream out the guide tube and sand down the guide post. Three shims were used to set the guide height - all hand made from brass strip. The guide sits with just the thickness of the braid between it and the building board - with all four tyres firmly on the board. And, for those unbelievers that I was actually making up two of these great little cars.... here is Cooper #1 behind Cooper #2.... I'll now rest #2 for a spell whilst #1 catches up in the build process.. it's how I'm running these builds - they are "leap-frogging"... in that way, neither is the test dummy - and they should both come through the build process relatively equal... Once #1 reaches #2 - it will be time to return to the bodies.... whilst I contemplate how the suspension is going to be fabricated and fitted.... frats, Rosco
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Post by David Lawson on Jan 17, 2015 7:35:25 GMT -5
Excellent work on the chassis and all very neat.
My only comment is that rather than shim the post to set the guide height I cut the post to the length to give me the correct height. I'm not saying I'm right and you're wrong but I find my way easier.
David
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Post by rosco01 on Jan 17, 2015 16:51:59 GMT -5
Thank you, David - I concur entirely.. and it was the "plan"... However, when I reached the guide post/tube stage - I had ordered in four Slot-It revised guides.... the 4 grub screw variety. It was on this platform that I fitted the tube to the chassis - and had it set at the correct height.
Some few days later, a well respected member of this forum suggested I opt for the universal guide instead... for some "corner marshaling" reason - still beyond my comprehension...
Rather than risk destroying the now built up front bracket assembly by lowering the guide tube, I opted to employ shims to space it down....
Cooper #1 will have this tube fitted at a lower height from the building board.. and perhaps just one thin thrust washer between it and the guide...
Thanks for your input, David - much appreciated.
frats, Rosco
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Post by rosco01 on Jan 19, 2015 17:02:46 GMT -5
Shorty today - just a repeat of what I posted on Ember's thread.
I want to fit ferules under the intake air cover and decided the best approach was to slice away at the "meat" until four of these little trumpets could be inserted.
One slice too far and I had the body hinging on the opposite side... which, as the body was cast - is also on a very thin join line.
I sliced through that as well and now have the "lifting" section of the rear as a separate piece. I was then able to get right into the intake cover and grind out enough to fit the cut-down ferules...
My plan is now to use some "milliput" epoxy putty then run a complete length of fibre-glass tape across the two halves - using c/a as a catalyst. I am considering adding further strength to the assembly by drilling and fitting a bent-to-shape length of brass rod - c/a'd into the "meat" of the body.
Another little project is currently drawing my attention away from these little cars at present.. but not for much longer.
frats, Rosco
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Post by rosco01 on Feb 12, 2015 19:28:37 GMT -5
Hi folk, I now have a deadline - have accepted a position in this year's Tasman proxy series... so, the parallel build has been ditched for a focus on getting one model up and ready by April.
Started work again yesterday - have now nearly completed the front suspension details. Body is in limbo waiting for Tamiya light putty to arrive from Honkers.
I started out trying to make up piano wire wishbones for the little Cooper and ditched the concept early finding it a little too intricate for such strong wire.
I resorted to an old friend in brass rod - and used 1mm for the wishbones and 0.8mm for the steering rod and knuckle.
I made up some brake backing plates from 016" brass strip and drilled a centre out for an interference fit on the front axle tube. I then marked out and drilled 1mm holes for the wishbones and 0.8mm holes for the steering linkages.
Once these were done, I ground the strip to a 11mm diameter and pressed them onto the axle tube.
Fitting the brass rod was relatively easy, but I filed nicks in the front bracket to "locate" them.
Soldering on the bracket end first - then the brake plate and finally trimming excess from the outer end seemed to work best. I then set about the steering linkage - running it across the entire front - angling it back from the bracket outwards to the brake plate and soldering in place then trimming...
I'm not sure how I'm going to go with any spring or damper arrangement on the front... there is precious little room.. but I will most likely concoct something up.
I have just started on the rear - but this time, it will have to run with a clearance gap around the rear axle - which is not inside a tube... I intend to fit a loose tube to position the plate until all wishbones are in place - then remove the tube.
the front assembly is very rigid... I expect there won't be issue with the rear having a floating axle pass through the centre hole....
Apologies for absence of pix..... my ISP data allowance has been exhausted.... until 20th of this month.... I should have both assemblies completed by then...
frats, Rosco
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Post by rosco01 on Apr 2, 2015 1:43:50 GMT -5
Wow, I didn't realise just how far back this thread came to a halt. Update. Chassis finished and has been tested. Body finished except for weeks and weeks of issues with paint. Currently at clear coat stage awaiting silver stripe after strip back to etch primer for second time.
Will post up some pix shortly.
frats, Rosco
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Post by rosco01 on Apr 3, 2015 23:58:14 GMT -5
First time I tried to post up my pix - it all went "somewhere" - hope I'm more successful this time... Ok - a few pix to update the build. back soon - see if this lot goes up on the board..? frats, Rosco
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Post by rosco01 on Apr 4, 2015 0:05:30 GMT -5
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